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The highly pathogenic avian influenza virus (HPAIV) H5N1, first isolated in 1996 in China, spread rapidly across Eurasia and caused major epizootics in wild and domesticated birds, as well as spillover infections in humans characterised by high mortality. Avian influenza viruses are therefore candidate viruses for a human pandemic. Surprisingly, HPAIV was not isolated in North America until 2014. With the help of intensive biological sampling and viral genome sequencing, the intrusion of HPAIV into North America could be retraced to two separate events. First, migratory birds carried HPAIV from East Siberia via Beringia and dispersed the virus along the Pacific flyway. After reassortment with genes of local low pathogenic avian influenza viruses, HPAIV H5 caused 2015 a major epizootic on poultry farms in the US Mid‐West. After costly containment, HPAIV dropped below the detection limit. In 2021, Eurasian HPAIV H5 viruses arrived a second time in North America, carried by migratory birds to Canada via the Atlantic flyway, using Iceland as a stop. The H5 virus then spread with water birds along the East Coast of the United States and dispersed across the United States. In contrast to the 2015 poultry outbreak, spillover infections into diverse species of mammals were now observed. The events culminated in the 2024 HPAIV H5 epizootic in dairy cows affecting 300 dairy herds in 14 US states. The cattle epizootic was spread mainly by milking machinery and animal transport. On affected farms infected cats developed fatal neurological diseases. Retail milk across the United States frequently contains viral RNA, but so far only a few milk farm workers have developed mild symptoms. The tracing of HPAIV with viral genome sequencing complicated the taxonomical naming of influenza viruses raising fundamental problems in how to mirror biological complexity in written plain language, rendering communication with the lay public difficult. [ABSTRACT FROM AUTHOR]

A case of massive fish mortality is reported in an aquatic body in the municipality of Izamal in Yucatan, Mexico. The fish analyzed exhibited signs of hemorrhage and suffocation. Analysis of the phytoplankton samples revealed the presence of a flagellated microalga with characteristics consistent with Prymnesium parvum, particularly due to the presence of the haptonema. The average densities of the microalgae were approximately 16 × 106 cells L−1. The documentation of this species in the Yucatán Peninsula and the observed effects represent an emerging risk for the aquatic ecosystems of the region. This risk is linked to the extensive connectivity between aquatic systems in the region, combined with the significant dispersion capability of the species, which is magnified by the increasing eutrophication conditions in these bodies of water. [ABSTRACT FROM AUTHOR]

The fungal order Entomophthorales occurs worldwide, with most species infecting arthropods as pathogens. Species in this order can cause epizootics and change the behavior of infected hosts. Molecular data are available only for 20% of the known species, and distributions of species are seldom summarized. Significant diversity of hosts, poor molecular data availability, and poor resolution of the phylogenetic relationships within this fungal order suggest that the diversity of these fungi is not sufficiently described. The subfamily Erynioideae includes 111 arthropod pathogens, divided among six genera, with the genus Pandora being one of the most diverse genera. Sequences of 18S, 28S, and ITS for two species are used to place these Pandora species in a phylogenic tree of the subfamily; this tree also supports our synonymy of the genus Furia with Pandora. Among the two species specifically covered in this paper, Pandora gloeospora was observed during epizootics occurring in mushroom flies (Diptera: Sciaridae) on Agaricus bisporus cultures in Pennsylvania, Delaware, and Maryland (US) mushroom farms and also in Florida on Pleurotus sp. Outside the US, P. gloeospora was found infecting several Nematocera (Diptera) in Europe (France) and Asia (China). Pandora sylvestris n. sp. was collected during epizootics occurring in larvae of hickory tussock moths, Lophocampa caryae (Lepidoptera: Erebidae), in hardwood forests in Michigan and Vermont. [ABSTRACT FROM AUTHOR]

The review is devoted to discussing the results of survey in the Hissar high-mountain natural plague focus on the territory of the Republic of Tajikistan in 2015–2023. Regular examination of the focus was carried out in 1970–1991. According to its results, the main carrier of the plague pathogen was the juniper vole, in the population of which a strain of the non-main subspecies central asiatica (0.PE4) of Hissar biovar (0.PE4h) was steadily circulating, the strain considered avirulent for humans. During that period, 853 strains were isolated in the focus, of which 799 (93.7%) were from the juniper vole and its fleas. Secondary carriers – the silver vole, the pygmy wood mouse, and the gray hamster – were rarely involved in epizootics. The red marmot, which has epidemiological significance due to its hunting by the local population, occupies a special position in the focus. Socio-political phenomena at the end of the 20th – early 21st century caused a long break in the work of the Tajik Plague Control Station. In 2008, the Station was transformed into the Republican Center for Combating Quarantine Diseases under the Ministry of Health and Social Protection of the Population of the Republic of Tajikistan. In 2015, studies were resumed, but carried out on a small scale. In 2021–2023, epizootiological monitoring in the Hissar focus was performed jointly with Russian specialists with the testing of field material samples for plague and other natural-focal infections. Currently, against the background of low numbers and population density of small mammals and their blood-sucking ectoparasites – potential carriers and vectors of zoonoses – the circulation of agents of plague, tularemia, pseudotuberculosis, tick-borne viral encephalitis, Ixodidae tick-borne borreliosis, human granulocytic anaplasmosis, human monocytic ehrlichiosis has not been registered. Markers (DNA) of causative agents of leptospirosis and intestinal yersiniosis have been identified. Joint Tajik-Russian cooperation on issues of ensuring the epidemiological well-being of the population of the Republic of Tajikistan must be continued.

