scispace - formally typeset
Search or ask a question

Showing papers in "Journal of Wildlife Diseases in 2012"


Journal ArticleDOI
TL;DR: Serologic and virologic surveys should be promoted during epizootic periods to document infected wild animals and extended to interepidemic periods to explore the role of wild animals as possible reservoirs of RVFV.
Abstract: Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting primarily domestic ruminants and humans. Numerous vector species are known or implicated in the transmission of RVFV. The role of mammals in the maintenance of RVFV, and the existence of a wild mammal reservoir in the epidemiologic cycle of RVFV, remain largely unknown. Our objective is to present a detailed review of studies undertaken on RVFV, often associated with wild mammals, with the aim of focusing future research on potential reservoirs of the virus. Natural and experimental infections related to RVFV in several mammalian orders, including Artiodactyla, Chiroptera, Rodentia, Primata (nonhuman), Perissodactyla, Carnivora, Proboscidea, Erinaceomorpha, and Lagomorpha, are reviewed; the first four orders have received the greatest attention. The possible role of wild ruminants, especially African buffalo (Syncerus caffer), is also discussed. Conflicting results have been published concerning rodents but, based on the literature, the likely candidate species include the African genera Arvicanthis and Micaelamys and the widely introduced roof rat (Rattus rattus). Members of the orders Chiroptera and Rodentia should receive greater attention associated with new research programs. For the other orders mentioned above, few data are available. We are unaware of any investigation concerning the orders Afrosoricida and Soricomorpha, which are represented in the geographic area of RVFV and can be abundant. As a first step to resolve the question of wild mammals as a reservoir of RVFV, serologic and virologic surveys should be promoted during epizootic periods to document infected wild animals and, in the case of positive results, extended to interepidemic periods to explore the role of wild animals as possible reservoirs.

112 citations


Journal ArticleDOI
TL;DR: The mortality factors thought to be important in the decline of the historic California Condor population, particularly lead poisoning, remain the most important documented mortality factors today.
Abstract: We document causes of death in free-ranging California Condors (Gymnogyps californianus) from the inception of the reintroduction program in 1992 through December 2009 to identify current and historic mortality factors that might interfere with establishment of self-sustaining populations in the wild. A total of 135 deaths occurred from October 1992 (the first post-release death) through December 2009, from a maximum population-at-risk of 352 birds, for a cumulative crude mortality rate of 38%. A definitive cause of death was determined for 76 of the 98 submitted cases, 70% (53/76) of which were attributed to anthropogenic causes. Trash ingestion was the most important mortality factor in nestlings (proportional mortality rate [PMR] 73%; 8/11), while lead toxicosis was the most important factor in juveniles (PMR 26%; 13/50) and adults (PMR 67%; 10/15). These results demonstrate that the leading causes of death at all California Condor release sites are anthropogenic. The mortality factors thought to be important in the decline of the historic California Condor population, particularly lead poisoning, remain the most important documented mortality factors today. Without effective mitigation, these factors can be expected to have the same effects on the sustainability of the wild populations as they have in the past.

88 citations


Journal ArticleDOI
TL;DR: Oral rabies vaccine performance in the field may be affected by a variety of factors, including vaccine bait density and distribution pattern, habitat, target species population density, and the availability of competing foods, so data support that ONRAB may serve as an effective tool for raccoon rabies control.
Abstract: Control of rabies in mesocarnivore reservoirs through oral rabies vaccination (ORV) requires an effective vaccine bait. Oral rabies vaccine performance in the field may be affected by a variety of factors, including vaccine bait density and distribution pattern, habitat, target species population density, and the availability of competing foods. A field study in which these covariates were restricted as much as possible was conducted along the international border of the state of Maine (ME), USA, and the province of New Brunswick (NB), Canada, to compare the performance of two oral rabies vaccines in raccoons (Procyon lotor) and striped skunks (Mephitis mephitis). RABORAL V-RG® (vaccinia-rabies glycoprotein recombinant oral vaccine in fishmealcoated sachet) or ONRAB® (adenovirus-rabies glycoprotein recombinant oral vaccine in Ultralite bait matrix) were distributed in ME and NB, respectively, by fixed-wing aircraft at a density of 75 baits/km2 along parallel flight lines spaced 1.0 km apart. Sera were col...

