Surveillance Strategy for Detecting Pseudogymnoascus Destructans (PD) and White-Nose Syndrome in Montana 2016-2017

The devastating bat disease, White-Nose Syndrome (WNS), caused by the fungus Pseudogymnoascus destructans (Pd), was detected in western Washington state in March of 2016.  This detection was 1,300 miles from the previous westernmost detection and highlighted the urgency for surveillance in other western states like Montana.  Early detection of the disease may provide valuable insights into the statewide status of WNS, research opportunities, mitigation options and cave management.  The goals of Montana’s surveillance plan include 1) surveying for WNS/Pd in new geographic areas outside the WNS-affected zone and/or biologically important sites and 2) surveying for WNS infection in bat species that are not currently known to be susceptible.  In the absence of information or a risk assessment to help Montana focus on priority surveillance areas other than winter hibernacula, the 2017 strategy focuses on sampling at six hibernacula representing all regions where aggregations of bats overwinter.  Both active and passive sampling of bats and hibernacula environments will be conducted.  Active sampling can detect Pd from swabs of bats or in hibernacula soils.  Passive sampling will be conducted into the early summer specifically targeting bats found dead outside of hibernacula, bats showing clear signs of WNS infection, and bats found dead as part of a large mortality event.  Bats submitted for rabies testing may also be sampled when circumstances or characteristics of the carcass indicate WNS may be the cause of mortality.  While surveillance efforts can be costly it may provide information with enough time to better inform decision making

2015 Wildlife Disease Retrospective

Montana Fish, Wildlife and Parks is developing a Wildlife Health Program.  One of the functions of the program is to integrate disease surveillance, population health monitoring, and wildlife health diagnostic services to provide information to the public and wildlife professionals on the dynamics, risk, and impacts of disease in Montana’s wildlife.   The knowledge gained from this program is aimed at improving conservation efforts and the safety of both humans and domestic animals.  The Wildlife Health Laboratory is a statewide lab that receives hundreds to thousands of biological samples each year for disease surveillance projects, epidemiologic and morbidity investigations, and forensics.  An overview of notable zoonotic and non-zoonotic diseases detected from 2015 laboratory submissions will be discussed, providing relevance, repercussions and general background or recent history of the diseases in Montana

Hemorrhagic Disease in Montana’s Wild Ruminants

Epizootic hemorrhagic disease and bluetongue virus have been documented in Montana for decades.  Montana has experienced localized and variable population declines in wild cervids when these outbreaks occur.  Transmission is seasonal in North America, with infection occurring in the late summer and fall.  In northern states, transmission ends once adult vectors cease activity with the onset of winter.  Montana is in an epidemic zone where outbreaks appear periodically and mortality events can be significant.  Montana Fish, Wildlife and Parks wildlife health lab has tested samples from suspected outbreak events, research captures and opportunistically for detection of EHD and BTV.  Environmental factors and virus-vector-host interactions are knowledge gaps that need to be addressed to improve our understanding of these orbivirus dynamics.  Enhanced reporting, surveillance, and research efforts are potential tools that may improve our understanding of the role these viruses play in wild ruminant populations across the state

Sarcoptic Mange in Yellowstone's Wolves: Dynamics, Impacts, and the Role of Citizen Science

Sarcoptic Mange, caused by the mite (Sarcoptes scabiei) invaded the wolf (Canis lupus) population within Yellowstone National Park in 2007. Since its invasion, we have followed the mite’s spread throughout the park, conducting monthly observational surveys to assess individual infection status and pack prevalence. The spatio-temporal patterns of mange invasion have been largely consistent with patterns of host connectivity and density, and we demonstrate that the area of highest resource quality, supporting the greatest density of wolves, have been the region’s most susceptible to parasite-induced declines. Heavily infected individuals suffer twice the mortality rate as uninfected individuals and pack growth rates are much more likely to decline in the presence of mange. Future monitoring will be augmented by a new citizen science website, aimed at collecting visitor photographs of wolves and acting as an interactive public resource for information and research updates on Yellowstone’s wolves

Spatial and Temporal Patterns of Trichinella in Montana’s Black Bears, 2004-2014

Trichinella nematodes are a globally distributed, zoonotic parasite transmitted through the consumption of infected animal tissue. Humans are at risk of contracting Trichinella by consuming undercooked bear or mountain lion meat, and thus historically, Montana Fish, Wildlife, and Parks subsidized Trichinella-testing of hunter-harvested black bears (Ursus americanus) and mountain lions (Puma concolor). Here, we summarize 11 years of data (2004-2014) on the spatial and temporal distribution of Trichinella in Montana’s black bears. Risk of infection was spatially variable, highest in northwest Regions 1 and 4, and was positively associated with black bear and grizzly bear (Ursus arctos horrobilis) densities. Prevalence has been significantly declining across the state over time from a state-wide prevalence of 0.05 in 2004 to 0.02 in 2014. Potential causes and consequences are discussed.  Montana Fish, Wildlife, and Parks stopped subsidizing Trichinella testing in 2015; hunters are asked to thoroughly cook their meat to an internal temperature of 165° F, which inactivates Trichinella species and most other parasites

