Imported pet hamsters probably carried the Delta variant of coronavirus into Hong Kong and caused an outbreak among humans, according to a new study. The researchers from the University of Hong Kong and government officials conducted a genomic analysis of viral samples from the rodents to confirm the fear that a pet shop was the source of the Covid-19 outbreak.
Hamsters are the only second animal known to be able to infect humans. While transmission of Sars-CoV-2 from humans to other mammals have been reported, there was no previous documentation, with the exception of farmed mink, of these animals infecting humans. After a pet store worker tested positive for Covid-19, animals in the store and in the warehouse supplying it were tested for evidence of Sars-CoV-2 infection.
The viral swabs and blood samples from pet animals were tested by RT-PCR and serological assays, respectively. The positive samples from the RT-PCR test were further studied by full genome sequencing analysis. The study showed that the virus can circulate within hamsters and lead to human infections.
Researchers said that the sequences were highly similar, but distinct. “The viral genomes obtained from hamsters are phylogenetically related with some sequence heterogeneity and phylogenetic dating suggest infection in these hamsters occurred around 21 November 2021. Two separate transmission events to humans are documented, one leading to onward household spread,” it said.
