A SEROLOGIC ASSESSMENT OF EXPOSURE TO VIRAL PATHOGENS AND LEPTOSPIRA IN AN URBAN RACCOON (PROCYON LOTOR) POPULATION INHABITING A LARGE ZOOLOGICAL PARK

Canine distemper virus phylogenetic structure and ecological correlates of infection in mesocarnivores across anthropogenic land use gradients

Anthropogenic land use impacts infectious diseases at the wildlife-domestic-human interface by changing host spatial distribution, behavior, density, and population dynamics. Canine distemper virus (CDV) is a significant cause of morbidity and mortality in many wild and domestic animals. Given the propensity of CDV to infect synanthropic mesocarnivores, it is important to investigate host and environmental factors affecting mesocarnivore CDV infection. Here, we investigated patterns of CDV infection and developed a statistical model to identify environmental variables related to CDV risk in commonly affected mesocarnivores. We sampled carcasses (N = 270) submitted to the Southeastern Cooperative Wildlife Disease Study from January 2019 to December 2022 and sequenced the CDV H-gene of 32 CDV-positive animals. Overall, 158 out of 270 mesocarnivores (58.5%) and four species (raccoon, red fox, gray fox, and striped skunk) were diagnosed with CDV across 13 states. Ripley's K analysis showed positive cases were more spatially clustered at larger distances than expected due to chance. A generalized linear model for CDV-infected animals showed surface imperviousness, precipitation, and subadult/adult age classes were significant positive explanatory variables, but elevation had a significant negative association with CDV infection likelihood. H-gene sequence diversity among wild mesocarnivores in the southeastern United States was geographically separated into groups east and west of the Mississippi River, with only two eastern samples clustering with western groups. By identifying areas of intense human development at the highest risk for CDV, it may be possible to focus surveillance efforts in these areas, allowing for earlier outbreak identification, potentially preventing cross-species CDV transmission.

IMPORTANCE

Anthropogenic land use change can impact infectious disease spread by altering animal distribution and behavior. Canine distemper virus (CDV) is a significant cause of morbidity and mortality in wild and domestic carnivores. This study investigated how land use influences CDV infection in wild carnivores by examining tissues collected between 2019 and 2022 from wild carnivores found dead in the southeastern United States. CDV strains were geographically distinct, with differences between populations east and west of the Mississippi river. Statistical models showed areas with increased human development and higher precipitation had higher CDV risk; however, there was lower risk associated with higher elevations and younger animals. The importance of this study is that it identifies geographic structure of CDV in the southern United States, and identifies land-use associations with potential high-risk areas for CDV transmission-information that is useful for wildlife disease surveillance and control strategies.

Epidemiological Survey of Canine Distemper Virus Infection: Exploring the Link Between Virus Spread and Invasive Raccoon (Procyon lotor) Population Growth in Hokkaido, Japan

Invasive raccoons (Procyon lotor) naturalized in Hokkaido, Japan, potentially spreading infectious diseases. Canine distemper virus infection is a serious epizootic disease, for which the raccoon is one of the hosts. We investigated the virus's prevalence in Hokkaido's wild raccoons, using 611 serum samples collected from captured raccoons in 2007-2012, 2021, and 2022. Higher seropositivity rates were confirmed in 2007 (32.7%), 2021 (46.4%), and 2022 (46.8%) than in 2008-2012 (0.00%-6.06%), suggesting the occurrence of an epidemic in 2007, 2021, and 2022 and its disappearance in 2008-2012. However, the infection status has recently changed, with high seropositivity rates consecutively confirmed in 2021 and 2022. Logistic regression analysis was performed to investigate the relationships among the catch per unit effort (an index of animal population density), host and environmental factors, and antibody status. The catch per unit effort correlated with seropositivity in 2007. As for environmental factors, the forest area ratio had a weak influence on seroprevalence in 2007; however, the residential area ratio had a clear influence on seroprevalence in 2021 and 2022. The epidemic occurred in forested areas in 2007; nonetheless, recent raccoon population growth and habitat expansion may have caused widespread infections even around residential areas in 2021 and 2022. Continuous monitoring of the infection and reinforcement of raccoon control programs are necessary to avoid serious damage through disease transmission to sympatric native raccoon dog (Nyctereutes procyonoides) and fox (Vulpes vulpes) populations, as well as health consequences for domestic dogs (Canis familiaris).

Enteritis in raccoons (Procyon lotor) caused by an infection with zoonotic Salmonella and carnivore parvovirus

BACKGROUND

The raccoon (Procyon lotor) is a potential carrier of a large number of zoonotic pathogens, and its population is increasing in urban areas in Europe. In the present study, we investigated two cases of fatal enteritis in raccoons in Germany. Parvoviruses are a common cause of enteritis in raccoons, however in these cases an additional infection with zoonotic Salmonella was found, which has not yet been described in other countries than the United States.

CASE PRESENTATION

Two female raccoons, aged 14 and 18 weeks, were submitted for necropsy. Histopathology of the small intestine revealed crypt degeneration and necrosis, atrophy and fusion of villi, as well as numerous bacteria partially covered by fibrinous pseudomembranes. By microbiological culture of small intestinal samples Salmonella enterica subsp. enterica Serovar Kottbus and Salmonella enterica subsp. enterica Serovar Ferruch were isolated, respectively. In addition, carnivore protoparvovirus type 1 was identified in the small intestine of both animals.

CONCLUSIONS

The infection of raccoons with carnivore protoparvovirus type 1 results in immunosuppression, which facilitates the spread of other pathogens. Both isolated Salmonella serovars represent a significant zoonotic threat for humans being in contact with the raccoon. Furthermore, in raccoons with sudden death a double infection with carnivore protoparvovirus type 1 and Salmonella should be considered as an important differential diagnosis.

Canine Adenoviruses in Wildlife: Role in At-Risk Species Conservation and Interface with Domestic Animals

Canine adenovirus type 1 (CAdV-1) and type 2 (CAdV-2) are well known pathogens of domestic dogs but are little investigated in wild animals. The few available studies about CAdV-1 in wild animals show that it circulates in various species and that transmission of the virus in the interface between wildlife and domestic animals is a frequent event. Furthermore, wild animals are usually subject to asymptomatic infections, but cases of serious and fatal diseases have been documented, with possible effects on the conservation of the species. In contrast, CAdV-2 infection was reported only recently and sporadically in some wild animals, with few data regarding its pathogenic role in these species. However, the real prevalence of these viruses in wildlife is still uncertain due to the use of serological tests that are largely unable to distinguish antibodies against CAdV-1 and CAdV-2. This review, reporting all the data currently available on CAdV-1 and CAdV-2 infection in wild animals, highlights the importance of these pathogens for wildlife conservation and their role in the potential transmission of the infection to domestic dogs.

