Cases of mange in animals are on the rise worldwide, and a team of Virginia Tech researchers is spearheading a local and international effort to coordinate the research among a global network of experts studying mange in wildlife.
The International Meeting on Sarcoptic Mange in Wildlife was held at Virginia Tech on June 4 and 5, 2018, hosted by the College of Natural Resources and Environment. The intensive two-day workshop brought together scientists and wildlife managers spanning four continents and varied backgrounds in order to provide a wide-ranging assessment of the latest developments and research of mange disease in wildlife.
Participants also identified and prioritized the primary gaps in knowledge and research needed to better our understanding of the pervasive Sarcoptes scabiei mite and the diseases it causes among wildlife, domesticated animals, and humans. A report of the meeting and findings was recently published in the journal Parasites and Vectors.
Sarcoptic mange is an infectious disease caused by the burrowing mite, Sarcoptes scabiei. Modern-day infestations have occurred among American black bears, wolves, and foxes in North America; llama livestock and canids in Latin America; wombats in Australia; gazelles, sheep, and endangered, captive red pandas in Asia; and a series of endangered large mammals in Africa.
The parasitic mite is re-emerging in North America, having been used in the early 1900s as an invasive parasite for the biological control of coyotes and wolves prone to preying on ranchers’ livestock. However, invasive parasites often create negative impacts for native flora and fauna, including the potential to spill over to native endangered species.
Increasing knowledge of how invasive parasites, such as the mite Sarcoptes scabiei, spread and affect novel species may help to better understand past epidemics and predict future outbreaks of mange and other infectious diseases of public health importance.
The workshop is part of a larger investigation led by Luis E. Escobar, assistant professor of disease ecology in the Department of Fish and Wildlife Conservation. The project conception included Lisa Belden, professor in the College of Science; Anne Zajac, professor of parasitology in the Virginia-Maryland College of Veterinary Medicine; and Megan Kirchgessner, a wildlife veterinarian with the Virginia Department of Game and Inland Fisheries. Escobar and Belden are both faculty affiliates of Virginia Tech’s Global Change Center, a branch of the Fralin Life Science Institute, which provided the grant for the workshop.
According to Escobar, reports of sarcoptic mange among American black bears in Virginia and neighboring states, such as Maryland and Pennsylvania, have increased significantly over the past several years. The team of Virginia Tech researchers is collaborating with state and regional partners, such as Van Wick and the Wildlife Center of Virginia, to learn how diseases can affect wide populations of wildlife by using sarcoptic mange and black bears as a model.
“If we can understand how changes in habitat can facilitate the spread of diseases, we can apply that knowledge to understand other diseases, like rabies, which also occurs in wildlife in this region and is much more dangerous for humans, pets, and livestock,” said Escobar, an expert in the field of disease biogeography. “The knowledge we plan to develop with mange in North America can also be applied to other diseases affecting wildlife around the world.”
Sarcoptic mange is a highly contagious disease that spreads between mammals via physical contact or through a contaminated environment, like burrows or nests. Domestic animals, wildlife, and humans can all be infested with the S. scabiei mite, which is termed mange in animals and scabies in humans. While various lineages of the mite display preference and the ability to flourish on specialized hosts, cases have shown that the mite can transfer across species, such as between predator and prey or between wildlife and domestic pets.
In mammals, signs of sarcoptic mange often include hair loss and a thickening and wrinkling of the skin. In addition to challenges for maintaining body temperature due to loss of fur, persistent irritation and scratching can cause lesions and lead to secondary infection. The most severe infestations may result in emaciation, lethargy, hypothermia, and death of the animal.
Through this preliminary research, Escobar seeks to understand why the mite finds some areas and hosts suitable now, where it did not before, such as the case for black bears in Appalachia. The Virginia Tech team of researchers is working toward future publications and the generation of preliminary data to develop a National Science Foundation grant proposal to expand their efforts to untangle the factors that better explain why diseases affect some regions and species but not others.
“From this meeting, we made a strong international network of collaborators,” said Escobar. “Most importantly, we’ve identified gaps in our knowledge of how Sarcoptic scabiei is affecting animal populations across the globe, setting a benchmark for research priorities for mange in wildlife over the next decade.”
The International Meeting on Sarcoptic Mange in Wildlife workshop was funded by a Seed Grant of the Global Change Center at Virginia Tech and supported by the Department of Fish and Wildlife Conservation in the College of Natural Resources and Environment at Virginia Tech.