The parasitic mite Sarcoptes scabiei causes mange in nearly 150 species of mammals by burrowing under the skin, triggering hypersensitivity responses that can alter animals' behavior and result in extreme weight loss, secondary infections, and even death. Since the 1990s, sarcoptic mange has increased in incidence and geographic distribution in Pennsylvania black bear (Ursus americanus) populations, including expansion into other states. Recovery from mange in free-ranging wildlife has rarely been evaluated. Following the Pennsylvania Game Commission's standard operating procedures at the time of the study, treatment consisted of one subcutaneous injection of ivermectin. To evaluate black bear survival and recovery from mange, from 2018 to 2020 we fitted 61 bears, including 43 with mange, with GPS collars to track their movements and recovery. Bears were collared in triplicates according to sex and habitat, consisting of one bear without mange (healthy control), one scabietic bear treated with ivermectin when collared, and one untreated scabietic bear. Bears were reevaluated for signs of mange during annual den visits, if recaptured during the study period, and after mortality events. Disease status and recovery from mange was determined based on outward gross appearance and presence of S. scabiei mites from skin scrapes. Of the 36 scabietic bears with known recovery status, 81% fully recovered regardless of treatment, with 88% recovered with treatment and 74% recovered without treatment. All bears with no, low, or moderate mite burdens (<16 mites on skin scrapes) fully recovered from mange (n=20), and nearly half of bears with severe mite burden (≥16 mites) fully recovered (n=5, 42%). However, nonrecovered status did not indicate mortality, and mange-related mortality was infrequent. Most bears were able to recover from mange irrespective of treatment, potentially indicating a need for reevaluation of the mange wildlife management paradigm. [ABSTRACT FROM AUTHOR]

Yellow fever virus (YFV) is the agent of yellow fever (YF), which affects both humans and non-human primates (NHP). Neotropical NHP are highly susceptible to YFV and considered sentinels for YFV circulation. Brazil faced a significant YF outbreak in 2017–2018, with over 2000 human cases and 2000 epizootics cases, mainly in the State of Minas Gerais, Brazil. This study aimed to investigate whether YFV circulation persisted in NHP after the human outbreak had subsided. To this end, NHP carcass samples collected in Minas Gerais from 2021 to 2023 were screened for YFV. RNA was extracted from tissue fragments and used in RT-qPCR targeting the YFV 5'UTR. Liver and lung samples from 166 animals were tested, and the detection of the β-actin mRNA was used to ensure adequacy of RNA isolation. YFV RNA was detected in the liver of 18 NHP carcasses collected mainly from urban areas in 2021 and 2022. YFV positive NHP were mostly represented by Callithrix, from 5 out of the 12 grouped municipalities (mesoregions) in Minas Gerais state. These findings reveal the continued YFV circulation in NHP in urban areas of Minas Gerais during 2021 and 2022, with the attendant risk of re-establishing the urban YFV cycle. [ABSTRACT FROM AUTHOR]

Saprolegniosis is a major destructive disease in freshwater aquaculture. The destructive economic impact of saprolegniosis on freshwater aquaculture necessitates further study on the range of Saprolegnia species within Atlantic salmon fish farms. This study undertook a thorough analysis of a total of 412 oomycete and fungal isolates that were successfully cultured and sequenced from 14 aquaculture sites in Scotland across a two-year sampling period. An ITS phylogenetic analysis of all isolates was performed according to whether they were isolated from fish or water samples and during enzootic or epizootic periods. Several genera of oomycetes were isolated from sampling sites, including Achlya, Leptolegnia, Phytophthora, and Pythium, but by far the most prevalent was Saprolegnia, accounting for 66% of all oomycetes isolated. An analysis of the ITS region of Saprolegnia parasitica showed five distinct phylotypes (S2–S6); S1 was not isolated from any site. Phylotype S2 was the most common and most widely distributed phylotype, being found at 12 of the 14 sampling sites. S2 was overwhelmingly sampled from fish (93.5%) and made up 91.1% of all S. parasitica phylotypes sampled during epizootics, as well as 67.2% of all Saprolegnia. This study indicates that a single phylotype may be responsible for Saprolegnia outbreaks in Atlantic salmon fish farms, and that water sampling and spore counts alone may be insufficient to predict Saprolegnia outbreaks in freshwater aquaculture. [ABSTRACT FROM AUTHOR]

Introduction and purpose. Hendra and Nipah are two highly dangerous zoonotic viruses belonging to the group of henipaviruses. Although they have been known for over 20 years, no human drug or vaccine has been invented. This paper aims to to describe the epidemiology of the reported paramyxoviruses, the pandemic potential of henipaviruses, and a standardised action plan to counter their spread. This paper reviews scientific articles from 2012-2023 published in scientific databases such as Pubmed, Researchgate, and Google Scholar. The keywords used were pandemic potential of henipaviruses, Hendra virus, Nipah virus, and henipavirus epidemics. State of knowledge description. The mortality rate of henipaviruses varies between 50 and 100%. The Nipah virus is particularly dangerous, with epidemics recurring virtually every year in Asia since 1998. The Hendra virus situation may be manageable because there is an effective vaccine for horses most vulnerable to infection. Due to human activity, the habitats and climate of the animals serving as virus reservoirs are changing. Because of frequent henipavirus outbreaks in Asia and Australia, extensive efforts are being made to contain and neutralise them rapidly. Conclusions. As henipaviruses pose a high pandemic threat, more research into drugs and vaccines is required. It is also essential to develop effective bio-assurance plans, introduce controls on their operation and educate the population on the issue. Reservoir animals, through anthropogenic environmental changes, are changing habitats and feeding sites, making more and more territories vulnerable to the disease. New species of henipaviruses constantly emerge and pose an epizootic challenge to public health. Hence, an essential action is to increase the amount of research into the virus's epidemic development and conduct it as widely as possible. [ABSTRACT FROM AUTHOR]

Granuloviruses are insect viruses commonly used as biological insecticides for pest control in agriculture. Most pest control programs rely on the most virulent strains and doses to cause acute mortality events. However, we hypothesize that sublethal infections are key to maintaining persistent epidemics that regulate pest populations in the long‐term. The tomato leafminer (TLM), Tuta absoluta (Meyrick) (= Phthorimaea absoluta Meyrick) (Lepidoptera: Gelechiidae), is one of the most limiting pests of greenhouse and field tomatoes. Previous efforts have identified a strain of Phthorimaea operculella granulovirus (PhopGV), coded VG013, associated with field populations of the TLM, which causes significant acute mortalities and is being used as active ingredient of a biological insecticide. The aim of this study was to determine the effect of sublethal infections and transmission mechanisms of PhopGV‐VG013 on TLM populations. Six viral doses were tested for their virulence and effects on TLM development rate, and intrinsic population growth rate. A sublethal dose was selected to compare the density‐dependent mortality of TLM populations and vertical transmission was examined by testing for PhopGV in the offspring of surviving infected individuals. Horizontal transmission was assessed by testing for PhopGV in frass of infected larvae, and the infection of virus‐free larvae confined with infected larvae in the same leaf. We found that sublethal doses of PhopGV have slight effects on TLM population growth rates, and none on the strength of density‐dependent mortality. Although we found for the first time that PhopGV‐VG013 is transmitted to approximately 7.5% of the offspring of individuals that survive the virus challenge, we found no evidence suggesting horizontal transmission from sublethal infections. Our results show that sublethal infections of highly virulent ganulovirus strains may favor long‐term pathogen persistence but have a limited role in host population regulation. [ABSTRACT FROM AUTHOR]

