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Horizontal transmission of entomopathogenic fungi plays an important role in the epizootiology, because it is directly associated with the spread of causal agents of insect diseases. In hosts with restricted mobility, the presence of secondary pests in the agroecosystem can help in the formation of secondary disease outbreaks and increase the mortality of the target pest. For this purpose, the dissemination of Beauveria bassiana inoculated using tile-type baits was evaluated in a banana plantation infested with Cosmopolites sordidus (Piracicaba) and one with C. sordidus and Metamasius hemipterus (Botucatu). In Piracicaba, insects contaminated with the pathogen were not found in the control group, and infection rates in the plots that received B. bassiana ranged between 8 and 15%. In Botucatu, the infection rate of insects in the control reached 17%, whereas in the fungal treatment plots, it varied from 28 to 54%. The present results demonstrate the influence of M. hemipterus in the dissemination of B. bassiana in populations of C. sordidus, a target pest of this crop. [ABSTRACT FROM AUTHOR]

Coral diseases have increased in frequency over the past few decades and have important influences on the structure and composition of coral reef communities. However, there is limited information on the etiologies of many coral diseases, and pathways through which coral diseases are acquired and transmitted are still in question. Furthermore, it is difficult to assess the impacts of disease on coral populations because outbreaks often co-occur with temperature-induced bleaching and anthropogenic stressors. We developed spatially explicit population models of coral disease and bleaching dynamics to quantify the impact of six common diseases on Florida Keys corals, including aspergillosis, dark spots, white band, white plague, white patch, and Caribbean yellow band. Models were fit to an 8-year data set of coral abundance, disease prevalence, and bleaching prevalence. Model selection was used to assess alternative pathways for disease transmission, and the influence of environmental stressors, including sea temperature and human population density, on disease prevalence and coral mortality. Classic disease transmission from contagious to susceptible colonies provided the best-fit model only for aspergillosis. For other diseases, external disease forcing, such as through a vector or directly from pathogens in the environment, provided the best fit to observed data. Estimates of disease reproductive ratio values (R 0) were less than one for each disease, indicating coral colonies were below densities required for diseases to become established through contagious spread alone. Incidences of white band and white patch disease were associated with greater susceptibility or slower recovery of bleached colonies, and no disease outbreaks were associated with periods of elevated sea temperatures alone. Projections of best-fit models indicated that, at least during the period of this study, disease and bleaching did not have substantial impacts on populations and impaired rates of population growth appeared to be attributable to other stressors. By applying epidemiological models to field data, our study gives qualitative insights into the dynamics of coral diseases, relative stressor impacts, and directions for future research. [Copyright &y& Elsevier]

The objective of this study was to determine the prevalence of gastrointestinal parasitic nematodes in sheep at necropsy at a slaughterhouse in Tabasco, Mexico. Adult parasites from gastrointestinal tract were recovered and preserved in formaldehyde for their later counting and identification. Adult nematodes were separated by species and the final count was transformed to Log + 1 to decrease the variance. GLM procedure using SAS statistic program was performed for data analysis. Provenance, sex, physiological status, and sampling month were considered as the variation sources. From a total sample of 242 slaughtered animals necropsied for monitoring gastrointestinal parasites, 57.4% including Nematoda, Trematoda or Cestoda classes. The main identified species corresponded to Haemonchus contortus in the abomasum. Cooperia curticei, Trichostongylus colubriformis, Strongyloides papillosus and Bunostomum trigonocephalum were found in the small intestine and Oesophagostomum columbianum, and Trichuris ovis in the large intestine. Fasciola hepatica and Moniezia expansa were the Trematoda and Cestoda parasites found in liver and small intestine, respectively with prevalence lower than 7%. The average of the total count of adult nematodes in the gastrointestinal tract of the infested animals was 2175 ± 445. Among the factors studied, the slaughter month and the provenance of the animals affected the prevalence of parasite infestation in sheep at slaughter. The main adult parasites found were H. contortus, C. curticei and T. colubriformis with average counts higher than 1009, 813 and 335, respectively. [ABSTRACT FROM AUTHOR]

On the Indian sub-continent, nearly 5,000 years ago, the domestication of the riverine buffalo-the incredible Asian dairy animal was initiated. It plays a versatile role in socio-economic upliftment of its owners from the rural agricultural communities in Asian, African, South American and a few European countries. Comparatively, buffaloes are lesser evolved and susceptible to infectious diseases than cattle. However, poor body thermoregulation and wallowing nature predisposed them to snail borne infections, especially tropical fasciolosis-an incessant major constraint on buffalo production and improvement programmes. This review article is an insight into the global prevalence, varied epizootiological factors, offers possible explanation to pathophysiological clinical signs, deleterious effects of the tropical liver fluke, involving hepato-biliary system, haemopoitic system, endocrine glands and their secretions, oxidative stress, altered metabolism and significant fall in food conversion efficiency with unaffected digestibility of nutrients. Besides, the authors have briefly discussed and reviewed the developments and significance of successful immunodiagnostic approaches for detecting and forecasting the disease during early pre-patency and feasibility of developing a cost effective immunoprotection strategies against tropical fasciolosis. [ABSTRACT FROM AUTHOR]

