485 results match your criteria: "National Wildlife Health Center[Affiliation]"

Cell-associated microbial aggregates (CAMAs) (also referred to as coral-associated microbial aggregates) have been observed in 24 coral species from the Pacific Ocean, and studies indicate most contain gram-negative bacilli from the genus Here, we used histology with Gram staining to evaluate the morphology and distribution of CAMAs in six species of scleractinian corals from Hawaii and Palmyra. Within CAMAs, we observed the coexistence of bacteria with differing morphologies and Gram-staining properties both within and among coral species. and had mostly gram-negative bacilli, whereas gram-negative cocci dominated in .

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Paralytic shellfish toxins (PSTs), including saxitoxin (STX) and its congeners, are neurotoxins that can be produced during harmful algal blooms and cause illness or death in humans, fish, seabirds, and marine mammals. Since 2014, multiple large-scale seabird mortality events have occurred in Alaska waters, with STXs detected in some carcasses. To investigate the sublethal behavioral and ecological effects of STX on seabirds, we conducted captive dosing trials with common murres (Uria aalge).

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The increasing emergence of virulent pathogens necessitates novel approaches to predict and manage infectious disease risks. The importance of integrating observational and experimental approaches to studying host-pathogen interactions has long been recognized, as captive studies can mechanistically test hypotheses derived from field studies and identify causal factors shaping host susceptibility or tolerance of infection. However, captive experiments can also determine biomarkers of infection outcomes that could improve later interpretation of field data and identify at-risk hosts in wild populations.

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Identification of novel hepaciviruses and -associated viruses metatranscriptomics in North American lagomorphs.

Virus Evol

July 2025

Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, 2 - 40 Clunies Ross Street, Acton, ACT 2601, Australia.

Cottontails ( spp.) and jackrabbits ( spp.) within the Leporidae family are native to North America and are found in a wide range of habitats, including deserts, forests, and grasslands.

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More than 60% of emerging infectious diseases of humans have a wildlife origin, and when these diseases spread through human populations to new geographical areas, there is a considerable risk of spillback from humans to wildlife species. Spillback events can have severe consequences for wildlife populations, where the disease may cause morbidity and mortality, and human populations, where the establishment in wildlife may lead to prolonged transmission or new exposures in humans. Mitigating these consequences requires identifying the key risk factors that lead to human-wildlife transmission events and implementing risk-reducing actions, a challenge given that cross-species transmission events are rare and often data deficient.

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Disease, alone or combined with other stressors such as habitat loss and contaminants, affects wildlife populations worldwide. However, interactions among stressors and how they affect demography and populations remain poorly understood. The amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd) is a sometimes-lethal pathogen linked with population declines and extirpations of amphibians globally.

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Chronic Wasting Disease (CWD) is a prion disease that affects species, and is the only known prion disease transmitted among wildlife species. The key pathological feature is the conversion of the normal prion protein (PrP) misfolding into abnormal forms (PrP), triggering the onset of CWD infections. The misfolding can generate distinct PrP conformations (strains) giving rise to diverse disease phenotypes encompassing pathology, incubation period, and clinical signs.

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The impacts of white-nose syndrome (WNS) on many bat species in eastern North America have been well documented because of the length of time that the causative agent, Pseudogymnoascus destructans (Pd), has been present and the ability to monitor bat hibernacula in that region. However, the disease outcomes for bat species in western North America are less known because of the more recent arrival of Pd and the challenges associated with monitoring hibernating bat populations in parts of the western USA. We report on mortality events involving Yuma myotis (Myotis yumanensis) bats at two locations in King and Benton counties, Washington, USA, that were attributed to WNS during the late winters of 2020-21 and 2024, respectively.

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Climate-related drivers of migratory bird health in the south-central USA.

Biol Rev Camb Philos Soc

June 2025

U.S. Geological Survey, National Wildlife Health Center, 6006 Schroeder Rd, Madison, WI, 53711, USA.

Migratory birds are species of concern that play important ecological roles while also supporting recreational opportunities for the hunting and birdwatching public. Direct and indirect effects of climate variability, extremes, and change on migratory bird health manifest at the individual, population, species, and community levels. This review focuses on the effects of climate on migratory birds that spend part of their life cycles in the south-central USA.

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Over the past billion years, the fungal kingdom has diversified to more than two million species, with over 95% still undescribed. Beyond the well-known macroscopic mushrooms and microscopic yeast, fungi are heterotrophs that feed on almost any organic carbon, recycling nutrients through the decay of dead plants and animals and sequestering carbon into Earth's ecosystems. Human-directed applications of fungi extend from leavened bread, alcoholic beverages and biofuels to pharmaceuticals, including antibiotics and psychoactive compounds.

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An Enigmatic Wild Passerine Mortality Event in the Eastern United States.

Vet Sci

January 2025

Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.

The ability to rapidly respond to wildlife health events is essential. However, such events are often unpredictable, especially with anthropogenic disturbances and climate-related environmental changes driving unforeseen threats. Many events also are short-lived and go undocumented, making it difficult to draw on lessons learned from past investigations.

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We hypothesized that bighorn sheep ewes with chronic nasal carriage are the source of infection that results in fatal lamb pneumonia. We tested this hypothesis in captive bighorn ewes at two study facilities over a 5-year period, by identifying carrier ewes and then comparing lamb fates in groups that did (exposed pens) or did not (non-exposed pens) include one or more carrier ewes. Most (23 of 30) lambs born in exposed pens, but none of 11 lambs born in non-exposed pens, contracted fatal pneumonia.