The relevance of the study is driven by the need to elucidate the essence of veterinary and sanitary control over the movement of animals at the national level to facilitate its further correlation with the experiences of European countries. The purpose of the study is to analyse the state of the legal provision in the defined sphere and formulate suggestions for enhancing the legal regulation of state veterinary and sanitary control over the movement of animals. The paper uses a system of general scientific methods of cognition (dialectical, formal-logical, analysis, and synthesis), and a special formal-legal method. The paper analyses the national experience of legal regulation of state veterinary and sanitary control over the movement of animals through the disclosure of its features. The essence of state veterinary and sanitary control during the movement of animals is established and its place in the legal system is determined. The boundaries of the legal regulation of this issue are outlined, legal forms of implementing such control, subjects and objects of such activity, the sequence of procedures required by veterinary-sanitary legislation for animal movement, and the specificities of legal responsibility for violations of veterinary and sanitary requirements during animal transportation are defined. The need to develop normatively established requirements for the safe movement of animals is substantiated, which encompass not only the procedures for protecting animals from epizootics and cruel treatment during their preparation for transportation or during transportation itself but also ensure the population’s access to quality and safe food products while guaranteeing the well-being of the animals. The practical importance of the paper lies in a number of proposals for improving Ukrainian legislation in this area.

Entomopathogenic fungi stand out in the biological control of several agriculturally important insects. Six isolates of Metarhizium anisopliae, Cordyceps javanica, Beauveria sp. and B. bassiana were screened to control Anthonomus grandis, Euschistus heros, Oebalus poecilus, O. ypsilongriseus and Thyanta perditor, important insect pests of soybean, cotton and rice. The bioassays were conducted in a completely randomized design, with four replications (10 insects/replication). Significant differences for virulence were observed between the tested fungal species and isolates. For A. grandis, the most virulent isolate was M. anisopliae BRM 2335, followed by Beauveria BRM 14527 and BRM 67744 [82.5 to 97.5 % of mortality; average lethal time (LT50) of 5.9 to 7.8 days]. M. anisopliae BRM 2335 was also highly virulent to the four stink bug species (75 to 97.5 % of mortality; LT50 of 5.2 to 9.7 days). For the stink bugs, Beauveriasp. BRM 67744 was infectious to O. poecilus (75 % of mortality), but failed to control E. heros (16.9 % of mortality). C. javanicaBRM 27666 and BRM 14526 showed average virulence to the stink bugs and A. grandis (17.5 to 57.3 % of mortality; LT50 of 6.0 to 9.7 days). M. anisopliae was consistently more virulent to the stink bugs than the other fungi. Therefore, M. anisopliaeBRM 2335 was selected for further studies under screenhouse and field conditions to control A. grandis and other stink bug species, especially E. heros.

Animal sociality emerges from individual decisions on how to balance the costs and benefits of being sociable. Novel pathogens introduced into wildlife populations should increase the costs of sociality, selecting against gregariousness. Using an individual-based model that captures essential features of pathogen transmission among social hosts, we show how novel pathogen introduction provokes the rapid evolutionary emergence and coexistence of distinct social movement strategies. These strategies differ in how they trade the benefits of social information against the risk of infection. Overall, pathogen-risk-adapted populations move more and have fewer associations with other individuals than their pathogen-risk-naive ancestors, reducing disease spread. Host evolution to be less social can be sufficient to cause a pathogen to be eliminated from a population, which is followed by a rapid recovery in social tendency. Our conceptual model is broadly applicable to a wide range of potential host–pathogen introductions and offers initial predictions for the eco-evolutionary consequences of wildlife pathogen spillover scenarios and a template for the development of theory in the ecology and evolution of animals’ movement decisions.

The rapid development of intensive fish farming has been associated with the spreading of infectious diseases, pathogens and parasites. One such parasite is Sparicotyle chrysophrii (Platyhelminthes: Monogenea), which commonly infects cultured gilthead seabream (Sparus aurata)—a vital species in Mediterranean aquaculture. The parasite attaches to fish gills and can cause epizootics in sea cages with relevant consequences for fish health and associated economic losses for fish farmers. In this study, a novel stratified compartmental epidemiological model of S. chrysophrii transmission was developed and analysed. The model accounts for the temporal progression of the number of juvenile and adult parasites attached to each fish, as well as the abundance of eggs and oncomiracidia. We applied the model to data collected in a seabream farm, where the fish population and the number of adult parasites attached to fish gills were closely monitored in six different cages for 10 months. The model successfully replicated the temporal dynamics of the distribution of the parasite abundance within fish hosts and simulated the effects of environmental factors, such as water temperature, on the transmission dynamics. The findings highlight the potential of modelling tools for farming management, aiding in the prevention and control of S. chrysophrii infections in Mediterranean aquaculture.

Wild boar population (Sus scrofa) has been growing rapidly in most countries of the world over the past decades. The invasive species has high reproduction rates and well-developed adaptive responses, which allows it to successfully expand the boundaries of its habitat, create significant economic losses to agriculture and horticulture, urban ecosystems, and threatens the loss of biological diversity and the spread of zoonotic infections. The purpose of the paper was to analyse the factors that contribute to the expansion of the Sus scrofa species in the world, to determine the ecological mechanisms of population regulation against the background of rapid anthropogenic transformation of the habitat and global climatic anomalies; to assess changes in the dynamics of population size in hunting farms of Ukraine for the period from 2010 to 2020 in the Chernihivska oblast, in particular. Conventional methods of retrospective analysis, synthesis, environmental, general biological, and epizootic research were used. The paper analyses the world experience and identifies the main factors of low effectiveness of strategies for controlling the rapidly growing population of wild boar in agroecosystems, mixed forest and urban ecosystems. Due to the unique features of forming a life strategy, the Sus scrofa species demonstrate successful development, expansion of the range of available food resources, effective use of daily diversification of ecological niches in the conditions of transformed ecosystems, etc. It is established that the reason for the inefficiency of ecological mechanisms of pressure on the population of the species in the "predator-prey" system is the absence of large predators in the forest ecosystems of Chernihivska oblast. At the same time, the absence of deterrent mechanisms in the predator-prey system ensured the manifestation of next-level mechanisms, namely, the appearance of foci of African swine fever along the forest cycle in the natural biocenoses of the region. Response – the response of populations was manifested by a rapid short-term decrease in the population of Sus scrofa, as a temporary deterrent effect with a subsequent recovery trend. The results obtained can be used in the development of practical recommendations for biological monitoring, environmental control, and the development of effective forest management measures to prevent biological safety associated with the uncontrolled distribution of Sus scrofa and African swine fever based on universal ecological mechanisms of population regulation