84 citations


Journal ArticleDOI
TL;DR: The results, based on histopathology, show the presence of white-nose syndrome in Europe, and two bats found dead in March 2010 with geomycosis in the Czech Republic had characteristics resembling Geomyces destructans infection in bats confirmed withwhite-nosed syndrome in US hibernacula.
Abstract: White-nose syndrome, associated with the fungal skin infection geomycosis, caused regional population collapse in bats in North America. Our results, based on histopathology, show the presence of white-nose syndrome in Europe. Dermatohistopathology on two bats (Myotis myotis) found dead in March 2010 with geomycosis in the Czech Republic had characteristics resembling Geomyces destructans infection in bats confirmed with white-nose syndrome in US hibernacula. In addition, a live M. myotis, biopsied for histopathology during hibernation in April 2011, had typical fungal infection with cupping erosion and invasion of muzzle skin diagnostic for white-nose syndrome and conidiospores identical to G. destructans that were genetically confirmed as G. destructans.

63 citations


Journal ArticleDOI
TL;DR: PrPCWD is detected in feces from naturally exposed free-ranging elk from Rocky Mountain National Park, Colorado for the first time and the potential of PMCA is demonstrated as a new, noninvasive CWD diagnostic tool to complement IHC is demonstrated.
Abstract: Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting captive and free-ranging cervids. Currently, tests for CWD in live animals involve relatively invasive procedures to collect lymphoid tissue biopsies and examine them for CWD- associated, protease-resistant cervid prion protein (PrP CWD ) detected by immunohistochemistry (IHC). We adapted an ultrasensitive prion detection system, protein misfolding cyclic amplification (PMCA), to detect PrP CWD in Rocky Mountain elk (Cervus elaphus nelsoni) feces. Our PMCA reproducibly detected a 1.2310 7 dilution of PrP CWD (a 10% infected brain homogenate diluted 1.2310 6 -fold into 10% fecal homogenates), equivalent to approximately 100 pg of PrP CWD /g of feces. We developed a semiquantitative scoring system based on the first PMCA round at which PrP CWD was detected and fit a nonlinear regression curve to our serial dilutions to correlate PMCA scores with known PrP CWD concentrations. We used this PMCA scoring system to detect PrP CWD and estimate its concentration in feces from free-ranging elk from Rocky Mountain National Park, Colorado. We compared our results to PrP CWD IHC of rectoanal mucosa-associated lymphoid tissue and obex from the same animals. The PMCA successfully detected PrP CWD in feces from elk that were positive by IHC, with estimated prion loads from 100 to 5,000 pg PrP CWD /g of feces. These data show for the first time PrP CWD in feces from naturally exposed free-ranging elk and demonstrate the potential of PMCA as a new, noninvasive CWD diagnostic tool to complement IHC.

56 citations


Journal ArticleDOI
TL;DR: This is the first report of infection of eastern hellbender with Bd and Ranavirus, and it is unclear whether chytridiomycosis or ranaviral disease develops in wild populations of hellbenders.
Abstract: Hellbenders (n=97) were collected from the Little and Hiwassee Rivers in eastern Tennessee, USA, during 2009 and 2010. Location and morphometrics for each animal were recorded, and nonlethal tissue samples were collected to estimate the prevalence of infection with Batrachochytrium dendrobatidis (Bd) and Ranavirus in each watershed and year. Real-time polymerase chain reaction was performed on skin swabs for Bd and on tail clips for ranaviruses. Overall prevalences of DNA of Bd, Ranavirus, and coinfections (i.e., detectable DNA of both pathogens in the same individual) were 26%, 19%, and 5%, respectively. Differences in infection prevalence were detected between watersheds and years. Gross lesions were observed in 31 animals (32%), but the types of lesions were not consistent with chytridiomycosis or ranaviral disease. This is the first report of infection of eastern hellbenders with Bd and Ranavirus. Despite infection by both pathogens, it is unclear whether chytridiomycosis or ranaviral disease develops...

54 citations


Journal ArticleDOI
TL;DR: It is suggested that reptiles living in closer proximity to humans potentially have higher exposure to bacteria of human origin; however, it is not clear from this study to what extent this potential exposure translates to ongoing exchange of bacterial strains or genetic traits.
Abstract: Increased overlap between humans and wildlife populations has increased the risk for novel disease emergence. Detecting contacts with a high risk for transmission of pathogens requires the identification of dependable measures of microbial exchange. We evaluated antibiotic resistance as a molecular marker for the intensity of human–wildlife microbial connectivity in the Galapagos Islands. We isolated Escherichia coli and Salmonella enterica from the feces of land iguanas (Conolophus sp.), marine iguanas (Amblyrhynchus cristatus), giant tortoises (Geochelone nigra), and seawater, and tested these bacteria with the use of the disk diffusion method for resistance to 10 antibiotics. Antibiotic-resistant bacteria were found in reptile feces from two tourism sites (Isla Plaza Sur and La Galapaguera on Isla San Cristobal) and from seawater close to a public use beach near Puerto Baquerizo Moreno on Isla San Cristobal. No resistance was detected at two protected beaches on more isolated islands (El Miedo on Isla ...

