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The purpose of the project is to investigate the occurrence of antimicrobial resistance related to use of antimicrobials and biosecurity in the Finnish pork production chain from nursing to slaughter and processing of meat. Additionally, utilising the information about production, management, medication and biosecurity, possible factors related to development and spread of antimicrobial resistance will be identified. Finally, consumers’ exposure to resistant microbes is evaluated. The results will be helpful in improving control measures in order to prevent the emergence and spread of antimicrobial resistance. This poster presents the workflow of the project, when and where the samples are collected. Ten farms’ antimicrobial treatments and indications were used to compile boxplots to visualise differences. Observed resistance features are also presented., FI; en; pdf; efsafocalpoint@evira.fi

Food items of animal origin, such as pork products, have been suggested as the main source of zoonotic salmonella infections in Europe. Contaminated feed can potentially introduce the pathogen into the animal-derived food chains. The prevalence of salmonella in different feeds for Finnish pigs was estimated as below 2% (medians) and on average in pigs 0.25% (mean). Feed was estimated on average as the cause of 35% of salmonella infections in fattening pigs and 55% in sows. Around 5% of the 300–400 domestic human salmonella infections reported per year were estimated as attributable to pig feeds. Year 2013 was employed as a reference. The present costs for the prevention of salmonella contamination in pig feeds were estimated at 1.8–3.0 million euros per year for the year 2013. The costs due to feed contamination, measures due to detected contamination and the resulting salmonella infections in pigs and humans were estimated at €2.4 (0.3–6.1) million annually. According to a scenario, if salmonella prevalence in Finnish pig feed would be similar to that acquired using data from other EU counties, the prevalence in fattening pigs and people could increase by 55-fold on average. If specific measures to eliminate salmonella from feed were not carried out, the costs due to preventive actions against salmonella were at least €1.1–1.8 million per year. Additionally, the costs due to the eradication of feedborne salmonella on pig farms, consequential measures at slaughterhouses, and the health costs to humans could rise to approximately €33 million per year. According to the results, the present feed salmonella control, including the preventive actions, is cost-effective and generates benefits to society., FI; fi; pdf; efsafocalpoint@evira.fi

Food additives are compounds accepted in the EU for use in foods, for example to improve preservability or modify the structure, taste or colour. Some food additives are naturally occurring substances, while others are man-made. During the acceptance of a food additive, requirements for purity and other quality factors are determined and toxicological studies ascertain its safety or may lead to nonacceptance for use. This risk profile aims to define the basic level of food additive exposure of consumers for the development of a national monitoring system. The study comprises all food additives for which an acceptable daily intake (ADI) value is determined by EFSA. The exposure of consumers was roughly estimated based on maximum use levels detailed in the regulations. This population-level assessment was adjusted if necessary with use level information from industry. Based on the rough exposure estimate, the additives were divided into two groups: compounds for which the exposure in Finland is at a safe level, even with conservative estimates, and compounds for which the exposure needs to be studied in the future with more accurate data. The latter group included some colours, preservatives and sweeteners, as well as, due to the lack of information, some compounds modifying the structure of foods., FI; fi; pdf; efsafocalpoint@evira.fi

Production animals can be carriers or reservoirs of zoonotic pathogens. The infection can occur via different routes, for example from contacts with pest animals and wildlife. Farm-level actions in controlling the number of pest animals and preventing their access to production animals and feed are crucial. In this project rodents were trapped on Finnish cattle (n=18) and swine (n=20) farms on two consecutive nights using approximately one hundred instantly killing traps, which were checked and cleared after each night. A questionnaire concerning farm management, biosecurity and pest control was completed on the farm visits, to provide background on the factors affecting rodent yield and presence of zoonotic pathogens. The intestinal package of the caught rodents and other small mammals were cultured for detecting campylobacteria, salmonella, yersinia and toxin-producing E. coli. The determination of the possible antimicrobial resistance profile of at least E. coli indicator bacteria strains will be carried out. In this poster the preliminary results of the questionnaire and trapping are presented., FI; en; pdf; efsafocalpoint@evira.fi; leena.seppa-lassila@evira.fi

Flavourings are products that are not intended to be consumed as such, but which are added to food in order to modify the odour or taste. Presently, about 2,500 chemically defined flavouring substances have been authorised in the EU. In addition to these,the EU regulation on flavourings includes flavouring preparations, thermal process flavourings, smoke flavourings, flavour precursors and other flavourings or mixtures. This report describes the main points on the legislation, evaluation, approval and safety of use of flavourings. The risk posed by flavouring substances is generally considered low because the amounts of flavouring substances used are usually low and many flavouring substances are simple compounds with known metabolites. Many flavouring substances are natural compounds and they are present, for instance, in traditional food. However, some natural flavourings may have adverse effects on human health. The intake of some flavourings may be high among brandloyal consumers or high users. Estimating the intake of flavourings is difficult because the methods used for intake estimates include large uncertainties and because information on the occurrence and concentrations of flavourings in food is scarce. Annex III B of Regulation (EC) N:o 1334/2008 includes a list of substances with flavouring properties that should not be added to food as such, but that may be end up in foods with certain food raw materials such as spices. Some of these substances may have adverse effects on human health, and these compounds are also discussed. &nbsp

This report compiles basic information needed when assessing the pest risk related to different plant species and sectors of plant production, namely information on a) the volume of pathways of entry and b) the value at risk in the sectors of plant production. The report covers all the products that can act as pathways for pest entry into Finland as comprehensively as possible. Also, the volume of traffic into Finland is reported. The amount of goods traded into Finland was estimated mainly based on official statistics. The value of plant production was assessed based on the volume of production and producer prices., FI; pdf; efsafocalpoint@evira.fi

Salmonellosis is one of the most significant zoonoses worldwide and also in Finland. Salmonella Typhimurium definitive phage type (DT) 1 and Salmonella Infantis are considered endemic in Finland. These serovars have frequently caused outbreaks among humans. Salmonella Agona was not frequently encountered in Finland until a small outbreak among cattle farms occurred in 1994-1995. Bacterial typing methods are used for outbreak investigations and for surveillance, where the data can be used for risk assessment calculations in addition to the future prevention of outbreaks.In particular the identification of factors that contribute to the persistence and spread of infection in endemic situations, estimations of the effect of animal reservoirs on human cases, and the identification of other risk factors for human infections are among the important reasons for typing. Salmonella Infantis became more common in cattle in the 1980s, after it established itself in the broiler chicken production in Finland in 1971. In the 1990s, S. Infantis became the predominant serovar among cattle in Finland. In 1995, a feedborne outbreak of S. Infantis in cattle occurred. By XbaI-PFGE methodology we were able to identify the feedstuff-related genotype, which contained a 60 kb plasmid. Farms infected with the feedstuff-related genotype were also identified. The stability of the feedstuff-related genotype was followed on selected farms. The plasmid was stable on the farms during the follow-up period. The feedstuff-related genotype did not persist in the cattle population. Moreover, there was a general decline in bovine salmonella infections from 1997 onwards. The genetic diversity of the S. Infantis isolates taken from Finnish cattle was also assessed. The S. Infantis infection in cattle is highly clonal as 99 per cent of the isolates had XbaI-PFGE profiles clonally related to each other. The major genotype was predominant both at the starting year of our analysis in 1985 and as the infection seemed to fade out in 2003. There is a trend towards less genetic diversity of the S. Infantis infection among domestic isolates from humans and poultry. The ribo/IS200-types and the most common XbaI-PFGE profiles determined among the analysed cattle isolates could also be detected among domestic isolates from poultry and humans. In our analysis of successive isolates from the same cattle herds, we frequently detected minor changes in banding patterns during long-lasting infections in individual herds. The sampling and testing of several isolates from a herd in outbreak investigations is therefore advisable. In 1997, another small outbreak of Salmonella Agona among cattle farms occurred. The PFGE genotype of that outbreak was possibly related to that of the first outbreak, in 1994-1995. In 1999, a large outbreak of S. Agona of domestic origin involving more than 50 human cases occurred. Despite epidemiological investigations carried out by the local authorities, the source of the outbreak remained unknown. Based on our typing data, this outbreak was unrelated to the cattle farm outbreaks, though it did occur in the same region of Finland. The outbreak profile for the 1999 outbreak could not be found in any of the older isolates. Salmonella Typhimurium DT1 has become the most common S. Typhimurium phage type among cattle farms in Finland, and has been detected annually since 1980. The infection is highly homogenous. The most common XbaI-PFGE profile can be seen in isolates from humans, domestic animals, hedgehogs and wild birds, so molecular subtyping by XbaI-PFGE alone is not discriminatory enough in analysing our endemic infection. A combination of XbaI-, BlnI-, and SpeI-PFGE can be applied in the analysis of outbreaks. Two clusters were formed by the combination of the XbaI-, BlnI-, and SpeI-PFGE profiles, IS200-profiles and possession of the serovar-specific virulence plasmid. The major cluster, typical of our endemic infection, had no virulence plasmid. Suomalaisessa nautakarjassa esiintyvien kotoperäisten salmonellatartuntojen seuranta Väitöskirjatutkimuksessa kuvailtiin nautakarjassa yleisimmin esiintyviä Salmonella Infantis-, Salmonella Agona- ja Salmonella Typhimurium faagityyppi 1-tartuntoja. Tutkimusaineisto ulottuu 1980-luvulta aina tähän päivään saakka. Väitöskirjatyössä sovellettiin DNA-perusteisia tutkimusmenetelmiä ja pystytettiin tartuntojen seurantaan ja jäljittämiseen parhaiten soveltuvat menetelmät. Tutkimus osoitti, että nautakarjassa 1980-luvulta asti tartuntoja aiheuttaneet Salmonella Infantis-bakteerikannat ovat hyvin läheistä sukua keskenään. Nautakarjassa esiintyviä DNA-tyyppejä nähtiin myös ihmisistä ja siipikarjasta eristetyissä bakteerikannoissa. 1990-luvun puolessa välissä joillekin suomalaisille maatiloille tuli rehun välityksellä Salmonella Infantis-tartunta. Tutkimus pystyi osoittamaan rehussa esiintyneen DNA-tyypin, ja siten selvittämään rehun kautta suoraan tai välillisesti tartunnan saaneet tilat. Suomalaisissa ihmisissä esiintyi 1990-luvun lopulla isohko Salmonella Agona epidemia. Tutkimuksen perusteella tämä epidemia ei liittynyt nautakarjassa 1990-luvun puolessa välissä esiintyneisiin pariin pieneen Salmonella Agona -tartuntaryvästymään, sillä ihmisten tartunnat aiheuttanutta DNA-tyyppiä ei nähty missään aikaisemmin eristetyssä näytteessä. Salmonella Typhimurium faagityyppi 1:stä on tullut Suomen nautakarjassa yleisimmin esiintyvä Salmonella Typhimuriumin faagityyppi. Faagityyppi 1 aiheuttaa myös säännöllisesti epidemioita ihmisissä. Ihmisten lisäksi faagityyppiä esiintyy kotieläimissä sekä mm. siileissä ja linnuissa. Tutkimus osoitti, että kotimaista alkuperää oleva faagityyppi 1 tartunta on erittäin homogeeninen. Tämä tekee tartunnan alkuperän osoittamisen erittäin haasteelliseksi. Salmonellatartuntojen määrä sekä ihmisissä että eläimissä on merkittävästi vähentynyt 2000-luvulla verrattuna aiempiin vuosikymmeniin. Salmonellatartuntoja seuraamalla voidaan tunnistaa tekijöitä, jotka vaikuttavat tartunnan esiintyvyyteen ja leviämiseen. Salmonellatartuntojen määrän vähentäminen ja tartuntojen ennaltaehkäisy ovat myös tärkeitä osa-alueita joissa seurannan tuloksia voi hyödyntää. Lisäksi DNA-tyypitysmenetelmien avulla voidaan selvittää tartunnan aiheuttaja ja osoittaa tartuntareitit. Väitöskirjan tekijä on 41-vuotias eläinlääketieteen lisensiaatti Nanna Lindqvist. Työ perustuu neljään tieteelliseen julkaisuun ja on englanninkieliseltä nimeltään Molecular characterization of endemic salmonella infections in cattle.

We aim at studying consumers’ Perceived Sensory Quality (PSQ) concept. We manipulated a priori both familiarity (contrast local vs. foreign cheeses) and quality level (contrast PDO or traditional cheeses vs. their non-PDO and/or industrial counterpart). The study was run in four European countries. Thus, eight cheeses (one PDO or traditional cheese and one non-PDO cheese from each of the four European countries) were assessed by a total of 438 consumers (from 100 to 120 consumers from each region) in terms of PSQ and liking. The cheeses were also described by a trained panel. PSQ depended on both consumers’ and cheeses’ origin. The main finding is that in the three countries with PDO culture, consumers identified domestic PDO cheese as having a significantly higher PSQ than its non-PDO counterpart, whereas they were not able to differentiate PDO and non-PDO cheeses from other countries. Overall, sensory drivers of PSQ were similar across consumers of different origin but, the relationship between PSQ and liking is higher for non-local cheeses than for local cheeses. Overall, the results support the idea that PSQ is related to liking but is also modulated by product familiarity.

