SARS-CoV-2 infections in cats: assessing their zoonotic potential and role in sustaining the COVID-19 pandemic

SARS-CoV-2 is a new coronavirus of animal origin that recently emerged in humans and has spread rapidly across the world. It is likely that SARS-CoV-2 will establish as an endemic virus of humans, which has the potential to lead to infections in animals that live in close proximity to humans. There have been sporadic reports of infections in pet cats in households with COVID-19 patients, which demonstrates that cats are susceptible to SARS-CoV-2 infection. This means that cats could potentially act as virus reservoirs, or sources of infection for other species. Experimental infections have demonstrated that cats are susceptible to SARS-CoV-2 infection and infected cats are capable of transmitting SARS-CoV-2 to other cats. The virus replicates in the respiratory tract and infectious virus can be detected in nasal washes, oropharyngeal and rectal swabs. In addition, traces of the virus have been detected in faeces and occasionally urine. The risk of human-to-cat infection and the potential for the establishment of cats as a reservoir for SARS-CoV-2 is unknown. In light of recent reports in The Netherlands and Denmark of SARS-CoV-2 jumping from humans into mink, transmitting between mink and then jumping back into humans, further research is warranted to investigate animals that are susceptible to COVID-19, including domestic pets. In this project we will investigate the susceptibility of domestic cats to SARS-CoV-2 infection and their capacity to transmit the virus to cats and other species as the pandemic progresses. A successful cross-species jump of SARS-CoV-2 from humans into cats not only expands the host range of the virus but might also generate an additional source of infections for humans and other species, which would make the elimination of SARS-CoV-2 more complex. Only by assessing the potential of SARS-CoV-2 viruses isolated from cats to infect other species, including humans, will it be possible to effectively gauge and control virus transmission to all potentially susceptible species.