The article discusses a study on the prevalence of tick-borne encephalitis virus (TBEV) infection in Japan. A brief discussion on TBEV as a causative agent for severe human encephalitis and rodents as hosts for TBEV is provided. Large-scale epizootiological surveys of rodents from various areas of the country were performed under the study. Ixodes persulcatus was found to be the principal tick vector of the Far-Eastern subtype of TBEV. The study showed that rodents infected with TBEV are distributed in several regions in Hokkaido and in Shimane Prefecture in Honshu. The factors for the low incidence rate of TBE in Japan are mentioned.

Abstract: Protists are a diverse group of eukaryotes that possess a unicellular level of organization. As unicellular organisms, the differentiation of cells into tissues does not occur, although when cell differentiation does occur, it is limited to sexual reproduction, alternate vegetative morphologies or quiescent life history stages. Protistan parasites may possess simple or complex life histories that are important factors to consider when investigating protistan diseases of decapods. Unfortunately, the life histories of many protistan parasites of decapods are insufficiently described, resulting in the fact that modes of infection and transmission are often unidentified. This is surprising considering the economic importance of many marine decapods and the ability of protistan parasites to produce significant, but generally transient and area limited mortalities. However, the marine disease landscape is changing and will continue to change as climate change and ocean acidification will play important roles in disease occurrence and distribution. As a result, the following discussion attempts to summarize current knowledge on several crab diseases, their protistan etiological agents, the impact of disease on economically important crab populations and draw attention to areas of needed research. The discussion is not complete as only selected diseases are addressed, or perfect as the Microsporidia are included in the discussion (a traditional error continued in this summary) despite the recent, but controversial placement of the taxon with the fungi. [ABSTRACT FROM AUTHOR]

The article traces the infection patterns with ectoparasitic flagellates belonging to the genus Ichthyobodo at an Atlantic salmon Salmo salar (L.) hatchery in western Norway during an 11-month period. Based on the findings, the species Ichthyobodo necator in the redefined and restricted sense existed. The first peak of the infection happened among fry in March and the second among fingerlings and pre-smolt in August and September. It was found on the patterns of infection on the farmed salmon that I. necator species acts as opportunistic parasite of salmon, growing in period when susceptible hosts are active and the environment is apt for parasite proliferation.

The article presents am epizootiological study of foot and mouth disease (FMD) in the Sudan. Reports about FMD indicated that the condition is a major hindrance to animal production in the area. In order to lessen the effect of FMD, herdsmen tend to add powder originating from the ground seed pods of Acacia trees to drinking water of infected animals to treat mouth ulcers. Researchers found that FMD commonly occurs in the cold and dry season.

Abstract: This study reports a molecular survey of Hepatozoon species and of the order Piroplasmida in the Province of Burgos, northern Spain. The diagnostic techniques employed included PCR and the sequencing of the 18S rRNA gene. Eighty-nine blood samples from domestic animals plus 138 blood/coagulated blood samples from wild mammals were examined. Theilerid protozoa were found at relatively high frequencies in bovines (14.6%) and horses (36%). Theileria buffeli, T. sergenti and T. annulata were diagnosed in cows. T. equi was common in horses and T. annae was found in a donkey for the first time. A new piroplasmid was found in the European badger (20%). This appears to be distantly related to both T. annae and a piroplasmid isolated from Lontra canadensis. A moderate prevalence (14%) for T. annae was recorded in red foxes. A species of hepatozoon was found in one bank vole (17%), while 28% of the red foxes examined were found to be infected with H. canis. Twenty-five wild house mice were studied and found not to be carriers of piroplasmids or Hepatozoon species. Wild boars, roe deer, hares, Apodemus sp. and moles were also negative for haematozoan infection. The present study indicates that piroplasmid protozoa are present at a low to moderate frequency in some domestic herbivores in the Burgos area. They also infect certain wild mammalian species, which may act as zoonotic carriers. [Copyright &y& Elsevier]