UMR BFP - Equipe Virologie; International audience; High-throughput sequencing (HTS) technologies have revolutionized plant pest research and are now raising interest for plant pest diagnostics, with plant virus diagnostics at the forefront of development. However, the application of HTS in plant pest diagnostics raisesimportant challenges that plant health regulators will have to address. Adapted infrastructures, technical guidelines and training are pivotal for further use and adoption of the HTS technologies in the phytosanitary framework.

European bat lyssavirus type 2 (EBLV-2) was first isolated in Finland from a Daubenton’s bat (Myotis daubentonii) in 2009. Rabies in bats was already suspected in 1985, when a Swiss biologist died in Finland of lyssavirus infection, later identified as EBLV-2 infection. However, the origin of the infection could not be confirmed at that time. In 2010–2011, during active surveillance study, samples from 774 bats were analyzed for EBLV viral RNA. In addition, sera from 423 bats were analyzed for the presence of lyssavirus antibodies. Antibodies were detected in 2010 and 2011 from two locations and from one location, respectively. All seropositive bats were Daubenton’s bats. No EBLV viral RNA was detected in any of these bats. In 2016, EBLV-2 was detected from a diseased Daubenton’s bat for the second time. These data provide proof that EBLV-2 is endemic in the Finnish Daubenton’s bat population. In phylogenetic analysis, the Finnish EBLV-2 strains formed a monophyletic group separate from other bat-type lyssaviruses with significant support. EBLV-2 shared the most recent common ancestry with Bokeloh bat lyssavirus (BBLV) and Khujand virus (KHUV). EBLV-2 showed limited diversity compared to rabies virus (RABV) and appears to be well adapted to its host bat species. The slow tempo of viral evolution was evident in the estimations of divergence times for EBLV-2: the current diversity was estimated to have built up during the last 2000 years. The Finnish EBLV-2 strains and a Swiss strain (1993) were estimated to have diverged from other EBLV-2 strains during the last 1000 years, and the Finnish strains (1985 and 2009) appear to have evolved from a common ancestor during the last 200 years. Rabies vaccine is used to protect against rabies virus before or after potential exposure. Since all the currently available vaccines are based on RABV, the vaccines are also used to protect against other lyssaviruses, and additionally against EBLV-2 infection based on cross-protection. We assessed the level of protection afforded by two commercial rabies vaccines, one for humans and one for animals, against intracerebral challenge in mice with EBLV-2 isolated from a bat in 2009. We compared this with protection using the same mouse model against challenge with RABV isolated from a Finnish raccoon dog in 1989. When challenged with RABV, all the vaccinated mice survived. When challenged with EBLV-2, 75% to 80% of the vaccinated mice survived. All vaccinated mice developed sufficient to high virus-neutralizing antibody (VNA) titers against RABV, ranging from 0.5 to 128 IU/ml. RABV-based vaccines also appear to offer good cross-protection against EBLV-2 circulating in the Finnish bat population. To investigate the factors influencing the response to rabies vaccination, we assessed the success of vaccination measured from the antibody response in dogs (n = 10 071) and cats (n = 722) sampled during 2009–2013. We examined the factors influencing the response to vaccination when animals failed to reach a rabies antibody titer of ≥0.5 IU/ml. Eurooppalainen lepakkolyssavirus-2 (EBLV-2) eristettiin ensimmäisen kerran Suomessa vesisiipasta (Myotis daubentonii) vuonna 2009. Lepakkorabiesta epäiltiin jo vuonna 1985, kun sveitsiläinen biologi kuoli Suomessa lyssavirusinfektioon, joka myöhemmin varmistui EBLV-2-infektioksi. Infektion alkuperää ei kuitenkaan pystytty tuolloin vahvistamaan. Vuosina 2010–2011 tehdyssä toisessa aktiivisessa seurantatutkimuksessa etsittiin EBLV:n virus-RNA:ta analysoimalla 774 lepakosta kerätyt näytteet. Lisäksi analysoitiin 423 lepakosta kerätyt seeruminäytteet lyssaviruksen vasta-aineiden varalta. Vasta-aineita löydettiin vuonna 2010 kahdelta ja vuonna 2011 yhdeltä paikkakunnalta. Kaikki seropositiiviset lepakot olivat vesisiippoja. Yhdestäkään näissä lepakoista ei löydetty EBLV:n virus-RNA:ta. EBLV-2 todettiin seuraavan kerran vuonna 2016 sairaasta vesisiipasta. Tämä aineisto osoittaa, että EBLV-2 on kotoperäinen Suomen vesisiippapopulaatiossa. Fylogeneettisessä analyysissä suomalaiset EBLV-2-kannat muodostivat muista lepakkotyypin lyssaviruksista selvästi erillisen monofyleettisen ryhmän. EBLV-2 jakoi tuoreimman yhteisen alkuperän Bokeloh-lepakkolyssaviruksen (BBLV) ja Khujand-viruksen (KHUV) kanssa. EBLV-2:n monimuotoisuus todettiin RABV-virukseen verrattuna rajalliseksi, ja virus näyttää olevan hyvin sopeutunut isäntälepakkolajiinsa. Suomalaisten EBLV-2-kantojen ja sveitsiläisen kannan (1993) arvioitiin eriytyneen muista EBLV-2-kannoista viimeisen 1000 vuoden aikana, ja suomalaiset kannat (1985 ja 2009) näyttävät kehittyneen yhteisestä alkuperästä viimeisen 200 vuoden aikana. Rabiesrokotetta käytetään rabiesvirukselta suojautumiseen ennen mahdollista altistumista. Koska kaikki nykyisin saatavilla olevat rokotteet pohjautuvat RABV-virukseen, rokotteita käytetään myös muilta lyssaviruksilta suojautumiseen, myös EBLV-2-infektiota vastaan, ristikkäissuojaan perustuen. Arvioimme kahden kaupallisesti saatavilla olevan rabiesrokotteen, toisen ihmisille ja toisen eläimille tarkoitetun, tehoa hiirten aivojensisäisessä altistuksessa suomalaisesta lepakosta vuonna 2009 eristetyllä eurooppalaisella lepakkolyssavirus-2:lla (EBLV-2). Vertasimme samaa hiirimallia käyttäen tätä tehoon suomalaisesta supikoirasta vuonna 1989 eristettyä perinteistä rabiesvirusta (RABV) vastaan. RABV-virukselle altistettaessa kaikki rokotetut hiiret selvisivät hengissä. EBLV-2-virukselle altistettaessa 75–80 % rokotetuista hiiristä selvisi hengissä. RABV-pohjaiset rokotteet näyttävät myös tarjoavan hyvän ristikkäissuojan suomalaisessa lepakkopopulaatiossa kiertävää EBLV-2-virusta vastaan. Rabiesrokotevasteeseen vaikuttavien tekijöiden analysoimiseksi arvioimme rokotuksen tehoa mittaamalla vasta-ainevasteen koirilla (n = 10 071) ja kissoilla (n = 722), joista otettiin näytteet vuosina 2009–2013. Tutkimme rokotevasteeseen vaikuttavia tekijöitä tapauksissa, joissa eläimet eivät saavuttaneet rabiesvasta-ainetitteriä ≥ 0,5 IU/ml. Rokotteen vasta-ainetitteri oli 10,7 %:ssa koiranäytteistä (95 %:n luottamusväli CI 10,1–11,3) ja 3,5 %:ssa kissanäytteistä (95 %:n CI 2,3–5,0) < 0,5 IU/ml.

The Chronic bee paralysis virus (CBPV) is the aetiological agent of chronic bee paralysis, a contagious disease associated with nervous disorders in adult honeybees leading to massive mortalities in front of the hives. Some of the clinical signs frequently reported, such as trembling, may be confused with intoxication syndromes. Therefore, laboratory diagnosis using real-time PCR to quantify CBPV loads is used to confirm disease. Clinical signs of chronic paralysis are usually associated with viral loads higher than 108 copies of CBPV genome copies per bee (8 log(10) CBPV/bee). This threshold is used by the European Union Reference Laboratory for Bee Health to diagnose the disease. In 2015, the accuracy of measurements of three CBPV loads (5, 8 and 9 log(10) CBPV/bee) was assessed through an inter-laboratory study. Twenty-one participants, including 16 European National Reference Laboratories, received 13 homogenates of CBPV-infected bees adjusted to the three loads. Participants were requested to use the method usually employed for routine diagnosis. The quantitative results (n = 270) were analysed according to international standards NF ISO 13528 (2015) and NF ISO 5725-2 (1994). The standard deviations of measurement reproducibility (S-R) were 0.83, 1.06 and 1.16 at viral loads 5, 8 and 9 log(10) CBPV/bee, respectively. The inter-laboratory confidence of viral quantification (+/- 1.96 S-R) at the diagnostic threshold (8 log(10) CBPV/bee) was +/- 2.08 log(10) CBPV/bee. These results highlight the need to take into account the confidence of measurements in epidemiological studies using results from different laboratories. Considering this confidence, viral loads over 6 log(10) CBPV/bee may be considered to indicate probable cases of chronic paralysis.

sous presse; The NutriNet Santé study collected, on a voluntary basis, the dietary consumption of French vegetarian populations (N = 1766, including 188 vegan individuals) from 18 to 81 years (18-77 years for the vegan). Taking advantage of the availability of contamination data generated in the context of the second French total diet study, dietary exposures of French vegetarian populations to several contaminants were estimated. Results showed that exposures to persistent organic pollutants (PCBs, PCDD/Fs for instance) was dramatically lower than those of the general French population due to the non consumption of food of animal origins. On the other hand, exposures to phytoestrogens, some mycotoxins (T2 and HT2 toxins) and some trace elements (Cd, Al, Sn, Ni) were higher in the vegetarian population compared to those of the general population. Despite some limitations of this approach (both the consumption study and the total diet study were not aimed to estimate dietary exposure of the vegetarian populations), this study showed that dietary habits can dramatically influence the exposure of some contaminants.

In the present chapter, dietary exposures of different vegetarian populations to pesticide residues as well as those to contaminants are discussed, based on French data. For 48 pesticide residues out of 421, it was shown that, based on theoretical calculation of the exposure, vegetarians could have higher exposures than those of the general population, the pescetarian population being very close to the situation observed for the general population. On the other hand, biomonitoring studies demonstrated that there was a trend toward lower organochlorine contamination in the vegan population compared to that of the general population. With regard to contaminants, exposures to phytoestrogens or to some trace elements (Cd, Al, Ni) were higher for the vegetarian population compared to those of the general population. Otherwise, the vegetarian population studied in the present study was less exposed than the general population to other contaminants such as some persistent organic pollutants, some mycotoxins, and some trace elements.