51 citations


Journal ArticleDOI
TL;DR: The results indicate that the association between overland runoff and otter mortalities is affected by geography as well as parasite type, and highlight the complex mechanisms that influence transmission of terrestrially derived pathogens to marine wildlife.
Abstract: Toxoplasma gondii and Sarcocystis neurona have caused significant morbidity and mortality in threatened Southern sea otters (Enhydra lutris nereis) along the central California coast. Because only terrestrial animals are known to serve as definitive hosts for T. gondii and S. neurona, infections in otters suggest a land to sea flow of these protozoan pathogens. To better characterize the role of overland runoff in delivery of terrestrially derived fecal pathogens to the near shore, we assessed the temporal association between indicators of runoff and the timing of sea otter deaths due to T. gondii and S. neurona. Sea otter stranding records 1998–2004, from Monterey and Estero bays were reviewed and cases identified for which T. gondii or S. neurona were determined to be a primary or contributing cause of death. Precipitation and stream flow data from both study sites were used as indicators of land-based runoff. Logistic regression was applied to determine if a temporal association could be detected betwe...

50 citations


Journal ArticleDOI
TL;DR: Smaller (older) beluga whales had lower white blood cell, lymphocyte, and eosinophil counts as well as lower sodium, potassium, and calcium levels but higher creatinine levels than smaller belugas, and values for hematology and serum chemistry for comparisons with other wild belugs are provided.
Abstract: We collected blood from 18 beluga whales (Delphinapterus leucas), live-captured in Bristol Bay, Alaska, USA, in May and September 2008, to establish baseline hematologic and serum chemistry values and to determine whether there were significant differences in hematologic values by sex, season, size/age, or time during the capture period. Whole blood was collected within an average of 19 min (range=11–30 min) after the net was set for capture, and for eight animals, blood collection was repeated in a later season after between 80–100 min; all blood was processed within 12 hr. Mean hematocrit, chloride, creatinine, total protein, albumin, and alkaline phosphatase were significantly lower in May than they were in September, whereas mean corpuscular hemoglobin concentration, monocytes, phosphorous, magnesium, blood urea nitrogen, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltranspeptidase, and creatinine kinase were significantly higher. Mean total protein, white blood cell count, neutrophi...

48 citations


Journal ArticleDOI
TL;DR: Phylogenetic analyses demonstrated that jackal RABV in ENP is part of the same transmission cycle as other dog-jackal R ABV cycles in Namibia.
Abstract: Canine distemper virus (CDV) and rabies virus (RABV) occur worldwide in wild carnivore and domestic dog populations and pose threats to wildlife conservation and public health. In Etosha National Park (ENP), Namibia, anthrax is endemic and generates carcasses frequently fed on by an unusually dense population of black-backed jackals (Canis mesomelas). Using serology, phylogenetic analyses (on samples obtained from February 2009–July 2010), and historical mortality records (1975–2011), we assessed jackal exposure to Bacillus anthracis (BA; the causal bacterial agent of anthrax), CDV, and RABV. Prevalence of antibodies against BA (95%, n=86) and CDV (71%, n=80) was relatively high, while that of antibodies against RABV was low (9%, n=81). Exposure to BA increased significantly with age, and all animals >6 mo old were antibody-positive. As with BA, prevalence of antibodies against CDV increased significantly with age, with similar age-specific trends during both years of the study. No significant effect of a...

48 citations


Journal ArticleDOI
TL;DR: Hantavirus–host relationships in the Southern Cone are less strictly concordant with the single-host–single-virus pattern reported elsewhere, but seasonal and multiyear patterns in climate and human disturbance affect host population densities, prevalence of infection, and disease risk to humans.
Abstract: Thirteen hantavirus genotypes, associated with at least 12 sigmodontine reservoir rodents, have been recognized in the four countries that represent the Southern Cone of South America. Host-virus relationships are not as well defined as in North America; several Southern Cone hantaviruses appear to share a common host and some viruses do not occur throughout the range of their host. Although hantavirus-host relationships in the Southern Cone are less strictly concordant with the single-host-single-virus pattern reported elsewhere, recent studies suggest that much of the ambiguity may result from an incomplete understanding of host and hantavirus systematics. Although some Southern Cone host species are habitat generalists, some sympatric species are habitat specialists, helping to explain how some strict host-virus pairings may be maintained. In some cases, host population densities were higher in peridomestic habitats and prevalence of hantavirus infection was higher in host populations in peridomestic habitats. Seasonal and multiyear patterns in climate and human disturbance affect host population densities, prevalence of infection, and disease risk to humans. Unusually high hantavirus antibody prevalence in indigenous human populations may be associated with frequent and close contact with host rodents. Ongoing studies are improving our understanding of hantavirus-host ecology and providing tools that may predict human risk.

