A vet in Thailand probably contracted the coronavirus from an infected domestic cat last year, researchers conclude in a new study. It is the first documented case of suspected cat-to-human transmission, although experts emphasize that the risk of cats infecting humans with the virus generally remains low.
One of the cat’s two owners, who both had Covid-19, likely passed the virus on to the cat, who then sneezed into the vet’s face, according to the paper, written by scientists at Prince of Songkla University. in Thailand. Genomic sequencing confirmed that the cat and all three humans were infected with an identical version of the virus, which was not widespread among the local population at the time.
Cats are much more likely to contract the virus from humans than to transmit it to them, scientists say. But the case reminds us that people infected with the virus should take precautions around their pets — and that veterinarians and shelter workers who may come into contact with infected animals should do the same, said Dr. Scott Weese, an infectious disease veterinarian at the University of Guelph in Ontario.
“When things become human diseases, too often we forget everything else,” he said. “I think it’s important for us to recognize that this virus can still move between species.”
Previous research has shown that pet owners can infect their cats and that cats can transmit the virus to each other under certain circumstances. But it was difficult to prove that cat-to-human transmission occurs in natural environments. (Mk, hamster, and deer have been reported to spread the virus to humans.)
The new article appeared this week in the journal Emerging Infectious Diseases, which is published by the US Centers for Disease Control and Prevention. It strongly advocates cat-to-human transmission, said Dr. Weese: “They have a pretty good story here.”
On August 4, a father and son in Bangkok developed symptoms of Covid-19 and then tested positive for the virus. Due to a shortage of hospital beds in Bangkok, the two men were taken on a 20-hour ambulance ride on August 8 to a hospital in Songkhla, a province in southern Thailand. For unknown reasons, they brought their cat with them.
When the men were hospitalized, the cat was sent to a veterinary hospital for examination. Although the cat appeared healthy, the vet, a 32-year-old woman, collected nasal and rectal swabs that tested positive for the virus. As the vet wiped the cat’s nose, the animal sneezed into her face. (The vet wore gloves and a mask during the study, but no face shield or eye protection.)
On August 13, the vet developed Covid-19 symptoms, including fever and cough. Shortly after, she tested positive for the virus.
Genomic sequencing revealed that the cat’s owners, the cat and the vet were all infected with the same version of the Delta variant, which was different from viral samples taken from other patients in Songkhla at the time.
PCR testing suggests the cat had a high viral load at the time of the veterinary examination. None of the vet’s close contacts are known to have had Covid-19 at the time, and she had no previous encounters with the pet’s owners, adding support to the theory that the cat was the source of the infection from the pet. veterinarian. (It was not clear if she later met the owners.)
The CDC recommends that people infected with the virus avoid contact with their pets. “If you’re trying to stay away from people because you’re potentially contagious,” said Dr. Weese, “Then try to stay away from animals at the same time.”