Molecular Detection of Viral and Bacterial Pathogens in Red Foxes (Vulpes vulpes) from Italy

Animals, including wildlife, are part of One-Health concept since many infectious diseases can affect both humans and animals. In this study, 126 red foxes (Vulpes vulpes) from Northern Italy in 2022-2023 were tested by molecular assays for Protoparvovirus carnivoran 1 (PPVC-1), Canine adenovirus type 1 and 2 (CAdV-1 and CAdV-2), Circovirus canine (CanineCV), Canine distemper virus (CDV), and Leptospira spp. A total of 39 of 126 (30.9%) red foxes were infected with at least one pathogen and five of these were coinfected: 20/126 (15.9%) red foxes tested positive for PPVC-1, 3/126 (2.4%) for CAdV, 20/126 (15.9%) for CanineCV, and 2/126 (1.6%) for Leptospira spp. DNA. No foxes tested positive for CDV RNA. The pathogens identified were genetically analysed. New findings were reported such as a fox with multiple feline panleukopenia virus (FPV) and canine parvovirus type 2b (CPV-2b) infection associated with quasispecies dynamics, typical genetic characteristics of the identified CanineCV, and the first detection in red foxes of Leptospira ST198 related to L. interrogans serogroup Australis. Further studies are necessary to investigate the transmission between domestic animals and wildlife and to understand the role of red foxes in the maintenance of these pathogens not only in the wild but also in urban and peri-urban environments.

THREE CASES OF CLINICAL LEPTOSPIROSIS IN PATAGONIAN MARAS (DOLICHOTIS PATAGONUM)

Rodents are typically viewed as asymptomatic reservoirs for leptospirosis infection, as clinical disease in rodents is rarely described. This report includes three separate cases of leptospirosis in Patagonian maras (Dolichotis patagonum) over a 3-yr period in multiple locations within a single zoo. All three cases presented with varying clinical signs including lethargy, conjunctival hyperemia, hyperbilirubinemia, and presumed renal azotemia. Infection with Leptospira spp. was diagnosed antemortem by PCR on whole blood (n = 1, Case 1) or urine (n = 2, Cases 2 and 3). Leptospira antibody titers measured by serum microagglutination testing (n = 3) were elevated or increased in all three animals over a 1-3-wk period for Leptospira serovars Bratislava and Hardjo (Case 1) and Grippotyphosa (Case 2 and 3). Two of the three animals responded to treatment with penicillin and doxycycline and supportive care, whereas one animal did not respond to treatment. Postmortem findings in this individual included conjunctivitis, chemosis, dehydration, icterus, tricavitary serosanguinous effusions, necrotizing hepatitis, diffuse pulmonary congestion, and edema. Immunohistochemical examination identified scattered Leptospira organisms within hepatocytes and renal tubular epithelial cells. A wild raccoon (Procyon lotor) at the institution tested positive by PCR on kidney tissue for the same Leptospira spp. serovar and was the suspected source of infection. This case series highlights the clinical importance of leptospirosis as a differential for Patagonian maras presenting with lethargy, ocular signs, acute hepatic disease, and azotemia.

Pathogenic Leptospira are widespread in the urban wildlife of southern California

Leptospirosis, the most widespread zoonotic disease in the world, is broadly understudied in multi-host wildlife systems. Knowledge gaps regarding Leptospira circulation in wildlife, particularly in densely populated areas, contribute to frequent misdiagnoses in humans and domestic animals. We assessed Leptospira prevalence levels and risk factors in five target wildlife species across the greater Los Angeles region: striped skunks (Mephitis mephitis), raccoons (Procyon lotor), coyotes (Canis latrans), Virginia opossums (Didelphis virginiana), and fox squirrels (Sciurus niger). We sampled more than 960 individual animals, including over 700 from target species in the greater Los Angeles region, and an additional 266 sampled opportunistically from other California regions and species. In the five target species seroprevalences ranged from 5 to 60%, and infection prevalences ranged from 0.8 to 15.2% in all except fox squirrels (0%). Leptospira phylogenomics and patterns of serologic reactivity suggest that mainland terrestrial wildlife, particularly mesocarnivores, could be the source of repeated observed introductions of Leptospira into local marine and island ecosystems. Overall, we found evidence of widespread Leptospira exposure in wildlife across Los Angeles and surrounding regions. This indicates exposure risk for humans and domestic animals and highlights that this pathogen can circulate endemically in many wildlife species even in densely populated urban areas.

Molecular characterization and genetic diversity of parvoviruses prevalent in cats in Central and Eastern China from 2018 to 2022

Cats are a potential source of genetic diversity for parvoviruses. Herein, 134 samples were collected from cats with clinical gastroenteritis and analyzed for the presence of viral DNA via polymerase chain reaction, which revealed 48 positive samples. Identity analysis of VP2 nucleotide sequences indicated that these 48 strains, belonging to feline panleukopenia virus (FPV) and canine parvovirus type-2 (CPV-2; including new CPV-2a and CPV-2c genotypes), shared 94.59-99.94% nucleotide identity with the reference strains. The FPV strain F8 (isolated from Vietnam) appeared to be a recombinant of strains HB2003 and JS1901, whereas the Chinese CPV-2b strain BM-(11) isolated in 2011 was believed to be a recombinant of strains AH2008 and JS1901. In phylogenetic tree analysis based on VP2 nucleotide sequences, all obtained FPV strains and most reference FPV strains were clustered together, except strain BJ-22, which originated from monkeys. Further, two new CPV-2a strains (AH2005 and AH2008) were close to the newly reported Chinese CPV-2a strains but were distant from the other CPV-2a strains, namely CPV-339 (from the United States) and K022 (from South Korea). Additionally, the FPV and CPV-2 strains had high mutation rates in the antigenic regions of the VP2 protein. According to model prediction of the CPV-VP2 protein, these mutations may cause changes in the tertiary structure of VP2. The findings of this study can be used to improve the pre-evaluation of vaccination efficacy against diseases caused by FPV and CPV-2 in domestic cats and understand their genotypic transmission and mutation trends.

CANINE DISTEMPER VIRUS ECOLOGY: INSIGHTS FROM A LONGITUDINAL SEROLOGIC STUDY IN WILD RACCOONS (PROCYON LOTOR)

Increasing reports of canine distemper virus (CDV) in a variety of hosts, and changing CDV dynamics, have led to renewed interest in the ecology of CDV infections in wildlife. Longitudinal serologic studies provide insights into intrapopulation and intraindividual pathogen dynamics, but few studies in wildlife have been conducted. We used data from 235 raccoons (Procyon lotor) captured on more than one occasion between May 2011 and November 2013 to investigate CDV dynamics in Ontario, Canada. Using mixed multivariable logistic regression, we found that juvenile raccoons were more likely to be seronegative from August to November than from May to July. Using paired titers from CDV-exposed individual raccoons, we determined that the winter breeding season, when there is high intraspecific contact and an increase in susceptible juveniles, may be a period of high risk for CDV exposure. Interestingly, CDV seropositive adult raccoons had nondetectable titers ranging from 1 mo to 1 yr later. Based on our preliminary investigation using two different statistical approaches, CDV exposure was associated with a decrease in parvovirus titer. This result raises important questions about whether virus-induced immune amnesia occurs after CDV exposure, which has been described for measles virus, a closely related pathogen. Overall, our results provide significant insights into CDV dynamics. Further research is needed to investigate whether CDV-induced immune amnesia occurs in raccoons and to determine the potential impacts of a reduced population immunity that may occur secondary to CDV exposure, particularly as it relates to rabies control efforts.

