A recent Gujarat-based study has revealed that dogs, cows and buffaloes are infected with COVID-19 in the state. The study however clarified that there is no evidence that the infected animals can be carriers for humans due to lower viral load even as it's most likely that they got the infection from proximity to infected humans.
Preprint of the study ‘Surveillance and molecular characterization of SARS-CoV-2 infection in non-human hosts in Gujarat, India' by researchers of Kamdhenu University and Gujarat Biotechnology Research Center was recently made available online.
The nasal or rectal samples from 413 animals including 195 dogs, 64 cows, 42 horses, 41 goats, 39 buffalos, 19 sheep, 6 cats, 6 camels and 1 monkey were collected from different places of Gujarat.
‘A total of 95 (24%) of the animals were found positive, comprising 67 dogs, 15 cows and 13 buffalos. Nasal samples gave better results compared to rectal samples… One positive sample from the dog was sequenced completely that indicated 32 mutations – it was found to be of Delta variant (B.1.617.2),' the study said.
The study says that ‘In contrast to humans, where only respiratory and oral droplets serve as main source of infection, both respiratory and fecal secretions of animals may act as important as source of infection and act as an additional source of virus for environmental contamination and transmission.’
‘The positive cases in animals coincided with the second wave of COVID-19 infection in India and positive human cases. Thereafter, with the decline of human cases the positivity became reduced to zero level. Hence, it can be concluded that the positive animals acquired the infection from human sources but the studied species were not able to cause reverse transmission,' mentioned the study, indicating that the cat family however requires further probe in Indian conditions.