Crayfish plague is a severe disease of European crayfish species and has rendered the indigenous crayfish populations vulnerable, endangered or even extinct in the most of Europe. Crayfish plague is caused by an oomycete Aphanomyces astaci, a fungal-like water mould that lives its vegetative life in the cuticle of crayfish and infects other crayfish by producing zoospores. Zoospores swim around for a few days in search of crayfish, and when they find one they attach onto its surface, encyst and germinate to start a new growth cycle as new growing hyphae penetrate the crayfish tissues. Unrestricted growth of A. astaci leads to the death of the infected animal in just a few weeks. Crayfish plague induced mortalities started in Italy around 1860. Although the disease was known about since 1860 its cause remained unknown for several decades. Little was done to prevent the spread of the disease. A lively crayfish trade probably facilitated the spread of the crayfish plague, which reached Finland in 1893. The crayfish plague has remained the most important disease problem of the Finnish noble crayfish Astacus astacus, since then. The consensus was that the disease killed all infected animals in a short time, and it appeared almost impossible to restore the flourishing crayfish populations to the levels that existed before. Following the example of neighbouring Sweden, a North American crayfish species, the signal crayfish Pacifastacus leniusculus that appeared resistant to crayfish plague was introduced to Finland in 1960s. As expected, the signal crayfish slowly started to replace the lost populations of the noble crayfish to become an important part of the crayfish fisheries. The introduction of the signal crayfish significantly added to the management problems of the noble crayfish stocks left. Signal crayfish appeared to be a chronic carrier of the crayfish plague agent, and spread the disease to the dwindling vulnerable noble crayfish populations. Later research showed that the crayfish plague agent is a parasite of North American crayfish that in normal circumstances does not harm the host animal. Intriguingly, the crayfish plague agent carried by the signal crayfish, genotype Ps1, is different from the pathogen originally introduced into Europe, genotype As. The diagnosis of crayfish plague especially when based on the isolation of the pathogen is challenging and accordingly the genotype difference was mostly unrecognized until recently. In this study we determined the genotype of the causative agent from most of the detected Finnish crayfish plague cases between 1996 -2006. It appeared that most of the epidemics in the immediate vicinity of signal crayfish populations were caused by genotype Ps1, whereas genotype As was more prevalent in the noble crayfish areas. Interestingly, a difference was seen in the outcome of the infection. The Ps1 infection was always associated with acute mortalities, while As infections were also frequently found in existing but weak populations. The persistent nature of an As infection could be verified in noble crayfish from a small lake in southern Finland. This finding explained why many of the efforts to introduce a new noble crayfish population into a water body after a crayfish plague induced mortality were futile. The main conclusion from the field study data of this research was the difference in virulence between the Ps1 and As genotype strains. This was also verified in a challenge trial with noble crayfish. While the Ps1 strains did not show much variation in their growth behaviour or virulence, there was much more variation in the As strains. The As genotype arrived in Finland more than 100 years ago, and since that date it seems to have adapted to the novel host, the noble crayfish, to some extent. In order to gain insight into a possible vector of this genotype, we studied another North American crayfish species present in Europe, the spiny-cheek crayfish Orconectes limosus from a Czech pond. This crayfish species appeared to carry a novel genotype of A. astaci, named Orconectes genotype, designated Or . It seems possible that many of the North American crayfish species carry their own type of crayfish plague agent, with variable features such as virulence. These differences should be further tested in the future. The results of this study alleviate the necessity to study the noble crayfish mortalities for the verification of crayfish plague, including the study for the genotype of the A. astaci strain. Crayfish fisheries and conservation management decisions should not be made without a prior control of the donating population and the receiving water body for the eventual presence of a low-virulent A. astaci. Rapurutto on eurooppalaisten rapulajien vakavin tautiongelma, joka on saattanut kotoperäiset rapulajit uhanalaisiksi lähes kaikkialla Euroopassa. Rapuruton aiheuttaa leväsieni Aphanomyces astaci, joka elää sienenkaltaisena rihmastona ravun kuoressa, ja siirtyy isäntäeläimestä toiseen siimallisten uimaitiöiden välityksellä. Taudille herkät rapulajit eivät pysty rajoittamaan rihmaston kasvua tehokkaasti ja kuolevat yleensä tartuntaan parissa viikossa. Ensimmäiset rapujen joukkokuolemat raportoitiin Italiassa 1860-luvulla, ja Suomeen tartunta levisi 1893. Siitä lähtien rapurutto on tuhonnut merkittävän osan Suomen alkuperäisen rapulajin jokiravun (Astacus astacus) kannoista. Tuhoutuneita kantoja korvaamaan tuotiin Pohjois-Amerikasta täplärapuja, jotka eivät olleet herkkiä taudille. Ne kuitenkin kantoivat taudinaiheuttajaa kuoressaan ja tartuttivat sitä edelleen jokirapuihin. Geneettisesti täplärapujen kantama rapurutto, genotyyppi Ps1, eroaa alun perin Suomeen tulleesta taudinaiheuttajasta, genotyypistä As. Tässä tutkimuksessa määritettiin Suomessa vuosina 1996-2006 todettujen rapuruttotapausten genotyyppi. Täplärapujen esiintymisalueen läheisyydessä Etelä-Suomessa jokiravuilla esiintyi yleensä Ps1-tyypin aiheuttamia tartuntoja, kun taas muualla Suomessa As-tyypin rapurutto oli yleisempi. Ps1-tyyppi aiheutti aina rapukuolemia, kun taas As-tyyppiä löytyi usein myös heikoista jokirapukannoista. Rapukuoleman jälkeen heikkoon rapukantaan piileväksi jäänyt As-tyypin rapuruttotartunta todennettiin pienessä eteläsuomalaisessa järvessä. Genotyyppien välinen taudinaiheutuskyvyn ero todettiin myös kokeellisesti. Ps1-rapuruttokantojen välillä ei ollut merkittäviä eroja taudinaiheutuskyvyssä tai kasvunopeudessa, toisin kuin As-kannoilla. As-tyypin rapurutto näyttää sopeutuneen jossakin määrin uuteen isäntälajiinsa jokirapuun. Sen alkuperäistä isäntälajia ei tunneta. Tutkimme sen selvittämiseksi Eurooppaan tuotua toista rapulajia amerikkalaista kääpiörapua (Orconectes limosus), joka kuitenkin osoittautui aiemmin kuvaamattoman rapuruttotyypin Or kantajaksi. On mahdollista, että pohjoisamerikkalaisilla rapulajeilla esiintyy paljon enemmänkin lajinomaisia rapuruttotyyppejä, joiden ominaisuudet kuten taudinaiheutuskyky voivat poiketa toisistaan. Tämä tutkimus osoitti, että rapuruttotapaukset on varmistettava laboratoriotutkimuksella, joka sisältää myös rapuruton tyypin määrittämisen. Jokirapukantojen hoidossa on otettava huomioon piilevän rapuruton mahdollisuus. Siksi istutussuunnitelmiin täytyy aina sisällyttää sekä istukkaiden että vastaanottavan vesistön rapuruttotilanteen tutkiminen.

Fat is a remarkable source of energy in diet. The majority of dietary fat consists of fatty acids, which have a great influence on health. Much attention in nutritional discussion has focused on the saturation of fatty acids in food. Another group of fatty acids with significance to health is trans fatty acids (TFAs). Trans fatty acids resemble saturated fat in a physiological sense but are shown to increase the risk of cardiovascular disease even more than saturated fat. Nevertheless, there are differences in the biological activity of different TFA isomers. The analysis of fatty acids has met an increasing demand for more and more precise identification. The correlation between saturated fat and cardiovascular diseases found in earlier decades has changed the nutritional recommendations to reduced-fat dairy products. Reduced-fat dairy products are a way of reducing total energy in diet, too. Dairy products may have a modified fatty acid profile if fat sources other than milk are used. Modern methods, with a greater weight on mass spectrometric methods, for fatty acid analysis and the effects of fat on the chemical and sensory characteristics of dairy products are reviewed. Fat reduction changes the properties of cheese. The aim of the first part of the study was to characterise cheeses on the Finnish market and find out specifically the appealing characteristics of reduced-fat cheeses. The cheeses in the study were Emmental, Edam and Havarti-type cheeses. Chemical composition, sensory profile and consumer liking were studied. Cheese properties and liking were linked to identify the appealing characteristics of different cheeses. The second part of the study included fatty acid analysis. Dairy products on the market have variable fat sources ofvegetable origin. It is known from the literature that hardened vegetable fats may have TFAs, but the current situation on the Finnish market was not known. The aim of the second part of the study was to survey the fatty acid profiles of milk-based dairy products (cheeses, vegetable fat ice creams, and vegetable fat cream substitutes) and spreads and shortenings on the market. Products with reduced-fat or modified fat were included. Free fatty acids are produced by lipolysis from fat. They have effect on the flavour of cheeses. Lipolysis can be enhanced by homogenisation. The aim of the third part of the study was to validate chromatographic method for free fatty acid analysis from cheese and to study the effect of homogenisation on free fatty acids in Emmental. The content of free fatty acids was joined to the sensory profile to find out if they have impact on flavour in the pilot Emmental cheeses. This study shows that it is possible to create reduced-fat cheeses with appealing characteristics. The properties influencing liking were slightly different in reduced-fat cheeses than in regular fat cheeses. Generally reduced-fat cheeses were lacking flavour. The liking of reduced-fat cheeses might increase if flavour intensities could be increased. However, it is desirable that flavour intensity is not increased with salt, as this has negative health effects. The second part of the study shows that several milk-based products and spreads on the Finnish market do not contain remarkable amounts of trans fat. In addition, the fatty acid profiles of the cheeses are shown not to be affected by cheese variety or fat reduction. More interestingly, products have variable amounts of essential fatty acids and n-3 fatty acids. Accurate identification requires good separation between fatty acid isomers. In this study polar and highly polar columns with 60 m or 100 m length were sufficient for cis/trans separation for nutritional purposes. The analysis of fatty acid methyl esters by GC-MSD gave detailed information on fatty acids in dairy food. Free fatty acids of Emmental cheese were quantitatively analysed by GCMSD without derivatisation. Internal standards were used to correct for the effect of sample treatment. The method was suitable for cheese and for shortand medium-chain fatty acids. These volatile fatty acids contribute to the flavour of cheese. The homogenisation of cheese milk increased the content of free fatty acids and the intensity of taste in trial cheeses. The defects, and on the other hand, the appealing characteristics of reduced-fat cheeses were studied. These results contribute to the development of appealing cheeses with reduced-fat content. The survey on fatty acids in dairy-based products gave up-to-date information on products on the market. These results have significance to nutritionists, dieticians, legislators and consumers, as this knowledge was not available before. Rasva on merkittävä ruokavalion energianlähde. Suurin osa siitä on rasvahappoja, joilla on erilaisia terveydellisiä vaikutuksia. Keskustelu ravitsemuksesta on keskittynyt ruoan sisältämiin tyydyttyneisiin rasvahappoihin, ns. kovaan rasvaan. Toinen terveydelle haitallinen ryhmä on trans-rasvahapot (TFA). Trans-rasvahapot muistuttavat toiminnallisesti tyydyttynyttä rasvaa, mutta niiden on osoitettu olevan sydänterveydelle jopa haitallisempia. TFA-isomeerien välillä on kuitenkin eroja biologisessa aktiivisuudessa. Rasvahappoanalytiikalta vaaditaankin yhä tarkempaa rasvahappojen tunnistusta. Aiempina vuosikymmeninä löydetty tyydyttyneen rasvan ja sydän- ja verisuonitautien yhteys on muuttanut ravitsemussuosituksia vähärasvaisten maitotuotteiden suuntaan. Vähärasvaisten maitotuotteiden käyttö myös pienentää ruokavalion kokonaisenergiamäärää. Maitotuotteiden rasvahappoprofiili muuttuu, jos tuotteen rasva on muuta kuin maitorasvaa. Tämän tutkimuksen kirjallisuusosa sisältää yhteenvedon nykyaikaisista rasvahappojen analyysimenetelmistä pääpainon ollessa massaspektrometrisissä menetelmissä ja rasvan vaikutuksesta maitotuotteiden kemialliseen ja aistittavaan ominaislaatuun. Rasvan vähentämisellä on vaikutusta juuston ominaisuuksiin. Tutkimuksen ensimmäisen osan tavoitteena oli kartoittaa markkinoilla olevien juustojen ominaisuuksia ja löytää erityisesti kevytjuustojen miellyttävyyteen vaikuttavat tekijät. Tutkitut juustot olivat emmental-, edam- ja murukolojuustoja. Juustoista tutkittiin kemiallinen koostumus, aistinvarainen profiili ja miellyttävyys. Yhdistämällä juuston ominaisuudet miellyttävyyteen selvitettiin siihen vaikuttavat juuston ominaispiirteet. Tutkimuksen toinen osa sisälsi rasvahappoanalyysejä. Markkinoilla olevissa maitopohjaisissa tuotteissa on käytetty erilaisia kasviperäisiä rasvanlähteitä. Kirjallisuuden perusteella tiedetään, että kovetetuissa kasvirasvoissa saattaa olla trans-rasvaa, mutta kotimaan markkinoilla olevien tuotteiden osalta ei ollut ajantasaista tietoa. Tutkimuksen toisen osan tavoitteena oli kartoittaa markkinoilla olevien maitopohjaisten tuotteiden (juustot, kasvirasvajäätelöt, kasvirasvasekoitteet) sekä levitteiden ja leivontamargariinien rasvahappoprofiilit. Tutkimukseen valittiin vähärasvaisia ja kasvirasvaa sisältäviä tuotteita. Rasvan hajoamisessa, lipolyysissä, syntyy vapaita rasvahappoja, jotka vaikuttavat juuston aromiin ja makuun. Lipolyysiä voidaan lisätä rasvan homogenoinnilla. Tutkimuksen kolmannen osan tavoitteena oli validoida kromatografinen menetelmä juuston vapaiden rasvahappojen määrittämiseen ja tutkia maidon homogenoinnin vaikutus emmentaljuuston vapaisiin rasvahappoihin. Vapaiden rasvahappojen määrä yhdistettiin koejuuston aistinvaraiseen profiiliin rasvahappojen flavoriin aiheuttaman vaikutuksen arvioimiseksi. Tämä tutkimus osoitti, että miellyttävien kevytjuustojen valmistus on mahdollista. Ominaisuudet, jotka vaikuttavat miellyttävyyteen, ovat kuitenkin hieman erilaiset kevyt- ja täysrasvaisilla juustoilla. Yleisesti voidaan todeta, että kevytjuustojen flavori oli heikko. Ne voisivat olla pidetympiä, jos flavori olisi voimakkaampi. Voimakkuutta ei kuitenkaan olisi hyvä vahvistaa suolalla sen negatiivisten terveysvaikutusten takia. Tutkimuksen toisessa osassa todettiin, että monet Suomen markkinoilla olevat maitopohjaiset tuotteet ja levitteet eivät sisällä trans-rasvaa merkittävissä määrin. Samalla osoitettiin, että eri juustotyypeillä ja eri rasvaisilla juustoilla oli samanlainen rasvahappoprofiili. Enemmän huomionarvoista onkin, että tuotteissa on vaihtelevia määriä välttämättömiä ja n-3-sarjan rasvahappoja. Rasvahappojen tarkka identifiointi vaatii eri isomeerien välille hyvän erottumisen. Tässä työssä polaariset ja erittäin polaariset kolonnit, joiden pituudet olivat 60 m ja 100 m, olivat riittävän erotuskykyiset cis- ja trans-isomeerien erottamiseen tarkoituksena saada tietoa ravitsemuksellisesti merkittävistä rasvahapoista. Rasvahapon metyyliestereiden analysointi GC-MSD-tekniikalla antoi yksityiskohtaista tietoa maitotuotteiden rasvahapoista. Emmentaljuuston sisältämät vapaat rasvahapot analysoitiin kvantitatiivisesti GC-MSD -tekniikalla ilman derivatisointia. Menetelmässä käytettiin sisäisiä standardeja korjaamaan näytteenkäsittelyn vaikutus. Menetelmä soveltui lyhyiden ja keskipitkien rasvahappojen analysointiin juustosta. Näillä helposti haihtuvilla rasvahapoilla on vaikutusta juuston flavoriin. Juustomaidon homogenointi kasvatti koejuuston vapaiden rasvahappojen pitoisuutta ja maun intensiteettiä. Tässä työssä tutkittiin kevytjuustojen heikkouksia ja toisaalta miellyttävyyteen vaikuttavia ominaisuuksia. Nämä tulokset auttavat maukkaiden kevytjuustojen tuotekehityksessä. Tutkimus maitopohjaisten tuotteiden rasvahappokoostumuksesta antoi uutta tietoa markkinoilla olevista tuotteista. Näillä tuloksilla on merkitystä ravitsemustieteilijöille, ravitsemusterapeuteille, lainsäätäjille ja kuluttajille, koska saatavilla olevaa tietoa ei aiemmin ollut. Fettet utgör en betydande energikälla i kosten. Största delen av fettet är fettsyror som har olika inverkningar på hälsan. Diskussionen om kosten har koncentrerat sig på de mättade fettsyrorna, det s.k. hårda fettet, som maten innehåller. En annan grupp som är skadlig för hälsan är transfettsyrorna (TFA). Transfettsyrorna påminner funktionsmässigt om mättat fett, men de har påvisats vara rentav skadligare med tanke på hjärthälsan. Mellan TFA-isomererna förekommer ändå skillnader i den biologiska aktiviteten. Av fettsyraanalytiken krävs en allt exaktare identifiering av fettsyrorna. Det under de gångna årtiondena funna sambandet mellan mättat fett och hjärt- och kärlsjukdomar har ändrat näringsrekommendationerna i riktning mot fettsnåla mjölkprodukter. Användning av fettsnåla mjölkprodukter minskar också totalenergimängden i kosten. Mjölkprodukternas fettsyraprofil förändras, om fettet i produkten är annat än mjölkfett. I litteraturavsnittet till denna undersökning ingår ett sammandrag av moderna metoder att analysera fettsyror med huvudvikten förlagd på massaspektrometriska metoder och fettets inverkan på mjölkprodukternas kemiska och sensoriska särart. En minskning av fettet påverkar ostens egenskaper. Målet med den första delen av undersökningen var att kartlägga egenskaperna hos ostarna på marknaden och finna särskilt de faktorer, som påverkar hur tilltalande lättostarna är. De undersökta ostarna var emmentalerostar, edamerostar och grynpipiga ostar. Ostarna undersöktes med tanke på den kemiska sammansättningen, den sensoriska profilen och det hur tilltalande de var. Genom att kombinera ostens egenskaper med det hur tilltalande den var utreddes vilka särdrag som påverkar det hur tilltalande osten verkar. I den andra delen av undersökningen ingick fettsyraanalyser. I de mjölkbaserade produkterna på marknaden har använts olika vegetabiliska källor till fett. Utgående från litteraturen vet man att härdade vegetabiliska fetter kan innehålla transfett, men i fråga om produkterna på den inhemska marknaden fanns ingen aktuell information. Syftet med den andra delen av undersökningen var att kartlägga fettsyraprofilerna för de mjölkbaserade produkterna (ostarna och den glass och de fettblandningar, som innehåller vegetabiliskt fett) jämte de bredbara fetterna och bakningsmargarinerna. Med i undersökningen valdes fettsnåla produkter och produkter som innehåller vegetabiliskt fett. I fettets sönderfallningsprocess, lipolysen, formas fria fettsyror som påverkar ostens arom och smak. Lipolysen kan ökas genom att fettet homogeniseras. Syftet med den tredje delen av undersökningen var att validera en kromatografisk metod att bestämma de fria fettsyrorna i osten och undersöka hur en homogenisering av mjölken påverkar de fria fettsyrorna i emmentalerost. Mängden fria fettsyror kombinerades med försöksostens sensoriska profil i avsikt att utvärdera inverkan som fettsyrornas flavour orsakar. Denna undersökning visade att det är möjligt att framställa tilltalande lättostar. Egenskaperna som påverkar det hur tilltalande osten är skiljer sig ändå något mellan lätta och helfeta ostar. Allmänt kan konstateras att lättostarnas flavour var svag. De kunde vara populärare, om flavouren var starkare. Det är ändå inte någon god idé att öka styrkan med hjälp av salt på grund av saltets negativa inverkningar på hälsan. I andra delen av undersökningen konstaterades att många mjölkbaserade produkter och bredbara fetter på den finländska marknaden inte innehåller transfett i några betydande mängder. Samtidigt påvisades också att olika typer av ost och olika feta ostar hade en likadan fettsyraprofil. Mer beaktansvärt är det att produkterna innehåller varierande mängder oumbärliga fettsyror och n-3 fettsyror. En exakt identifiering av fettsyrorna kräver en god separation mellan olika isomerer. I detta arbete var polära och ytterst polära kolonner med längderna 60 m och 100 m tillräckligt separationsdugliga för separation av cis- och transisomererna i avsikt att få information om näringsmässigt betydande fettsyror. En analysering av metylestrarna i fettsyran med GC-MSD-teknik gav detaljerad information om fettsyrorna i mjölkprodukterna. De fria fettsyrorna som emmentalerosten innehåller analyserades kvantitativt med GC-MSD-teknik utan derivatisering. I metoden användes interna standarder för att korrigera provprepareringens inverkan. Metoden lämpade sig för analysering av korta och medellånga fettsyror i ost. Dessa flyktiga fettsyror påverkar ostens flavour. En homogenisering av ostmjölken ökade längden på de fria fettsyrorna och intensiteten hos maken i försöksosten. I detta arbete undersöktes lättostarnas svagheter och å andra sidan också vilka egenskaper som inverkar på det hur tilltalande ostarna är. Resultaten är till hjälp i produktutvecklingen av smakliga lättostar. Undersökningen av mjölksyrasammansättningen hos mjölkbaserade produkter gav ny information om produkterna på marknaden. Resultaten är viktiga för näringsfysiologerna, näringsplanerarna, lagstiftarna och konsumenterna, eftersom det inte tidigare fanns tillgång till sådan information.

