Journal of Wildlife Diseases最新文献

As part of wildlife conservation efforts, the reintroduced Eurasian lynx (Lynx lynx) populations in Switzerland are the subject of ongoing health surveillance. Cardiac pathologies, such as heart murmurs and histological changes in the cardiac tissue, including intramural cardiac vessels, are frequently observed. Here we describe four cases of subaortic stenosis (SAS), a congenital heart disease rarely reported in felids, in free-ranging adult male lynx from Switzerland. The affected lynx presented macroscopically with grades 1 to 3 of SAS. Histopathology confirmed characteristic subvalvular fibrous tissue as well as myocardial fibrosis and arteriosclerosis. Clinical data for one lynx, including the documentation of a systolic heart murmur, provide further case-specific insights. Our findings suggest that SAS might be linked to the recurrently noted cardiac pathologies and could be associated with the low genetic variability of lynx in Switzerland. This highlights the importance of integrating health and genetic data into conservation strategies to preserve healthy, viable wildlife populations.

Birds are host to four orders of parasitic insects: flies (Diptera), lice (Psocodea: Phthiraptera), true bugs (Hemiptera), and fleas (Siphonaptera). These parasites can lower host fitness and thus require birds to invest in defenses to minimize fitness losses. In Puerto Rico, virulent parasites, such as Philornis spp. flies, threaten endangered species and subspecies of birds. Philornis larvae are hematophagous and burrow beneath the skin of both nestling and adult birds. Unfortunately, little is known regarding the prevalence and intensity of subcutaneous Philornis flies of adult birds in Puerto Rico. Here, we inspected 430 birds, representing 38 species, for Philornis infestation. We found Philornis larvae on only four birds, despite previous studies reporting high Philornis prevalence on adults of a single Puerto Rican species, Pearly-eyed Thrashers (Margarops fuscatus). Our results are consistent with other studies suggesting that the prevalence and intensity of Philornis is low in most adult and fledgling birds, compared to nestlings. Our data suggest that Philornis infestation is not a major threat to adult birds in Puerto Rico. In contrast, we show that parasitic lice are relatively common on Puerto Rican birds. Of 309 birds dusted for ectoparasites, 164 (53%) were infested with lice. None of the 309 birds were infested with parasitic fleas or bugs. Our results confirm other recent work showing relatively high prevalence and intensity of lice on birds in humid regions of the world.

Highly pathogenic avian influenza (HPAI) poses major conservation issues worldwide. In France, recurrent outbreaks of HPAI (H5) in wild birds have occurred since 2020, yet our understanding of the disease's dynamics have remained limited. By leveraging data from the national wildlife health surveillance network (SAGIR), we conducted a spatiotemporal analysis of the HPAI outbreaks in wild birds. Between 2016 and 2022, two different spatiotemporal patterns of the disease were observed in France: sporadic episodes of the virus in four episodes, forming either isolated cases or self-limited clusters at the maximum and epizootic circulation in 2022. During sporadic circulation episodes, observations were concentrated in well-defined spatiotemporal clusters with low prevalence. Those self-limited clusters, places where the density of positive events was substantially larger than in the rest of France, reflected three epidemiologic patterns: 1) recurrent clusters linked to migration and waterfowl habitats; 2) clusters involving synanthropic species in diverse areas and related to outbreaks in poultry farms; and 3) outbreaks in colonial bird species, observed once in 2020 and once in 2022, involving Red Knots (Calidris canutus) and Eurasian Griffon Vultures (Gyps fulvus), respectively. Beginning in summer 2022, the epizootic episode, characterized by a high prevalence along the northern French coasts, involved Northern Gannets (Morus bassanus) and Laridae. During this epizootic, cluster boundaries were far less well-defined. The ecology of the affected bird species and the characteristics of the circulating viral strains (often adapted to these species) may explain this new spatiotemporal dynamic compared with previously observed sporadic circulation, driven mainly through migration. Our study provides a better understanding of the dynamics of HPAI outbreaks in wild birds; nevertheless, knowledge gaps remain, and improved surveillance of HPAI in wild birds is still needed.

