Dr. Andrew Allison, an assistant professor of veterinary virology at the UF College of Veterinary Medicine, has received a two-year, $101,772 grant from the Morris Animal Foundation to study recent outbreaks of a rodent-borne virus that causes deaths in conservation animal populations worldwide, including elephants.
“Encephalomyocarditis virus, or EMCV, is naturally maintained in wild rats and mice, and has a broad host range, infecting most, if not all, mammal species,” Allison said. “This virus is very well-known to the zoological community worldwide, as it has repeatedly caused severe outbreaks resulting in mortality of zoo mammals, most notably elephants, for decades.”
Currently, there is no commercial vaccine to protect animals from getting the virus, Allison said, adding that once an outbreak occurs in a zoo, prevention and control measures typically entail rodent removal around affected areas and/or quarantine of susceptible animals.
The Allison laboratory has been investigating recent EMCV outbreaks in zoos in the United States that have resulted in the deaths of numerous African and Asian mammals, including elephants, hippos, and multiple primate species, including those that are endangered.
“Understandably, these outbreaks and the loss of unique and rare megafauna are a major concern to zoos,” Allison said. “As EMCV outbreaks will undoubtedly continue to occur in the future, new avenues of vaccine research and a better understanding of the virus are critically needed in order to adequately protect animals from fatal disease.”
In the absence of commercially available vaccines, zoos may revert to producing autogenous vaccines — vaccines developed against the strain that was recovered from their animals — in hopes of providing immunity to those animals, Allison said. However, it is not known how protective such vaccines are against the multiple EMCV strains that normally circulate in rodents in the USA and abroad, he also noted.
With the new funding, Allison hopes to determine the sources and drivers of recent outbreaks; whether antibodies created against autogenous vaccines are cross-protective against various EMCVs found in nature; and the duration and magnitude of antibody responses in different species of vaccinated zoo animals. His research team will also investigate whether certain mutations in the virus may result in a loss of vaccine protection.
“Ultimately, these studies will allow us to better understand how EMCV is transmitted to zoo animals and the rodent species involved, and how diverse the viruses circulating in nature are and how that diversity dictates the effectiveness of vaccination,” Allison said.
Findings from Allison’s research will inform disease management guidelines to help protect elephants and other at-risk African and Asian megafauna, including hippopotamus, rhinoceros, antelope, lions, tigers and primates, from the virus, according to the foundation.