Parapoxviruses (PPVs) of the family Poxviridae are zoonotic viruses which cause contagious pustular skin infections of sheep, goats and cattle worldwide. Cases of contagious pustular stomatitis in Finnish reindeer have been reported for many years. The aims of this study were to establish specific and rapid detection methods for the causative agent of the disease and characterise the viruses circulating in Finland. The causative agent of reindeer pustular stomatitis was originally considered to be PPV Orf virus (ORFV). PCR methods amplifying different regions of the PPV genomes were developed to analyse clinical samples obtained from outbreaks of the disease in reindeer and later from viruses isolated from the disease of sheep and cattle in Finland. Subsequent phylogenetic analysis of the partial gene sequences indicated that reindeer virus from the early outbreaks is most closely related to ORFV whereas the PPV strains from the 1999-2000 outbreak is most closely related to the cattle PPV Pseudocowpox virus (PCPV). Furthermore, the phylogenetic analyses of Finnish reindeer, bovine and sheep isolates indicated that the viruses causing the disease in reindeer are very closely related to the PCPVs and ORFVs infecting Finnish cattle and sheep, respectively. Since the initial classification of the viruses causing disease in Finnish reindeer relied solely on the partial sequence analysis of two conserved PPV genes, the genome of PCPV-like reindeer isolate (F00.120R) was sequenced and analysed together with that of a reference strain of PCPV (VR634). The genomes of F00.120R and VR634 viruses were found to consist of a central core region of conserved genes, flanked by more variable terminal regions as seen in other poxvirus genomes. F00.120R was found to have four, possibly fragmented, genes at the left terminus and another near the central region of the genome that are not present in ORFV or Bovine papular stomatitis virus (BPSV; another PPV) genomes. In addition, the F00.120R genome was found to lack six genes seen near the right genome terminus of other PPVs. The protein coding contents and G+C profile of the genomes, as well as gene order and predicted protein homologies indicated that F00.120R is an isolate of PCPV and that PCPV is correctly classified as a member of the genus Parapoxvirus. These results expand the host range of PCPV to reindeer. The observed six gene deletion at the right terminus of the F00.120R genome was further investigated. The results showed that a 5431 bp sequence containing genes 116-121 was likely to have been deleted from the F00.120R genome prior to the 7th cell culture passage. These findings conclude that the genome of reindeer PCPV is 140 kbp in length and has 137 genes. Poxvirusten heimoon kuuluvat zoonoottiset parapoxvirukset (PPV) aiheuttavat rakkulaista ihotautia lampailla, vuohilla ja naudoilla maailmanlaajuisesti. Suomalaisissa poroissa on esiintynyt jo ainakin 90-luvun alusta lähtien suutautia, jonka aiheuttajaksi epäiltiin alun perin PPV-sukuun kuuluvaa orfvirusta (ORFV) samankaltaisten oireiden perusteella. Työn tavoitteena oli tunnistaa suutaudin aiheuttajavirus, kehittää polymeraasiketjureaktioon (PCR) perustuvat menetelmät taudin diagnostiikkaan sekä karakterisoida poro-, lammas- ja nautanäytteistä löytyviä viruskantoja. Parapoxvirusten eri geeneihin perustuvilla PCR-menetelmillä tutkittiin eri vuosien suutautinäytteitä sekä lampaiden ja nautojen ihotautinäytteitä. Monistetut geenialueet sekvensoitiin ja niiden perusteella tehtiin fylogeneettisiä analyysejä. Tulokset osoittivat, että vuosina 1992 1994 tautia aiheutti lampaiden ORFV-kaltainen virus, mutta 1999 2000 epidemian aiheuttajaksi paljastui naudan valelehmärokkoviruksen (Pseudocowpoxvirus; PCPV) kaltainen virus. Lisäksi vertailtaessa porojen parapoxviruksia vuosilta 1992 2007 nautojen ja lampaiden viruksiin havaittiin, että nämä Suomesta eristetyt virukset ovat keskenään hyvin samankaltaisia, jopa identtisiä tutkittujen geenien osalta. Tieto on tärkeä taudin vastustamisessa: suoria kontakteja porojen, lampaiden ja nautojen välillä on suositeltavaa välttää. Koska aiheuttajaviruksen tunnistaminen perustui alun perin vain kahteen geenialueeseen, työssä sekvensoitiin PCPV-kaltaisen poron PPV:n (F00.120R) koko genomi. Genomivertailuissa tämän viruksen sekä työssä määritetyn tunnetun PCP-viruksen (VR634) genomit osoittautuivat rakenteeltaan ja geenisisällöltään samankaltaiseksi kuin aikaisemmin sekvensoitujen ORFV ja naudan papulaarinen stomatiitti viruksen (BPSV; myös PPV) genomit. F00.120R ja VR634 virusten genomit koostuvat genomien keskellä olevasta konservoituneiden geenien alueesta, jonka molemmilla puolilla genomin päissä ovat vaihtelevien geenien alueet. Sama rakenne on osoitettu myös muilla sekvensoiduilla poxviruksilla. F00.120R virukselta löytyi lisäksi neljä geeniä, joita ei ole todettu muilla poxviruksilla. Sen sijaan F00.120R genomin oikeasta päädystä havaittiin puuttuvan kuusi sellaista geeniä, jotka löytyvät ORF-virukselta. Tutkittaessa tätä genomin puuttuvien geenien aluetta osoittautui, että kyseiset kuusi geeniä ovat hävinneet genomista soluviljelyn aikana ennen seitsemättä soluviljelypasaasia. F00.120R viruksen genomin emäskoostumus, geenien järjestys genomissa sekä samankaltaisuus VR634 viruksen geenien kanssa varmentavat poron viruksen olevan PCPV. Nämä tulokset laajentavat PCP-viruksen isäntäeläinkirjon poroon.