Bacterial and Viral Pathogens with One Health Relevance in Invasive Raccoons (Procyon lotor, Linné 1758) in Southwest Germany

In Europe, raccoons are invasive neozoons with their largest population in Germany. Globally, this mesocarnivore acts as a wildlife reservoir for many (non-)zoonotic (re-)emerging pathogens, but very little epidemiological data is available for southwest Germany. This exploratory study aimed to screen free-ranging raccoons in Baden-Wuerttemberg (BW, Germany) for the occurrence of selected pathogens with One Health relevance. Organ tissue and blood samples collected from 102 animals, obtained by hunters in 2019 and 2020, were subsequently analysed for two bacterial and four viral pathogens using a qPCR approach. Single samples were positive for the carnivore protoparvovirus-1 (7.8%, n = 8), canine distemper virus (6.9%, n = 7), pathogenic Leptospira spp. (3.9%, n = 4) and Anaplasma phagocytophilum (15.7%, n = 16). West Nile virus and influenza A virus were not detected. Due to their invasive behaviour and synanthropic habit, raccoons may increase the risk of infections for wildlife, domestic animals, zoo animals and humans by acting as a link between them. Therefore, further studies should be initiated to evaluate these risks.

Canine Distemper Virus in Endangered Species: Species Jump, Clinical Variations, and Vaccination

Canine morbillivirus (Canine distemper virus, CDV) is the cause of distemper in a large number of different species, some of which are endangered. The clinical outcome associated with infection is variable and based on many factors, including the host species, the immune response of the individual animal to the infection, and variation in virus tropism and virulence. Unfortunately, the viral characteristics associated with virulence versus attenuation are not fully characterized, nor are the specific mutations that allow this virus to easily move and adapt from one species to another. Due to its wide host range, this virus is difficult to manage in ecosystems that are home to endangered species. Vaccination of the domestic dog, historically considered the reservoir species for this virus, at dog-wildlife interfaces has failed to control virus spread. CDV appears to be maintained by a metareservoir rather than a single species, requiring the need to vaccinate the wildlife species at risk. This is controversial, and there is a lack of a safe, effective vaccine for nondomestic species. This review focuses on topics that are paramount to protecting endangered species from a stochastic event, such as a CDV outbreak, that could lead to extinction.

Epidemiological Study of Pathogenic Leptospira in Raccoons (Procyon lotor) in a Suburb of Tokyo, Japan

Leptospirosis is a zoonosis that affects humans and animals worldwide. Raccoons (Procyon lotor), adopted in urban environments, may act as potential reservoirs of Leptospira. We investigated the prevalence of pathogenic Leptospira in the kidney and urine samples of raccoons living in Tokyo, as well as anti-leptospiral antibodies in their serum, and aimed to examine the factors that expose raccoons to Leptospira. Polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect leptospiral DNA and anti-leptospiral antibodies, respectively. Thirty-six of 156 raccoons (23.1%) were positive by PCR, and 16 of 165 raccoons (9.7%) were positive by ELISA. The prevalence and seroprevalence rates differed depending on the raccoon dispersal period. We used univariable logistic regression to estimate the environmental factors associated with pathogenic Leptospira and anti-leptospiral antibodies in raccoons. Significant differences were observed in the PCR results for the seasons (spring−summer) (p = 0.01), average monthly temperature (p < 0.01), and average monthly rainfall (p < 0.01). No significant difference was seen in the ELISA results, but raccoons in larger urban areas tended to have higher seroprevalence rates (p = 0.06). We identified a pattern of leptospiral spread in raccoon dispersal and environmental factors that expose raccoons to Leptospira.

Clinical disease and treatment of Leptospira kirschneri sv Grippotyphosa in a Sumatran tiger (Panthera tigris sumatrae)

CASE DESCRIPTION

A 12-year-old sexually intact male zoo-managed Sumatran tiger (Panthera tigris sumatrae) was evaluated for a 3-day history of vomiting, hyporexia, and lethargy. Radiographs were supportive of gastrointestinal obstruction, and an exploratory laparotomy was performed.

CLINICAL FINDINGS

Diffuse tan foci were present on the liver parenchyma, and the tiger became icteric throughout the procedure. Hepatic histopathology and immunohistochemistry resulted in a diagnosis of leptospirosis. Serum microagglutination testing for Leptospira spp antibody titers were positive for L kirschneri serovar Grippotyphosa, rising from 1:400 to 1:3,200 in 2 days.

TREATMENT AND OUTCOME

The tiger was treated with antimicrobials, ursodiol, and mirtazapine, and increased biosecurity measures were instituted. Free-ranging wildlife on grounds were trapped, euthanized, and submitted for necropsy to screen for disease vectors. The tiger's urine was intermittently opportunistically collected from the enclosure and remained PCR assay negative for Leptospira spp until being positive once again on day 595. Although the tiger was without clinical signs at that time, antimicrobial therapy and increased biosecurity protocols were instituted a second time until urinary Leptospira shedding was confirmed to have stopped. By 1,071 days after initial presentation, the tiger remained nonclinical, with no additional urinary shedding episodes.

CLINICAL RELEVANCE

While domestic and nondomestic free-ranging felids have been reported as subclinical Leptospira spp carriers, this report indicates the clinical importance of leptospirosis when a tiger presents with generalized gastrointestinal signs and icterus. Due to the zoonotic potential, biosecurity measures are necessary. This patient had a clinically successful outcome with antimicrobial therapy and supportive care.

Demographic and Pathogens of Domestic, Free-Roaming Pets and the Implications for Wild Carnivores and Human Health in the San Luis Region of Costa Rica

Habitat loss and degradation, restricted ranges, prey exploitation, and poaching are important factors for the decline of several wild carnivore populations and additional stress from infectious agents is an increasing concern. Given the rapid growth of human populations in some regions like Costa Rica, pathogens introduced, sustained, and transmitted by domestic carnivores may be particularly important. To better understand the significance of domestic carnivore pathogens for wildlife, we determine the prevalence of infection and possible mechanisms for contact between the two groups. The demographics, role in the household, and pathogens of pet dogs and cats was studied during three annual spay/neuter clinics in San Luis, Costa Rica. Most dogs were owned primarily as pets and guard animals, but ~10% were used for hunting. Cats were owned primarily as pets and for pest control. Both roamed freely outdoors. We detected high prevalences of some pathogens (e.g., carnivore protoparvovirus 1 and Toxoplasma gondii). Some pathogens are known to persist in the environment, which increases the probability of exposure to wild carnivores. This study demonstrated that domestic pets in San Luis, home to a number of protected and endangered wildlife species, are infected with pathogens to which these wild species are potentially susceptible. Additionally, results from our questionnaire support the potential for domestic and wild animal contact, which may result in disease spillover.

Cross-sectional evaluation of multiple epidemiological cycles of Leptospira species in peri-urban wildlife in California

OBJECTIVE

To perform a cross-sectional survey to estimate prevalence of and potential risk factors for Leptospira spp infection and exposure in peri-urban wildlife throughout California.

ANIMALS

723 animals representing 12 wildlife species.

PROCEDURES

Blood and urine samples were obtained from wildlife in California from 2007 to 2017. Live animals were captured in humane traps, anesthetized, and released. Carcasses were donated by wildlife services and necropsied for urine, blood, and kidney tissue samples. Samples were tested for antibodies against 6 serovars of Leptospira spp with a microscopic agglutination test and for pathogenic Leptospira spp DNA with a real-time PCR assay targeting the LipL32 gene. Potential risk factors for Leptospira spp exposure were assessed by logistic regression. Genetic relatedness of Leptospira spp were assessed with DNA sequencing of the rrs2 gene and multiple locus sequence analysis.

