A lion inflamed with SARS-CoV-2 at an Indiana zoo likely transmitted the virus to at least two of the keepers caring for the big cat, according to a new study. This is the first case shown of an inflamed zoo animal transmitting the coronavirus to a human, according to the researchers. However, such transmission is likely infrequent and, in this case, is likely due to the fact that the lion had to be fed by hand, the scientists wrote in the study.
It has long been known that SARS-CoV-2, the virus that causes COVID-19, can infect many species and can be transmitted between humans and animals. The virus likely jumped from an animal to a human first, and beyond Studies have indicated that cats and puppies contract SARS-CoV-2 from owners at incredibly high rates. Other studies have shown that deer transmitted the virus to humans and inflamed hamsters in a Hong Kong puppy shop triggered a human outbreak of the delta variant.
However, “animal-to-human transmission of SARS-CoV-2 has not been reported in the past in a zoo,” the researchers wrote in the paper, which was published Jan. 31 in the medRxiv preprint database (opens in a new tab). (The results have not yet been peer-reviewed. )
Related: Bored chimpanzees in Czech zoo video chat during lockdown
The unidentified African lion (Panthera leo), who was in his 20s and resided at the Potawatomi Zoo in South Bend, tested positive for SARS-CoV-2 in December 2021 after coughing and becoming out of breath. All 10 caregivers who had been in close contact with the inflamed feline were quickly examined and all tests came back negative. But later in the week, 3 of the guards tested positive, as they had not been in contact with any other inflamed humans.
In the new study, researchers genetically sequenced viral patterns taken from inflamed lions and zookeepers. The effects showed that the lion and two of the caregivers shared a genetic strain of the virus, but the third caregiver’s pattern may not be well sequenced.
The lion was old (wild lions rarely made it past adolescence) and suffered from kidney disease and vertebral degeneration, which meant it had to be fed by hand. This has a much better chance that caregivers will contract lion disease before it shows symptoms. Leon tested positive, keepers wore respirators when interacting with the lion and all other animals at the zoo.
Related: Meerkats seem to rejoice when zoo visitors return after closure
Researchers suspect the SARS-CoV-2 lion from an asymptomatic zookeeper. The lion had won two doses of a non-human COVID-19 vaccine in September and October 2021.
COVID-19 is particularly harmful to felines, which have the same receptors for the virus as humans, meaning they can be in very poor health or even die from the disease, New Scientist reported (opens in a new tab). The lion was euthanized several days after testing positive, due to the severity of his symptoms.
A wide variety of zoo animals have become inflamed with SARS-CoV-2, and gorillas, snow leopards, hippos, hyenas and giraffes have been added. New York City Zoo in April 2021.
—Hundreds of animal species may harbor new coronaviruses
—New coronavirus discovered and from dogs to humans
—San Diego Park Gorillas Get COVID-19
However, the threat of most humans contracting the virus from an animal remains very low and humans are much more likely to infect animals than vice versa, according to the Centers for Disease Control and Prevention (opens in a new tab).
“You’d have to be in very close contact with those animals to get infected,” co-author Leslie Boyer (opens in a new tab), medical director of the Institute for Immunochemistry, Pharmacology and Venom Emergency Response (VIPER) at the University of Arizona, told New Scientist. “People like veterinarians, farmers [and] zookeepers who approach the buccal and nasal regions of those animals are at the highest risk of such transmission. “
He studied marine biology at the University of Exeter (Penryn campus) and, after graduating, introduced his own blog site “Marine Madness”, which he continues to manage with other ocean enthusiasts. He is also interested in evolution, climate change, robots, area exploration, environmental conservation, and everything else that has been fossilized. When he’s not at work, he can be found watching sci-fi movies, betting old Pokémon games, or running around (probably slower than you’d like).
Live Science is part of Future US Inc. , a leading foreign media organization and virtual publisher. Visit our company (opens in a new tab).