(NEXSTAR) — An unspecified number of otters have tested positive for COVID-19 at Georgia Aquarium in Atlanta.

A handful of Asian small-clawed otters were tested for COVID at the aquarium after they began exhibiting COVID symptoms, including sneezing, runny noses and mild lethargy. Some began coughing, the aquarium said in a Facebook post.

“They are off exhibit and being cared for behind-the-scenes by our expert animal health and care teams,” the aquarium said.

The aquarium suspects the otters contracted the infection from “an asymptomatic staff member,” despite taking extra safety precautions, and stressed that animal to human transmission is “incredibly rare.”

The otters do not have direct contact with guests.

This isn’t the first time animals have tested positive for COVID-19. In January, several gorillas at the San Diego Zoo Safari Park in California tested positive for coronavirus in what was believed to be the first known cases among primates in the U.S. and possibly the world.

It appeared that the infection came from a member of the park’s wildlife care team who also tested positive for the virus but was asymptomatic and wore a mask at all times around the gorillas.

The gorillas were treated for their symptoms and made a full recovery, the park said.

The Associated Press contributed to this report.