Journal of Wildlife Diseases最新文献

Liver changes in a Bald Eagle (Haliaeetus leucocephalus) were associated with the presence of Myxidium anatidum. The myxozoan parasites were present in bile ducts. The genus and species were determined using an 18S rRNA PCR combined with sequencing of the product and a MegaBLAST search.

Over the past 75 years, the Wildlife Disease Association has served as a primary professional resource for the dissemination of scientific information and the generation of seminal contributions on diverse wildlife health issues. Historical examination of the organization's records from 1951 onwards reveals a dynamic evolution in communicative formats, from newsletters, to microfiches and bulletins, to culmination in the current periodical, the Journal of Wildlife Diseases. Using rabies as one major example, to date nearly 300 documents have appeared as Letters to the Editor, short communications, full research articles, engaging perspectives, or expansive reviews. Given the high case fatality, global distribution, broad host susceptibility, and significance to agriculture, human and veterinary medicine, and conservation biology, rabies serves as an ideal One Health exemplar shepherded by the Journal over time. Expansive topics have encompassed individual species case reports and series; sensitive and specific diagnostic methods for enhanced laboratory-based surveillance; disease ecology and control and prevention issues; epidemiological insights; disease emergence; public health engagement; pathogenesis; bio-economics; modeling considerations; host-agent biological traits, serological surveys, and novel vaccinology applied to free-ranging animals; and modern virological techniques. As such, using rabies as a subjective surrogate, the Journal has served as a critical resource, not only to chart the course of progress in the wildlife health field historically, from its rather humble North American origins during the mid-20th century, but also as its continued scientific relevance today in promotion of the transdisciplinary mission of a global professional organization.

Oral rabies vaccination (ORV) has successfully prevented appreciable spread of the raccoon rabies virus variant (RRVV) west of the Appalachian Mountains in the US. However, local and regional elimination of RRVV has been challenging, particularly in areas of the eastern US with routine spillover transmission to striped skunk (Mephitis mephitis) populations. We used rabies antibody seroprevalence monitoring data from two ORV baiting strategies, a 75 baits/km2 applied from 2012 to 2013 and a 300 baits/km2 applied from 2014 to 2016, in West Virginia, US, and home range estimates on the basis of data from striped skunks collared with a global positioning system in 2014 and 2015, to identify factors influencing skunk home range size and movements with respect to land cover classes and to compare the efficiency of hypothetical aerial ORV baiting scenarios that may improve bait uptake by skunks and increase post-ORV rabies antibody seroprevalence. When baits were deployed in late August, the mean core and overall skunk home ranges were 0.135 km2 (±0.086 km2 SD) and 0.648 km2 (±0.400 km2 SD), respectively. Skunks preferred, and maintained smaller home ranges in, pasture and had larger home ranges in deciduous-mixed forest. The ORV baiting scenarios that we explored varied in bait density, flight-line spacing between baiting transects, and flight patterns followed to deliver baits. Bait density was the most important factor that we identified; higher bait density increased predicted seroprevalence and possible bait uptake. The crisscross flight pattern compared with the parallel pattern had higher costs without a substantial increase in hypothetical bait uptake. This research provides insight into skunk ecology in a rural area of the eastern US and how various aerial baiting strategies might influence the efficiency and effectiveness of ORV related to skunks.

Baylisascaris procyonis larva migrans is a debilitating and potentially lethal zoonotic, parasitic condition that can infect a large variety of paratenic hosts, including birds and mammals and even humans. The typical pathway to develop baylisascariasis is to ingest B. procyonis eggs from contaminated feces or through contaminated soil where contaminated fecal matter has decayed. I hypothesized that earthworms (Lumbricus terrestris) living in soils contaminated with B. procyonis eggs from decayed feces of its definitive host, raccoons (Procyon lotor), would incidentally ingest B. procyonis eggs, and in turn, if earthworms were consumed by songbirds, songbirds would become infected with B. procyonis larvae, resulting in baylisascariasis. I placed 100 earthworms in B. procyonis-infused soil and determined that 92% of earthworms had a mean and SE of 7.3±0.4 B. procyonis eggs in their alimentary canals. When B. procyonis-infected earthworms were fed to European Starlings (Sturnus vulgaris), 94% (17/18) of starlings displayed signs of ataxia, torticollis, and paralysis, and 11/18 (61%) died within 22 d of first ingestion of B. procyonis-infected earthworms. White blood cell counts of starlings that ingested B. procyonis-infected earthworms increased nearly threefold, percentage of eosinophils increased 25-fold, and percentage of lymphocytes increased and percentage of heterophils decreased from day 0 to day 12 postingestion. Starlings within the control group remained healthy and displayed normal behaviors. This study highlights an overlooked pathway of baylisascariasis in paratenic hosts, which has potential as a mortality factor for many species within terrestrial ecosystems.

We necropsied a red fox (Vulpes vulpes) with gross and histologic lesions suggestive of leptospirosis, with intralesional argyrophilic bacteria. Real-time PCR detected Leptospira spp. in multiple organs. We identified Leptospira interrogans related to the Australis serogroup by typing the 16S rRNA and Lfb1 genes and by multilocus sequence typing.