Copyright of Nouveau Praticien Vétérinaire Élevages et Santé is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nouveau Praticien Vétérinaire Élevages et Santé is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to assess the epidemiological and epizootiological situation on tularemia in the Republic of Karelia, and to develop a set of preventive (anti-epidemic) measures. Materials and methods. On the basis of statistical observation data, primary medical documentation and literature data, the morbidity of the population, the number of vaccinated persons, the results of laboratory studies of small mammals, arthropods and environmental objects, the species composition of hosts and vectors of infection were assessed. The situation in the republic was compared to the situation in Finland and neighboring regions of Russia. Results and discussion. The incidence of tularemia was registered in the Republic of Karelia in 1950–1971 (52 cases) and in 2010–2020 (121 cases). In the last decade, mainly the ulceroglandular forms have been diagnosed, the urban population predominated among the patients. In all cases, infection was transmitted through mosquito bites, i. e., not associated with professional activities. There are floodplainswamp and forest types of natural foci in the republic. The results of their monitoring are indicative of the activation of the epizootic process, covering almost the entire territory of Karelia. In several areas bordering tularemia disadvantaged areas of Finland and Russia, a high infection rate of rodents was detected, but tularemia patients were not registered. For an adequate assessment of the situation, it is necessary to increase the efficiency of surveying natural foci, study the immune structure of the population and improve the diagnosis of infection. The main areas of preventive (anti-epidemic) measures are vaccination of persons with professional risk of infection and persons living near the activated micro-foci of infection; reduction of the area of fields not used in agriculture; reclamation work, combating landfills, regular removal of waste from the territories of permanent and temporary residence of the population; the use of effective repellents; raising awareness of the population and authorities about the situation, symptoms of the disease, measures of its prevention.

Résumé: Des millions d'oiseaux d'élevage abattus, des centaines de fous de Bassan morts sur le littoral, des mammifères marins agonisants atteints de troubles neurologiques : ces événements font régulièrement la une de l'actualité. Leur point commun ? Les virus influenza aviaires hautement pathogènes (VIAHP). Les VIAHP sont des virus capables de se répliquer de manière systémique, engendrant des infections asymptomatiques comme une mortalité foudroyante, en fonction de la sensibilité des espèces hôtes. Connus depuis maintenant plusieurs décennies, ces virus ont vu leur circulation particulièrement augmenter ces dernières années et ont été responsables d'épizooties massives sur plusieurs continents. Aux effets dévastateurs qu'ils peuvent causer dans les filières avicoles et dans la faune sauvage, les VIAHP sont également capables de franchir la barrière d'espèce. Mieux les connaître et mieux maîtriser leur diffusion revêt donc plusieurs objectifs : protéger la santé publique, garantir la sécurité alimentaire, préserver la biodiversité ou encore l'économie des filières avicoles. Cet article de synthèse fait un état de l'art des connaissances actuelles sur les VIAHP : de leur épidémiologie aux mécanismes d'émergence en passant par les mesures de lutte. Millions of farmed birds culled, hundreds of gannets dead on the coast, dying marine mammals suffering from neurological disorders: these events regularly make the headlines. What do they have in common? Highly pathogenic avian influenza viruses (HPAIV). HPAIVs are viruses capable of replicating systemically, causing both asymptomatic infections and devastating mortality, depending on the susceptibility of the host species. Known for several decades now, these viruses have seen their circulation particularly increased in recent years, and have been responsible for massive epizootics on several continents. In addition to the devastating effects they can cause in poultry and wildlife, HPAIVs are also capable of crossing the species barrier. Improving knowledge about these viruses and better control of their spread therefore has several objectives: to protect public health, to guarantee food safety, to preserve biodiversity and the economy of the poultry industry. This article reviews the current state of knowledge on HPAIVs: from their epidemiology to the mechanisms of emergence and control measures. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi (EPF) specifically infect and kill insects can serve as a potential biological control agent. Several biotic and abiotic factors affect their occurrence, persistence, and epizootics caused by them. In biotic factors, fungi characters (host range, latency, spore density and dispersal, mainly host-pathogen compatibility), insect host factors (behavioral, morphological, and physiological), plant-mediated effects (plant architecture, surface chemistry, and leaf topology) are included supports or causes the barrier to mycobiopesticide. Abiotic factors which affect the EPF field persistence are mainly environmental (temperature, sunlight, humidity, rainfall) physical and chemical soil properties (soil texture, pH, E.c, moisture, C/N content, and organic matter) that greatly influence the entomopathogenic fungi. To use them as biocontrol agents, we have to overcome these factors by providing them nutrients, protectants, and using different control practices.

Abstract Yellow fever (YF) is a viral disease whose transmission involves non-human primates (NHP), mosquitoes, and humans. Between 2016 and 2018 occurred the largest YF outbreak in the last 100 years in Brazil. We analyzed epidemiologic profile and geographic distribution of epizootics and described most frequent histopathological findings in NHP that died during YF outbreak in the state of Espírito Santo. We consider 487 epizootics notifications registered at the State Health Department from January 2017 to July 2020. Throughout the state, 51 (65.4%) municipalities reported epizootics, with more cases in central and metropolitan areas. Reverse transcription polymerase chain reaction and immunohistochemistry were laboratory tests performed for diagnosis of yellow fever, with 160 (32.9%) positive results, 314 (64.5%) negative and 13 (2.7%) inconclusive. Histopathological findings were compared statistically between positive and negative animals for YF. The liver was the most affected organ. Hemorrhage, hepatocyte necrosis, steatosis, cholestasis and eosinophilic degeneration were statistically more frequent in positive animals. Tubular necrosis, nephritis, congestion and lymphoid hypoplasia on spleen were statistically correlated to positive animals. Knowledge of pathogenic aspect of YF is necessary to guarantee that samples from Neotropical primates are properly used for YF surveillance purposes, to ensure appropriate diagnoses and subsequent public health responses.