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Veterinary medicine is unique in that graduating veterinarians can be licensed to practice independently at the time of graduation. A veterinary curriculum needs to not only prepare graduate veterinarians to meet the expectations of their professional community but also ensure those veterinarians have an accurate perception of expected job requirements. This paper evaluates and compares veterinary students' perceived expectations of graduate-level independence with their self-perceived competence over their clinical (fourth) year.

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Disease may be both a cause and a consequence of stress, and physiological responses to infectious disease may involve stress coping mechanisms that have important fitness consequences. For example, glucocorticoid and glycemic responses may affect host fitness by altering resource allocation and use in hosts, and these responses may be affected by competing stressors. To better understand the factors that affect host responses to infection, we challenged the immune system of field-acclimatized pygmy rattlesnakes, Sistrurus miliarius, with a sterile antigen, lipopolysaccharide (LPS), and measured the glucocorticoid and glycemic response in healthy non-reproductive snakes, snakes afflicted with an emerging mycosis (ophidiomycosis) and pregnant snakes.

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Pathology of tissue loss in three key gorgonian species in the Mediterranean Sea.

J Invertebr Pathol

November 2024

Department of Earth and Environmental Sciences (DISAT), University of Milan-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy; MaRHE Center (Marine Research and High Education Center), Magoodhoo Island, Faafu Atoll 12030, Maldives; NBFC (National Biodiversity Future Center), 90133 Palermo, Italy.

The Mediterranean is known for its marine biodiversity, especially gorgonian forests. Unfortunately, these are experiencing rapid declines due to climate change, manifested by repeated marine heat waves resulting in mass mortality events since the early 1990 s. To better understand why gorgonians are declining, more systematic approaches to investigate the exact causes are needed, and pathology may aid in this goal.

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Freshwater mussels (order: Unionida) are highly imperiled globally and are increasingly the focus of captive propagation efforts to protect and restore wild populations. The Upper Tennessee River Basin (UTRB) in Virginia is a freshwater biodiversity hotspot hosting at least 45 of North America's ~300 species of freshwater mussels, including 21 threatened and endangered species listed under the U.S.

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There is an increasing need for robust wildlife health programs that provide surveillance and management for diseases in wildlife and wild aquatic populations to manage associated risks. This paper illustrates the value of a systematic method to enhancing wildlife health programs. The U.

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The skin I live in: Pathogenesis of white-nose syndrome of bats.

PLoS Pathog

August 2024

Department of Pediatrics, Medicine and Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.

The emergence of white-nose syndrome (WNS) in North America has resulted in mass mortalities of hibernating bats and total extirpation of local populations. The need to mitigate this disease has stirred a significant body of research to understand its pathogenesis. Pseudogymnoascus destructans, the causative agent of WNS, is a psychrophilic (cold-loving) fungus that resides within the class Leotiomycetes, which contains mainly plant pathogens and is unrelated to other consequential pathogens of animals.

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Antibody response of endangered riparian brush rabbits to vaccination against rabbit hemorrhagic disease virus 2.

J Vet Diagn Invest

September 2024

Wildlife Health Laboratory, California Department of Fish and Wildlife, Rancho Cordova, CA, USA.

Rabbit hemorrhagic disease virus 2 (RHDV2; , ), the cause of a highly transmissible and fatal lagomorph disease, has spread rapidly through the western United States and Mexico, resulting in substantial mortality in domestic and wild rabbits. The disease was first detected in California in May 2020, prompting an interagency/zoo/academia/nonprofit team to implement emergency conservation actions to protect endangered riparian brush rabbits () from RHDV2. Prior to vaccinating wild rabbits, we conducted a vaccine safety trial by giving a single SC dose of Filavac VHD K C+V (Filavie) vaccine to 19 adult wild riparian brush rabbits captured and temporarily held in captivity.

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It has been proposed that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that spread through human populations as a pandemic originated in Asian bats. There is concern that infected humans could transmit the virus to native North American bats; therefore, the susceptibility of several North American bat species to the pandemic virus has been experimentally assessed. Big brown bats (Eptesicus fuscus) were shown to be resistant to infection by SARS-CoV-2, whereas Mexican free-tailed bats (Tadarida brasiliensis) became infected and orally excreted moderate amounts of virus for up to 18 d postinoculation.

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The threat posed by emerging infectious diseases is a major concern for global public health, animal health and food security, and the role of birds in transmission is increasingly under scrutiny. Each year, millions of mass-reared game-farm birds are released into the wild, presenting a unique and a poorly understood risk to wild and susceptible bird populations, and to human health. In particular, the shedding of enteric pathogens through excrement into bodies of water at shared migratory stop-over sites, and breeding and wintering grounds, could facilitate multi-species long-distance pathogen dispersal and infection of high numbers of naive endemic birds annually.

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American pikas () are small lagomorphs that live in mountainous talus areas of western North America. Studies on the histopathology of American pikas are limited. We summarize here the clinical histories, and gross and histologic findings of 12 American pikas, including 9 captive (wild-caught) and 3 wild animals.

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The environmental tenacity of influenza A viruses (IAVs) in the environment likely plays a role in their transmission; IAVs are able to remain infectious in aquatic habitats and may have the capacity to seed outbreaks when susceptible wild bird hosts utilize these same environments months or even seasons later. Here, we aimed to assess the persistence of low-pathogenicity IAVs from naturally infected ducks in Northwestern Minnesota through a field experiment. Viral infectivity was measured using replicate samples maintained in distilled water in a laboratory setting as well as in filtered water from four natural water bodies maintained in steel perforated drums (hereafter, mesocosms) within the field from autumn 2020 to spring 2021.

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