On Feb. 4, 2022, pet hamsters probably carried the Delta variant of SARS-CoV-2 into Hong Kong and sparked a human COVID-19 outbreak, according to a genomic analysis of viral samples from the rodents. The research confirmed earlier fears that a pet shop was the source of the outbreak, which has so far infected about 50 people and led to the culling of some 2,000 hamsters across the city.

Hamsters are only the second animal known to be able to infect people, after mink. In late 2020, small outbreaks of COVID-19 in people in Denmark and the Netherlands were linked to farmed mink, sparking panic and mass culls.