This is the first known instance of natural transmission to great apes, the zoo said in a statement on Monday.
Two gorillas developed coughs, the zoo said in its press release.
Preliminary results of samples showed the animals had tested positive, and U.S. Department of Agriculture laboratories confirmed the results.
The tests confirmed the presence of the virus in only some of the gorillas. Zoo officials are assuming that the entire troop has been exposed.
Veterinarians are monitoring the gorillas.
“Aside from some congestion and coughing, the gorillas are doing well,” Lisa Peterson, executive director of the San Diego Zoo Safari Park, said in a statement. “The troop remains quarantined together and are eating and drinking. We are hopeful for a full recovery.”