Abstract: Mycoplasma conjunctivae is considered the major cause of infectious keratoconjunctivitis (IKC) in Alpine ibex (Capra i. ibex) and chamois (Rupicapra r. rupicapra). While it is known that domestic sheep can act as healthy carriers for M. conjunctivae, this question has not been addressed in wild ungulates so far. In this study, bacteriological investigations and field observations were performed to assess whether free-ranging Alpine ibex can be healthy carriers of M. conjunctivae. Among 136 ibex without clinical signs of IKC, M. conjunctivae was identified 26 times (19.1%) by TaqMan PCR. To assess the potential pathogenicity of M. conjunctivae strains isolated from asymptomatic eyes, strains from three healthy ibex and from 15 IKC-ibex and IKC-chamois were analysed genetically by DNA sequence analysis of the variable part of the lppS gene. No significant differences were observed between strains from asymptomatic and clinically affected animals, reflecting the assumption that healthy ibex may act as carriers for M. conjunctivae strains that may be pathogenic for other individuals. Our results further indicate that development of IKC is associated with M. conjunctivae load in the eyes. In addition, a questionnaire survey revealed that IKC is generally less common in ibex than chamois and that infection in wild ungulates is not necessarily linked to the presence of sheep. These data support the hypothesis that apparently healthy ibex may be important in the epizootiology of IKC and indicate that host predilection may play a role in IKC development. [Copyright &y& Elsevier]

Abstract: Very limited information is available on epizootiology of haematozoan infections in French domestic animals. In an attempt to address this issue, prevalence of piroplasmida was studied in carnivores and ruminants, whereas prevalence of Hepatozoon spp. was only investigated in carnivores. In total, 383 animals were included in the survey (namely 116 cats, 108 dogs, 91 sheep and 68 cows). Parasite diagnosis was carried out using molecular methods such as PCR and sequencing of the 18S rRNA gene. In addition, ruminant samples were analyzed with the reverse line blotting technique (RLB). Results of RLB and PCR plus sequencing were in total agreement. In carnivores, haematozoan prevalence was close to 1%. Two cats were infected by H. canis (1.7% prevalence) and one of them was co-infected by Cytauxzoon sp. (0.8%). This represents the first finding of both pathogens in French cats. One dog was infected by H. canis (0.9%) and another by Babesia canis vogeli (0.9%). In ruminants, haematozoan prevalence (piroplasmida) was significantly higher than in carnivores (4.8% in sheep and 8.8% in cow). Theileria ovis was found in 1 sheep, Theileria sp. in 2 sheep, Theileria buffeli in 5 cows and B. major in 1 cow. Evidence presented in this contribution indicates that haematic protozoa are not widely distributed in domestic mammal populations of France. [Copyright &y& Elsevier]

Monitoring of a population of the phytophagous cassava green mite, Mononychellus tanajoa (Bondar), and its natural enemies was undertaken in central Bahia, Brazil, in mid-1996. In spite of the presence of extremely high densities of the predatory phytoseiid mite Neoseiulus idaeus Denmark & Muma, the phytophagous mite population reached such high densities itself that there was total overexploitation of the cassava plants, leading to total leaf loss. Meanwhile, the mite-pathogenic fungus Neozygites tanajoae Delalibera, Humber & Hajek did not affect the M. tanajoa population in its growth phase as there was no inoculum present, even though we predict from a simple regression model that there was the potential for epizootics at that time. Soon after the M. tanajoa population crashed due to defoliation, there could have been an epizootic but there were simply no mite hosts to infect. These data demonstrate the ineffectiveness of one natural enemy (the predator) in terms of prey population regulation and demonstrate the importance of timing in the possible effectiveness of the other (the pathogen). For the pathogen, this probably explains its sporadic effect on host populations as previously reported. We conclude that the fungus is likely to be most useful as an adjunct to biological control with predatory mites other than N. idaeus. [ABSTRACT FROM AUTHOR]

Abstract: A balanced approach to coral disease investigation is critical for understanding the global decline of corals. Such an approach should involve the proper use of biomedical concepts, tools, and terminology to address confusion and promote clarity in the coral disease literature. Investigating disease in corals should follow a logical series of steps including identification of disease, systematic morphologic descriptions of lesions at the gross and cellular levels, measurement of health indices, and experiments to understand disease pathogenesis and the complex interactions between host, pathogen, and the environment. This model for disease investigation is widely accepted in the medical, veterinary and invertebrate pathology disciplines. We present standard biomedical rationale behind the detection, description, and naming of diseases and offer examples of the application of Koch''s postulates to elucidate the etiology of some infectious diseases. Basic epidemiologic concepts are introduced to help investigators think systematically about the cause(s) of complex diseases. A major goal of disease investigation in corals and other organisms is to gather data that will enable the establishment of standardized case definitions to distinguish among diseases. Concepts and facts amassed from empirical studies over the centuries by medical and veterinary pathologists have standardized disease investigation and are invaluable to coral researchers because of the robust comparisons they enable; examples of these are given throughout this paper. Arguments over whether coral diseases are caused by primary versus opportunistic pathogens reflect the lack of data available to prove or refute such hypotheses and emphasize the need for coral disease investigations that focus on: characterizing the normal microbiota and physiology of the healthy host; defining ecological interactions within the microbial community associated with the host; and investigating host immunity, host-agent interactions, pathology, pathogenesis, and factors that promote the pathogenicity of the causative agent(s) of disease. [Copyright &y& Elsevier]