During 2010-2022, in the field crop rotations of the Forest-Steppe of Ukraine with the use of the latest chemical means, the peculiarities of biology, ecology and distribution of soil and other harmful species of arthropods were clarified. In particular, according to the technologies of high-quality grain production through the use of tank mixtures of plant protection agents and relatively high rates of fats, which influenced the formation of the structure of the entomocomplex with the predominance of certain species of weevils, gnats, gnawing scoops and lamellae. According to the phenophases of cultivated plants, this feature was accompanied both by the state of biological resources and by the technologies of crop production in general, with the optimization of phytosanitary, nature protection and economically justified resourcesaving methods of controlling the number of phytophages. It has been established that in cultural ecosystems under intensive technologies in the composition of modern bioresources, the number of organisms, both flora and fauna, in particular, harmful phytophagous insects at the first stages of the formation and development of grain crops, probably changes. In the years of observation, it was noted that the biodiversity of agrocenoses is quite numerous in terms of species and quantity, mainly against the background of organo-mineral systems and under conditions of relatively low rates of application of fats. This makes it possible to model such processes by entomological and zoological objects as sensors, in particular from the standpoint of systematic monitoring and forecasting, as well as sustainable management on a resource-saving basis. At the same time, the long-term dynamics of the factors of the formation of entomocomplexes are taken into account, with the clarification of the influence of the systems of basic and minor nutrition, tillage and measures to protect grain and other crops, with an assessment of the selfmanagement mechanisms of the arthropod complex, and the dominant species are determined in the theological aspect. Based on the results of research, separate biocenotic relationships of cultivated plants and their harmful organisms under different nutrition systems of wheat, corn, soybean, chickpea, sunflower in periods of drought and relatively optimal weather conditions were clarified, with clarification of the levels of trophic chains of primary and secondary coenoses. The structure of arthropods of the newest systems of application of liquid forms of fertilizers, as well as with an assessment of the influence of tank mixtures of agrochemicals on the level of migration and survival of phytophagous insects in short-rotational crop rotations. The new parameters of grain crop protection systems with biologically oriented complexes based on entomological and zoological test objects of the factors of crop production intensification are substantiated. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is an infectious disease of domestic and wild pigs, which went beyond its natural range (African continent) in the XXI century and since 2007 (emergence in Georgia) has spread to many European and Asia-Pacific countries. According to the immediate notifications and follow-up reports, by early 2021 Europe accounted for about 68% of globally reported outbreaks. However, the greatest losses in the pig industry were inflicted by the outbreak recorded in Asia in 2020, when 6,733,791 animals died that accounted to 82% of the total global losses due to ASF. Just after several years of the current ASF epizootic, without any vaccine or treatment available, it became clear that major problems for the pig industry (mostly for small farmers) as well as destabilization of the global market of pig products were unavoidable. In this regard, in 2014 (Bern, September 2014) a regional standing group of experts on African swine fever (SGE ASF) was established under FAO/OIE GF-TADs umbrella. The aim of the group is to foster closer collaboration between the affected countries, increase transparency and share experience in prevention and control. The work of the permanent expert ASF missions under the GF-TADs umbrella has proven effective and become a model for other regions. A similar group was established in Asia in April 2019 to counter rapid spread of the disease in the Asia-Pacific region, where more than 60% of the world’s pig population is concentrated, and a new permanent ASF expert group for the Americas is being considered. The many-year efforts resulted in the establishment of the FAO/OIE/GF-TADs platform as a progressive mechanism to combat such transboundary disease as African swine fever.

The article examines the process of the emergence and subsequent development of zemstvo veterinary service in the Tula province at the turn of the 19th and 20th centuries. This direction at the initial period of local governments activity did not receive due attention. However, the spread of extensive diseases of livestock gave a powerful impetus to the expansion of activities in this direction in the future. The development of zemstvo veterinary service is a vivid example of the awareness of the importance of livestock health problem, as well as a point-based and largely effective solution of the problem.

Upon reading the decisions of the Court of Cassation, regional or national epidemic crises emerge. It is possible to see over the course of these two centuries of practice the establishment of organizational practices and methods whose purpose is to prevent the appearance or spread of the disease. Citizens will resort to the supreme jurisdiction to find someone responsible for the health crisis or prevent a constraint perceived as unfair. The article will approach the epidemic episodes of the 19th and 20th centuries through the prism of public health case law.

Abstract Background Yellow fever (YF) is a severe, infectious, but non-communicable arboviral hemorrhagic disease. In the last decades, yellow fever virus (YFV) infections have been prevalent in endemic areas in Brazil, affecting human and non-human primate (NHP) populations. Monitoring of NHP infection started in 1999, and reports of epizootic diseases are considered important indicators of viral transmission, particularly in relation to the sylvatic cycle. This study presents the monitoring of YFV by real-time RT-PCR and the epidemiological findings related to the deaths of NHPs in the south-eastern states and in the north-eastern state of Bahia, during the outbreak of YF in Brazil during 2017 and 2018. Methods A total of 4198 samples from 2099 NHPs from south-eastern and north-eastern Brazilian states were analyzed by real-time reverse transcription polymerase chain reaction (rtRT-PCR). Results A total of 4198 samples from 2099 NHPs from south-eastern and north-eastern Brazilian states were collected between 2017 and 2018. The samples were subjected to molecular diagnostics for YFV detection using real-time reverse transcription polymerase chain reaction (rtRT-PCR) techniques. Epizootics were coincident with human YF cases. Furthermore, our results showed that the YF frequency was higher among marmosets (Callithrix sp.) than in previous reports. Viremia in species of the genus Alouatta and Callithrix differed greatly. Discussion Our results indicate a need for further investigation of the role of Callithrix spp. in the transmission cycles of YFV in Brazil. In particular, YFV transmission was observed in a region where viral circulation has not been recorded for decades and thus vaccination has not been previously recommended. Conclusions This highlights the need to straighten epizootic surveillance and evaluate the extent of vaccination programmes in Brazil in previously considered “YFV-free” areas of the country.