RESULTS

Statewide Leptospira spp seroprevalence was 39.1%, and prevalence of positive PCR assay results for Leptospira spp DNA was 23.0%. Risk factors for Leptospira spp exposure included being an adult, being from northern California, and being a western gray squirrel, coyote, striped skunk, raccoon, gray fox, or mountain lion. Antibodies against serovar Pomona predominated in most species, followed by serovar Copenhageni. Complete rrs2 sequences were identified as Leptospira interrogans and multiple locus sequence type analysis revealed sequence type 140.

CONCLUSIONS AND CLINICAL RELEVANCE

Pathogenic Leptospira spp appeared to be common and widespread among peri-urban wildlife in California. Our data highlight the potential for exposure to infectious disease for both humans and domestic animals at the urban-wildland interface.

Canine distemper in neotropical procyonids: Molecular evidence, humoral immune response and epidemiology

Canine Distemper Virus (CDV) can produce a fatal multisystem disease in carnivores and other mammals and is an important threat for wildlife conservation. However, integrative and comparative studies in wild carnivores are scarce and some areas of the world lack of genetic studies. We explore the dynamic of host-CDV in a procyonid community during an outbreak. This study reports for the first time an index case occurred in a common raccoon (Procyon lotor) and for which a complete CDV diagnosis was performed. The long-term epidemiological analysis in two sympatric populations of common raccoons and white-nosed coatis (Nasua narica) was achieved through seroneutralization, RT-PCR and direct immunofluorescence assays. Additionally, hematologic analyses were performed and phylogenetic reconstruction of CDV was done using molecular data from this study. Overall prevalence for white-nosed coatis was 19.6 % and for common raccoons was 25.3 % by seroneutralization, and 13.3 % and 17.3 % by RT-PCR. Antibodies titer average for white-nosed coatis was 1:512 and 1:156 for common raccoons. Significant difference in prevalence between white-nosed coatis and common raccoons was detected during one season (summer 2013). White-nosed coatis showed differences in erythrocytes and monocytes counts between positives and negative animals. A 100 % similarity was found between CDV of white-nosed coati and CDV of common raccoon and is a new CDV sequence not previously described; this sequence is close to Asian and European lineage. An endemic state of distemper in both species was observed but showed different dynamics over time per host species. Differences in cellular and humoral responses were also detected between procyonids. The evidence found here may have serious implications for CDV understanding in wild carnivores, it reveals clear differences in the response over time to the same CDV strain, in two close related carnivore species.

Environmental conditions for Jamestown Canyon virus correlated with population-level resource selection by white-tailed deer in a suburban landscape

Suburban landscapes can alter spatial patterns by white-tailed deer (Odocoileus virginianus) and increase animal contact with vectors, pathogens, and humans. Close-contact relationships at a landscape level can have broad implications for disease epidemiology. From 1995–1999, we captured and radio-collared 41 deer in two suburban forest preserves in Chicago, Illinois. We collected blood to determine if animals were seronegative or seropositive for Jamestown Canyon virus and tracked deer movements within suburban habitats. We developed utilization distributions at the population-level and evaluated resource selection for seronegative and seropositive deer. We used maximum likelihood estimation for model selection via Akaike information criterion and then restricted maximum likelihood estimation to attain unbiased estimates of the parameters in the top-ranking models. The top-ranking model describing the resource selection of seronegative deer received almost the full weight of evidence (Akaike information criterion ω_i = 0.93), and included the proportion of wetlands, precipitation in year t, and an interaction of the proportion of wetlands and precipitation in year t. The top-ranking model describing resource selection of seropositive deer received the full weight of evidence (Akaike information criterion ω_i = 1.00). The model included distance to nearest populated place, distance to nearest river, length of road in each grid cell, precipitation in year t, and an interaction of the length of road in each grid cell and precipitation in year t. These results are valuable for mapping the spatial configuration of hotspots for Jamestown Canyon virus and could be used to educate local residents and recreationalists to reduce human exposure.

Leptospira Seroprevalence Detection and Rabies Virus Absence in an Urban Raccoon (Procyon lotor) Population in a Highly Populated Area, Costa Rica

Leptospirosis and rabies are zoonotic diseases of public health importance and endemic diseases in tropical countries such as Costa Rica. Peridomestic wild animals such as raccoons (Procyon lotor) have been implicated as competent hosts of Leptospira spirochetes and rabies virus. This study focused on understanding the role of urban raccoons in the dynamics of leptospirosis and rabies in a tropical environment. A total of 97 specimens of the common raccoon were captured within the Greater Metropolitan Area of Costa Rica; 32.6% (31/95) of raccoons presented evidence of antibodies (> 1: 100) against Leptospira sp. Attempts to cultivate Leptospira failed, but 19 serovars were identified, which are also responsible for causing disease in humans in Costa Rica. Detected titers ranged from 1: 100 to 1: 6400. Lymphoid hyperplasia in kidneys and spirochetes were demonstrated in 3 of 20 necropsied cases (15%). Twenty brain samples were analyzed by hematoxylin and eosin stain for evidence of encephalitis and Negri body detection and simultaneously frozen brain material was employed to perform a rapid immunoassay test for rabies antigen. All tested samples were negative. This study is the first report of Leptospira seroprevalence in raccoons that cohabit urban areas in Costa Rica. We also highlight the importance of the raccoon as one of their natural competent host and sentinel animals within highly populated urban environments in tropical cities.

Environmental and Behavioral Risk Factors for Severe Leptospirosis in Thailand

A nationwide prevention and control campaign for leptospirosis in Thailand has led to a decreased incidence rate, but the mortality and case fatality rates have remained stable. Regarding the limited knowledge of risk factors, a case-control study of the association between environmental and behavioral exposure with severe leptospirosis was implemented to identify the risk factors among adults in Thailand. The study was conducted in 12 hospital-based sites. Hospitalized patients with suspected clinical symptoms of leptospirosis were tested for leptospirosis by culture, loop mediated isothermal amplification (LAMP), real-time PCR, and the microscopic agglutination test (MAT). All participants answered a standardized questionnaire about potential risk factors. Risk factors were identified by univariable and multivariable logistic regression. Of the 44 confirmed cases, 33 (75.0%) presented with severe illness, as determined by clinical criteria, and were categorized as severe cases. Non-severe cases were defined as patients with non-severe symptoms of leptospirosis. Living nearby a rubber tree plantation (adjusted OR 11.65, 95% CI 1.08–125.53) and bathing in natural bodies of water (adjusted OR 10.45, 95% CI 1.17–93.35) were both significantly associated with an increased risk of severe leptospirosis. We recommend designating rubber plantations in Thailand as high-risk zones and closely monitoring hospitalized patients in those areas.