Temporal variability of Black Band Disease (BBD) prevalence, incidence, recurrence, recovery and virulence was estimated in a Diploria strigosa population from an upwelling zone of Venezuela, for 1 year between August 2004 and August 2005. The sampling spanned both upwelling and non-upwelling seasons, and included three samplings, roughly 60 days apart, within each season. The negative effects of BBD epizootiology in the sampling population (El Mercado reef) were positively correlated with sea surface temperature (taken as an upwelling estimator). Disease prevalence, incidence and recurrence decreased signiifcantly during upwelling, and the recovery rate increased. Contrary to expectations, tissue mortality did not decrease significantly during the upwelling season, remaining at 1.2 ± 0.7 mm day-1. BBD prevalence, and the ensuing rates of tissue mortality were higher than values previously reported for other Caribbean reefs, even during upwelling episodes, suggesting that nutrient enrichment of the local waters by upwelling counteracts the expected reductions of the disease prevalence and virulence due to the lower temperature. Colonies which had previously been infected with BBD were up to six times more susceptible to new infections than those which were not infected during the preceding 7 months, suggesting that the infected colonies never healed completely. The high variability between tissue mortality values among coral colonies also suggests that overall host health-status may alter susceptibility to BBD infections. [ABSTRACT FROM AUTHOR]

Internal parasitism in sheep constitutes one of the most important limitations in the successful development of sheep production. The first step for achieving parasite control is related to the study of the epizootiology of the etiological agents, and among them the knowledge on the species that circulate in the herds. For performing this type of study, three sheep production units of Matanzas province were selected, which animals and management system are representative of the rest of the province. The animals were found to be infested in a sympatric way by two species of the Haemonchus genus (H. placei and H. contortus) which exceed 90% of the fecal count during the whole year. Also Trichostrongylus columbriformis and Oesophagostomum columbianum were found in lower amount. The highest infestation rates were present in the rainy season in the three units, which shows evident seasonality. The offspring were infested according to the management system implemented and the lambed ewes were the most susceptible ones in a group of ewes incorporated to reproduction. These elements are essential for the implementation of parasite control plans. [ABSTRACT FROM AUTHOR]

Abstract: The epizootiology of Amblyospora camposi was studied in a natural population of Culex renatoi, a bromeliad-inhabiting mosquito, and its intermediate host, Paracyclops fimbriatus fimbriatus, over a 2-year period. Twenty Eryngium cabrerae plants were sampled monthly from January 2003 to January 2005 and the prevalence of A. camposi in P.f. fimbriatus and Cx. renatoi populations was determined. The monthly prevalence rates of meiospore infections in Cx. renatoi larvae never exceeded 5.5% and was detected in 50% of the monthly samples. Meiospores were available in plants over the course of the study at a mean concentration of 2×104 meiospores/ml. Within each plant the parasite was maintained by horizontal transmission. P.f. fimbriatus with vegetative stages and mature spores were found regularly in bromeliads suggesting efficient meiospore infectivity to field copepod populations. The mean concentration of spores from copepods found in plants was 8×102 spores/ml. Infections in copepods were detected in 54% of the monthly samples with a prevalence rate ranging from 0.55 to 17.4% and an overall average of 5.1%. Vegetative stages in fourth instar mosquito larvae (probably derived from the horizontal pathway via spores formed in copepods) were detected in 12.5% of the monthly samples with an overall prevalence rate of 1.1%. Infections in female and male adults were detected in 20.8% of the monthly samples with an overall average of 4.1% and 6.8%, respectively. [Copyright &y& Elsevier]

Abstract: A comprehensive model was developed to simulate virus epizootics in a stage structured insect population and analyse scenarios for the biological control of cotton bollworm (CBW), Helicoverpa armigera, in cotton, using wild-type or genetically modified baculoviruses. In simulations on dosage and timing of a wild-type strain and a genetic recombinant of H. armigera single nucleocapsid nucleopolyhedrovirus (HaSNPV), the economic injury level was not exceeded against a prevailing population of 12larvaem−2 when virus was applied 10 times during the season. An early start of virus applications in each of three successive CBW generations, with sprays starting soon after egg deposition, and a short, 3-day spray interval were necessary for effective control. A recombinant virus with a lower mean time to kill provided better short-term protection than the wild-type virus. However, the number of pupae entering diapause at the end of the growing season was higher due to reduced horizontal transmission. These pupae are founders of H. armigera populations in the next season indicating that the use of fast acting genetically modified viruses in one year may enhance CBW populations in the following year. Hence, simulations indicate that there is a trade-off between short-term and long-term objectives in the biocontrol with insect viruses: fast acting recombinant viruses provide better control in the short-term at the expense of potentially inferior population suppression in the long-term. The model may be used as a decision tool for evaluating virus application strategies in interaction with virus genotype and climatic conditions that affect the phenology and population dynamics of CBW. [Copyright &y& Elsevier]