Journal ArticleDOI
TL;DR: This work builds on a previous ENM analysis of the potential distribution of human monkeypox in Africa by refining georeferencing criteria and using more-diverse environmental data to identify environmental parameters contributing to monkeypox distributional ecology.
Abstract: As ecologic niche modeling (ENM) evolves as a tool in spatial epidemiology and public health, selection of the most appropriate and informative environmental data sets becomes increasingly important. Here, we build on a previous ENM analysis of the potential distribution of human monkeypox in Africa by refining georeferencing criteria and using more-diverse environmental data to identify environmental parameters contributing to monkeypox distributional ecology. Significant environmental variables include annual precipitation, several temperature-related variables, primary productivity, evapotranspiration, soil moisture, and pH. The potential distribution identified with this set of variables was broader than that identified in previous analyses but does not include areas recently found to hold monkeypox in southern Sudan. Our results emphasize the importance of selecting the most appropriate and informative environmental data sets for ENM analyses in pathogen transmission mapping.

Journal ArticleDOI
TL;DR: The identification of this microorganism in buffalo is an important observation in view of the large and ever-increasing epidemic of the closely related M. tuberculosis complex species M. bovis in some African buffalo populations in South Africa.
Abstract: Mycobacterium tuberculosis complex species cause tuberculosis disease in animals and humans. Although they share 99.9% similarity at the nucleotide level, several host-adapted ecotypes of the tubercule bacilli have been identified. In the wildlife setting, probably the most well-known member of this complex is Mycobacterium bovis, the causative agent of bovine tuberculosis. The recently described oryx bacillus is an extremely rare slow-growing member of the antelope clade of the M. tuberculosis complex and is closely related to the dassie bacillus, Mycobacterium africanum and Mycobacterium microti. The antelope clade is a group of strains apparently host adapted to antelopes, as most described infections were associated with deer and antelope, most specifically the Arabian oryx (Oryx leucoryx). In this study, oryx bacillus was isolated from a free-ranging adult female African buffalo (Syncerus caffer), in good physical condition, which tested strongly positive on three consecutive comparative intradermal ...

Journal ArticleDOI
TL;DR: These findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises and support cross-reactivity between TeV2 and TeV3, which was previously detected in an ill captive desert tortoise in California.
Abstract: Following field observations of wild Agassiz's desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tortoises, with gross lesions consistent with trauma and puncture wounds, respectively, were necropsied. Tortoise 1 was from the central Mojave Desert and tortoise 2 was from the northeastern Mojave Desert. We extracted DNA from the tongue of tortoise 1 and from the tongue and nasal mucosa of tortoise 2. Sequencing of polymerase chain reaction products of the herpesviral DNA-dependent DNA polymerase gene and the UL39 gene respectively showed 100% nucleotide identity with TeHV2, which was previously detected in an ill captive desert tortoise in California. Although several cases of herpesvirus infection have been described in captive desert tortoises, our findings represent the first conclusive molecular evidence of TeHV2 infection in wild desert tortoises. The serologic findings support cross-reactivity between TeHV2 and TeHV3. Further studies to determine the ecology, prevalence, and clinical significance of this virus in tortoise populations are needed.

Journal ArticleDOI
TL;DR: Prevalence of antibody to selected viral pathogens important for domestic pigs and livestock in 556 wild boar sera collected during 2005–06 and 2009–10 in four counties in Croatia is determined and it is suggested that wild boars may act as a reservoir for several pathogens and a source of infection for domestic Pigs and other livestock as well as humans.
Abstract: We determined prevalence of antibody to selected viral pathogens important for domestic pigs and livestock in 556 wild boar (Sus scrofa) sera collected during 2005–06 and 2009– 10 in four counties in Croatia. These counties account for an important part of the Croatian commercial pig production and have a high density of wild boars. Samples were tested for antibodies to porcine parvovirus (PPV), Aujeszky’s disease virus (ADV), porcine circovirus type 2 (PCV2), swine influenza virus, porcine respiratory and reproductive syndrome virus (PRRSV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus, and swine vesicular disease virus (SVDV). Antibodies to all of the infectious pathogens except SVDV were detected. There was a statistically significant difference in prevalence between the two periods for PPV, ADV, PCV2, PRRSV, and PRCV, with a higher prevalence of PPV and ADV in the 2009–10 period (P<0.05). During the same period, the prevalence of PCV2, PRRSV, and PRCV was lower (P<0.05)....