EVIDENCE OF TWO COCIRCULATING CANINE DISTEMPER VIRUS STRAINS IN MESOCARNIVORES FROM NORTHERN COLORADO, USA

Canine distemper virus (CDV) is a highly contagious pathogen that principally infects wildlife and domestic carnivores. Peridomestic species such as raccoons ( Procyon lotor) experience outbreaks with high mortality. Clinical signs of infection include anorexia, fever, respiratory infection, and neurologic complications. Although not zoonotic, CDV poses a high risk to unvaccinated domestic animals and the conservation of endangered species. During 2013-16, we opportunistically collected wild and domestic carnivore specimens through a rabies surveillance program in northern Colorado, US. Brainstem and cerebellar tissue samples were independently tested for rabies and CDV by fluorescent antibody test. We tested a total of 478 animals for CDV, comprised of 10 wild and domestic carnivore species. A total of 15% (72/478) of all animals sampled tested positive for CDV, consisting of 24% (71/300) of raccoons and 4% (1/26) of coyotes ( Canis latrans), but coinfection with rabies virus was not observed among CDV-positive animals. We extracted RNA from positive tissues, and a reverse-transcription PCR was used to create complementary DNA. We amplified and sequenced the hemagglutinin gene from 60 CDV-positive tissues, and a median joining network and maximum likelihood phylogenetic tree revealed two major lineages among samples. Phylogenetic analysis indicated that our sequences were most similar to the America-2 ( n=55) and the America-3 ( n=5) CDV lineages circulating in North America. Our results indicated two distinct and distantly related clades of CDV overlapping geographically and temporally among raccoon populations in northern Colorado.

Procyonidae, Viverridae, Hyenidae, Herpestidae, Eupleridae, and Prionodontidae

This chapter covers the diseases and pathology of multiple taxonomic groups within the order Carnivora including Procyonidae several of the Feliformia carnivores. The overwhelming majority of knowledge about disease pathogenesis for these species is biased toward raccoons and concern for disease spread to humans and companion animals. Procyonids and feliform carnivores are ubiquitous in their environments and share habitat and environmental resources with other nondomestic and domestic carnivores and humans. As reservoirs for a number of important multispecies or zoonotic pathogens, surveys for pathogens that may be harbored or vectored by several of the species in this chapter, for example, raccoons (e.g., canine distemper virus, rabies, and leptospirosis) and civets (e.g., SARS coronavirus), have been active areas of investigation. Unfortunately, less research has focused on the potential effects of these pathogens on their hosts.

Public Preference for Pet-Rabies Prophylaxis: Opportunities and Information Dissemination

Risky human behavior and high density of rabies vectors in urban environments combine to increase the risk of rabies. Pet vaccination, wildlife vector management, and public health education may be the most efficient ways to prevent urban rabies epidemics. Racial, ethnic, and socio-economic factors influence the use of low-cost rabies vaccination clinics, understanding rabies reporting requirements, and learning preferences. In collaboration with the City of Greensboro and Animal Control in Guilford County, NC, we conducted a survey of rabies prevention and transmission across socio-economic strata representing Latinos, African Americans, and Whites, and different income and education levels. Compliance with vaccination was low among Latinos; African Americans and Latinos were not aware of low-cost rabies vaccination clinics; and most respondents were willing to report rabid animals but did not know whom to call. White respondents preferred online information delivery, whereas Latinos and African Americans preferred postal mail. Communication targeting the public requires the consideration of different message decoding and interpretation based on the ethnicity, income, and educational level, and other barriers such as language. Differing message delivery methods may be required to achieve full dissemination.

SURVEILLANCE FOR ANTIBODIES AGAINST SIX CANINE VIRUSES IN WILD RACCOONS (PROCYON LOTOR) IN JAPAN

Raccoons (Procyon lotor) are found worldwide. They are frequently seen in crowded inner cities as well as in forests or wooded areas, often living in proximity to humans and their pets. We examined sera from 100 wild raccoons in Japan for antibodies to six canine viruses with veterinary significance to assess their potential as reservoirs. We also aimed to understand the distribution of potentially infected wildlife. We found that 7% of samples were seropositive for canine distemper virus (CDV), 10% for canine parvovirus type 2, 2% for canine adenovirus type 1, 6% for canine adenovirus type 2, and 7% for canine coronavirus. No samples were found to be seropositive for canine parainfluenza virus. Seropositivity rates for canine distemper virus and canine parvovirus type 2 were significantly different between areas, and younger raccoons (<1 yr old) were more frequently seropositive than older raccoons. Because raccoons belong to the suborder Caniformia, similar to dogs (Canis lupus familiaris), our results suggest that they can act as reservoirs for some of these important canine viruses and might be involved in viral transmission. Further study should include isolation and analysis of canine viruses in wild raccoons from a wider area.

Detection of canine adenovirus 1 in red foxes (Vulpes vulpes) and raccoons (Procyon lotor) in Germany with a TaqMan real-time PCR assay

We developed a real-time (rt)PCR assay based on TaqMan probe technology for the specific detection of canine adenovirus 1 (CAdV-1). The assay is able to detect three 50% tissue culture infectious dose/mL in CAdV-1–containing cell culture supernatant. Viral genomes were not amplified of canine adenovirus 2 or of several bovine, porcine, and avian adenoviruses. In silico analysis provided no indication of amplification of other heterologous genomes. The sensitivity of the real-time assay exceeded that of a conventional gel-based CAdV-1 PCR by a factor of 100. Following the integration of the novel PCR into the Hessian wildlife-monitoring program, CAdV-1 DNA was detected in none of the tested raccoons ( n = 48) but in 11 of 97 foxes.

HEALTH SURVEY OF FREE-RANGING RACCOONS (PROCYON LOTOR) IN CENTRAL PARK, NEW YORK, NEW YORK, USA: IMPLICATIONS FOR HUMAN AND DOMESTIC ANIMAL HEALTH

We conducted health assessments on 113 free-ranging raccoons ( Procyon lotor ) in Central Park, New York City, US, in February 2010, September 2010, and November 2011 in conjunction with a trap-vaccinate-release program to control a raccoon rabies epizootic. Five individuals were sampled at two time points for 118 raccoon examinations in total. We tested 13 of 13 and 8 of 13 euthanized raccoons for rabies and canine distemper virus (CDV), respectively, by antigen testing on brain tissue; all were negative for both viruses. Endoparasitism was the most common necropsy finding, with definitive identification of Baylisascaris procyonis in six of eight (75%) necropsied raccoons. Multiple intestinal parasites were detected in feces of living raccoons, including ascarid-type ova in 25 of 80 (31%) raccoons, with B. procyonis confirmed in one sample. Median blood lead level was 7.3 μg/dL (n=104). Rabies virus neutralizing antibody titer was ≥0.5 IU/mL in 9 of 88 (10%) raccoons naive to rabies vaccination and in 13 of 20 (65%) previously vaccinated raccoons. The majority of raccoons we tested were seropositive for canine parvovirus-2 (54/59, 92%) and Toxoplasma gondii (39/60, 65%). Fewer were seropositive for Rickettsia rickettsii (3/30, 10%). None were seropositive for CDV (n=108), canine adenovirus-1 (n=60), or Borrelia burgdorferi (n=30). Ectoparasites found during 16 of 118 (13.6%) physical examinations included Ixodes texanus ticks (15/118, 12.7%) and Trichodectes octomaculatus lice (1/118, 0.8%). We detected Campylobacter jejuni in 5 of 79 (6%) fecal samples. We detected 11 Salmonella enterica serotypes in 70 of 111 (63.1%) enteric cultures, the most common of which were Salmonella Newport (20/70, 29%) and Salmonella Oranienburg (20/70, 29%). These results indicate that raccoons in Central Park likely are involved in the environmental occurrence and potential disease transmission of a variety of infectious and noninfectious diseases of concern for human, wildlife, and domestic animal health.