The impact of health and disease on wildlife population dynamics and individual survival is complex and poorly understood, especially in cryptic species such as chelonians. Eastern box turtles (Terrapene carolina carolina) are declining due to anthropogenic and natural factors, including disease, though the relative importance of these factors for individual survival is unknown. Determining survival rates in free-ranging chelonians is challenging because individuals are difficult to locate and recapture, deceased turtles can be quickly scavenged, and turtles can die underground during a brumation period. The purpose of this study was to estimate the apparent survival rate for wild eastern box turtles detected with common box turtle pathogens, including Terrapene herpesvirus 1, Terrapene adenovirus, and box turtle Mycoplasmopsis sp., using Cormack-Jolly-Seber models. We used mark-recapture data from 778 individuals from five box turtle populations collected over 7 yr (2016-22), paired with concurrently collected demographic and quantitative PCR pathogen detection data. Apparent survival estimates were different among the five sites, ranging from 71% to 88%, but similar between sexes. We found that pathogens modeled as a function of survival had a positive effect; turtles detected with a pathogen were two to six times more likely to survive than those without detected pathogens. However, this may be an artifact of high, unbiased pathogen prevalence paired with a relatively low probability of pathogen detection via intermittent testing. This analysis provides important estimates of apparent survival for the declining eastern box turtle and valuable information on the interaction between pathogen detection and estimates of individual survival, which can be used to better understand the drivers of population persistence in this species.

Understanding the factors that influence wildlife disease spread can help inform monitoring and mitigation efforts. Rabbit hemorrhagic disease virus 2 (RHDV2) infection is a highly contagious viral disease that is usually fatal for rabbit and hare species. We obtained RHDV2 infection case counts for wild lagomorph species from 2020 to 2024 across 14 US states from a publicly available US Department of Agriculture Animal and Plant Health Inspection Service dataset. We used Bayesian conditional autoregressive models to assess the effects of land cover, domestic RHDV2 infection case counts, and environmental factors on wild RHDV2 infection case counts. Our findings suggested that wild RHDV2 cases were positively related to RHDV2 cases in domestic lagomorphs, developed land cover, and lower annual precipitation. These results can be used to target RHDV2 surveillance in wild lagomorphs to urban areas where RHDV2 has been detected in domestic lagomorphs. Overall, our study provides insights into where surveillance could be prioritized to better understand the spread of RHDV2 into new areas.

Turtle acanthocephalans are a depauperate group of helminths, yet they parasitize a quarter of all turtle species in North America. Despite acanthocephalans being common in turtles, their potential as disease-causing agents remains unknown. In other vertebrate hosts, acanthocephalans are known to cause pathologic changes upon attachment (via with their armed proboscis) to the intestinal wall of the host. Herein, we report new turtle host associations, ultrastructural characterization, and molecular data for turtle acanthocephalans. However, the primary goal of this study was to evaluate whether there is pathology associated with acanthocephalans in turtle hosts. In total, 63 turtles comprising six sampled species were examined for acanthocephalans via surveillance of wild turtles in Oklahoma, USA, between 2010 and 2022. A mean intensity of 395 acanthocephalans per turtle was recovered from 30 (83%) of 36 red-eared sliders (Trachemys scripta elegans), morphologically and molecularly identified as Neoechinorhynchus chrysemydis (n=382), Neoechinorhynchus emydis (n=187), Neoechinorhynchus emyditoides (n=1,803), and Neoechinorhynchus pseudemydis (n=2,901). Only one (11%) of nine snapping turtle (Chelydra serpentina) was infected with acanthocephalans, morphologically and molecularly identified as juveniles of N. chrysemydis (n=1) and Neoechinorhynchus cylindratus (n=12), a fish acanthocephalan. Histopathologic examination revealed changes to the intestinal walls of infected red-eared sliders, including villous atrophy and excessive mucus production. Additionally, the presence of boluses of worms expelled within turtle feces was observed. Noninfected turtles showed no evidence of gross or histopathologic lesions in the intestines. Overall, these findings indicate that acanthocephalans can potentially elicit pathologic changes to turtle hosts, probably as a result of intestinal irritation due to acanthocephalan attachment.

Ophidiomycosis, caused by Ophidiomyces (O.) ophidiicola, is a disease associated with variably high morbidity and mortality in both snakes under human care and free-living snakes. Within Illinois, USA, ophidiomycosis surveillance has primarily focused on snake populations in southern Illinois, adjacent to agricultural land. The purpose of this study was to determine the occurrence of O. ophidiicola DNA across multiple snake species and locations in an urban county of northeastern Illinois, containing historically diverse and abundant snake populations. During the summer of 2023, 51 snakes, representing five species, were collected, examined, and evaluated via skin swab for the presence of O. ophidiicola using quantitative PCR. Detection of O. ophidiicola was similar between seven distinct sites and five species: 31% (9/29) in common water snakes (Nerodia sipedon), 29% (2/7) in eastern fox snakes (Pantherophis vulpinus), 17% (1/6) in DeKay's brownsnakes (Storeria dekayi), 40% (2/5) in common garter snakes (Thamnophis sirtalis), and 50% (2/4) in eastern milk snakes (Lampropeltis triangulum). Gross lesions consistent with O. ophidiicola infection, including crusts, discoloration, swelling, and ulceration, were noted in 65% (33/51) of the snakes sampled in the study and 75% (12/16) of the O. ophidiicola-positive snakes. Results indicate that O. ophidiicola in snakes in northeastern Illinois exists at a similar or higher positivity rate than has been documented in other studies across North America. Future studies may enable improved characterization of ophidiomycosis dynamics.