Journal ArticleDOI
TL;DR: Serum samples from Antarctic fur seals and from Weddell seals from Bouvetøya and Ross seals were analyzed for enzyme activity, and concentrations of protein, metabolites, minerals, and cortisol provided a baseline for future monitoring of health parameters of these Antarctic seal species.
Abstract: Information on health parameters, such as antibody prevalences and serum chemistry that can reveal exposure to pathogens, disease, and abnormal physiologic conditions, is scarce for Antarctic seal species. Serum samples from Antarctic fur seals (Arctocephalus gazella, n=88) from Bouvetoya (2000–2001 and 2001–2002), and from Weddell seals (Leptonychotes weddellii, n=20), Ross seals (Ommatophoca rossii, n=20), and crabeater seals (Lobodon carcinophagus, n=9) from the pack-ice off Queen Maud Land, Antarctica (2001) were analyzed for enzyme activity, and concentrations of protein, metabolites, minerals, and cortisol. Adult Antarctic fur seal males had elevated levels of total protein (range 64–99g/l) compared to adult females and pups (range 52–79 g/l). Antarctic fur seals had higher enzyme activities of creatine kinase, lactate dehydrogenase, and amylase, compared to Weddell, Ross, and crabeater seals. Antibodies against Brucella spp. were detected in Weddell seals (37%), Ross seals (5%), and crabeater seals...

Journal ArticleDOI
TL;DR: M Magellanic Penguins from two colonies in Argentina showed sporadic, nonepidemic signs of avian pox during five and two of 29 breeding seasons, and phylogenetic proximity with an Avipoxvirus found in Black-browed Albatross from the Falkland Islands in 1987 suggests a long-term circulation of seabird Avipoxic viruses in the southwest Atlantic.
Abstract: Avian pox is an enveloped double- stranded DNA virus that is mechanically transmitted via arthropod vectors or mucosal membrane contact with infectious particles or birds. Magellanic Penguins (Spheniscus magel- lanicus) from two colonies (Punta Tombo and Cabo Dos Baho´as) in Argentina showed spo- radic, nonepidemic signs of avian pox during five and two of 29 breeding seasons (1982- 2010), respectively. In Magellanic Penguins, avian pox expresses externally as wart-like le- sions around the beak, flippers, cloaca, feet, and eyes. Fleas (Parapsyllus longicornis) are the most likely arthropod vectors at these colonies. Three chicks with cutaneous pox-like lesions were positive for Avipoxvirus and revealed phylogenetic proximity with an Avipoxvirus found in Black-browed Albatross (Thalassarche melanophrys) from the Falkland Islands in 1987. This proximity suggests a long-term cir- culation of seabird Avipoxviruses in the south- west Atlantic. Avian pox outbreaks in these colonies primarily affected chicks, often result- ed in death, and were not associated with handling, rainfall, or temperature.

Journal ArticleDOI
TL;DR: Results suggest that C. burnetii infection is common among marine mammals in this region, and specifically among Pacific harbor seals sampled in inland and outer coastal areas of the Pacific Northwest.
Abstract: Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii. Humans are commonly exposed via inhalation of aerosolized bacteria derived from the waste products of domesticated sheep and goats, and particularly from products generated during parturition. However, many other species can be infected with C. burnetii, and the host range and full zoonotic potential of C. burnetii is unknown. Two cases of C. burnetii infection in marine mammal placenta have been reported, but it is not known if this infection is common in marine mammals. To address this issue, placenta samples were collected from Pacific harbor seals (Phoca vitulina richardsi), harbor porpoises (Phocoena phocoena), and Steller sea lions (Eumetopias jubatus). Coxiella burnetii was detected by polymerase chain reaction (PCR) in the placentas of Pacific harbor seals (17/27), harbor porpoises (2/6), and Steller sea lions (1/2) collected in the Pacific Northwest. A serosurvey of 215 Pacific harbor seals sampled in inland and outer coastal areas of the Pacific Northwest showed that 34.0% (73/215) had antibodies against either Phase 1 or Phase 2 C. burnetii. These results suggest that C. burnetii infection is common among marine mammals in this region.