Ranaviruses cause systemic infection in fish, amphibians and reptiles. Disease outbreaks associated with ranaviruses have been reported worldwide, and their harmful impact on aquaculture and natural populations of host animals has drawn attention to this group of viruses. In this research, genetic relationships among members of genus Ranavirus, including several known and less studied isolates, were investigated. Sequences of several viral genes were obtained and the phylogenetic analyses based on the sequence data were performed. The results confirm that the genus Ranavirus encompasses genetically divergent isolates. Most of the ranaviruses characterized to date are closely related to epizootic haematopoietic necrosis virus (EHNV) and frog virus 3 (FV3). Santee-Cooper ranaviruses and grouper iridoviruses cluster separately from the main group of ranaviruses. Methods based on polymerase chain reaction (PCR) and subsequent restriction enzyme analysis (REA) were developed for the detection and differentiation of ranaviruses. PCR based on viral DNA polymerase (DNApol) gene was able to detect 13 different ranavirus isolates. The differentiation of isolates was accomplished with REA of the viral DNApol and neurofilament-triplet H1-like protein genes. Quantitative PCR based on the viral DNApol gene was developed in order to detect a wide range of ranaviruses and to estimate the number of virions in a sample. Pathogenicity of nine different ranavirus isolates to rainbow trout (Oncorhynchus mykiss) was studied. None of the isolates caused signs of disease, but virus was isolated from few of the fish collected during the challenge trial. The results indicate that persistent ranavirus infections may occur in certain conditions and that rainbow trout could act as a vector species for ranaviruses. Fish epithelial cells were infected with four different ranaviruses in order to study the host immune response to ranavirus infection. All ranavirus isolates elicited apoptosis in the fish epithelial cells, but the immune response elicited varied between different ranaviruses. A strong pro-inflammatory response was induced by FV3 and EHNV, whereas European catfish virus and doctor fish virus elicited a mild increase in the expression of regulatory cytokine TGF-β. Gene expression of beta-2 microglobulin was enhanced by all viral isolates, indicating that a pathogen presentation pathway based on MHC class I molecules was activated due to ranavirus infection. Ranavirukset aiheuttavat systeemisen infektion kaloissa, sammakkoeläimissä ja matelijoissa. Ranavirusten aiheuttamia taudinpurkauksia on raportoitu ympäri maailmaa niin kasvatetuissa kuin luonnonvaraisissa isäntäeläimissäkin. Tässä tutkimuksessa selvitettiin useiden aikaisemmin tunnettujen ja ennestään tuntemattomien ranavirusten geneettisiä sukulaisuussuhteita. Useita ranavirusten perimään kuuluvia geenejä sekvensoitiin ja niiden perusteella tehtiin fylogeneettisiä analyysejä. Tulokset vahvistavat, että Ranavirus-sukuun kuuluu geneettisesti toisistaan poikkeavia viruksia. Useimmat ranaviruksista ovat läheistä sukua epizootic haematopoietic necrosis (EHN)- ja frog virus 3 (FV3)-viruksille, kun taas Santee-Cooper ranavirukset ja grouper iridovirukset eroavat selvästi muista ranaviruksista. Tutkimuksessa kehitettiin polymeraasiketjureaktioon (PCR) ja restriktioentsyymianalyysiin (REA) perustuvia tunnistus- ja erottelumenetelmiä ranaviruksille. Ranavirusten DNA polymeraasi (DNApol)-geeniin perustuvan PCR:n avulla tunnistettiin 13 eri ranaviruskantaa. Virukset eroteltiin toisistaan ranavirusten DNApol- ja NF-H1-geeneihin perustuvalla REA-menetelmällä. DNApol-geeniin perustuvalla kvantitatiivisella PCR-menetelmällä pystyttiin ranavirusten tunnistamisen lisäksi selvittämään viruspartikkeleiden määrä näytteessä. Yhdeksän eri ranaviruskannan taudinaiheuttamiskykyä tutkittiin kirjolohella (Oncorhynchus mykiss). Mitkään tutkituista viruksista eivät aiheuttaneet taudin oireita, mutta osasta kirjolohia pystyttiin eristämään ranavirus kokeen aikana. Tulosten mukaan ranavirukset voivat tietyissä olosuhteissa säilyä isäntäeläimessä ja kirjolohi voi näin ollen toimia ranavirusinfektion välittäjänä. Ranavirusten aiheuttamaa immuunivastetta tutkittiin infektoimalla kalojen epiteelisoluja neljällä eri ranaviruskannalla. Kaikki neljä viruskantaa aiheuttivat ohjelmoitua solukuolemaa eli apoptoosia, mutta eri virukset saivat aikaan toisistaan poikkeavan immuunigeenien ilmentymisen kalojen epiteelisoluissa. EHNV ja FV3 aiheuttivat voimakkaan pro-inflammatorisen vasteen, kun taas European catfish virus ja doctor fish virus lievästi lisäsivät regulatorisen sytokiinin TGF-betan ilmentymistä. Kaikki ranavirukset lisäsivät beta-2 mikroglobuliini-geenin ilmentymistä, mikä osoittaa, että luokan I MHC -molekyyleihin perustuva antigeenien esittely aktivoitui ranavirusinfektion seurauksena.

Campylobacter, mainly Campylobacter jejuni and C. coli, are worldwide recognized as a major cause of bacterial food-borne gastroenteritis. Epidemiological studies have shown handling or eating of poultry to be significant risk factors for human infections. Campylobacter contamination can occur at all stages of a poultry meat production cycle. The aim of this thesis was to study the occurrence and diversity of Campylobacter in broiler and turkey production in Finland. In summer 1999, 2.9 % of slaughtered broiler flocks were Campylobacter-positive. From the isolated strains 94 % were C. jejuni and 6% were C. coli. During years 2005-2006 one turkey parent flock, the hatchery, six different commercial turkey farms and different stages of the slaughterhouse were monitored during one and the half year. No Campylobacter were detected in either of the samples from the turkey parent flock or from the hatchery using the culture method. Instead PCR detected DNA of Campylobacter from the turkey parent flock and samples from the hatchery. Six out of 12 commercial turkey flocks were found negative at the farm level but only two of those were negative at slaughter. Campylobacter-positive samples within the flock at slaughter were detected between 0% and 94% with evisceration and chilling water being the most critical stages for contamination. All of Campylobacter isolates were shown to be C. jejuni. Campylobacter-positive turkey flocks were colonized by a limited number of Campylobacter genotypes both at the farm and slaughter level. In conclusion, in our first study in 1999 a low prevalence of Campylobacter in Finnish broiler flocks was detected and it has remained at a low level during the study period until the present. In the turkey meat production, we found that flocks which were negative at the farm became contaminated with Campylobacter at the slaughter process. These results suggest that proper and efficient cleaning and disinfection of slaughter and processing premises are needed to avoid cross-contamination. Prevention of colonization at the farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of Campylobacter-positive poultry meat in Finland. With a persistent low level of Campylobacter-positive flocks, it could be speculated that the use of logistic slaughtering, according to Campylobacter status at farm, might have be advantageous in reducing Campylobacter contamination of retail poultry products. However, the significance of the domestic poultry meat for human campylobacteriosis in Finland should be evaluated. Kampylobakteerit, erityisesti Campylobacter jejuni ja C. coli, ovat maailman yleisimpiä suolistotulehdusten aiheuttajia. Useat tutkimukset ovat osoittaneet riittämättömästi kuumennetun siipikarjanlihan olevan merkittävä ihmisten tartuntojen lähde. Kampylobakteerit voivat kontaminoida siipikarjan ja siipikarjanlihan tuotantoketjun eri vaiheissa. Tämän tutkimuksen tarkoituksena oli selvittää kampylobakteerin esiintymistä kotimaisessa siipikarjanlihan tuotannossa. Kesällä 1999 tehtiin ensimmäinen kattava tutkimus kampylobakteerien esiintymisestä kotimaisissa broileriteurastuserissä. Kampylobakteereita todettiin 2.9 % teurastuseristä. Eristetyistä kannoista 94 % oli C. jejuni ja 6 % C. coli -lajeja. Vuonna 2005-2006 kalkkunan tuotantoketjua seurattiin 1,5 vuoden ajan, näytteitä otettiin vanhempaispolven parvesta, hautomolta, tuotantopolven tiloilta sekä teurastamolla eri kohdista. Tutkimuksessa kampylobakteereita ei eristetty vanhempaispolven parvesta eikä hautomonäytteistä. Tiloilla kahdestatoista kasvatuserästä kuudesta ei todettu kampylobakteeria, mutta vain kaksi eristä oli negatiivisia teurastettaessa. Kampylobakteerin esiintyvyys teurastamon eri kohdissa vaihteli nollasta 94 prosenttiin. Teurastusprosessin merkittävimmät kontaminaatiokohdat olivat suolistus ja vesijäähdytys. Kaikki eristetyt kannat olivat C. jejuni -lajia. Tutkimuksessa kampylobakteerikantoja tyypitettiin eri genotyypitysmenetelmillä. Hyvin läheisiä tyyppejä todettiin sekä ihmisistä että siipikarjasta eristetyistä kannoista. Kalkkunoista eristetyissä kannoissa esiintyi usein parvelle tyypillinen genotyyppi, joka säilyi samana kasvatustilalta aina teurastamoon ja leikattuun lihaan asti. Kampylobakteerin alhainen esiintyvyys broileriteurastuserissä raportoitiin vuonna 1999 ja tilanne on säilynyt Suomessa yhä hyvänä. Seurattaessa kampylobakteerin esiintymistä kalkkunantuotantoketjussa todettiin tilatasolla negatiivisten parvien kontaminoituvan helposti teurastamolla. Hyvä teurastamohygienia ja laitteiden puhtaanapito ovat merkittäviä tekijöitä pyrittäessä välttämään kontaminaatiota teurastamolla. Suomessa todennäköisesti tehokkain keino vähentää kampylobakteeri-positiivista siipikarjanlihaa on estää kasvatusparvien tartunnat tilatasolla. Tähän pyritään hyvällä tuotantohygienialla ja tautisuojauksella. Suomessa, jossa kampylobakteeri-positiivisia eriä on vähän, positiivisten parvien teurastusjärjestelyillä voisi olla vaikutusta kontaminoituneen lihan määrään. Tärkeää olisi arvioida tarkemmin kotimaisen siipikarjanlihan merkitys suomalaisten kampylobakteeri tartunnoissa.