Characterization of a novel Canine distemper virus causing disease in wildlife

Canine distemper virus (CDV) is a common cause of a multisystemic disease in both domestic dogs and wildlife species, including raccoons and foxes. Outbreaks of CDV in domestic dogs in eastern Tennessee have occurred since 2012, and it was determined that these outbreaks resulted from a novel genotype of CDV. We hypothesized that this virus is also infecting area wildlife and may be a source of the virus for these outbreaks in dogs. From 2013 to 2014, autopsies were performed and tissues collected from raccoons (Procyon lotor; n = 50) and gray foxes (Urocyon cinereoargenteus; n = 8) for CDV testing. A real-time reverse transcription PCR was used to document the presence of CDV in tissue samples, and a portion of the virus was subsequently sequenced for phylogenetic analysis. A high percentage of wildlife, both with (86%) and without (55%) clinical signs, tested positive for CDV, with the majority (77%) testing positive for the novel genotype. Microscopic findings, including syncytia in the lungs and viral inclusion bodies in urothelium, astrocytes, neurons, and bronchiolar epithelium, were also consistent with canine distemper. Minimal inflammation in the central nervous system of affected animals was indicative of the acute neurologic form of the disease. Pneumonia and parasitism were also commonly found in CDV-infected animals. Based on these results, CDV appears to be prevalent in eastern Tennessee wildlife. Subclinical or clinically recovered shedders are a potential source of this novel genotype for domestic dogs, and this genotype is genetically distinct from vaccine strains.

Raccoon contact networks predict seasonal susceptibility to rabies outbreaks and limitations of vaccination

Infectious disease transmission often depends on the contact structure of host populations. Although it is often challenging to capture the contact structure in wild animals, new technology has enabled biologists to obtain detailed temporal information on wildlife social contacts. In this study, we investigated the effects of raccoon contact patterns on rabies spread using network modelling. Raccoons (Procyon lotor) play an important role in the maintenance of rabies in the United States. It is crucial to understand how contact patterns influence the spread of rabies in raccoon populations in order to design effective control measures and to prevent transmission to human populations and other animals. We constructed a dynamic system of contact networks based on empirical data from proximity logging collars on a wild suburban raccoon population and then simulated rabies spread across these networks. Our contact networks incorporated the number and duration of raccoon interactions. We included differences in contacts according to sex and season, and both short-term acquaintances and long-term associations. Raccoons may display different behaviours when infectious, including aggression (furious behaviour) and impaired mobility (dumb behaviour); the network model was used to assess the impact of potential behavioural changes in rabid raccoons. We also tested the effectiveness of different vaccination coverage levels. Our results demonstrate that when rabies enters a suburban raccoon population, the likelihood of a disease outbreak affecting the majority of the population is high. Both the magnitude of rabies outbreaks and the speed of rabies spread depend strongly on the time of year that rabies is introduced into the population. When there is a combination of dumb and furious behaviours in the rabid raccoon population, there are similar outbreak sizes and speed of spread to when there are no behavioural changes due to rabies infection. By incorporating detailed data describing the variation in raccoon contact rates into a network modelling approach, we were able to show that suburban raccoon populations are highly susceptible to rabies outbreaks, that the risk of large outbreaks varies seasonally and that current vaccination target levels may be inadequate to prevent the spread of rabies within these populations. Our findings provide new insights into rabies dynamics in raccoon populations and have important implications for disease control.

Spatial patterns of neutral and functional genetic variations reveal patterns of local adaptation in raccoon (Procyon lotor) populations exposed to raccoon rabies

Local adaptation is necessary for population survival and depends on the interplay between responses to selective forces and demographic processes that introduce or retain adaptive and maladaptive attributes. Host-parasite systems are dynamic, varying in space and time, where both host and parasites must adapt to their ever-changing environment in order to survive. We investigated patterns of local adaptation in raccoon populations with varying temporal exposure to the raccoon rabies virus (RRV). RRV infects approximately 85% of the population when epizootic and has been presumed to be completely lethal once contracted; however, disease challenge experiments and varying spatial patterns of RRV spread suggest some level of immunity may exist. We first assessed patterns of local adaptation in raccoon populations along the eastern seaboard of North America by contrasting spatial patterns of neutral (microsatellite loci) and functional, major histocompatibility complex (MHC) genetic diversity and structure. We explored variation of MHC allele frequencies in the light of temporal population exposure to RRV (0-60 years) and specific RRV strains in infected raccoons. Our results revealed high levels of MHC variation (66 DRB exon 2 alleles) and pronounced genetic structure relative to neutral microsatellite loci, indicative of local adaptation. We found a positive association linking MHC genetic diversity and temporal RRV exposure, but no association with susceptibility and resistance to RRV strains. These results have implications for landscape epidemiology studies seeking to predict the spread of RRV and present an example of how population demographics influence the degree to which populations adapt to local selective pressures.

Seasonal prevalence of antibodies to Leptospira interrogans in Antillean manatees from a landlocked lake in Tabasco, Mexico

Factors that alter the dynamics of ecologic systems can influence transmission of infectious diseases and may lead to decreases in natural populations. Leptospirosis is a cosmopolitan disease of zoonotic importance that affects most mammals. At the southern Gulf of Mexico, Antillean manatees (Trichechus manatus manatus) inhabit highly variable environments, with extended floods during the rainy season and drought conditions during the dry season that affect food availability and the thermal environment for manatees. We tested for changes in prevalence and titers of antibodies to 12 serovars of Leptospira interrogans in manatees between dry and rainy seasons. We determined titers for L. interrogans through microscopic agglutination tests (MAT) from 10 manatees, six during the dry season (DS), and six during the rainy season (RS) in Laguna de las Ilusiones, a landlocked lake hosting a population of about 20 manatees. All individuals were antibody positive (titers ≥ 100) to at least one serovar. The serovars bataviae, bratislava, canicola, and icterohaemorrhagiae had overall prevalences ≥ 50%; bataviae, bratislava, and canicola had prevalences ≥ 50% during both seasons. Serovars icterohaemorrhagiae and pyrogenes had prevalences ≥ 50% during DS and pomona, tarassovi, wolfii, and autumnalis during RS. Significant differences in prevalence between seasons were found for pomona, tarassovi, and autumnalis. Titers of tarassovi, wolfii, autumnalis, and bataviae were significantly higher during RS. There was a high prevalence of L. interrogans during the RS independent of high availability of plant foods, coinciding with the epizootiology of the bacteria that are endemic to tropical regions. Another factor possibly influencing prevalence is high anthropogenic pressure at the lake, causing an increase in potential sources of infection. Because of possible cross-reaction in MAT, further research is needed on the molecular discrimination of serovars in animals in the lake.

Leptospiral uveitis - there is more to it than meets the eye!

Leptospirosis, caused by pathogenic species of genus Leptospira, is a highly prevalent zoonotic disease throughout many parts of the world, and an important emerging disease within the United States. Uveitis is a common complication of systemic infection in humans. A similar condition in horses is characterized by recurrent bouts of inflammation. In this article, we review advances in our understanding of leptospiral uveitis and its pathogenic mechanisms.