Journal ArticleDOI
TL;DR: The findings highlight that canine pathogens pose a serious hazard to the viability of maned wolves and other wild carnivore populations in the area and emphasize the need for monitoring and protecting wildlife health in remaining fragments of the Cerrado biome.
Abstract: The maned wolf, Chrysocyon brachyurus, is an endangered Neotropical canid that survives at low population densities. Diseases are a potential threat for its conservation but to date have been poorly studied. We performed clinical evaluations and investigated the presence of infectious diseases through serology and coprologic tests on maned wolves from Galheiro Natural Private Reserve, Perdizes City, Minas Gerais State, southeastern Brazil. Fifteen wolves were captured between 2003 and 2008. We found high prevalences of antibody to canine distemper virus (CDV; 13/14), canine parvovirus (CPV; 4/14), canine adenovirus type 2 (13/14), canine coronavirus (5/11), canine para-influenza virus (5/5), and Toxoplasma gondii (6/8), along with Ancylostomidae eggs in all feces samples. Antibodies against Leishmania sp. were found in one of 10 maned wolves, and all samples were negative for Neospora caninum. Evidence of high exposure to these viral agents was also observed in unvaccinated domestic dogs from neighboring ...

Journal ArticleDOI
TL;DR: Results indicate that, although hundreds of thousands of birds concentrate at Delaware Bay during spring, dynamics of AIV infection differ among species, perhaps due to differences in susceptibility, potential for contact with AIV at this site, or prior exposure.
Abstract: To gain insight into avian influenza virus (AIV) transmission, exposure, and maintenance patterns in shorebirds at Delaware Bay during spring migration, we examined temporal AIV prevalence trends in four Charadriiformes species with the use of serial cross-sectional data from 2000 through 2008 and generalized linear and additive models. Prevalence of AIV in Ruddy Turnstones (Arenaria interpres morinella) increased after arrival, peaked in mid-late May, and decreased prior to departure. Antibody prevalence also increased over this period; together, these results suggested local infection and recovery prior to departure. Red Knots (Calidris canutus rufa), Sanderlings (Calidris alba), and Laughing Gulls (Leucophaeus atricilla) were rarely infected, but dynamic changes in antibody prevalence differed among species. In Red Knots, declining antibody prevalence over the stopover period suggested AIV exposure prior to arrival at Delaware Bay with limited infection at this site. Antibody prevalence was consistentl...

Journal ArticleDOI
TL;DR: In this paper, the authors retrospectively evaluated a combined data set from Delaware Bay, USA, collected from 2000 to 2009, and found that prevalence trends and subtype diversity can be effectively determined by either direct sampling of birds or indirect sampling of feces.
Abstract: Although influenza A viruses have been isolated from numerous shorebird species (Family: Scolopacidae) worldwide, our understanding of natural history of these viruses in this diverse group is incomplete. Gaining this information can be complicated by sampling difficulties related to live capture, the need for large sample sizes related to a potentially low prevalence of infection, and the need to maintain flexibility in diagnostic approaches related to varied capabilities and resources. To provide information relevant to improving sampling and testing of shorebirds for influenza A viruses, we retrospectively evaluated a combined data set from Delaware Bay, USA, collected from 2000 to 2009. Our results indicate that prevalence trends and subtype diversity can be effectively determined by either direct sampling of birds or indirect sampling of feces; however, the extent of detected subtype diversity is a function of the number of viruses recovered during that year. Even in cases where a large number of vir...

Journal ArticleDOI
TL;DR: Investigation of the impact of Puumala virus (PUUV) on survival and reproductive maturation probability of its reservoir host, the bank vole, indicates that PUUV infection may alter bank voles population dynamics by affecting both survival and maturation in its host.
Abstract: Many zoonotic diseases are caused by rodent-borne viruses. Major fluctuations in the transmission of these viruses have been related to large changes in reservoir host population numbers due to external factors. However, the impact of the pathogen itself on the demography of its reservoir host is often overlooked. We investigated the impact of Puumala virus (PUUV) on survival and reproductive maturation probability of its reservoir host, the bank vole (Myodes glareolus). Three years (2004-06) of data from nine independent sites in southern Belgium were collected and analyzed with a capture-mark-recapture (CMR) method that includes statistical correction for the variation in capture probability of voles. A multistate model based on four states of reproductive activity and PUUV immunoglobulin G (IgG) antibody status was used to estimate survival and probability of transition from one reproductive or infection state to another. Although survival estimates for reproductively active voles were similar between infected and noninfected individuals, PUUV infection in reproductively inactive voles decreased mean monthly survival by 14%. PUUV infection was associated with a threefold increase in the probability of reproductive maturation in bank voles. Moreover, the probability of PUUV IgG seroconversion was three times higher for reproductively active voles compared to reproductively inactive voles. Our model indicates that PUUV infection may alter bank vole population dynamics by affecting both survival and maturation in its host. Additional studies, using CMR methodology with shorter time intervals between trapping sessions and possibly a longer duration, are needed to confirm these findings.