Recent Finnish studies have revealed an array of filarioid nematodes and associated diseases that appear to be emerging in northern ungulates. All filarioid species produce microfilariae that are present in the host blood, and known vectors are haematophagous arthropods. Infections attributable to a species of the genus Setaria appear to have emerged in Scandinavian reindeer in 1973. The infections were associated with an outbreak of peritonitis. In the same year, tens of thousands of reindeer died in the northern part of the reindeer herding area of Finland. Severe peritonitis and large numbers of Setaria sp. worms were common findings. However, the prevalence of Setaria sp. in Scandinavian reindeer subsequently diminished. In Finland, the latest outbreak of peritonitis in reindeer started in 2003 in the southern and middle parts of the reindeer herding area. The proportion of reindeer viscera condemned due to parasitic lesions identified during meat inspections increased dramatically. These increases caused substantial economic losses and increased the workload associated with meat processing. The focus of the outbreak moved northward by approximately 100 km/yr, and by 2005 only the reindeer in Upper Lapland were free of lesions. During the same period, the peritonitis outbreak was apparently fading away in the southern area. The causative, agent based on morphological and molecular data, was identified as Setaria tundra. Reindeer calves with heavy infections of S. tundra expressed decreased thriftiness, poor body condition, and an undeveloped winter coat. Meat/post mortem inspection of diseased reindeer carcasses revealed ascites fluid, green fibrin deposits, adhesions, and live and dead S. tundra nematodes. Histopathology indicated granulomatous peritonitis with lymphoplasmacytic and eosinophilic infiltration. No specific bacterial growth was found. No significant impact on pH values of meat or on the organoleptic evaluation of meat was found. There was a significant positive correlation between worm counts and the degree of peritonitis, and a negative correlation between the degree of peritonitis and the back-fat layer. Based on the evidence in both ante and post mortem inspections and histological examinations, present studies and historical data indicate that S. tundra can act as a significant pathogen in reindeer. The prevalence and density of Setaria microfilariae (smf)in blood circulation were higher in reindeer calves than in adults; the overall prevalence was 42%. In order to monitor the dynamics of S. tundra in nature, wild cervids also were sampled. The overall smf prevalences for moose, wild forest reindeer and roe deer were 1.4-1.8%, 23% and 44%, respectively. The focus of microfilaremia in reindeer moved north while simultaneously declining in the south as the observed peritonitis outbreak decreased. Experimentally, in reindeer calves infected in their first summer of life the peak microfilaremia was recorded in their second summer. Captive reindeer were smf positive throughout the year, but smf disappeared from the blood after 2 years. The prepatent period of S. tundra was estimated to be about 4 months, with a life span of at least 14 months. Moose are apparently not a suitable reservoir host for the S. tundra haplotype occurring in reindeer. The previous report of a peritonitis outbreak in moose associated with Setaria sp. nematodes in Finnish Lapland in 1989 was caused by another S. tundra haplotype. It may well be that among other factors, the high percentage of wild forest reindeer with signs of peritonitis caused by S. tundra may also have contributed to a substantial population decline for this herd in Kainuu (1700 to 1000 in 2001-2005). Although S. tundra is at present maintained primarily in the reindeer population, roe deer seem to be a suitable host and asymptomatic carrier. Mosquitoes, particularly Aedes spp. and to a lesser extent Anopheles spp., play an important role in the transmission of S. tundra in reindeer herding areas in Finland. The prevalence of S. tundra larvae in naturally infected Finnish mosquitoes varied from 0.5-2.5%. The rate of development in mosquitoes is temperature-dependent. The life cycle of Setaria tundra; Adult nematodes inhabit the peritoneal cavity of reindeer and produce microfilariae in to the host’s blood circulation, especially on summer months. The life span of the adult S. tundra female is at least 14 months.Microfilariae get with the blood meal into the intermediate mosquito (Culicidae) host. Microfilariae penetrate the gut of the mosquito and develop through two moults into infective third-stage larvae. The development is temperature dependent and takes about two weeks at 21°C (mean). When the mosquito is feeding again, the third-stage larvae break out and penetrate the skin of the host through mosquito’s puncture wound. Then they develop to the adult stage through two moults in the host and find their way to the abdominal cavity. The prepatent time is approximately 4 months. Ivermectin has good efficacy against adult S. tundra nematodes and circulating smf, and therefore there is an obligation to treat heavily infected reindeer calves with ivermectin by injection for animal welfare reasons. At the population level, massive antiparasitic treatment with ivermectin can reduce the number of carriers among reindeer population. The fact that this could not prevent the emergence of the S. tundra outbreak in new areas in the North indicates that the transmission dynamics of S. tundra are efficient. The 1973 outbreak of S. tundra in Sweden was associated with unusually warm weather and abnormally high numbers of mosquitoes and gnats. The summers of 1972 and 1973 in Finland were also very warm, as were those in 2002 and 2003. Warm summers apparently promote transmission and the genesis of disease outbreaks by favouring the development of S. tundra in its mosquito vectors, by improving the rate of mosquito development and reducing their mortality from frost, and finally, by forcing reindeer to stay in herds on mosquito-rich wetlands. Mosquito-borne diseases are among those most sensitive to weather and obviously will be influenced by climate change. Thus, I predict that global climate change will promote the further emergence of filarioid nematodes and diseases caused by them in the subarctic ecosystem. Moreover, I believe that future outbreaks can be predicted based on the mean temperatures of two consecutive summers. This study indicated that S. tundra probably has an important impact on boreal ecosystems. It also revealed the absence of baseline knowledge concerning temporal parasitic biodiversity in cervids at high latitudes. Therefore, it is important to gain knowledge about these parasites, their ecology, transmission dynamics, and their impact on human and animal health. The putative relationship between climate change and a vector-borne disease identified in this thesis indicates the potential and obvious threats to the individual and population health of arctic ungulates. Setaria tundra, yleistyvä porojen loinen; taudinpurkaus Suomen poroissa 2003–2006 Tiivistelmä Hyönteisvälitteinen sukkulamato, Setaria tundra aiheutti laajan ja nopeasti levinneen joukkosairastumisen poroilla vuosina 2003–05. Loinen kuuluu Filarioidea –heimoon, joka on maailmanlaajuisesti merkittävä, kymmenien miljoonien ihmisten ja eläinten terveyteen vaikuttava loisryhmä. Väitöskirjatutkimus käsittelee S. tundra –loisen aiheuttamia vaikutuksia poron ja hirvieläinten terveyteen yksilö- ja populaatiotasolla, viimeisimmän ja aikaisemmin Skandinaviassa tapahtuneiden epidemioiden pohjalta, loisen rakenteellista ja geneettistä tunnistamista ja tartunnan diagnosointia. Väitöskirja selvittää loisen elinkierron pohjoisessa luonnossa ja epidemian syntyyn myötävaikuttaneita tekijöitä, loisen isäntäeläimet, mahdolliset kantajat luonnonvaraisissa hirvieläimissä sekä välittäjähyönteiset. Myös mahdollisiin loisen vastustamiskeinoihin porotaloudessa esitetään ratkaisumalleja. Tutkimus osoittaa loisen yleistymisen ja kohonneen kesälämpötilan välisen yhteyden, joiden havaintojen perusteella pohditaan ilmaston muutoksen mahdollisia vaikutuksia hirvieläinpopulaatioihin, niistä riippuvaisiin alkuperäiselinkeinoihin ja elintarviketuotantoon pohjoisissa ekosysteemeissä. Filarioidea -sukkulamatoheimo Filarioidea – heimon loiset ovat yleismaailmallisia loisia joilla on suuri vaikutus ihmisten ja eläinten terveyteen, varsinkin maapallon lämpimillä vyöhykkeillä. Viimevuosien sekä nauta- että poroteurastamoissa tehdyt havainnot viittaavat hyönteisvälitteisten sukkulamatojen (Filarioidea) ja niiden aiheuttamien muutosten yleistymiseen myös Suomessa. Filarioidea-sukkulamadot asuvat isäntäeläimen kudoksissa tai ruumiinonteloissa ja tuottavat toukkia (mikrofilaria) isäntäeläimen ihoon tai verenkiertoon. Loisten väli-isäntinä ja aktiivisina vektoreina toimivat verta imevät niveljalkaiset. Setaria -suku Setaria (Onchocercidae) – suvun loiset ovat sorkka ja kavioeläinten loisia. Sukuun kuulu 43 lajia jotka asuvat normaalisti isäntäeläimen vatsaontelossa ja tuottavat mikrofilarioita verenkiertoon. Tunnetut vektorit ovat verta imeviä hyönteisiä. Setraia tundra –loisen historia Suomessa Ensimmäiset kirjatut havainnot Setaria – loisista poroilla tehtiin Skandinaviassa 1970-luvun alussa. Loisten massaesiintyminen yhdistettiin Ruotsissa ja Norjassa 1973 esiintyneeseen porojen vatsakaIvontulehdusepidemiaan. Samana vuonna Suomessa kuoli kymmeniä tuhansia poroja jolloin yleisinä ruumiinavauslöydöksinä oli voimakas vatsakalvon tulehdus ja suuri määrä Setaria – loisia vatsaontelossa. Tämän jälkeen Setaria – loiseen yhdistetyt muutokset sekä havainnot loisesta laskivat Suomen poroilla lähes huomaamattomiksi satunnaislöydöksiksi aina 30 vuoden ajaksi. Vatsakalvontulehdusepidemia Vuonna 2003 syksyllä poroteurastuskauden alussa kiiri hälyttäviä raportteja eteläisen- ja keskisen poronhoitoalueen poroteurastamoista poron vasoilla yleisesti esiintyvästä voimakkaasta vatsakalvontulehduksesta ja loisten massaesiintymisestä vatsaontelossa. Vasojen elinten ja vatsakalvojen hylkäämiset lihantarkastuksessa loismuutosten takia kasvoivat voimakkaasti, epidemia oli syntynyt. Epidemia aiheutti tuntuvia taloudellisia tappioita ja lisääntynyttä työtaakkaa poroteurastamoilla. Epidemian keskus siirtyi noin 100km:n vuosivauhtia pohjoista kohti, niin että vuonna 2005 vain Ylä-Lapin porot olivat vapaita loismuutoksista. Samaan aikaan epidemia laantui sen syntysijoilla, poronhoitoalueen eteläisissä osissa. Taudin aiheuttajaksi osoittautui loisen sekä rakenteellisten että geneettisten ominaisuuksien perusteella Setaria tundra. S. tundra –tartunnan oireet ja löydökset Vasojen olemus, joilla oli voimakas S. tundra – tartunta, ilmensi alentunutta kuntoa ja niiden talvikarva oli huonosti kehittynyt. Yleiset lihantarkastuslöydökset olivat lisääntynyt oljen tai veren värinen, vihertäviä partikkeleita sisältävä neste vatsaontelossa, vihertävää tai kellertävää saostumaa herakalvoilla ja sidekudoskiinnikkeitä vatsakalvon ja eri elinten välillä sekä eläviä 3 – 8 cm:n mittaisia valkeita sukkulamatoja sekä joskus kuolleita eri hajoamisvaiheissa olevia loisia. Histopatologiset tutkimukset vahvistivat muutokset loisten aiheuttamiksi; lympfoplasmosyyttinen ja eosinofiilinen tulehdussolureaktio ja –kertymä. Vaikka tulehdusreaktio näytti usein hyvin märkämäiseltä, ei mitään spesifistä bakteerikasvustoa havaittu. Vatsakalvon tulehdus ei myöskään aiheuttanut merkittäviä muutoksia lihan pH – arvoihin tai aistinvaraiseen laatuun. Mitä suurempi oli loisten lukumäärä vatsaontelossa, sen vakavampiasteinen oli myös tulehdusreaktio. Tulehdusreaktion voimistuminen vastaavasti pienensi poron kunnon mittarina käytettyä selän rasvakerroksen paksuutta. Aikuisilla poroilla esiintyi myös yleisesti S. tundra – tartuntaa, mutta vatsakalvon tulehdusta esiintyi erittäin harvoin. Kokonaisuudessaan tehdyt tutkimukset vahvistivat sen käsityksen, että S. tundra - infektio on vahingollinen poron vasojen terveydelle. Mikrofilariat verenkierrossa Kuten vatsakalvon tulehduskin, oli myös S. tundra – loisen mikrofilarioiden yleisyys ja tiheys poron vasojen verenkierrossa merkittävästi suurempi kuin aikuisten porojen. Myös mikrofilarioiden esiintyvyyden vaihtelu kuvasti epidemian liikettä pohjoiseen, etelässä infektoituneiden porojen määrä pieneni samalla kun teurastamoilla havaittujen tulehdusreaktioiden määrä laski. Mikrofilariat ilmestyivät luonnollisesti infektoituneiden poronvasojen verenkiertoon marras-jolukuulla. Mikrofilariamäärät olivat suurimmillaan seuraavana kesänä jolloin suurimmat tiheydet olivat lähes 4000 kpl/ml verta. Tämän jälkeen mikrofilariat hävisivät verenkierrosta vuoden kuluessa. Loisen aikuistumiseen porossa kuluu noin 4 kuukautta ja elinikä on ainakin 14 kuukautta. Setaria tundra luonnonvaraisissa hirvieläimissä Loisen isäntien ja luonnon reservoaarien selvittämiseksi kerättiin verinäytteitä myös luonnonvaraisista hirvieläimistä. Kun poron koko populaation S. tundra – infektioprosentti oli 42% oli se metsäpeuralla 23%, hirvellä 1.4-1.8% ja metsäkauriilla 44%. Tutkimuksen perusteella metsäpeura sekä metsäkauris voivat toimia loisen luonnollisina oireettomina kantajina ja levittäjinä. Metsäpeuralla havaittu samanaikainen korkea vatsakalvontulehduksen esiintyminen herättää myös kysymyksiä mahdollisesta yhteydestä Kainuun metsäpeurapopulaation lähes samanaikaiseen jyrkkään vähenemiseen. Hirven osuus porojen epidemian tämänkertaisessa synnyssä ei ole todennäköinen. Vuoden 1989 S. tundra – massaesiintymä hirvellä oli loisen eri haplotyypin aiheuttama. Hyönteisvektorit Hyttynen, etenkin Aedes –suku on S. tundra –loisen tärkein väli-isäntä ja vektori Suomessa. Epidemian aikana 0,5-2,5% luonnonvaraisista hyttysistä olivat loisen kantajia. Hyttysen veriaterian mukana saaman mikrofilarian kehitys infektiokykyiseksi toukaksi kestää noin kaksi viikkoa. Kehityksen nopeuteen vaikuttaa ympäristön lämpötila niin että lämpö jouduttaa kehitystä. Ruotsissa 1973 S. tundra –loisen massaesiintymä yhdistettiin epätavallisen lämpimään ja kesään ja huomattavaan hyttysten runsauteen. Kesät 2002 ja 2003 olivat myös Suomessa erittäin lämpimiä. Tutkimustemme mukaan lämpimät kesät suosivat loisen elämänkiertoa ja mahdollisia taudinpurkauksia. Lämpö suosii itse hyttysen elinkiertoa ja vähentää pakkasten aiheuttamaa kuolleisuutta ja kiihdyttää loisen kehittymistä hyttysessä. Lisäksi lämmin sää saa porot tokkaantumaan hyttysrikkaille soille ja kosteikoille joissa loisen leviämismahdollisuudet ovat ihanteelliset. Setaria tundra –loisen elämänkierto Aikuiset loiset asuvat isäntäeläimen vatsaontelossa ja tuottavat mikrofilarioita sen verenkiertoon, erityisesti kesäkuukausina. Naaraspuolisen loisen elinikä on vähintään 14 kuukautta. Mikrofilariat kulkeutuvat veriaterian mukana väli-isäntänä toimivaan hyttyseen. Ne tunkeutuvat hyttysen suoliston seinämän läpi ja kehittyvät kahden nahanluonnin kautta infektiokykyisiksi kolmannen asteen toukiksi. Kehitysnopeus on lämpötilariippuvaista ja kestää 21 °C lämpötilassa noin kaksi viikkoa. Kun hyönteinen aterioi tämän jälkeen, toukat murtautuvat ulos ja tunkeutuvat uuteen isäntäeläimeen hyttysen pistohaavasta. Loinen kehittyy kahden nahanluonnin kautta sukukypsäksi noin neljässä kuukaudessa. Vastustaminen Valtaosa (n 80%) siitosporoistamme lääkitään vuosittain ivermektiini-loislääkkeellä. Ivermektiini-injektio osoittautui tehokkaaksi aikuisia poron vatsaontelossa olevia S. tundra –loisia ja verenkierrossa kiertäviä mikrofilarioita vastaan. Tämä antaa mahdollisuuden ja velvollisuuden hoitaa voimakkaasta infektiosta kärsiviä vasoja. Populaatiotasolla on mahdollista vähentää infektion kantajia siitosporoista ja näin ennaltaehkäistä taudinaiheuttajan siirtymistä vasoihin. Se, että laajasta ja intensiivisestä porojen loislääkityksestä huolimatta, epidemia levisi vääjäämättä pohjoiseen, osoittaa loisen erittäin tehokasta leviämiskykyä, jälkeläistuotantoa ja hyttysvektorin suurta tehokkuutta. Ilmasto ja sää Ilmasto- ja säätekijät vaikuttavat merkittävästi hyttysten levittämien sairauksien esiintyvyyteen ja leviämiseen. Siksi loisten esiintymiselle voi ilmastonmuutoksella olla arvaamattomat seuraukset Pohjolassa. Tutkimustulostemme mukaan S. tundra -loisen yleistyminen voidaan ennakoida kahden edeltävän kesän lämpötilan mukaan; 14 °C ylittävä kesän keskilämpötila on hälyttävä. On ilmeistä että ilmastonmuutos edesauttaa S. tundra- ja sen sukulaisloisten ja niiden mahdollisesti uusissa isäntäeläimissään aiheuttamien muutosten tai vahingollisten vaikutusten leviämistä subarktisiin ekosysteemeihin. Niillä voi olla ennalta arvaamattomia vaikutuksia eläinpopulaatioihin ja sitä kautta alueen elintarviketuotantoon, niistä riippuvaisiin yhteisöihin sekä ihmisten terveyteen. Tutkimus osoitti sen aukon, joka liittyy näiden, aikaisemmin lähinnä trooppisten alueiden ongelmina pidettyjen, hyönteisvälitteisten loisten tutkimukseen Pohjolassa. Jatkotutkimukset, jotka kohdistua hyönteisvälitteisten loisten ekologiaan, dynamiikkaan, tartuntateihin ja niiden seurantaan nisäkäspopulaatiossa ja vaikutuksiin sekä ihmisten että eläinten terveyteen, ovat välttämättömiä.

