Nearly nine months into this epidemic, the scientific community is still uncertain about the exact origin of SARS-CoV-2. Some are called bats, others pangolins. However, this is to be sure whether many animals can in fact contract the novel coronavirus. It has been proven among primates, dogs, cats, bats, hamsters, rabbits, lions, tigers and – more recently – minks.
What makes this study so unique? The authors claim that it is the first to feature a proven animal-to-human SARS-CoV-2 broadcast.
‘Strong proof’ of farm workers contracting COVID from sink
The research was done by a group of Dutch animal scientists. For each of the 16 farms studied, scientists performed a comprehensive analysis of mink, both on or on each farm. Researchers use whole genome sequencing for this process, which helps in locating sources of transmission.
Across all 16 farms, a total of 720,000 animals were included in the study. Meanwhile, 97 humans were also tested. In that group, 66 humans (67%) showed evidence of a COVID infection.
“Due to the longitudinal use of the first 4 farms, we have strong evidence that at least two people in those farms were infected with mink. Unfortunately, based on our research, we cannot provide definitive conclusions on the direction of most infections, so we do not know the total number of people who were infected with mink, “the study reads.” We conclude that The virus was initially brought from humans and has evolved on mink farms, most likely reflecting the widespread prevalence among minks in the first SARS-CoV-2 mink farms, several weeks before detection. ”
‘First proven zoonotic transmission of SARS-CoV-2 to humans’
Genetic analysis of SARS-CoV-2 samples taken from infected farm workers was similar to samples taken from mink. However, other samples taken from “unrelated SARS-CoV-2 patients living around fields” were not identical. This strongly suggests that people working directly with mink contract coronaviruses from those animals.
“The genetic sequence from each of the infected mink farms fell into one of five distinct groups, showing transmission between different mink farms” the researchers wrote.
“Additional research will be required to determine the routes of transmission. We conclude that at least some of these workers are likely to be directly infected with infected mink and thus describe the first proven zoonotic transmission of SARS-COV-2 to humans. Close cooperation between human and animal health departments is essential for early detection and control of SARS-COV-2 infections, ”the study concludes.
This research is set to be presented at the ESCMID Conference on Coronavirus Disease.