Journal ArticleDOI
TL;DR: Detailed insights are provided into the intestinal excretion of an H3N8 LP AI virus in Mallards and the performance of diagnostic assays commonly used in wild bird surveillance for estimating potential risks for spillover of LP AI viruses from Mallards to domestic animals.
Abstract: Mallards (Anas platyrhynchos) and other dabbling ducks in the genus Anas are an important component of the wild bird reservoir for avian influenza (AI) virus; these viruses are maintained in migratory duck populations through a fecal-oral transmission route. We provide a detailed characterization of intestinal viral shedding in Mallards infected with a wild bird-origin low pathogenic (LP) AI virus. Five of eight, 1-mo-old Mallards inoculated with a high dose of an H3N8 LP AI virus became infected as determined by reisolation and seroconversion. Infected birds excreted high concentrations of virus for up to 14 days postinoculation (DPI) without exhibiting overt clinical signs of disease. The pattern of viral shedding was relatively consistent between individual birds, with peak shedding on 2-3 DPI and a progressive decline over the remainder of infection. Detection of viral shedding varied depending on sample type (excrement sample or cloacal swab) and diagnostic test (virus isolation or real-time quantitative reverse transcription polymerase chain reaction). Our data provide detailed insights into the intestinal excretion of an H3N8 LP AI virus in Mallards and the performance of diagnostic assays commonly used in wild bird surveillance. Such information is valuable for estimating potential risks for spillover of LP AI viruses from Mallards to domestic animals, developing accurate transmission models for Mallard populations and facilitating the interpretation and comparison of surveillance results from different studies.

Journal ArticleDOI
TL;DR: The liver, spleen, and lungs were the organs most affected in all three cases, and high numbers of T. gondii parasites were visualized immunohis-tochemically in all the tissue samples available from them.
Abstract: Toxoplasma gondii parasites belonging to endemic genotype II caused fatal infection in three (16%) of 19 Eurasian red squirrels (Sciurus vulgaris) sent for necropsy in Finland between May 2006 and April 2009. The liver, spleen, and lungs were the organs most affected in all three cases, and high numbers of T. gondii parasites were visualized immunohis-tochemically in all the tissue samples available from them. The genotyping of the parasite strains was based on the results of analysis of length polymorphism at six microsatellite markers (B18, TUB2, TgM-A, W35, B17, and M33). The length of the PCR product at the additional seventh marker (M48) was 233 base pairs from the first two cases that were found dead together, suggesting a common infection source, and 215 base pairs from the third. Eurasian red squirrels may be exceptionally susceptible to T. gondii infection.

Journal ArticleDOI
TL;DR: The results indicate that, at the low infection loads bullfrogs tend to carry, swabbing for PCR analyses may underestimate prevalence of B. dendrobatidis in this species, and highlight bullfrog disease screening as a management challenge.
Abstract: Chytridiomycosis, an emerging infectious disease caused by the chytrid fungus Batrachochytrium dendrobatidis, threatens anuran populations worldwide. Effects of B. dendrobatidis on frog species are variable. Some species typically develop nonlethal infections and may function as carriers; others typically develop lethal infections that can lead to population declines. Nonlethal infections in the bullfrog (Lithobates catesbeianus) are well-documented. In contrast, recently metamorphosed wood frogs (L. sylvaticus) can die from chytridiomycosis. We conducted an ex-situ experiment between May and July 2010 to determine whether B. dendrobatidis-infected bullfrogs could transmit the fungus to wood frog tadpoles when the two species shared a body of water. We tested for B. dendrobatidis infections with quantitative polymerase chain reactions (qPCR) in a subsample of the wood frog tadpoles and in all metamorphosed wood frogs and compared risk of death of froglets exposed and unexposed to infected bullfrogs. We de...

Journal ArticleDOI
TL;DR: The absence of epizootic respiratory disease in this experiment supports the hypothesis that Mycoplasma ovipneumoniae is an important agent of the bighorn sheep pneumonia that has previously inevitably followed experimental commingling with domestic sheep.
Abstract: To test the hypothesis that Mycoplasma ovipneumoniae is an important agent of the bighorn sheep (Ovis canadensis) pneumonia that has previously inevitably followed experimental commingling with domestic sheep (Ovis aries), we commingled M. ovipneumoniae–free domestic and bighorn sheep (n=4 each). One bighorn sheep died with acute pneumonia 90 days after commingling, but the other three remained healthy for >100 days. This unprecedented survival rate is significantly different (P=0.002) from that of previous bighorn-domestic sheep contact studies but similar to (P>0.05) bighorn sheep survival following commingling with other ungulates. The absence of epizootic respiratory disease in this experiment supports the hypothesized role of M. ovipneumoniae as a key pathogen of epizootic pneumonia in bighorn sheep commingled with domestic sheep.

