A coronavirus outbreak in Hong Kong has been linked to pet hamsters.
According to a new study, imported pet hamsters brought the delta version of the novel coronavirus into Hong Kong, causing a local outbreak.
The study, which was published on Jan. 28 in the database Preprints with The Lancet, is the first to show that SARS-CoV-2, the virus that causes COVID-19, may be transmitted from hamsters to humans. Although hamsters can be infected with the coronavirus in laboratory settings and are frequently employed in research, there was no indication of the rodents spreading the virus to humans before the Hong Kong incident, according to Nature.
According to Nature, the outbreak has so far afflicted roughly 50 individuals and forced government officials to slaughter thousands of pet hamsters in the city.
According to The Washington Post, the current investigation began after a pet shop worker in Hong Kong's Causeway Bay district tested positive for COVID-19 in January. According to Nature, the 23-year-old woman was infected with the delta variant, which was unusual because the variety hadn't been seen in the city since October 2021.
The woman had not come into touch with any other people who had been infected, but she had been working in a pet shop called Little Boss, which sells hamsters, rabbits, guinea pigs, and chinchillas, according to the study authors.
Early in the pandemic, there were cases of mink-to-human coronavirus transmission on mink farms, according to Live Science. Hong Kong health officials began inspecting animals at the pet shop for signs of coronavirus infection, suspecting that this could be another incidence of animal-to-human transmission. They also screened animals in the wholesale market where the pet shop's animals are purchased.
Officials found no signs of infection in any of the rabbits, guinea pigs, chinchillas, mice, or dwarf hamsters they examined. However, eight of the 16 Syrian hamsters tested at the pet shop had indications of SARS-CoV-2 infection, as evidenced by a positive PCR test and/or antibodies in their blood. Seven of the twelve Syrian hamsters tested at the warehouse had the same problem. They claimed that none of the rodents showed obvious signs of sickness.
During the course of the investigation, a woman who had recently visited the pet shop-tested positive for COVID-19, and her spouse and children followed suit. Investigators evaluated the genomes of coronavirus samples collected from the woman, her husband, and the pet shop worker, as well as the genomic sequences of viral samples collected from 12 of the 15 afflicted hamsters. According to Nature, all of these samples were a variation of the delta variant that had never been seen before in Hong Kong, however the sequences were not totally identical.
The team deduced that some of the hamsters contracted the coronavirus in November 2021, before being shipped to Hong Kong from the Netherlands, based on these minor genetic differences. The authors came to this conclusion in part because the viral sequences most closely resembled those of samples gathered from patients in European countries and uploaded to a public database.
The virus subsequently spread to more hamsters in Hong Kong, picking up a few mutations along the way, before infecting the pet store owner and a client on different occasions, according to the researchers. According to the scientists, the consumer then transferred the virus on to her spouse in a case of human-to-human transmission.
The viral sequences discovered in Hong Kong individuals and hamsters have four distinct alterations, according to the investigators, when compared to the delta variant samples from Europe. Two of these alterations are in genes that code for the spike protein, which the virus uses to infect cells, and could help the virus avoid some antibodies and enter cells more quickly. The researchers also discovered a third spike protein mutation, the ramifications of which need to be investigated further, they stated.
Despite the study's findings, Arinjay Banerjee, a virologist at the University of Saskatchewan in Saskatoon, Canada, told Nature that it's still possible that the hamsters contracted SARS-CoV-2 after arriving in Hong Kong. There are so many persons touching hamsters during the travel procedure, he explained. One batch of hamsters was transferred to a different plane in Doha, Qatar, while the second group was transferred to the same jet in Bangkok, Thailand, according to the study authors.
However, Marion Koopmans, a virologist at Erasmus University Medical Center, told Nature that she agrees with the authors that the hamsters were infected before being imported.
In either instance, the study reveals that hamsters may and do transmit the coronavirus to humans, but to be fair to the hamsters, senior author Leo Poon, a virologist at the University of Hong Kong, told Nature that people are still much more likely to catch the virus from each other.