The Japanese Government General of Korea used colonial Korea as food and military resource for Japan and as a barrier to the livestock infectious diseases from China. Therefore the colonial livestock sanitary policies focused on quarantine-based disease prevention. Unlike colonies in India, Africa, and America, where the European powers formed colonies the Korean Peninsula was close to Japan. The epizootics in Korea created an invisible boundary between the empire and the colony. Colonial livestock animals were considered inferior beings at risk of infection and contamination that needed improvement. Humans in the colony were passively incorporated into the livestock quarantine system. Korean Peninsula served as a test site for new systems such as the double quarantine system and rinderpest immune zone, and technologies developed in Japan, such as the immune serum and vaccines. Japan forcibly transplanted livestock sanitary regulations on the Korean Peninsula but the benefits were limited in enhancing the colony's capabilities in preventing livestock infectious diseases. Colonial Korea could not secure the necessary veterinarians according to its own needs, nor could it get an opportunity to cultivate related professionals. Therefore, colonial veterinary medicine and livestock sanitary policy were established with limited success in preventing epizootics during the colonial period. [ABSTRACT FROM AUTHOR]

Native freshwater fish of Australia have a diverse but largely undescribed endemic pathogen and parasite fauna. However, due to long-shared evolutionary histories and virulence/transmissibility trade-offs, effects of these endemic pathogens and parasites appear to be subtle: significant impacts are rarely observed and epizootics have not been recorded. In contrast, a number of alien pathogens and parasites are now established across southern Australia, causing manifestly harmful effects to native fish species and known or suspected epizootics in native fish populations. Undetected and/or undescribed alien viral pathogens are also suspected of being present. Alien pathogens and parasites were introduced to Australia with imports of live alien fish or their fertilised eggs. A review of the scientific and historical evidence indicates that they have had, and continue to have, greater impacts on native fish species than previously realised—especially for freshwater species. This review also documents a previously unknown, Murray-Darling-Basin-wide epizootic of Murray cod Maccullochella peelii in 1929–30, which may have contributed to strong declines in the related eastern freshwater cod Maccullochella ikei. A serious Chilodonella epizootic of M. peelii in 1982 is also examined. In addition, a possible role for alien viruses of the family Iridoviridae (Ranavirus and Megalocytivirus) in the general decline of the critically endangered silver perch Bidyanus bidyanus, and the rapid collapse of two specific native fish populations—upper Murrumbidgee River B. bidyanus and Shoalhaven River Macquarie perch Macquaria australasica—is suggested. It is argued that the severity of the impact of the virulent alien oomycete Saprolegnia parasitica, both historical and present day, has been underestimated. Finally, action is recommended against emerging new pathogen and parasite threats, and the extreme risk current alien fish importations pose in introducing them. These will further threaten already stressed native fish populations in southern Australia, particularly across the Murray-Darling Basin. [ABSTRACT FROM AUTHOR]

Streptococcus iniae is an emerging zoonotic pathogen of increasing concern for aquaculture and has caused several epizootics in reef fishes from the Caribbean, the Red Sea and the Indian Ocean. To study the population structure, introduction pathways and evolution of S. iniae over recurring epizootics on Reunion Island, we developed and validated a Multi Locus Sequence Typing (MLST) panel using genomic data obtained from 89 isolates sampled during epizootics occurring over the past 40years in Australia, Asia, the United States, Israel and Reunion Island. We selected eight housekeeping loci, which resulted in the greatest variation across the main S. iniae phylogenetic clades highlighted by the whole genomic dataset. We then applied the developed MLST to investigate the origin of S. iniae responsible for four epizootics on Reunion Island, first in inland aquaculture and then on the reefs from 1996 to 2014. Results suggest at least two independent S. iniae emergence events occurred on the island. Molecular data support that the first epizootic resulted from an introduction, with inland freshwater aquaculture facilities acting as a stepping-stone. Such an event may have been facilitated by the ecological flexibility of S. iniae , able to survive in both fresh and marine waters and the ability of the pathogen to infect multiple host species. By contrast, the second epizootic was associated with a distinct ST of cosmopolitan distribution that may have emerged as a result of environment disturbance. This novel tool will be effective at investigating recurrent epizootics occurring within a given environment or country that is despite the fact that S. iniae appears to have low genetic diversity within its lineage. [ABSTRACT FROM AUTHOR]

Streptococcus iniae is an emerging zoonotic pathogen of increasing concern for aquaculture and has caused several epizootics in reef fishes from the Caribbean, the Red Sea and the Indian Ocean. To study the population structure, introduction pathways and evolution of S. iniae over recurring epizootics on Reunion Island, we developed and validated a Multi Locus Sequence Typing (MLST) panel using genomic data obtained from 89 isolates sampled during epizootics occurring over the past 40years in Australia, Asia, the United States, Israel and Reunion Island. We selected eight housekeeping loci, which resulted in the greatest variation across the main S. iniae phylogenetic clades highlighted by the whole genomic dataset. We then applied the developed MLST to investigate the origin of S. iniae responsible for four epizootics on Reunion Island, first in inland aquaculture and then on the reefs from 1996 to 2014. Results suggest at least two independent S. iniae emergence events occurred on the island. Molecular data support that the first epizootic resulted from an introduction, with inland freshwater aquaculture facilities acting as a stepping-stone. Such an event may have been facilitated by the ecological flexibility of S. iniae, able to survive in both fresh and marine waters and the ability of the pathogen to infect multiple host species. By contrast, the second epizootic was associated with a distinct ST of cosmopolitan distribution that may have emerged as a result of environment disturbance. This novel tool will be effective at investigating recurrent epizootics occurring within a given environment or country that is despite the fact that S. iniae appears to have low genetic diversity within its lineage.

[Display omitted] • Genetic diversity of the entomopathogenic fungus Metarhizium rileyi was assessed with de novo microsatellite markers. • Thirteen SSR markers differentiate 12 genetic clusters and identified 43 clones in 136 M. rileyi isolates. • Prevalent genotypes could occur in epizootics of M. rileyi. Epizootics of the entomopathogenic fungus Metarhizium rileyi regulate lepidopteran populations in soybean, cotton, and peanut agroecosystems to the point that insecticide applications could be unnecessary. However, the contribution and how different strains operate during the epizootic are unknown. Several unanswered questions remain: 1. How many genotypes of M. rileyi are present during an epizootic? 2. Which genotype is the most common among them? 3. Are the genotypes involved in annual epizootics at the same location the same? Therefore, the development of molecular markers to accurately identify these genotypes is very important to answer these questions. SSR primers were designed by prospecting in silico to discriminate genotypes and infer the genetic diversity of M. rileyi isolates from the collection kept at Embrapa Soybean. We tested 13 SSR markers on 136 isolates to identify 43 clones and 12 different genetic clusters, with genetic diversity ranging from Hs = 0.15 (cluster I) to Hs = 0.41 (cluster IV) and an average diversity of 0.24. No clusters were categorically distinguished based on hosts or geographical origin using Bayesian clustering analysis. Nonetheless, some clusters comprised most of the isolates with a common geographic origin; for example, cluster VIII was mainly composed of isolates from Central-western Brazil, cluster II from Southern Brazil, and cluster XII from Quincy, Northern Florida, in the United States. Underrepresented regions (few isolates) from Pacific Island nations of Japan, the Philippines, and Indonesia (specifically from Java) were placed into clusters IX and X. Although the analyzed isolates displayed evidence of clonal structure, the genetic diversity indices suggest a potential for the species to adapt to different environmental conditions. [ABSTRACT FROM AUTHOR]

