A study has found evidence of zoonotic transmission of Covid-19 between farm workers and infected mink.
A Dutch study conducted by veterinary specialists provides evidence that the transmission of Sars-Cov-2 from animals to humans may be possible.
The research will be presented this week at the Conference on Coronavirus Disease, which will be organized on an online platform by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID).
Scientists found this evidence when investigating 16 mink farms that have experienced outbreaks of Sars-Cov-2 in the Netherlands.
The experts carried out genome sequencing to identify the sources of transmission of the new coronavirus in these locations, which have 720,000 animals in total.
97 people who work on these farms have been tested for the presence of Sars-Cov-2 in their body – and 66% of them have shown signs of infection, either by PCR or serology.
“Due to longitudinal follow up of the first 4 farms, we have strong evidence that at least two people on those farms were infected by minks,” wrote the research authors.
“Unfortunately, based on our research we cannot make definite conclusions on the direction of most of the infections, so we do not know the total number of people that were infected by minks. We conclude that initially the virus was introduced from humans and has evolved on mink farms, most likely reflecting widespread circulation among mink in the first SARS-CoV-2 mink farms, several weeks prior to detection.”
The scientists added: “Genetic analysis of SARS-CoV-2 from the human employees on the farms showed they were the same as those found in mink, and were not identical to those found in unrelated SARS-CoV-2 patients living in the vicinity of farms. Genetic sequences from each of the infected mink farms fell into one of five distinct clusters, showing transmission between different mink farms.”
According to them, more research is needed to determine the routes of transmission.
At the moment, the exact origin of Sars-CoV-2 is still unknown; but previous studies have already shown that animals such as ferrets, hamsters, rabbits, bats, cats, and dogs can be infected by the microorganism.