Entomophaga maimaiga Humber, Shimazu, et Soper (Zygomycotina: Entomophthoraceae) is a naturally occurring obligate fungal pathogen specific to gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae) larvae. This fungus is considered the most important natural enemy of this pest insect in North America and Asia. A critically important step for the development of E. maimaiga epizootics is the transmission of propagules to healthy larvae, a process known to require high humidity. Some pathogens are known to manipulate the time of day that hosts die so that propagules are produced to maximize chances of survival and thus enhance transmission. The objective of this study was to assess whether E. maimaiga manipulates L. dispar to die at a certain time of day. Laboratory bioassays were conducted at 15 and 20 °C to record the 24-h activity pattern of death and sporulation exhibited under an L14:D10 photoperiod and 100% r.h. by four isolates of E. maimaiga in its host L. dispar. Events were recorded every 4 h. Our results clearly demonstrate that E. maimaiga-infected L. dispar larvae die mainly in the afternoon and that the fungus sporulates during the night. The rhythm was independent of the fungal isolate tested and type of spores produced after larval death. By raising the temperature from 15 to 20 °C, the peak death time narrowed and sporulation was initiated earlier at night. [ABSTRACT FROM AUTHOR]

Abstract: Sheep are the moving banks of shepherds and their economic contribution in terms of meat, wool and skin/hide is immense. Various infectious diseases jeopardize the optimum productivity; among which sheep pox is more important as the disease restricts the export of sheep and their products besides other economic losses. Although, clinical signs are indicative of the disease but a laboratory confirmation is necessary for unequivocal diagnosis and studying epidemiology. The causative agent, sheep pox virus (SPV), is antigenically and genetically closely related to goat pox virus (GPV) and lumpy skin disease virus (LSDV), the other members of the genus capripox virus. In some countries, SPV and GPV are cross infective to small ruminants posing problem in diagnosis and epidemiology. However, recent studies have showed that the viruses are phylogenetically distinct and can be differentiated by molecular tools. Prophylaxis using attenuated vaccines is the choice of control measure as the immunity is long lasting. Detailed information on isolation, identification, pathology, epidemiology, diagnosis and prophylaxis would not only help in updating the knowledge of scientific fraternity but will be useful to the policy makers in order to formulate appropriate measures for control and eradication of the disease. This synthesis is to present an up-to-date review of the disease and its control to provide the reader with an overview of the problem. [Copyright &y& Elsevier]

Avian cholera is a significant infectious disease affecting waterfowl across North America and occurs worldwide among various avian species. Despite the importance of this disease, little is known about the factors that cause avian cholera outbreaks and what management strategies might be used to reduce disease mortality. Previous studies indicated that wetland water conditions may affect survival and transmission of Pasteurella multocida, the agent that causes avian cholera. These studies hypothesized that water conditions affect the likelihood that avian cholera outbreaks will occur in specific wetlands. To test these predictions, we collected data from avian cholera outbreak and non-outbreak (control) wetlands throughout North America (winter-spring 1995-1996 to 1998-1999) to evaluate whether water conditions were associated with outbreaks. Conditional logistic regression analysis on paired outbreak and non-outbreak wetlands indicated no significant association between water conditions and the risk of avian cholera outbreaks. For wetlands where avian cholera outbreaks occurred, linear regression showed that increased eutrophic nutrient concentrations (Potassium [K], nitrate [NO3], phosphorus [P], and phosphate [PO3]) were positively related to the abundance of P. multocida recovered from water and sediment samples. Wetland protein concentration and an El Niño event were also associated with P. multocida abundance. Our results indicate that wetland water conditions are not strongly associated with the risk of avian cholera outbreaks; however, some variables may play a role in the abundance of P. multocida bacteria and might be important in reducing the severity of avian cholera outbreaks. [ABSTRACT FROM AUTHOR]

The microsporidium Thelohania solenopsae Knell, Allen, and Hazard was released into colonies of red imported fire ants, Solenopsis invicta Buren, at four field sites in Louisiana. Social form of the ant affected the establishment of the microsporidium; long-term epizootics developed at two sites with predominantly polygyne populations, whereas the pathogen produced a low disease prevalence before it disappeared or did not infect ants at all at two monogyne sites. This study is the first report of artificial infection of monogyne S. invicta field colonies. When the microsporidium became established in mixed monogyne/polygyne ant populations, prevalence rates peaked at >75% in both social forms. In mixed ant populations, the social form suffering higher prevalence of the disease decreased proportionally to the other form, possibly indicating a competitive disadvantage. Host population density or site characteristics may have influenced spread of the disease; the rate of spread was 0.9 m/mo at one epizootic site and reached 9.4 m/mo at the other. There was little seasonal variation in prevalence, which averaged 47% in February, 51% in April/May, and 57% in October/November at the two epizootic sites. The strongest evidence of microsporidian impact on S. invicta populations was a negative correlation between colony numbers versus percentage infection and a sporadic decrease in the number of foragers. There was some evidence of a decrease in the size and number of colonies at one epizootic site and a decrease in brood at the other. This sporadic weakening of the S. invicta populations did not lead to significant immigration of other ant species. [ABSTRACT FROM AUTHOR]