The article is devoted to the study of the peculiarities of the formation of veterinary medicine in the Tobolsk governorate in the late 19th - early 20th centuries. The authors use a representative source base of both published and unpublished materials from the collections of the Tobolsk State Archive. The conditions of organization of veterinary service in Siberia as a “remote area” are considered. It is noted that the development of veterinary medicine in the Tobolsk governorate was influenced by the opening of a veterinary and paramedic school. The novelty of the research is seen in the fact that for the first time in the national historiography the role of the provincial veterinary inspector in the formation of the Institute of veterinary service is considered. The activity of provincial veterinary inspectors is analyzed: P. Zolotarev, A. Ya. Lempert, L. S. Sumtsov and N. A. Kargapolov, who made a great contribution to the development of the veterinary service of the Tobolsk governorate in the studied period. It is shown that these doctors were highly educated and had an extensive experience in veterinary medicine. It is indicated that, despite all efforts and significant progress in the development of veterinary services, there were objective difficulties in this area, including difficult climatic conditions, long distances between settlements, the beginning of the First world war, etc.

Dermatomycoses (dermatophytosis) are infectious diseases of animals and humans, which are characterized by lesions of the skin and its products by pathogenic fungi of genera Trichophyton and Microsporum. The actuality of the topic is to study the skin diseases of the animal organism due to the considerable prevalence, variety and complexity of dermatological problems. This is due to the fact that the data about the disease have not been investigated completely, and veterinary dermatology, as a science, itself lags far behind to the development of other areas of animal pathology. Infectious skin lesions in animals are a serious problem, the solution of which largely depends on many factors, in particular, environmental, living standards and level of scientific achievements in dermatology, the presence of homeless diseased animals. The aim of the research was to investigate the spreading of fungal pathogens of the skin of animals in Petrykivskyi district of the Dnipropetrovsk region on the basis of laboratory research data. The research was done on the basis of the Petrykivsky District Hospital of Veterinary Medicine in the winter period of 2017. Animal wool was examined by bacteriological method and fluorescence microscopy. By the distribution of the number of investigated samples, it can be concluded that the overwhelming majority of infected animals were dogs 15 (39.5%) and cats 11 (28.9%), among which were domestic and homeless animals. Rarely, the material from horses 8 (21.1%), hamsters 3 (7.9%) and rats 1 (2.6%), which were presented exclusively by domestic animals, was examined. It was found that 28 (73.7%) samples of the material were negative for the presence of pathogens of such infections, and in 10 (26.3%) cases the presence of pathogens of lesions was determined. The primary study of wool using a Woods lamp was confirmed bacteriologically. All cases of determining of the positive result for the infection were recorded for dogs 6 (60%) and cats 4 (40%), who were domestic, but had free access to outdoor. The epizootic situation of microsporia and trichophytosis in Petrykivskyi district of the Dnipropetrovsk region remains rather tense and is characterized by a significant development of epizootics that began in 2000. The highest incidence of fungal infections was detected in 2011, when 67 diseased animals were detected, which allowed to detect epizootics. Epizootic decrease was observed in 2013 34 cases and 28 cases in 2014. In 2015, a new outbreak of epizootics was recorded: 38 positive results were found on fungal infections of animals. The same trend took place in 2016, when the number of diseased animals continued to increase. In 2017, the smallest incidence rate of animals is 22 cases. In the pet category, the most often positive results of research on infection were noted for dogs 59.9%. More than 75% of the pathological material is derived from homeless animals. The largest area of the risk of spreading of infections of animals caused by microscopic fungi in Petrikivsky is v. Loboykivka and v. Petrikivka 54 and 46 cases respectively. The safest situation was in v. Hrechane and v. Malaya Petrykivka, where in the period from 2013 fixed 3 and 4 cases of infection respectively. Studies on the presence of microscopic fungi pathogens of animal lesions have one of the leading values for the sanitation of the agroindustrial complex and individual households, since animals are a potential source of infection for humans. Monitoring the spread of microscopic fungi that causes such lesions allows for the development and control of measures to spread them, which can protect people from infection.

The article, written on the basis of data from the Russian and European archives, is the most complete biography of the famous figure of the Russian medical and veterinary science of the middle of the XIX century Friedrich Brauell, one of the pioneers of anthrax research. The article describes in detail the period of formation of F. Brauell as a scientist – his education received in Germany, visit to the Russian Empire for service, confirmation of academic degree received at homeland. His first steps in the field of teaching and science at Kazan University are discussed in details, his efforts to create a collection of anatomical preparations are described. The main part of the article is devoted to his work in Derpat (Tartu) Veterinary School, where he fully revealed his talent as a major organizer of scientific and educational activities. Particular attention is paid to its study of the problem of anthrax and plague. In addition, the article deals with the issues of his personal life and family for the first time. Thus, the material contained in the article can be useful for scientists studying the history of medicine, infectious diseases and veterinary medicine.

Predators and pathogens often regulate the population dynamics of their prey or hosts. When species interact with both their predators and their pathogens, understanding each interaction in isolation may not capture the system's dynamics. For instance, predators can influence pathogen transmission via consumptive effects, such as feeding on infected prey, or non-consumptive effects, such as changing the prey's susceptibility to infection. A prey species' infection status can, in turn, influence predator's choice of prey and have negative fitness consequences for the predator. To test how intraguild predation (IGP), when predator and pathogen share the same prey/host, affects pathogen transmission, predator preference, and predator fitness, we conducted a series of experiments using a crop pest (Pseudoplusia includens), a generalist predator (Podisus maculiventris), and a generalist pathogen (Autographa californica multicapsid nuclear polyhedrovirus, AcMNPV). Using a field experiment, we quantified the effects of consumptive and non-consumptive predators on pathogen transmission. We found that a number of models provided similar fits to the data. These models included null models showing no effects of predation and models that included a predation effect. We also found that predators consumed infected prey more often when choosing between live infected or live healthy prey. Infected prey also reduced predator fitness. Developmental times of predators fed infected prey increased by 20% and longevity decreased by 45%, compared with those that consumed an equivalent number of non-infected prey. While this research shows an effect of the pathogen on intraguild predator fitness, we found no support that predators affected pathogen transmission. [ABSTRACT FROM AUTHOR]

