That question—and many similar ones—were explored in depth at the 65th Annual Wildlife Disease Association Conference, hosted July 31-Aug. 5 by the Wildlife Health Group at the Cornell University College of Veterinary Medicine (CVM). The event brought together nearly 400 participants from 25 countries, 38 states and nine provinces to advance the field of wildlife research and conservation.
Cornell wildlife disease ecologist Krysten Schuler said this year’s conference theme, “Sustainable Wildlife: Health Matters,” focused on addressing the spread of diseases that pass from wildlife to humans and domesticated animals, and vice versa. Diseases such as AIDS, Ebola and the Zika virus have spread around the world with alarming speed, often catching medical and public-health authorities off guard.
“We always seem to be in a defensive mode,” observed Cornell wildlife veterinarian Dr. Beth Bunting. “The goal of the conference was to consider wildlife health in a larger context, examining how factors like climate, ecosystem health, human interaction and genetics influence the emergence and spread of disease.”
Conference sessions included the challenges facing Javan rhinos (there are only 63 left in the world), chronic wasting disease in reindeer in Norway and a fungus that endangers hellbender salamanders in New York state. Speakers stressed the importance of exploring the environmental factors that trigger epidemics; communicating scientific data to policymakers more effectively; and updating our understanding of how diseases are passed between species.
In the session Vaccines for Conservation, Cornell wildlife veterinarian Martin Gilbert described how inoculating as few as two Amur tigers against canine distemper significantly slowed the decline of the population at Russia’s Sikhote Alin Biosphere Reserve. Ecologist Julie Rushmore’s research suggests disease outbreaks among chimpanzees could be prevented with fewer resources if chimps that spend the most time socializing with other chimps were targeted for vaccination, as opposed to using random selection. Virologist Michael Jarvis outlined an immunization method using benign viruses armed with antigens for the targeted pathogen; as the virus spreads through a species population, so does the vaccine.
Epidemiologist Sarah Cleaveland described a failed effort to vaccinate African wild dogs against rabies. When the species disappeared anyway, critics blamed the program and the vaccine. Both were cleared, but local governments still banned the handling of wild dogs. “Expect controversy when intervening in wildlife populations,” warned Cleaveland.
Cornell wildlife health professor Steven Osofsky said the session was meant to help colleagues think strategically about adding vaccines to their “conservation toolbox” while recognizing “the ethical, the philosophical, the socio-ecological, the political – and of course the practical” ramifications of wildlife vaccination.
“By thinking through all of these different issues,” Osofsky said, “we can be more effective conservation practitioners.”