The Atlanta zoo has now diagnosed 18 of its 20 gorillas with COVID-19, a disease outbreak that began just days before it was hoping to get a veterinary vaccine for the primates.
On Friday, Zoo Atlanta announced the first positive test among western lowland gorillas after employees noted coughing, runny noses, and changes in appetite. Veterinary lab tests at the University of Georgia confirmed the presence of respiratory illness.
The National Veterinary Services Laboratories in Ames, Iowa, has confirmed that four of the samples collected from the gorillas so far have turned up positive for the delta variant.
Monoclonal antibodies are being administered to gorillas at risk of complications from the virus at the zoo.
Officials say there is no evidence gorillas can spread the virus to humans, and visitors are too far away for them to spread the disease.
The gorillas live in four troops close together, making it impossible for zoo officials to isolate infected animals.
Zoo officials believe the virus was passed on by an asymptomatic employee caring for the gorillas. He was fully vaccinated and wearing protective equipment, such as a mask and gloves.
As a rule of thumb, if an animal care worker shows any signs of a cold, he or she needs to stay home, according to Dr. Sam Rivera, the zoo's senior director of animal health.
According to the member of the animal care team, a team member developed symptoms that she suspected might be consistent with COVID and, as a result, she was positive."
The Zoo Atlanta's senior director of animal health Sam Rivera said the zoo will provide the gorillas with a veterinary vaccine that they had been waiting to receive before the gorillas tested positive.
San Diego Zoo Safari Park treated eight gorillas for the virus in January. One silverback received a treatment of experimental antibodies and all recovered.