Gorillas at California Zoo Test Positive for Covid-19

Three iconic primates at the San Diego Zoo Safari Park show mild symptoms, including lethargy and runny noses

Three gorillas sit in a zoo exhibit, one holds a leaf and looks at the camera
Three of eight gorillas at the San Diego Zoo Safari Park show mild symptoms of a coronavirus infection Courtesy of San Diego Zoo Global

On Monday, the San Diego Zoo Safari Park announced that some of its gorillas had tested positive for the coronavirus that causes Covid-19. The gorillas are the first known great apes to become infected with the virus.

The park decided to test its gorillas for the virus when two of them began coughing on January 6. The staff sent fecal samples to the California Animal Health and Food Safety Laboratory System and the USDA’s National Veterinary Services Laboratories, which gave a presumptive positive on Friday and confirmed the diagnosis on Monday, according to a statement by the park. Officials suspect that the gorillas caught the virus from a staff member with an asymptomatic coronavirus infection.

“Aside from some congestion and coughing, the gorillas are doing well,” says Lisa Peterson, the park’s executive director, to the Associated Press’ Julie Watson. The gorillas are receiving fluids, vitamins and regular food, but no specific treatment for the coronavirus infection. “This is wildlife, and they have their own resiliency and can heal differently than we do,” Peterson adds.

Research published last fall in the Proceedings of the National Academy of Sciences suggests that great apes like gorillas, chimpanzees and orangutans could be highly susceptible to infections by the pandemic coronavirus because they are closely related to humans. Zoos including the San Diego Zoo Safari Park put in place strict health measures to reduce the risk of the virus spreading to their animals. At the park, staff fill out a daily questionnaire and wear personal protective equipment like masks and full protective suits when interacting with animals.

“We follow CDC guidelines, we follow San Diego County Health guidelines,” says Peterson in a video produced by the park. “Even with all those precautions, we still have an exposure that we think happened with that team member,” who had an asymptomatic infection.

Western lowland gorillas are critically endangered, as only 5,000 remain in the wild. The great apes live in family groups, so biologists worry that if the virus were introduced to wild gorillas, it could spread quickly, Natasha Daly reports for National Geographic. The park plans to share what it learns with conservationists and scientists working with gorillas in Africa, per the Associated Press.

The park will keep all eight of the gorillas together although only three tested positive for the viral infection.

“Some may have it and others may not,” says Peterson to National Geographic. “They live in a troop with a single silverback. He’s the leader. He guides them throughout the day. They look to him. It’s really best for them that they’re allowed to continue as they are.”

The gorillas pose no threat to members of the public, San Diego Zoo Global, which owns the Safari Park, tells NPR’s Dustin Jones. The park is closed to the public amid lockdown measures in California. And even during normal operation, visitors would not get close enough to the gorillas to catch a respiratory virus from them. Zoo spokesman Andrew James tells Reuters that the staff didn’t collect mucus or saliva samples in order to test for the virus because that kind of sample collection is too risky.

Western lowland gorillas now join several big cats, housecats, dogs and mink as animals that have naturally become infected with the coronavirus that causes Covid-19.

“The troop remains quarantined together and are eating and drinking,” says Peterson in a statement. “We are hopeful for a full recovery.”