Background: Yellow fever (YF) is a severe, infectious, but non-communicable arboviral hemorrhagic disease. In the last decades, yellow fever virus (YFV) infections have been prevalent in endemic areas in Brazil, affecting human and non-human primate (NHP) populations. Monitoring of NHP infection started in 1999, and reports of epizootic diseases are considered important indicators of viral transmission, particularly in relation to the sylvatic cycle. This study presents the monitoring of YFV by real-time RT-PCR and the epidemiological findings related to the deaths of NHPs in the south-eastern states and in the north-eastern state of Bahia, during the outbreak of YF in Brazil during 2017 and 2018. Methods: A total of 4198 samples from 2099 NHPs from south-eastern and north-eastern Brazilian states were analyzed by real-time reverse transcription polymerase chain reaction (rtRT-PCR). Results: A total of 4198 samples from 2099 NHPs from south-eastern and north-eastern Brazilian states were collected between 2017 and 2018. The samples were subjected to molecular diagnostics for YFV detection using real-time reverse transcription polymerase chain reaction (rtRT-PCR) techniques. Epizootics were coincident with human YF cases. Furthermore, our results showed that the YF frequency was higher among marmosets (Callithrix sp.) than in previous reports. Viremia in species of the genus Alouatta and Callithrix differed greatly. Discussion: Our results indicate a need for further investigation of the role of Callithrix spp. in the transmission cycles of YFV in Brazil. In particular, YFV transmission was observed in a region where viral circulation has not been recorded for decades and thus vaccination has not been previously recommended. Conclusions: This highlights the need to straighten epizootic surveillance and evaluate the extent of vaccination programmes in Brazil in previously considered "YFV-free" areas of the country. [ABSTRACT FROM AUTHOR]

The 2021 re-emergence of yellow fever in non-human primates in the state of Rio Grande do Sul (RS), southernmost Brazil, resulted in the death of many howler monkeys (genus Alouatta) and led the state to declare a Public Health Emergency of State Importance, despite no human cases reported. In this study, near-complete genomes of yellow fever virus (YFV) recovered from the outbreak were sequenced and examined aiming at a better understanding of the phylogenetic relationships and the spatio-temporal dynamics of the virus distribution. Our results suggest that the most likely sequence of events involved the reintroduction of YFV from the state of São Paulo to RS through the states of Paraná and Santa Catarina, by the end of 2020. These findings reinforce the role of genomic surveillance in determining the pathways of distribution of the virus and in providing references for the implementation of preventive measures for populations in high risk areas.

In January 2017, a yellow fever outbreak occurred in Espirito Santo, Brazil, where human immunization coverage is low. Histologic, immunohistologic, and PCR examinations were performed for 22 deceased nonhuman New World primates; typical yellow fever features were found in 21. Diagnosis in nonhuman primates prompted early public health response.

Since 1933 in the Rostov region, the official registration of tularemia began. In 1964-1949 the highest incidence was noted. Since 1947, they have been vaccinated against tularemia. In 1966 to 1973, there were no cases of tularemia. In July-August 1993, a large outbreak of tularemia (more than 200 people) was recorded. Until early 2017, the epidemic situation in tularemia in the Rostov region, according to the data of long-term monitoring, was assessed as stable, but low coverage with vaccinations against tularemia, both in the population of endemic territories and in individuals of certain professional categories was recorded. In january 2017, two residents of Rostov-on-Don received a clinical diagnosis of «tularemia». In june and july 2017, three cases of tularemia were reported. The most effective mechanism for preventing the spread of tularemia remains vaccination of the population from the contingent of risk. We consider it advisable to conduct studies of the immunity to tularemia in the population vaccinated in the last five years, to significantly increase the reliability of short- and long-term prognosis for tularemia in the region.

Amphibians, the most threatened group of vertebrates, are seen as indicators of the sixth mass extinction on earth. Thousands of species are threatened with extinction and many have been affected by an emerging infectious disease, chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd). However, amphibians exhibit different responses to the pathogen, such as survival and population persistence with infection, or mortality of individuals and complete population collapse after pathogen invasion. Multiple factors can affect host pathogen dynamics, yet few studies have provided a temporal view that encompasses both the epizootic phase (i.e. pathogen invasion and host collapse), and the transition to a more stable co-existence (i.e. recovery of infected host populations). In the Sierra Nevada mountains of California, USA, conspecific populations of frogs currently exhibit dramatically different host/ Bd-pathogen dynamics. To provide a temporal context by which present day dynamics may be better understood, we use a Bd qPCR assay to test 1165 amphibian specimens collected between 1900 and 2005. Our historical analyses reveal a pattern of pathogen invasion and eventual spread across the Sierra Nevada over the last century. Although we found a small number of Bd-infections prior to 1970, these showed no sign of spread or increase in infection prevalence over multiple decades. After the late 1970s, when mass die offs were first noted, our data show Bd as much more prevalent and more spatially spread out, suggesting epizootic spread. However, across the ~400km2 area, we found no evidence of a wave-like pattern, but instead discovered multiple, nearly-simultaneous invasions within regions. We found that Bd invaded and spread in the central Sierra Nevada (Yosemite National Park area) about four decades before it invaded and spread in the southern Sierra Nevada (Sequoia and Kings Canyon National Parks area), and suggest that the temporal pattern of pathogen invasion may help explain divergent contemporary host pathogen dynamics. [ABSTRACT FROM AUTHOR]

Rift Valley fever (RVF) is a zoonotic disease, that causes significant morbidity and mortality among ungulate livestock and humans in endemic regions. In East Africa, the causative agent of the disease is Rift Valley fever virus (RVFV) which is primarily transmitted by multiple mosquito species in Aedes and Mansonia genera during both epizootic and enzootic periods in a complex transmission cycle largely driven by environmental and climatic factors. However, recent RVFV activity in Uganda demonstrated the capability of the virus to spread into new regions through livestock movements, and underscored the need to develop effective mitigation strategies to reduce transmission and prevent spread among cattle populations. We simulated RVFV transmission among cows in 22 different locations of the Kabale District in Uganda using real world livestock data in a network-based model. This model considered livestock as a spatially explicit factor in different locations subjected to specific vector and environmental factors, and was configured to investigate and quantitatively evaluate the relative impacts of mosquito control, livestock movement, and diversity in cattle populations on the spread of the RVF epizootic. We concluded that cattle movement should be restricted for periods of high mosquito abundance to control epizootic spreading among locations during an RVF outbreak. Importantly, simulation results also showed that cattle populations with heterogeneous genetic diversity as crossbreeds were less susceptible to infection compared to homogenous cattle populations. [ABSTRACT FROM AUTHOR]