Abstract: To determine the transmission dynamics of furunculosis, Chinook salmon, Oncorhynchus tshawytscha held at various densities were challenged with a single infectious fish. Data from the in vivo experiments were compared to predicted values from a susceptible–infected–removed (SIR) model. Seven different densities were tested including 9.13, 4.56, 0.72, 0.36, 0.19, 0.06 and 0.03fish/L and each produced different transmission coefficients (β) of 0.01, 0.019, 0.0051, 0.0076, 0.0001, 0.0005 and 0.00, respectively. Furunculosis related mortality rates decreased as density of the host decreased. Mortality rates at the highest fish densities where disease specific mortality (DSM) was observed were 0.42, 0.44, 0.18 and 0.02 infected animals per day. The natural mortality rate also followed a similar pattern with 0.005, 0.005, 0.001, 0.005, 0.0001, 0.000 and 0.000 surviving animals per day. The results indicated that the transmission coefficient and the DSM of furunculosis was dependent on host density. It is possible that fish behavioral changes at the lower densities caused the reproductive rate of disease to be persistent even at very low densities. In summary, the simple SIR model suggested that low mortality does not always mean low prevalence of furunculosis in a given population. This is the first study evaluating host density as a risk factor for fish diseases using experimental furunculosis data. [Copyright &y& Elsevier]

Abstract: Epizootiological patterns of rabies are described, using antigenic and genetic analysis of samples obtained from infected domestic and wild mammals in 20 Mexican states during 1976–2002. Two independent origins are suggested for rabies in Mexican carnivores. One group shares ancestry with canine rabies, while the other group appears to share a common origin with bat rabies in North America. More than 12 sublineages were found in rabid dog populations, suggesting at least six major spatio-temporal foci. Coyote rabies was found as independent enzootic foci that probably emerged via spillover from dog rabies, translocated from major foci in the southcentral and western regions of Mexico. One focus of gray fox rabies was widely distributed in northwestern Mexico, overlapping with a focus in the same species in the southwestern United States. A skunk rabies focus distributed in the northcentral Mexican states appears to share a common origin with bat rabies foci in North America, and is a close relative of southcentral skunk and raccoon rabies in the United States. Two other skunk foci share a common ancestor with canine rabies and were distributed in northwest Mexico and Yucatan. [Copyright &y& Elsevier]

1. Wood bison (Bison bison athabascaeL.) abundance in Wood Buffalo National Park, Canada, declined from an excess of 10 000 bison in the late 1960s to a low of 2200 bison in the late 1990s.2. Bovine tuberculosis (Mycobacterium bovis) and brucellosis (Brucella abortus), were introduced to Wood Buffalo National Park in the late 1920s. As each of these pathogens has the potential to reduce survival and reproduction in bison, they are suspected to have played a role in the decline in bison abundance.3. We live-captured bison in the winters of 1997–2000, tested for tuberculosis, brucellosis and pregnancy and released animals with radio transmitters to evaluate survival.4. We found that bison that were positive for both diseases were less likely to be pregnant or to survive the winter than bison positive for one or neither disease. Further, in one population, bison that were tuberculosis-positive had a substantially lower pregnancy probability.5. Demonstrating a negative effect of diseases on survival and reproduction is a necessary, but not sufficient, test of the role of diseases in bison population decline.Journal of Animal Ecology(2005)74, 543 –551doi: 10.1111/j.1365-2656.2005.00953.x [ABSTRACT FROM AUTHOR]

During the period of 2001–2003, a total of 591 Actinobacillus pleuropneumoniae field isolates from the Czech Republic were serotyped with a high occurrence of cross-reactions. The cross-reactions were observed in 416 isolates. Most frequently, in 401 isolates (67.9%), cross-reactions with antisera specific for serotypes 9, 11, and/or 1 were observed. Two additional molecular methods, ribotyping and restriction analysis of PCR amplified apxIVA gene (PCR-REA), were therefore used for detailed characterisation of A. pleuropneumoniae. In this subsequent analysis, reference strains representing serotypes 1–12 and 25 field isolates showing the most frequent serotype cross-reactions were examined. PCR-REA enabled all reference strains to be distinguished except for the strains of serotypes 9 and 11. Ribotyping distinguished all reference strains except two pairs of serotypes: 3 versus 6, and 9 versus 11, respectively. Field isolates with serotype cross-reactivity 9, 11, and/or 1 could not be differentiated by either of these methods. [Copyright &y& Elsevier]

