Can Cats Transmit Coronavirus To Humans?
Human to cat to human coronavirus transmission requires further review
Cats can pass the coronavirus to each other, but it remains unclear whether felines can pass the SARS-CoV-2 virus to humans.
An international team of researchers said in a NEJM article published on May 13, 2020, ‘With reports of transmission of SARS-CoV-2 from humans to domestic cats, and to lions at the Bronx Zoo in New York, coupled with our data showing the ease of transmission between domestic cats, there is a public health need to recognize and further investigate the potential chain of human-cat-human transmission.’
Moreover, ‘cats may be a silent intermediate host of SARS-CoV-2, because infected cats may not show any appreciable symptoms that might be recognized by their owners,’ said these researchers.
These researchers evaluated the nasal shedding of SARS-CoV-2 from inoculated cats and the subsequent transmission of the virus by direct contact between virus-inoculated cats and cats with no previous infection with the virus.
Three domestic cats were inoculated with SARS-CoV-2 on day 0.
One day after inoculation, a cat with no previous SARS-CoV-2 infection was cohoused with each of the inoculated cats to assess whether transmission of the virus by direct contact would occur between the cats in each of the three pairs.
Nasal and rectal swab specimens were obtained daily and immediately assessed for infectious virus on VeroE6/TMPRSS2 cells.
On day 1, these researchers detected the coronavirus from 2 of the inoculated cats.
By day 3, the virus was detectable in all 3 inoculated cats, with continued detection of the virus until day 5 in all cats.
And, until day 6 in two of the three cats.
This information is of particular importance given the potential for SARS-CoV-2 transmission between family members in households with cats while living under “shelter-in-place” orders.
In 2016, an H7N2 influenza outbreak in New York City cat shelters highlighted the public health implications of cat-to-human transmission to workers in animal shelters.
‘Given the need to stop the coronavirus disease 2019 pandemic through various mechanisms, including breaking transmission chains, a better understanding of the role cats may play in the transmission of SARS-CoV-2 to humans is needed,’ concluded these researchers.
“Cats are still much more likely to get COVID-19 from you, rather than you get it from a cat,” says Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory, who recommends that pet owners first talk to their veterinarians about whether to have their animals tested.
Testing should be targeted to populations of cats and other species shown to be susceptible to the virus and virus transmission.
With respect to pets, “we’re targeting companion animals in communal residences with at-risk populations, such as nursing homes and assisted living facilities,” Poulsen said on May 13, 2020.
“There is a delicate balance of needing more information through testing and the limited resources and clinical implications of positive tests.”
The US Centers for Disease Control and Prevention (CDC) has issued guidelines for pet owners regarding SARS-CoV-2.
On April 30, 2020, the CDC said ‘Based on the limited information available to date, the risk of animals spreading COVID-19 to people is considered to be low.’
‘We are still learning about this virus, but it appears that it can spread from people to animals in some situations.’
This research was supported by a grant (HHSN272201400008C, to Dr. Kawaoka) from the Center for Research on Influenza Pathogenesis, funded by the National Institutes of Allergy and Infectious Diseases, and by a Research Program on Emerging and Re-emerging Infectious Disease grant (19fk0108113, to Dr. Kawaoka) from the Japan Agency for Medical Research and Development (AMED). No industry conflicts of interest were disclosed.
SARS-CoV-2 pandemic news published by CoronavirusToday.