The drive for risk-based food safety management, systems and control has spread world-wide in recent decades. Since the term is still internationally undefined, its use and implementation vary, producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was investigated as a basis for risk-based food safety management, which was defined as ‘food safety management based on risk assessment in order to achieve an appropriate level of protection (ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety targets up to a certain point, but the practical management measures that need to be in place in order to achieve the targets are to be addressed by the operators. On the plant level, food safety is usually managed through regulation, quality assurance systems and a hazard analysis and critical control point (HACCP) programme with its prerequisites. In Finland, food safety management on the food plant level is implemented through an HACCP-like regulated system termed an own-checking (OC) programme. A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef production chain according to the official standards of the Codex Alimentarius Commission (Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were examined in the light of risk-based food safety management. The targets set for beef processing plants by the government were converted into quantitative limits, and the results of salmonella monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to the salmonella incidence in humans at that time, and also the de facto ALOP. The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef production chain was embodied in the FSCP. This statement was considered to convey performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a significantly greater exposure than domestic products. If their salmonella prevalence or their share of the foods consumed in Finland increase, the number of human cases could rapidly rise. The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type of complex modelling. The resulting distributions were also regarded as an advantage compared to the results from models developed with the deterministic approach, because the presentation of results included the extent of the uncertainty, and also in this manner better illustrated the actual operational environment. Based on an inquiry, the personnel in food processing plants had a positive attitude towards food safety management systems, but the knowledge, training and involvement of those employees directly operating on the site with these systems were discovered to be deficient. Therefore, a generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and medium-sized food enterprises to offer assistance in understanding, training, and, first of all, detecting the critical steps of the processes, and thereby to contribute to the development of their own-checking systems towards risk-based food safety management. Hygram® was not considered a risk-based tool as such, but whenever the critical limits of the process have been defined as equal to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a tool for systematic hazard analysis and CCP detection when establishing a food safety management system. To conclude, the development of risk-based food safety management is a process in which risk assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers need to be overcome in order to put risk-based management systems into practice. This study showed that QMRA can be valuable in national risk management decision making, although few QMRAs are currently available. Appropriate tools for practical risk management decision making on the industrial level, such as Hygram®, need to be further developed. Elintarviketurvallisuutta on viime vuosina pyritty muuttamaan riskiperusteiseksi maailmanlaajuisesti. Väitöskirjassa riskiperusteisuus määriteltiin tieteelliseen riskinarviointiin perustuvaksi elintarviketurvallisuuden riskinhallinnaksi, jonka tavoitteena on kansallisesti hyväksytyn suojatason, ALOP -arvon, saavuttaminen. Elintarvikkeen aiheuttaman terveyshaitan riskiperusteista hallintaa tutkittiin riskinarvioinnin keinoin vallitsevan lainsäädännön ja omavalvontatoiminnan kautta. Naudanlihantuotantoa esimerkkinä käyttäen tehtiin mikrobiologinen riskinarviointi salmonellan esiintyvyydestä koko elintarvikeketjussa sekä sen vaikutuksesta kuluttajien salmonellatapausten määrään. Samalla esitettiin naudanlihan tuotantoketjulle ns. elintarviketurvallisuusmittareita, jotka määriteltiin salmonellavalvontaohjelman ja muiden säädösten mukaisista vaatimuksista. Valvontaohjelman tavoitteena on ollut 1995 lähtien säilyttää Suomen hyvä salmonellatilanne, mikä tulkittiin tosiasialliseksi ALOP -arvoksi. Toimitetun riskinarvioinnin perusteella osoitettiin, että asetetut tavoitteet on saavutettu koko naudanlihaketjun osalta. Tulosten mukaan naudanlihan kuluttajille aiheuttama salmonellariski (vuonna jota tutkimus käsitteli 3 salmonellatapausta per 100,000 asukasta) on Suomessa hieman suurempi kuin sianlihan, ja selvästi suurempi kuin broilerinlihan tai kananmunien aiheuttama riski. Naudanlihan osuus kuluttajan salmonellariskiin vaikuttaisi Suomessa merkittävämmältä kuin muualla. Tämä lienee seurausta siitä, että Suomessa salmonellaa valvotaan siipikarjassa järjestelmällisesti jo parvitasolla ennen lintujen ja niistä saatavien tuotteiden päätymistä elintarvikeketjuun, kun taas naudan- ja sianlihantuotannossa salmonellavalvonnan painopiste on teurastamoissa ja lihanleikkaamoissa. Väitöskirjassa esitetyn riskinarvioinnin avulla ensimmäistä kertaa laskettiin elintarviketurvallisuustavoitteiden ja salmonellavalvontaohjelman välisiä suhteita sekä arvioitiin niiden vaikutusta kansanterveyteen. Vaikka salmonellaa esiintyy Suomessa kansainvälisesti katsoen erittäin vähän, valvontaohjelman edellyttämä korkeintaan 1 %:n esiintyvyystavoite havaittiin liian korkeaksi ylläpitämään hyväksyttyä suojatasoa. Lisäksi naudanlihan ja siitä saatavien elintarvikkeiden tuonnin arvioitiin, riippumatta vähäisestä kulutusosuudesta, voivan altistaa suomalaisia kuluttajia salmonellatartunnalle merkittävästi enemmän kuin kotimaisten tuotteiden. Salmonellatapausten määrä voi kohota nopeasti, jos salmonellan esiintyvyys kyseisissä tuontielintarvikkeissa lisääntyisi tai niiden osuus kulutuksesta kasvaisi selvästi. Tutkimus osoitti tieteellisen riskinarvioinnin arvon kansallisessa riskinhallintaan liittyvässä päätöksenteossa ja se nosti esiin tarpeen kehittää yritystason riskinhallintaan soveltuvia työkaluja.

Canine distemper (CD) is one of the longest-known infectious diseases of dogs and is still prevalent in many parts of the world. Vaccination combined with biosecurity measures is the most productive way to prevent and control infectious diseases. The beneficial effects of vaccination are realized not only on the individual but also on the population level, the latter in the form of herd immunity (HI). Control of CD among dogs relies heavily on vaccination, while in fur farms and zoos with several species or large numbers of CD-susceptible animals in close contact, biosecurity measures in some cases offer the only available means for CD control. Modified live CD virus vaccines have been successfully used to control CD among farmed mink, and since no licensed vaccines for other species kept for fur exist, mink CD vaccines have also been used for foxes and raccoon dogs in CD emergency situations. CD vaccines for dogs (Canis familiaris) and mink (Mustela vison) were studied in experimental settings for their ability to induce virus-neutralising (VN) antibodies in target species. Mink vaccines were also assessed in silver foxes (Vulpes vulpes), blue foxes (Alopex lagopus) and raccoon dogs (Nyctereutes procyonoides). Purpose-bred beagle dogs were vaccinated twice with one of three CD vaccines: Candur® SHP, Canlan®-3 or Dohyvac® DA2P, and the levels of VN antibodies were determined at the time of vaccination and one month after the second vaccination. Fur animals were vaccinated once with Distemink®, Distem®-R-TC or vaccine 3 (which was not licensed in Finland) and the levels of VN antibodies were determined at vaccination and 2-4 times 1-4 months afterwards. Significant differences among vaccine groups were found both in the proportion of animals with measurable levels of VN antibodies and in the mean titres of antibodies. The levels of VN antibodies were also determined from a large field sample (n = 4 627) of vaccinated dogs. In addition to the three CD vaccines in the seroconversion study above, additional two vaccines, Duramune®-4 and Nobivac® DHP, had been used in the field. Each dog with a known vaccination history, date of birth, sex and breed was sampled once. Based on the overall geometric mean titre of the dogs vaccinated with a single vaccine brand, vaccines were divided into high-take (Candur®, Nobivac® and Duramune®) and low-take (Dohyvac® and Canlan®) groups. The vaccine groups differed significantly among dogs less than two years of age both in the proportion of dogs with detectable VN antibodies and in the mean titres. Both the number of vaccinations and age were associated with the titre and vaccine usage. To control for possible confounding factors, the comparison 8 of titres among vaccine usage groups was adjusted by classifying them according to the number of vaccinations (one to four) and the age group (less than one, one to two, or over two years old). The same division into low- and high-take vaccines was observed, irrespective of the number of vaccinations the dogs had received. The observations of this seroprevalence study regarding Candur® , Canlan® and Dohyvac® were consistent with the results of the seroconversion study. CD was reintroduced into Finland in 1990 after 16 years of absence. The disease remained at a low endemic level in 1990-1994, reached epidemic proportions in 1994-1995 and disappeared during 1995. The epidemic also involved vaccinated dogs. Among the virologically-confirmed cases the proportion of Dohyvac®-vaccinated dogs was higher than expected from the market shares on the assumption that all the vaccines had an equal take. As a result of this observation, Dohyvac® was withdrawn from and Nobivac® and Duramune® introduced to the market during 1995. A drastic redistribution of the market shares between the low-take and high-take vaccines took place, and this coincided with the decline and dying out of the outbreak. The observed occurrence pattern of CD from 1990-1996 was largely attributed to the changes in the level of HI, although the possible contribution of other factors, such as developments in the dog demographics, was also recognized. It was concluded that an HI above 75% is needed to keep CD in check, i.e., only sporadic cases of CD, at most, can occur. With the currently used vaccines an HI of 80% corresponds to a vaccine coverage of some 94%. It was concluded that the development of vaccine-induced immunity is a multifactorial process depending on the properties of the vaccine, on the individual variation, age, species and other factors influencing the immunocompetence of the host. On the individual level the prevention of clinical signs is sufficient, but on the population level, halting the circulation of the virus is crucial for the definitive control of CD. The ultimate test and criterion for a vaccine is its contribution to herd immunity. Heterogeneity in the dog population contributes to the occurrence of CD.

The prevalences of various genotypes of enterotoxin gene-carrying (cpe-positive) Clostridium perfringens type A in 24 different food poisoning outbreaks were 75% (chromosomal IS1470-cpe), 21% (plasmid-borne IS1470-like-cpe), and 4% (plasmid-borne IS1151-cpe). The results show that C. perfringens type A carrying the plasmid-borne cpe is a common cause of food poisoning.

Pigs coexist with diverse and dense commensal microbiota in their gastrointestinal tract (GIT). Lactobacilli, identified as common members of porcine intestinal microbiota, have been considered to be an important group of bacteria in maintaining the stability of GIT, in preventing intestinal infections and generally, in supporting intestinal health. Because several species of lactobacilli have GRAS (generally regarded as safe) status and some of them have an ability to interact with intestinal epithelial cells, thus promoting host-bacterial interactions, their possible applications as mucosal vaccine vector and/or probiotics have aroused interest. Selection criteria for lactobacilli to be used as vaccine vector or probiotic include the abilities to adhere to the intestinal epithelium cells and colonize the lumen of the GI tract. The adherence to host tissues, which enables the organism to overcome local defences such as mucociliary function and peristaltis, is usually mediated by specialized proteins called adhesins. These adhesins are responsible for recognizing and binding to specific receptor structures of the host cells. Bacterial adhesins are often found in hair-like appendages called pili or fimbriae that extend outward from bacterial surface. Alternatively, they can be directly associated with the microbial cell surface. Surface layer proteins (Slps) of lactobacilli have been shown to confer tissue adherence. In this study, S-layer positive lactobacilli from the intestine and faeces of pigs were isolated and their ability to adhere to pig and human intestinal cells as well as to extracellular matrix (ECM) components, collagen, laminin and fibronectin were studied. The adherence of S-layer carrying lactobacilli varied from strong to moderate for human and porcine small intestine enterocytes and for the components of ECM and basal membranes (BM). Removal of the intact Slps reduced the adhesion of some strains to fibronectin and laminin, whereas, the adhesiveness to laminin increased with some strains. Besides the putative binding properties of Slps, a very large number of surface layer protein subunits present in an S-layer make the use of the S-layer structure a very 7 interesting alternative to surface display antigens. Therefore, the aim of this study was to characterize the S-layer proteins. Two new surface layer proteins (SlpB and SlpD), with potential to be tested as antigen carriers, were characterized, and three S-layer protein (slpB, slpC and slpD) genes were isolated, sequenced, and studied for their expression in Lactobacillus brevis neotype strain ATCC 14869. Under different growth conditions, L. brevis strain was found to form two colony types, smooth (S) and rough (R), and to express the S-proteins differently by mechanism not involving DNA rearrangements. The adhesion studies indicate that L. brevis adheres to human and pig intestinal epithelial cells but it is not currently known whether the binding is mediated by the surface proteins in this L. brevis strain of human origin. To identify the S-layer positive lactobacilli strains used in this study, a polyphasic taxonomic approach was applied. The methods used included 16S rRNA gene sequence analysis, numerical analysis of 16 and 23 rRNA gene ribotypes and DNA-DNA reassociation. In addition, all strains were included in a multilocus sequence analysis (MLSA) study for species identification using housekeeping genes encoding the phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA). These results indicated that six out of eight porcine lactobacilli strains from Finland and the related L. sobrius strains, originating from porcine intestine from elsewhere, constitute a single species, L. amylovorus, and that the name L. sobrius should be considered as a later synonym of L. amylovorus. In the final part of this study, the adhesin FedF of Eschrichia coli F18 fimbriae was characterized. The work aims at developing lactobacilli as a live mucosal vaccine vector for pigs against diseases caused by F18+ E. coli. The F18 fimbriae carrying E. coli strains colonize the microvilli of porcine small intestinal epithelial cells and cause post-weaning diarrhoea (PWD) and edema disease (ED) in pigs. It has been shown that oral immunization of weaned piglets with adhesins can induce a protective mucosal immune response. Naked FedF appeared to be very unstable but in our study it could be produced as a fusion protein with maltose binding protein (MBP). Specific adhesion to isolated porcine intestinal epithelial cells was demonstrated with MBP-FedF fusions as well as the ability of anti-MBP-FedF antibodies to prevent binding of E. coli F18 to porcine epithelial cells.

