Imported pet hamsters in Hong Kong cause of cocirculation of two SARS-CoV-2 variant strains

In the last 24 hours, Hong Kong reported 782 New COVID-19 cases and 3 new COVID-19 deaths, bringing the total number of COVID-19 infections in the territory to 19,881 cases and 227 deaths so far in a population of about 7.1 million people.

The new COVID-19 surge has been driven by not only the Omicron BA.1 and BA.2 variants but also by a new delta subvariant called AY.127 and also the SARS-CoV-2 variant B.1.258 that were both transmitted from hamsters to humans via reverse zoonotic transmissions. The hamsters were reported to have been imported from the Netherlands.

The study findings were published in the peer reviewed journal: Emerging Microbes and Infections. https://www.tandfonline.com/doi/full/10.1080/22221751.2022.2040922
 

Coronaviruses are positive-sense, single-stranded RNA viruses belonging to the family Coronaviridae in the order Nidovirales [1]. There are four genera in the family Coronaviridae, namely, Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus [2].

Coronaviruses originating from mammals, especially bats and rodents, are generally considered to be the gene sources of Alphacoronavirus and Betacoronavirus, whereas avian coronaviruses are believed to be the gene sources of most Gammacoronavirus and Deltacoronavirus [2].

The seven human-pathogenic coronaviruses known to date, including the human coronaviruses HCoV-OC43, HCoV-229E, HCoV-NL63, and HCoV-HKU1, the highly virulent severe acute respiratory syndrome coronavirus (SARS-CoV-1) and Middle East respiratory syndrome coronavirus (MERS-CoV), the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have previously likely crossed species barriers to jump from mammlian animal species into humans [1,3,4].

While more than 70% of emerging human pathogens originate in animals, the majority involve wild animals and not pet animals [6]. Pet-related transmission of viruses to human is relatively uncommon. Examples include lymphocytic choriomeningitis virus (LCMV) (from mice, hamtsers, and guinea pigs), rabies virus (from unvaccinated cats and dogs), B virus (from pet non-human primates), and cowpox virus (from pet rats) [6-9].

Sporadic cases of pet shop-related transmission of these zoonotic viruses have been reported occasionally, with the largest cluster having involved 181 symptomatic LCMV-infected patients in contact with hamsters sourced from a single distributor in the United States in 1974 [10].

However, pet shop-related outbreak of the pandemic SARS-CoV-2 has not been reported prior to our recent investigation [11]. During the investigation of this unusal cluster of probable hamster-to-human SARS-CoV-2 transmission due to SARS-CoV-2 AY.127 variant, we incidentally found a hamster-related SARS-CoV-2 B.1.258-like spike variant.

In this study, we reported the investigation of this progressive outbreak and some genomic features of this newly identified hamster-associated SARS-CoV-2 spike variant.