Journal ArticleDOI
TL;DR: S. aureus, including MRSA, is being carried by wild animals, although at a low prevalence with the limited number of animals tested, and additional studies are needed to determine how this may impact human health.
Abstract: Livestock and pets have been identified as carriers of Staphylococcus aureus; however, the role of wild animals as a reservoir of S aureus strains has not yet been examined We conducted a pilot study to determine the prevalence of methicillin-sensitive S aureus (MSSA) and methicillin-resistant S aureus (MRSA) in 37 species of wild animals rehabilitated at a university clinic Nasal, wing, wound, and cloacal swabs were collected Of 114 animals, seven (61%) were MSSA-positive and three (26%) were MRSA-positive The MRSA isolates were obtained from two eastern cottontail rabbits (Sylvilagus floridanus) and a Lesser Yellowlegs (Tringa flavipes), a migratory shorebird Antibiotic resistance testing of the MRSA isolates revealed that two were additionally resistant to tetracycline and erythromycin, and the third isolate was also resistant to erythromycin, clindamycin, and levofloxacin All three isolates were positive for the Panton-Valentine leukocidin (PVL) gene Sequence typing of the staphylococcal p

Journal ArticleDOI
TL;DR: Preliminary reference intervals for health variables can be used to assess and monitor the population health and serve as indicators of nutritional status in these populations of wild elasmobranchs.
Abstract: Sharks are of commercial, research, conservation, and exhibition importance but we know little regarding health parameters and population status for many species. Here we present health indicators and species comparisons for adults of three common wild-caught species: 30 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) and 31 bonnethead sharks (Sphyrna tiburo) from the western Atlantic, and 30 spiny dogfish sharks (Squalus acanthias) from the eastern Pacific. All animals were captured during June–July 2009 and 2010. Median values and preliminary reference intervals were calculated for hematology, plasma biochemistry, trace nutrients, and vitamin A, E, and D concentrations. Significant differences, attributable to physiologic differences among the species, were found in the basic hematologic and plasma biochemistry variables. Significant species differences in arsenic and selenium plasma concentrations were found and appear to coincide with diet and habitat variability among these three species. Vita...

Journal ArticleDOI
TL;DR: The HPAI H5N1 isolated or detected indicates that migratory birds may play a role in the dispersal of HPAi virus, but a detailed mechanism of this role needs to be elucidated.
Abstract: Migratory (particularly aquatic) birds are the major natural reservoirs for type A influenza viruses. However, their role in transmitting highly pathogenic avian influenza (HPAI) viruses is unclear. Egypt is a “funnel” zone of wild bird migration pathways from Central Asia and Europe to Eastern and Central Africa ending in South Africa. We sought to detect and isolate avian influenza viruses in migratory birds in Egypt. During September 2003–February 2009, the US Naval Medical Research Unit Number 3, Cairo, Egypt, in collaboration with the Egyptian Ministry of Environment, obtained cloacal swabs from 7,894 migratory birds captured or shot by hunters in different geographic areas in Egypt. Samples were processed by real-time reverse transcriptase PCR for detection of the influenza A matrix gene. Positive samples were processed for virus isolation in specific-pathogen-free embryonated eggs and isolates were subtyped by PCR and partial sequencing. Ninety-five species of birds were collected. Predominant spec...

Journal ArticleDOI
TL;DR: It is demonstrated that both induction time and chase time were correlated with initial rectal temperature, although they were not significantly correlated with cortisol, aspartate aminotransferase, glucose, or creatine kinase.
Abstract: Baseline reference ranges of serum chemistry and hematology data can be important indicators for the status of both individuals or populations of wild animals that are affected by emerging pathogens, toxicants, or other causes of disease. Frequently, reference ranges for these values are not available for wildlife species or subspecies. We present hematologic and serum chemistry reference ranges for moose (Alces alces) adults, yearlings, and calves in Norway sampled from 1992-2000. Additionally, we demonstrated that both induction time and chase time were correlated with initial rectal temperature, although they were not significantly correlated with cortisol, aspartate aminotransferase, glucose, or creatine kinase. Overall, the reference ranges given here are similar to those given for American moose, with a few differences that can be attributed to environment, testing methodology, or subspecies or species status. This is the first report, to our knowledge, of reference ranges for moose in Norway.