The entomopathogenic fungus Entomophaga maimaiga has been reported infecting gypsy moth, Lymantria dispar, larvae in the United States since 1989. Laboratory bioassays demonstrated that larvae of numerous species of native tussock moths (Lymantriidae) are susceptible to E. maimaiga. From 1997 to 2001, larvae of gypsy moth and native lymantriids were collected in long-term plots in national forests in Virginia and West Virginia to evaluate infection levels. Throughout this time, gypsy moth populations were low although increasing the last 2 years, whereas native lymantriids remained uncommon throughout. Among gypsy moth larvae, infection by E. maimaiga first occurred during 2000 and increased in both areas during 2001 as gypsy moth populations increased. Seven species of native lymantriids were collected but only three were infected: Dasychira obliquata, Dasychira vagans, and Orgyia leucostigma. Infection of these native lymantriid species did not occur in 1997–1999 and was always <50% per species during 2000 and 2001. Ecological studies were conducted to evaluate when and where native lymantriids could be exposed to E. maimaiga inoculum. Field bioassays demonstrated that E. maimaiga resting spores were active in soil at bases of trees beginning in April, especially when soil was moist, but few gypsy moth larvae were infected by airborne conidia from resting spores early in the season. In 2000 and 2001, cadavers that produced conidia were collected throughout the season and conidia were the predominant spore form produced for at least the first month of the field season. Resting spore densities in soil were high during 1997 but titers declined through the study, with the exception of an increase following E. maimaiga infections in increasing gypsy moth populations in West Virginia during 2000. [Copyright &y& Elsevier]

This study was carried out in Ankara province, Turkey, between September 1996 and August 1998. During the study 1208 sheep, 1001 goats and 1059 cattle were examined for Haemaphysalis ticks. These examinations revealed that 380 (37.96%) goats, 346 (28.64%) sheep and 203 (19.16%) cattle had Haemaphysalis infestation. In total, 5254 Haemaphysalis ticks were collected from these animals. They were identified as H. parva, H. sulcata, H. punctata and Haemaphysalis nymphs. Of the 5254 Haemaphysalis ticks 89.70% were H. parva adults, 0.28% H. parva nymphs, 6.64% H. sulcata adults, 2.05% H. punctata adults and 0.13% H. punctata nymphs, while 0.89% were unidentified Haemaphysalis nymphs and 0.28% unidentified Haemaphysalis adults. The infestation rate of adult H. parva, H. sulcata and H. punctata reached the highest level on sheep, goats and cattle twice a year. These periods were determined as October and March for H. parva and H. punctata, and November and March for H. sulcata. Nymphs of H. parva were found on sheep and goats in April and August. Nymphs of H. punctata occurred on sheep and goats only in August. Nymphs of H. sulcata were not found on the animals. We dissected 1702 Haemaphysalis sp. and their salivary glands were stained with Methyl green/Pyronin. The salivary glands were examined under microscope, but no theilerial sporoblasts were found. [ABSTRACT FROM AUTHOR]

Abstract In 2002 phocine distemper virus (PDV) reappeared in the European harbour seal (Phoca vitulina ) population. This outbreak seems to have followed a similar pattern to the 1988 one which killed almost 60% of individuals in most localities. Harding et al. (2002) suggested that there is a relatively high (18%) risk that recurrent outbreaks of PDV could reduce the European harbour seal population by 90%. We show that incorporating the effects of observation error during population surveys and of the long-term immunity of survivors of morbillivirus outbreaks indicate a much lower level of risk (<1%). This suggests that, while the immediate effects of the disease are dramatic, it is unlikely that recurrent epidemics will pose serious conservation problems for this species under current conditions. [ABSTRACT FROM AUTHOR]

Molecular epizootiology of piroplasmids (Babesia spp., Theileria spp.) and Hepatozoon canis was studied in mammals from southern Europe (mainly from Spain, but also from Portugal and France). Partial amplification and sequencing of the 18s rRNA gene was used for molecular diagnosis. In some particular cases (B. ovis and B. bovis) the complete 18s rRNA gene was sequenced.Blood samples were taken from domestic animals showing clinical symptoms: 10 dogs, 10 horses, 10 cows, 9 sheep and 1 goat. In addition, DNA samples were isolated from blood of 12 healthy dogs and from spleen of 10 wild red foxes (Vulpes vulpes). The results of the survey were the following:

Gastrointestinal (GI) parasitism represents a severe health problem in small ruminant production systems world-wide. The objective of the present study was three-fold: (i) to assess the prevalence of GI parasitism in dairy breeds of sheep and goats in selected areas of Greece; (ii) to determine the species of existing gastrointestinal parasites; and (iii) to investigate the effect of climatic factors on the seasonal variation of parasite population dynamics in dairy sheep and goats reared in two different geographical areas of Greece. The study was conducted in four flocks of either sheep or goats that were equally allocated in northern and central Greece. In each flock, faecal samples were randomly collected from 30 animals at monthly intervals and were used for nematode egg counts and coprocultures. Two animals from each flock were slaughtered monthly and their GI tract were examined for adult worm population and identification. The study revealed that the parasitic burdens in sheep were significantly (P<0.05) higher than those in goats. Faecal egg counts for both sheep and goats were significantly (P<0.01) affected by the month of the year and there was also a significant interaction between month of the year and area of study (P<0.01). Teladorsagia, Haemonchus, Trichostrongylus and Chabertia were the most prevalent nematode genera in both sheep and goats. Such information could be useful for the development of strategic treatments when sheep and goats are reared under systems similar to those described in this study. [Copyright &y& Elsevier]