The collared peccary (Pecari tajacu) is a member of the Tayassuidae family widely distributed throughout the Americas, particularly in Brazil. These animals have important ecologic functions and, despite their good conservation status, are frequently affected by anthropogenic pressures. Candida spp. are commensal yeasts present in the microbiota of various hosts; however, under conditions that disrupt microbial balance, they can become opportunistic pathogens. Some Candida spp. are also of great relevance to the One Health framework, because they cause significant impacts on the health of humans and animals. The investigation of potentially zoonotic fungi in wild animals is fundamental for understanding the ecoepidemiologic dynamics, so this study aimed to detect Candida spp. in captive collared peccaries bred in naturalistic enclosures in the Brazilian Amazon. Swabs from the oral cavity were collected and processed according to classical microbiology techniques. Thirty animals were evaluated, and 93% (28/30) had at least one Candida species detected. A total of 42 Candida spp. isolates were recovered, with five identified species: Candida albicans, Candida krusei, Candida parapsilosis, Candida glabrata, and Candida tropicalis. One Candida isolate remained unidentified. These findings highlight the role of collared peccaries as potential reservoirs of opportunistically pathogenic yeasts and emphasize the importance of active surveillance of microbial diversity in wild animals.

Raillietiella orientalis(Ro) is a parasitic pentastome with a rapidly expanding geographic and herpetofaunal host range in the southeastern USA since its introduction, probably with the invasive Burmese python (Python bivittatus). However, little is known about the health impacts of Ro infection in native USA host species. Pygmy rattlesnakes (Sistrurus miliarius), small pit vipers native to the southeastern USA, were among the first documented naïve hosts of Ro in Florida, USA. Between December 2018 and February 2019, 17 free-ranging S. miliarius from central Florida were evaluated for Ro pentastomiasis and comorbidities. Necropsy revealed Ro pentastomiasis in eight (47%) rattlesnakes confirmed by morphologic and molecular methods. Pygmy rattlesnakes harbored more Ro pentastomes (mean) than documented in Burmese pythons in southern Florida; moreover, the mean length of mature female Ro in S. miliarius was greater than in pythons, suggesting altered host-parasite interactions in this naïve host. Microscopically, localized inflammation and parasitic hematin deposition were associated with Ro in respiratory and coelomic tissues. All 17 snakes (100%) had both fungal dermatitis consistent with ophidiomycosis and mixed endoparasitism; other findings included two (12%) snakes with ferlaviral pneumonia and one (6%) with gastric cryptosporidiosis. This study shows that although lesions directly attributable to Ro in S. miliarius were mild, mixed-pathogen coinfections were common, highlighting the need for further study of potential host health and fitness impacts in native Florida snakes.

The indiscriminate use of antibiotics during the past 50 yr in human and veterinary medicine and agriculture has enhanced the selection of antimicrobial resistant bacteria (AMRB) and genes (ARG), representing a serious threat to public health worldwide. Wildlife can act as reservoirs of antimicrobial resistant (AMR) environmental pollution, contributing to the dissemination of AMRB and ARG, especially in aquatic environments impacted by anthropogenic activities. The objective of this study was to evaluate the role of the coypu (Myocastor coypus), an invasive semiaquatic species, as an ecologic sentinel of AMR in the wetlands of Catalonia, Spain. A total of 116 free-living coypu were analyzed to detect the presence of AMRB and determine their antimicrobial susceptibility profile, and to detect the carriage of extended-spectrum β-lactamase and colistin resistance genes by conventional PCR. Resistant bacteria were detected in 16.3% of the samples (n=19), belonging to Aeromonas spp. (31.5%), Pseudomonas spp. (26.3%), and Enterobacterales (42.1%), with Escherichia coli (26.3%) as the principal enterobacterium. Most isolates showed AMR to aminopenicillins, lincosamides, and third-generation cephalosporins. Conversely, all isolates were sensitive to carbapenems. Analysis of ARG revealed 32% (6/19) of strains were positive for the blaCMY-2 gene (three isolates of E. coli, two of Pseudomonas spp., and one of Aeromonas hydrophila). These findings reinforce the value of testing invasive species such as coypus as bioindicators of AMR in environmental surveillance programs.