Serosurvey of leptospirosis in feral hogs (Sus scrofa) in Florida

Leptospira is a global pathogen of emerging public health importance in both developing and industrialized nations and can infect almost all mammalian species, including humans. As suburbanization and the popularity of outdoor recreational activities increases, so do human-wildlife and companion animal-wildlife interfaces. Florida offers a tropical climate favorable for outdoor activities and a semirural landscape that sustains an abundant feral hog population. Because no survey ofleptospirosis in feral hogs (Sus scrofa) in Florida has been published to our knowledge, we sought to establish preliminary seroprevalence ofleptospirosis exposure in feral hogs in Florida. Blood samples were collected opportunistically from 158 male and 166 female feral hogs taken at managed hunts and by permitted trappers in the northern, central, and southern regions of Florida. Samples were then analyzed using the microscopic agglutination test (MAT) for antibody titers to 20 Leptospira serovars representing 17 serogroups. A titer of > 1:100 was considered positive; 33% (107/324 total samples) were positive to at least one serovar, and 46% of those were positive to multiple serovars. Antibodies to L. interrogans serovar Bratislava strain Jez Bratislava (serogroup Australis) was the most common, with 18% (58/324) testing positive for antibodies. These initial data indicate that there is a significant possibility of feral hogs having a larger role in the complex etiology of leptospirosis in Florida than historically estimated and that further investigation is warranted.

Avaliação sorológica para leptospirose em mamíferos silvestres procedentes do Parque Zoológico Municipal de Bauru, SP

Com o objetivo de analisar a resposta sorológica à leptospirose, utilizando-se da técnica de Soroaglutinação Microscópica (SAM), no período de 2008 a 2009, foram avaliadas 72 amostras de soros de mamíferos silvestres pertencentes ao Parque Zoológico Municipal de Bauru. Destes, 60 (83,3%) foram reagentes aos seguintes sorovares: Pyrogenes (15,2%); Pomona (9,4%); Autumnalis (8,9%); Whitcombi (6,8%); Tarassovi (6,3%); Hardjo (5,7%); Butembo e Bratislava (4,7%); Wolffi (4,2%); Copenhageni (3,7%); Javanica, Hardjobovis e Hardjo prajitno (3,1%); Hebdomadis e Australis (2,6%); Canicola, Cynopteri e Djasiman (2,1%); Icterohaemorraghiae e Hardjominiswajezak (1,6%); Castellonis, Bataviae, Sentot, Gryppotyphosa e HardjoCTG, (1,0%); Panamá e Andamana, (0,5%). Além dos animais silvestres, foram analisados 50 soros de roedores sinantrópicos, capturados no interior do Parque, onde 48 (96%) foram reagentes à leptospirose. Os sorovares prevalentes foram: Bratislava (14,1%); Cynopteri (11,4%); Butembo (10,3%); Autumnalis (9,2%); Pyrogenes (8,7%); Hardjo miniswajezak (7,6%), Australis (5,4%), Hardjo (4,9%); Hardjo prajitno (3,8%), Djasiman e HardjoCTG (3,3%), Whitcombi, Copenhageni e Tarassovi (2,7%), Pomona e Shermani (2,2%), Canicola (1,1%), Castellonis, Bataviae, Gryppotyphosa, Panama, Wolffi, Andamana, Patoc e Hardjobovis (0,5%). Os resultados obtidos demonstraram a necessidade do monitoramento sorológico contínuo dos animais do zoo, e adoção de medidas de controle frente à leptospirose, tais como a verificação de pontos de alagamento nos recintos e o controle de roedores, visando a não disseminação desta zoonose no ambiente do parque.

Serosurvey of mountain lions in southern Arizona

An understanding of the prevalence of diseases in free-ranging populations of felids is limited, and there is even less known about the overall health and diseases of wild felids that inhabit or utilize urban areas. We collected serum samples from 9 radiocollared mountain lions (Puma concolor) in the mountains surrounding Tucson, Arizona, USA, from August 2005 to August 2008. We tested serum samples for evidence of exposure to 10 feline viruses: Feline Calicivirus (FCV), Feline Herpesvirus, Feline Enteric Coronavirus, Feline Syncytial Virus-Feline Foamy Virus, Feline Infectious Peritonitis, Feline Immunodeficiency Virus, Feline Panleukopenia Virus (FPLV), Feline Leukemia Virus, Canine Distemper Virus (CDV), and Toxoplasma gondii. The highest prevalences of exposure were: T. gondii (8/9), FPLV (7/9), and FCV (6/9). One male was seropositive for CDV, T. gondii, and FPLV. Mountain lions inhabiting smaller fragmented landscapes and urban areas have more contact with other felids and domesticated animals. Frequent contact among mountain lions, other felids, and domesticated animals can lead to higher risk of exposure and facilitate the spread of the disease from animal to animal. © 2012 The Wildlife Society.

Genetic variability and viral seroconversion in an outcrossing vertebrate population

Inverse correlations between genetic variability and parasitism are important concerns for conservation biologists. We examined correlations between neutral genetic variability and the presence of antibodies to canine distemper virus (CDV) and feline parvovirus (FPV) in a free-ranging population of raccoons. Over 3 years there was a strong relationship between age and seroprevalence rates. Most young animals were seronegative to CDV and FPV, but the oldest age class was greater than 80 per cent seropositive to both viruses. CDV-seropositive animals had greater heterozygosity and lower measures of inbreeding compared with CDV-seronegative animals. This relationship was strongest among the youngest animals and did not occur during a 1 year CDV epidemic. In contrast, FPV-seropositive animals only had significantly lower measures of inbreeding in 1 year, perhaps because FPV-associated mortality is relatively low or primarily occurs among very young individuals that were under-represented in our sampling. These results suggest that even in large outcrossing populations, animals with lower heterozygosity and higher measures of inbreeding are less likely to successfully mount an immune response when challenged by highly pathogenic parasites.

Characterization of major histocompatibility complex (MHC) DRB exon 2 and DRA exon 3 fragments in a primary terrestrial rabies vector (Procyon lotor)

The major histocompatibility complex (MHC) presents a unique system to explore links between genetic diversity and pathogens, as diversity within MHC is maintained in part by pathogen driven selection. While the majority of wildlife MHC studies have investigated species that are of conservation concern, here we characterize MHC variation in a common and broadly distributed species, the North American raccoon (Procyon lotor). Raccoons host an array of broadly distributed wildlife diseases (e.g., canine distemper, parvovirus and raccoon rabies virus) and present important human health risks as they persist in high densities and in close proximity to humans and livestock. To further explore how genetic variation influences the spread and maintenance of disease in raccoons we characterized a fragment of MHC class II DRA exon 3 (250bp) and DRB exon 2 (228 bp). MHC DRA was found to be functionally monomorphic in the 32 individuals screened; whereas DRB exon 2 revealed 66 unique alleles among the 246 individuals screened. Between two and four alleles were observed in each individual suggesting we were amplifying a duplicated DRB locus. Nucleotide differences between DRB alleles ranged from 1 to 36 bp (0.4–15.8% divergence) and translated into 1 to 21 (1.3–27.6% divergence) amino acid differences. We detected a significant excess of nonsynonymous substitutions at the peptide binding region (P = 0.005), indicating that DRB exon 2 in raccoons has been influenced by positive selection. These data will form the basis of continued analyses into the spatial and temporal relationship of the raccoon rabies virus and the immunogenetic response in its primary host.

