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October 01, 2021

COVID-19 surveillance study ongoing at wildlife rehabilitation center

Published on September 09, 2021

A study at the Wildlife Rehabilitation Center of Minnesota is investigating the efficacy of a surveillance system for detecting asymptomatic SARS-CoV-2 infections in center staff members and the animal patients.

The Centers for Disease Control and Prevention and the Council of State and Territorial Epidemiologists are funding the project, which began in early June and was initially set to conclude in August but was extended to December. The project is being overseen by Dr. Jan Mladonicky, a resident in veterinary public health and preventive medicine at the University of Minnesota Center for Animal Health and Food Safety.

Dr. Mladonicky spoke about the project during her presentation, “SARS-CoV-2 in Companion Animals and Wildlife,” during AVMA Virtual Convention 2021 on July 31.

Gloved researcher swabbing the mouth of a bat
A little brown bat has its mouth swabbed for a SARS-CoV-2 surveillance project at the Wildlife Rehabilitation Center of Minnesota. (Courtesy of Dr. Renee Schott)

She noted in the talk that while cats and dogs account for most of the confirmed animal cases of SARS-CoV-2, minks, gorillas, and big cats are susceptible to the virus as well. Laboratory studies found that rabbits, pigs, tree voles, and white-tailed deer can be infected with the coronavirus. Some infected animals can pass the virus to animals of the same species.

Dr. Mladonicky explained that physical distancing and other safety measures aren’t always possible within a wildlife rehabilitation setting.

“This is a concern, of course, because those rehabilitated animals will ultimately be released into the wild, opening up the potential to infect wild animals, which could open up the possibility of creating a wildlife reservoir for SARS-CoV-2,” she said. “This could, in turn, lead to viral transmission back to humans from these wildlife.”

Within a wildlife reservoir, variants of the coronavirus could flourish, Dr. Mladonicky added, making containment of the virus extremely difficult.

In her overview of the project, Dr. Mladonicky explained that the Wildlife Rehabilitation Center of Minnesota is one of the nation’s busiest wildlife hospitals, admitting approximately 15,000 patients annually, representing approximately 188 species. The center is staffed year-round by approximately 21 people with additional seasonal staff members and over 500 volunteers.

Animals tested for SARS-CoV-2 for the study are either sampled through a case- or an event-based surveillance strategy, Dr. Mladonicky explained. Members of the animal care team participate on a voluntary basis and provide interior nasal swabs.

When the surveillance study was rolled out in June, 51 animal care workers consented to participate. Of these, all but one have received their COVID-19 vaccine. As of Aug. 19, 275 samples had been collected from participants. To date, all results have been negative.

Nearly 200 animals were tested at the center during the same period. All tested negative for the virus.

“Ultimately, with this pilot study, we hope our results will contribute to the growing knowledge of the role of animal transmission, particularly in wildlife, in SARS-CoV-2 in the United States and pave the way for future zoonotic disease surveillance systems in settings where humans work in close proximity of wildlife,” Dr. Mladonicky said.