Lead and cadmium are toxic elements, which are a natural part of earth crust. They are taken up from the soil and transferred upwards in the plant and animal food chain. Cadmium is widely distributed throughout the natural environment with human activities having an important role in its dispersion into the biosphere. The natural sources of cadmium are volcanic eruptions and old granite rocks, which are an important geochemical source. Anthropogenic sources of cadmium are related mainly to mining, fertilizers and atmospheric deposition. Leaded gasoline has been most important source of atmospheric lead. However, most countries have now prohibited the use of leaded gasoline. This action has greatly reduced emissions of lead into the atmosphere. Anthropogenic sources of lead other than traffic are typically fossil fuel combustion, non-ferrous metal production and iron and steel production. Zinc and copper are important constituents in a number of different enzyme functions in man and animals. Zinc and copper reach the environment via industrial releases involving production and refining of metals. In 1997 emissions of heavy metal particulates were only a third of their values in the early 1990s due to the installation of sulphur removal systems. In this study lead, cadmium, copper and zinc levels in Finnish game animals (moose, hares) and farmed game animal (reindeer) were studied during twenty years period. About 500 moose were collected between 1980 and 1999 from south western, southern, central and south eastern Finland. About the same number of Mountain and European hare samples were collected during the period 1980 and 1993 from south western, southern, south eastern and northern Finland. About 300 reindeer were collected in 1990–1992 from southern, eastern, western and northern Lapland. After these initial projects, it was decided to collect moose and reindeer samples every year as part of national residue control program; fifteen moose and ten reindeer per year. In this residue control program, also cattle samples have been collected regularly; muscle, liver and kidney from 30 animals in every year. The lead and cadmium levels in muscle tissue has decreased in all studied animals during the monitoring years being now near to the limit of quantification; 0.01 mg/kg w.w. for lead and 0.001 mg/kg w.w for cadmium. Also the lead levels in liver and kidney samples have decreased during the monitoring period but the moose cadmium levels have increased. The zinc levels had also increased in moose samples but there were no significant 5 correlation with increasing cadmium and zinc levels. The lead levels in liver and kidney in moose varied in 1999 from 0.04 to 0.07 mg/kg w.w. and 0.05-0.07 mg/kg w.w. The corresponding values for cadmium are 0.71-1.28 mg/kg w.w. and 4.95- 6.18 mg/kg w.w. The cadmium and lead levels in Mountain hares are higher than in European hares and the kidney cadmium levels in Mountain hares are statistically significantly higher than the kidney cadmium levels in moose. The lead levels in liver and kidney samples in both adult and calves of reindeer have been invariably below the recommended maximum level in the EU (0.5 mg/kg). However, the kidney cadmium level exceeds the maximum level (1.0 mg/kg) in almost all adult reindeer samples and also in some calves. The meat of Finnish moose, reindeer and hares does not contain residues of cadmium and lead and therefore consumers can be assured that consumption of the meat is not a health risk. The consumption of the organs of the animals studied may represent a health risk for human. However, the levels are far from the toxic levels to the animals themselves.

The monitoring and control of infectious animal diseases, limiting or prevention of their spread and efforts towards their eradication are central tasks of the veterinary civil service. In addition to the cost-effectiveness of prophylaxis over disease and treatment, the animal welfare aspect is also involved. The purpose of this work is to review, describe and assess the available control measures against selected viral infections or diseases of domestic ruminants. The selected infections or diseases are bovine viral diarrhoea / mucosal disease (BVD), infectious bovine rhinotracheitis / infectious pustular vulvovaginitis (IBR), enzootic bovine leukosis (EBL) and maedi-visna (MV) of sheep. Decisive control and eradication measures are necessarily based on the biological, veterinary and diagnostic characteristics of the afflictions, as well as on their epidemiology in terms of the intrinsic determinants of the hosts, host-agent relationships, transmission of the infection and occurrence of these infections or diseases. This information is compiled with special reference to available or possible control and eradication measures, and those employed in major cattle and sheep producing countries are outlined and assessed briefly. The domestic and EU legislation that forms the official framework for disease control and eradication, as well as the official measures and the voluntary programmes are reviewed. The first recorded entries of the occurrence of BVD and EBL in Finland date back to the 1960s, those of IBR to the beginning of the 1970s and of MV to the beginning of the 1980s. Large-scale surveillance and health monitoring among dairy, suckler-cow and beef herds and sheep flocks, starting during the first half of the 1990s, enabled the estimation of actual prevalences of these infections and diseases. The successful eradication of IBR and EBL in 1994 and 1996, respectively, and the significant reduction in the occurrences of BVD and MV from 1990 to date, are reported in detail. The efficacies of the official control and eradication measures and of the voluntary control programmes are analyzed further with a heuristic formulation for the infection reproduction number (R), i.e. the number of secondary cases produced by one infective animal. The influence of the measures is resolved into probability of transmission, frequency of infectious contacts and length of the infectious period, and the impact of the measures on each component is graded on a three-step scale. The conclusion is drawn that the official measures complemented by voluntary actions for control and eradication have for the most part been adequate. In the case of BVD the decisive measures for final eradication have only been available since 2004 and their impact will be seen in the next few years. The role of continued surveillance and health monitoring for both overseeing the situation with BVD and MV, and maintaining an IBR and EBL-free status is emphasized. Tarttuvien eläintautien vastustaminen, niiden leviämisen rajoittaminen tai estäminen ja niiden juuriminen kuuluvat eläinlääkintöviranomaisten keskeisiin tehtäviin. Tärkeiksi nämä tehtävät tekee erityisesti sekä tautien ennalta ehkäisemisen edullisuus verrattuna taudin ilmenemisen ja hoidon aiheuttamiin kustannuksiin että eläinsuojelulliset näkökohdat. Tämä työ kohdistuu kotieläiminä pidettävien märehtijöiden neljän merkittävän virustaudin vastustus- ja juurimistoimenpiteiden kuvaamiseen ja niiden tehokkuuden arviointiin. Työssä käsitellyt taudit ovat naudan virusripuli, naudan tarttuva rinotrakeiitti, naudan tarttuva leukoosi sekä lampaiden maedi-visna. Ensimmäiset kirjatut havainnot virusripulin ja tarttuvan leukoosin esiintymisestä Suomessa ovat 1960-luvulta, rinotrakeiitin osalta 1970-luvun alusta ja maedi-visnan osalta 1980-luvun alkupuolelta. Vuonna 1990 aloitetut laajat seulonta- ja terveys-tarkkailututkimukset tekivät mahdollisiksi tautien esiintyvyyksien aiempaa luotettavammat määritykset. Työn kirjallisuuskatsauksessa kuvataan näiden tautien biologisia, eläinlääketieteellisiä ja diagnostisia ominaispiirteitä, sekä tautien yleistä esiintyvyyttä. Tautien epidemiologiaa käsitellään vastustustoimenpiteiden kannalta keskeisten eläinlajikohtaisten piirteiden ja isäntäeläinlajin ja taudinaiheuttajan välisten vuorovaikutusten osalta.Tautien vastustustoimia ja juurimishankkeita eräissä tärkeissä nautakarjaa ja lampaita tuottavissa maissa ja erityisesti Pohjoismaissa kuvataan lyhyesti. Työn toisessa osassa kuvataan tautivastustukselle Suomessa puitteet luova kotimainen ja EU -lainsäädäntö sekä vapaaehtoiset vastustusohjelmat. Tautien esiintyminen erityisesti vuoden 1990 jälkeen, rinotrakeiitin ja tarttuvan leukoosin onnistunut juuriminen sekä virusripulin ja maedi-visnan ilmaantuvuuden väheneminen kuvataan yksityiskohtaisesti. Vastustus- ja juurimistoimenpiteiden tehokkuutta eritellään tarkemmin käyttäen apuna tartuntatautien teoreettisen epidemiologian suuretta, tartunnan kertautumislukua (R). Tämä luku kuvaa sitä kuinka monta uutta tartuntaa yksi sairastunut eläin aiheuttaa. Johtopäätöksinä todetaan, että viralliset vastustustoimet yhdistettyinä vapaaehtoisiin ohjelmiin ovat olleet pääosin riittäviä. Erityisesti virusripulin osalta v. 2004 annetun asetuksen mukaisten tehokkaiden vastustustoimien vaikutus alkaa näkyä vasta lähivuosina. Jatkuvan tautiseurannan ja terveystarkkailun merkitystä korostetaan sekä virusripulin ja maedi-visnan tilanteen hallinnan että rinotrakeiitti- ja tarttuva leukoosi vapauden säilyttämisen kannalta.

The monitoring and control of infectious animal diseases, limiting or prevention of their spread and efforts towards their eventual eradication are central tasks of the veterinary civil service. In addition to the cost-effectiveness of prophylaxis over disease and treatment, the animal welfare aspect is also involved. The purpose of this work is to review, describe and assess the available control measures against selected viral infections or diseases of domestic ruminants. The selected infections or diseases are bovine viral diarrhoea / mucosal disease (BVD), infectious bovine rhinotracheitis / infectious pustular vulvovaginitis (IBR), enzootic bovine leukosis (EBL) and maedi–visna (MV) of sheep. Each is recognized as a signifi cant disease of domestic animals. Decisive control and eradication measures are necessarily based on the biological, veterinary and diagnostic characteristics of the affl ictions, as well as on their epidemiology in terms of the intrinsic determinants of the hosts, host–agent relationships and sources and transmission of the infection, and occurrence of these infections or diseases. This information is compiled and presented in the fi rst part of the thesis with special reference to available or possible control and eradication measures. These measures and programmes against the four affl ictions employed in major cattle and sheep producing countries in individuals and herds and on national and international levels are outlined and assessed briefl y. In the descriptive part of the thesis the domestic and EU legislation that forms the offi cial framework for disease control and eradication are outlined. The development in the situation concerning these four infections or diseases is described from the early records to date. The fi rst recorded entries of the occurrence of BVD and EBL in Finland date back to the 1960s, those of IBR to the beginning of the 1970s and of MV to the beginning of the 1980s. Large-scale surveillance and health monitoring among dairy, suckler-cow and beef herds and sheep fl ocks, starting during the fi rst half of the 1990s, enabled the estimation of actual prevalences of these infections and diseases. A common feature of the occurrence of these infections or diseases is that none has had a prevalence of more than an estimated few percent before 1990, and a maximum of 1% since then. This has formed a very favourable starting point for the nation-wide control and eradication measures. The voluntary control programmes or schemes, as well as the offi cial control and eradication measures are described. The successful eradication of IBR and EBL in 1994 and 1996, respectively, and the signifi cant reduction in the occurrences of BVD and MV from 1990 to date, are reported in detail. The effi cacies of the offi cial control and eradication measures and of the actions of the voluntary control programmes or schemes are analyzed further, making use of a heuristic formulation for the infection reproduction number (R), i.e. the number of secondary cases produced by one infective animal. The infl uence of the measures is resolved into the three components of R: the probability of transmission, frequency of infectious contacts and length of the infectious period, and the impact of the measures on each component is graded on a three-step scale. 9 The conclusion is drawn that the offi cial measures complemented by voluntary actions for control and eradication have for the most part been adequate. The signifi cance of fi nancial compensation from the state for the costs incurred in the control of notifi able diseases is noted. In the case of BVD the decisive measures for fi nal eradication have only been available since 2004 and their impact will be seen in the next few years. The role of continued surveillance and health moni toring for both overseeing the situation with BVD and MV, and maintaining an IBR and EBLfree status is emphasized.