A serological survey of infectious disease in Yellowstone National Park's canid community

BACKGROUND

Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park (YNP) after a >70 year absence, and as part of recovery efforts, the population has been closely monitored. In 1999 and 2005, pup survival was significantly reduced, suggestive of disease outbreaks.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed sympatric wolf, coyote (Canis latrans), and red fox (Vulpes vulpes) serologic data from YNP, spanning 1991-2007, to identify long-term patterns of pathogen exposure, identify associated risk factors, and examine evidence for disease-induced mortality among wolves for which there were survival data. We found high, constant exposure to canine parvovirus (wolf seroprevalence: 100%; coyote: 94%), canine adenovirus-1 (wolf pups [0.5-0.9 yr]: 91%, adults [>or=1 yr]: 96%; coyote juveniles [0.5-1.5 yrs]: 18%, adults [>or=1.6 yrs]: 83%), and canine herpesvirus (wolf: 87%; coyote juveniles: 23%, young adults [1.6-4.9 yrs]: 51%, old adults [>or=5 yrs]: 87%) suggesting that these pathogens were enzootic within YNP wolves and coyotes. An average of 50% of wolves exhibited exposure to the protozoan parasite, Neospora caninum, although individuals' odds of exposure tended to increase with age and was temporally variable. Wolf, coyote, and fox exposure to canine distemper virus (CDV) was temporally variable, with evidence for distinct multi-host outbreaks in 1999 and 2005, and perhaps a smaller, isolated outbreak among wolves in the interior of YNP in 2002. The years of high wolf-pup mortality in 1999 and 2005 in the northern region of the park were correlated with peaks in CDV seroprevalence, suggesting that CDV contributed to the observed mortality.

CONCLUSIONS/SIGNIFICANCE

Of the pathogens we examined, none appear to jeopardize the long-term population of canids in YNP. However, CDV appears capable of causing short-term population declines. Additional information on how and where CDV is maintained and the frequency with which future epizootics might be expected might be useful for future management of the Northern Rocky Mountain wolf population.

Interactions between zoo-housed great apes and local wildlife

Although there are published reports of wild chimpanzees, bonobos, and orangutans hunting and consuming vertebrate prey, data pertaining to captive apes remain sparse. In this survey-based study, we evaluate the prevalence and nature of interactions between captive great apes and various indigenous wildlife species that range into their enclosures in North America. Our hypotheses were threefold: (a) facilities housing chimpanzees will report the most frequent and most aggressive interactions with local wildlife; (b) facilities housing orangutans and bonobos will report intermediate frequencies of these interactions with low levels of aggression and killing; and (c) facilities housing gorillas will report the lowest frequency of interactions and no reports of killing local wildlife. Chimpanzees and bonobos demonstrated the most aggressive behavior toward wildlife, which matched our predictions for chimpanzees, but not bonobos. This fits well with expectations for chimpanzees based on their natural history of hunting and consuming prey in wild settings, and also supports new field data on bonobos. Captive gorillas and orangutans were reported to be much less likely to chase, catch and kill wildlife than chimpanzees and bonobos. Gorillas were the least likely to engage in aggressive interactions with local wildlife, matching our predictions based on natural history. However unlike wild gorillas, captive gorillas were reported to kill (and in one case, eat) local wildlife. These results suggest that some behavioral patterns seen in captive groups of apes may be useful for modeling corresponding activities in the wild that may not be as easily observed and quantified. Furthermore, the data highlight the potential for disease transmission in some captive settings, and we outline the associated implications for ape health and safety.

Prevalence and genetic characterization of Cryptosporidium isolates from common brushtail possums (Trichosurus vulpecula) adapted to urban settings

The common brushtail possum (Trichosurus vulpecula) is one of the most abundant native marsupials in urban Australia, having successfully adapted to utilize anthropogenic resources. The habituation of possums to food and shelter available in human settlements has facilitated interaction with people, pets, and zoo animals, increasing the potential for transmission of zoonotic Cryptosporidium pathogens. This study sought to examine the identity and prevalence of Cryptosporidium species occurring in possums adapted to urban settings compared to possums inhabiting remote woodlands far from urban areas and to characterize the health of the host in response to oocyst shedding. Findings indicated that both populations were shedding oocysts of the same genotype (brushtail possum 1 [BTP1]) that were genetically and morphologically distinct from zoonotic species and genotypes and most closely related to Cryptosporidium species from marsupials. The urban population was shedding an additional five Cryptosporidium isolates that were genetically distinct from BTP1 and formed a sister clade with Cryptosporidium parvum and Cryptosporidium hominis. Possums that were shedding oocysts showed no evidence of pathogenic changes, including elevated levels of white blood cells, diminished body condition (body mass divided by skeletal body length), or reduced nutritional state, suggesting a stable host-parasite relationship typical of Cryptosporidium species that are adapted to the host. Overall, Cryptosporidium occurred with a higher prevalence in possums from urban habitat (11.3%) than in possums from woodland habitat (5.6%); however, the host-specific nature of the genotypes may limit spillover infection in the urban setting. This study determined that the coexistence of possums with sympatric populations of humans, pets, and zoo animals in the urban Australian environment is unlikely to present a threat to public health safety.

Canine distemper virus strains circulating among North American dogs

Canine distemper virus (CDV) is a highly contagious virus that causes multisystemic disease in dogs. We received seven samples from dogs with CD from the United States during 2007. CDV isolates from these samples formed large, multinucleated syncytia in a Vero cell line expressing canine signaling lymphocyte activation molecule (SLAM). Based on the hemagglutinin gene sequences, the CDV isolates from three states (California, Missouri, and Oklahoma) formed two CDV genetic groups: group I (major; six of seven isolates) consisted of CDV isolates closely related to the European wildlife lineage of CDV, and group II (minor; one of seven isolates) was genetically related to the Arctic-like lineage of CDV. However, both CDV groups were genetically different from the current vaccine strains that belong to the American-1 lineage of the old (1930 to 1950) CDV isolates.

Complete protection of cats against feline panleukopenia virus challenge by a recombinant canine adenovirus type 2 expressing VP2 from FPV

Feline panleukopenia virus (FPV) is an important infectious pathogen of all members of the family Felidae. Here, we describe construction of a replication-competent recombinant canine adenovirus type 2 (CAV-2) expressing the VP2 protein of FPV (CAV-2-VP2) by transfection of MDCK cells with recombinant CAV-2 genome carrying a VP2 expression cassette. Ten 3-month-old cats were vaccinated with the recombinant virus with two boosters at 15-day intervals. All cats developed neutralizing antibodies of titers 1:16-1:32 by day 15 post-primary vaccination, increasing to 1:64-1:128 by day 45. Examination for clinical signs and viral presence, and total white blood cell counts in peripheral blood following FPV challenge, showed that all were completely protected. This recombinant virus appears to provide an effective alternative to attenuated and inactivated vaccines in immunizing cats against feline panleukopenia.