Two gorillas from the San Diego Zoo Safari Park located in Escondido, California, were found to be infected with the coronavirus after they showed symptoms of the virus last Wednesday, officials said.

The park’s staff said they proceeded to test the other animals to ensure that the infection did not spread. Last Friday, authorities conducted a fecal test, and the Agriculture Department’s National Veterinary Services Laboratories confirmed the infection.

COVID-19 in Gorillas

“Aside from some congestion and coughing, the gorillas are doing well. The troop remains quarantined together and are eating and drinking. We are hopeful for a full recovery,” Executive Director Lisa Peterson said.

Since the beginning of the COVID-19 pandemic, park staff members have conducted safety measures to avoid contamination of the animals. Officials implemented mandatory face mask rules and washing of hands regularly. Additionally, personnel were given unique uniforms that were only used around the animals. Officials suspect that an asymptomatic worker is responsible for the spread of the infection.

The owner of the park, San Diego Zoo Global, reassured the public that the two infected gorillas were no threat. The park has closed its doors to the public due to the pandemic, and officials said that even under normal operations, guests would not be allowed anywhere near a 300-pound gorilla, NPR reported.

Authorities noted that the incident is the first known natural transmission of the COVID-19 to great apes. Last year, it was recorded that other animals were also infected with the virus. A four-year-old Malayan tiger that called New York its home was infected last year, being the first animal in the United States to test positive for the COVID-19 virus.

Last November, the government of Denmark killed off about 17 million minks after it was revealed that they could be infected with the new virus. The Centers for Disease Control and Prevention (CDC) previously reported infected cats and dogs. The agency also announced that ongoing studies were observing the effects of the virus on animals and how they could get infected.