The Mexican long-nosed nine-banded armadillo (Dasypus mexicanus) has continued to expand its range since it was first documented in Texas, US, in the mid-1800s. It dispersed north and east and was found in Missouri, USA, starting in the 1980s. This species is known to contract leprosy, also known as Hansen's disease, caused by Mycobacterium leprae. Infected armadillos are considered to be a zoonotic source of leprosy in the US. A recent case (2021) of leprosy in a native Missourian who had a history of contacts with armadillos appears to have been locally acquired. However, no data were available on the presence or prevalence of leprosy in wild armadillos from Missouri. We sampled various tissues from 64 armadillos, 39 road killed and 25 hunter killed/culled, from southwestern and central Missouri in summer 2022 to determine the local prevalence of M. leprae. Two animals were PCR positive for M. leprae, providing evidence that this pathogen is moving northward along with the range expansion of Mexican long-nosed armadillos.

This study investigated the prevalence of widely researched amphibian pathogens within the Rhyacotritonidae, a salamander family endemic to the Pacific Northwest of the USA. We tested skin swabs (n=309) from southern torrent salamanders (Rhyacotriton variegatus) in northern California, USA, for the presence of three pathogens: Batrachochytrium dendrobatidis, Batrachochytrium salamandrivorans, and ranavirus (frog virus 3-like). Using quantitative PCR assays, we detected ranavirus DNA in 16% of swabs but did not detect either Batrachochytrium spp. Prevalence of ranavirus ranged from 0% to 40%, and was significantly different across nine sites in Humboldt and Del Norte counties. Viral load was significantly and positively associated with the water temperature of the microhabitat. Nevertheless, overall viral loads were generally low (none higher than 782 viral particles per swab), and we did not observe any animals exhibiting clinical signs typically associated with ranavirus disease. Further research is needed to determine if this species can develop ranavirus-associated disease.

Lead (Pb) exposure is a global concern because of its harmful effects on the environment, animals, and humans. Although research on Pb poisoning in humans and avian species is extensive, similar literature on mammalian carnivores is limited. Only two reports of suspected Pb poisoning in captive cheetahs (Acinonyx jubatus) exist, and none in wild cheetahs. We quantified cumulative life exposure to Pb in 62 cheetahs (33 males, 29 females) and 11 (unknown sex) leopards (Panthera pardus). Cheetahs were grouped according to time spent in captivity: wild (>10% of life in the wild) and captive (10-100% of life in captivity); all leopards were wild. Bone Pb concentration (BLC) was measured in tibias to assess the effects of time in captivity, age, and sex on Pb exposure. Lead was detected in all cheetah and leopard tibias. Mean BLC was 1.11±1.92 mg/kg for all cheetahs, with a significantly higher mean in captive (1.57±2.25 mg/kg) versus wild (0.27±0.39 mg/kg) cheetahs. Time in captivity had a significant effect on BLC, with BLC increasing with years spent in human care. Wild leopards had a higher BLC than wild cheetahs, with a mean BLC of 1.02±1.56 mg/kg. Higher BLC in captive than wild cheetahs was attributed to Pb exposure from the ammunition used to shoot ungulates for their diet. Increased exposure in wild leopards might be attributable to opportunistic scavenging, a behavior not typically seen in wild cheetahs. This study highlights the need for non-Pb ammunition options in support of conservation, animal welfare, and ultimately human health.

We investigated the prevalence, cyst density, and any associated pathologic changes of Besnoitia spp. in the testis, peritesticular structures, and udder skin of migratory caribou (Rangifer tarandus). Possible risk factors for infection, cyst density, and inflammation were investigated. Samples from 149 male and 229 female caribou were collected from seven different herds across Canada, Alaska (US), and Greenland, 2007-09. Biopsies were taken from the udder skin in females and from the epididymis, scrotal skin, testis (seminiferous tubules and tunica albuginea), and spermatic cord in males. The cyst density (cysts per square millimeters) of Besnoitia spp. in each tissue, as well as the type of associated inflammation, were determined by histopathologic examination. Individual (age class) and environmental (season and herd) risk factors were investigated for infection, cyst density, and inflammation. Besnoitia spp. cysts were detected in 22.2, 20.4, 11.2, 31.3, 10.4, and 8.0% of the sections of epididymis, scrotal skin, seminiferous tubules, spermatic cord, tunica albuginea, and udder skin, respectively. The median cyst densities varied from 0.07 cysts/mm2 in the seminiferous tubules to 1.02 cysts/mm2 in the udder skin. Age class and season were risk factors for infection, so adults and subadults were more at risk than calves, and infection was more prevalent in the fall months (September to December) relative to other seasons. Subadults, however, demonstrated a higher cyst density compared with adults and calves. During the winter months, a higher risk of inflammation was present compared with other seasons. Overall, the intensity of inflammation was light to mild, and both pericystic and concomitant inflammation were commonly present. Further research should determine whether these parasitic cysts and the associated inflammation influence the functionality of the testis, peritesticular structures, and udder and thus reproduction.

Highly pathogenic avian influenza (HPAI) H5Nx virus clade 2.3.4.4b has impacted wild birds and mammals in Canada since late 2021, including at-risk species. We compared detections and conservation status to highlight the need to integrate disease surveillance with conservation planning when assessing risks and to guide management.