Use of Real-time PCR to Detect Canine Parvovirus in Feces of Free-ranging Wolves

Using real-time PCR, we tested 15 wolf (Canis lupus) feces from the Superior National Forest (SNF), Minnesota, USA, and 191 from Yellowstone National Park (YNP), USA, collected during summer and 13 during winter for canine parvovirus (CPV)-2 DNA. We also tested 20 dog feces for CPV-2 DNA. The PCR assay was 100%sensitive and specific with a minimum detection threshold of 104 50% tissue culture infective dose. Virus was detected in two winter specimens but none of the summer specimens. We suggest applying the technique more broadly especially with winter feces

Modeling Management Strategies for the Control of Bighorn Sheep Respiratory Disease

Infectious pneumonia has plagued bighorn sheep populations and stymied recovery efforts across the western United States for decades.  Here we present a simple, non-spatial, stochastic, discrete-time model that captures basic bighorn sheep demographics and in which we simulate the dynamics of Mycoplasma ovipneumoniae, the suspected primary causative agent in bighorn sheep respiratory disease. We then use the model to explore the impacts of management approaches, including augmentation, depopulation and reintroduction, density reduction, and test-and-cull, aimed at reducing or eliminating the pathogen, its transmission, or associated infection costs. Results suggest that test-and-cull (testing 95% of a herd and removing PCR-positive individuals) and depopulation and reintroduction (assuming ability to only depopulate 95% of the herd) offer the best probability of eliminating the pathogen, although neither are expected to be 100% successful. Augmentation (adding 30 adult ewes) does not increase the probability of pathogen extinction, and in some cases may prolong pathogen persistence and diminish herd recovery.  Density reduction (randomly removing 25-50% of the herd) only modestly increases the probability of stochastic pathogen extinction and herd recovery.  Stochastic pathogen extinction and herd recovery is predicted to occur on occasion without any management intervention. Ultimately, decisions to manage respiratory disease in wild sheep must weigh the predicted success of the management tool against financial, logistical, ethical, and value-based considerations. Here, we aim to supply mechanistic-based predictions of the relative efficacy of currently employed or proposed tools, as well as characterize the sensitivity of these predictions to our assumptions about how the disease process works

Climate Change and Infectious Disease Dynamics

The International Panel on Climate Change has made an unequivocal case that the earth\u27s climate is changing in profound ways, and that human activities are contributing significantly to climate disruption (IPCC 2007). The weight of evidence demonstrates warming global temperatures, changing patterns of precipitation, and increasing climate variability, with more extreme events. Thus, the physical underpinnings of ecology are changing, with pervasive effects on disease dynamics. Interactions among environment, hosts, and pathogens drive disease processes, and climate change will influence every interaction in this triad, directly and indirectly

Infectious Diseases in Yellowstone’s Canid Community

Each summer Yellowstone Wolf Project staff visit den sites to monitor the success of wolf reproduction and pup rearing behavior. For the purposes of wolf monitoring, Yellowstone National Park (YNP) is divided into two study areas, the northern range and the interior, each distinguished by their ecological and physiographical differences. The 1,000 square kilometer northern range, characterized by lower elevations (1,500–2,200 m), serves as prime winter habitat for ungulates and supports a higher density of wolves than the interior (20–99 wolves/1,000 km2 versus 2–11 wolves/1,000 km2). The interior of the park encompasses 7,991 square kilometers, is higher in elevation, receives higher annual snowfall, and generally supports lower densities of wolves and ungulates

Infanticide in wolves: seasonality of mortalities and attacks at dens support evolution of territoriality

Evidence for territoriality is usually correlative or post hoc as we observe the results of past selection that are challenging to detect. Wolves (Canis lupus) are considered territorial because of competition for food (resource defense), yet they exhibit classic intrinsic behaviors of social regulation (protection against infanticide). This emphasis on prey and infrequent opportunity to observe wild wolf behavior has led to little investigation into the causes of or competitive underpinnings in the evolution of wolf territoriality. We report 6 cases of territorial wolf packs attacking neighboring packs at or near their den; 2 attacks were observed in detail. In all cases, except perhaps one, the attacking pack killed adult wolves either at the den or near it; in 4 cases, pups were probably lost. Loss of pups led to future loss of territory and in one case pack cessation. Intraspecific killing (measured in collared adults only) peaked in April, the month when pups were born and helpless in dens, even though aggressive interactions were at their seasonal low. Twelve of 13 (92%) of the wolves killed during the denning season (March, April, May) were reproductive (males and females), and 8 of 12 were dominant individuals (highest ranking wolf for that sex in the pack). Wolf–wolf killings were also high in October and December, the beginning and middle of the nomadic season, respectively. Aggressive interactions were more frequent during the nomadic season when wolves were roaming their territory as a group compared to the denning season when wolf activity was centered on the den and pack members less cohesive. We conclude that attacks on dens are a more effective form of interpack competition than interference during the breeding season, the current best-supported hypothesis, and that protected pup-rearing space is the primary cause of wolf territoriality