Abstract We present the first epidemiological data on the 2002 outbreak of phocine distemper virus (PDV) in European harbour seals (Phoca vitulina ). The epizootic curve to date supports a mortality rate and probability of infection identical to that of the 1988 outbreak, which killed 58% of the population. Thus immunity is playing no significant role in the dynamics of the current outbreak. Because the timing of the outbreak is important in determining local mortality rates, we predict higher mortality rates on the European continent than in Great Britain or Ireland. A stochastic model is used to quantify how recurrent epizootics affect the long-term growth, fluctuation, and persistence of the population. Recurrent PDV epizootics with the observed frequency and severity would reduce the long-term stochastic growth rate of the harbour seal population by half, and significantly increase the risk of quasi-extinction. [ABSTRACT FROM AUTHOR]

The entomopathogenic fungus Beauveria bassiana infects a wide range of insects and survives as a soil saprophyte and a plant endophyte. The objective of our study was to determine the role of rainfall in dispersing B. bassiana (Balsamo) Vuillemin to the surface of corn (Zea mays) from soil with different levels of crop residue. Laboratory studies which simulated field tillage systems, had levels of crop residue which covered 0.53 (control), 34, 59 and 84% of the soil surface. Simulated rainfall in a raindrop tower at an intensity of 73 mm/h caused a significant increase in the mean number of B. bassiana colony forming units (CFU) isolated from the surface of corn plants. Plants receiving rain had a mean (±S.E.M.) of 8.8±2.8 CFU per plant; controls had a mean of 0.03±0.01 CFU per plant. The mg of soil collected from the surface of plants also was significantly influenced by rainfall. Plants receiving rain had a mean of 15.7±1.7 mg of soil per plant while controls had a mean of 3.4±0.4 mg of soil per plant. Linear regression revealed highly significant negative relationships between the mean mg of soil and the mean number of CFU per plant, over the four levels of crop residue. The amount of soil and number of CFU per plant decreased significantly with increasing levels of crop residue. In field studies with conservation- and no-till systems, results were similar to those recorded in the raindrop tower. The mean number of CFU and mg of soil per plant were both higher in conservation-till plots than in no-till plots, where surface residue averaged 45 and 95%, respectively. Rainfall plays an active role in the dispersal of B. bassiana from the soil environment to the surface of whorl-stage corn. Increased levels of crop residue reduce the amount of soil and fungal transfer to the surface of young corn. [Copyright &y& Elsevier]

[Display omitted] • Sprays of B. bassiana (BotaniGard®) were applied against coffee berry borer (CBB). • Each spray directly/indirectly infected ca. 25% of CBB embedded in green berries. • Fresh spray deposits on coffee foliage/berries infected 30–40% of host-seeking CBB. • Bb sprays were most effective as components of IPM programs including sanitation. • Wild strains of B. bassiana exhibited greater epizootic potential than strain GHA. Beauveria bassiana (Bb) strain GHA is a major component of an integrated pest management (IPM) program for coffee berry borer (CBB) in Hawai'i. Efforts to measure effectiveness of GHA spray applications have been complicated by activity of naturally-occurring Bb. Studies were thus designed to provide more accurate efficacy assessments by accounting for this natural activity. BotaniGard® ES + Widespread Max® (WSM) surfactant (2.3 + 0.6 L/ha) were applied in commercial coffee fields. Live CBB were collected at various times post spray and monitored for infection. GHA killed 12–15% of founder females collected 1–3 days post spray and 9–10% collected after 10 days (infections attributed to secondary transmission); each spray thus resulted in 20–25% mortality. Results were comparable at high- and low-elevation sites in summer-wet climate zones. Sprays applied May–August produced similar rates of infection. Peak counts of CBB recently killed by GHA were recorded 4–5 and 12–16 days post spray (reflecting infection by sprayed conidia vs. conidia produced in the field). Cumulative mortality assessed by counts of GHA-killed CBB plateaued at 50–60%, even after numerous sprays, and was attributed to factors unrelated to efficacy. Half rates of BotaniGard/WSM were nearly as effective as full rates. Sprays on intermediate-elevation fields in a summer-dry climate zone were less effective, but efficacy varied with crop-architecture. GHA spray residues infected 30–40% of host-seeking CBB trapped one day post spray, but activity of the spray residues decreased substantially after two days, producing <11% infection. Recommendations for use of Bb for CBB IPM are presented. [ABSTRACT FROM AUTHOR]