Animals bred in the fur animal industry can both carry and spread viruses with the potential to infect humans. In a new study conducted by researchers at Uppsala University and others, researchers have identified 36 previously unknown viruses. The study has been published in the journal Nature.
"It is interesting that we see this diversity of known and potential zoonoses found in and transmitted between so many different types of animals and over such large geographical areas. On this basis, it is not difficult to imagine that humans and other animals will be affected by new viral diseases over time," explains John Pettersson, Associate Professor at Uppsala University and one of the study's co-authors.
How viruses are transmitted between different animal species is a key issue for studies focusing on the evolution of infectious diseases, especially viruses transmitted from mammals to humans, known as zoonoses. Research on the spread of disease between livestock often focuses on traditional livestock, such as pigs. However, animals in the fur industry are also potential carriers of new viruses, bacteria and parasites that can cause disease. For example, there have been recent reports of outbreaks of avian influenza (H5N1 A-virus) in European mink bred for their fur.
In a new study, researchers from China, Sweden, Australia, the United States and Belgium carried out 'metagenomic sequencing', which analyses RNA to find RNA and DNA viruses. The researchers analysed tissues from 461 fur animals used in the fur industry, including mink and red foxes. The animals had all died of infectious disease and come from livestock farmers in different parts of China.
The researchers identified 125 virus species, of which 36 were previously unknown and 39 posed a high risk of cross-species transmission. The viruses detected included coronaviruses and influenza A viruses.
The study found that 11 zoonotic viruses (already observed as causing disease in humans) and 15 cross-order viruses (found in two or more mammalian orders but not yet in humans) frequently jumped between hosts. Raccoons carried the highest number of high-risk viruses, i.e. viruses that are likely to be transmitted to and cause disease in humans. However, many other animal species were also found to be carriers of high-risk viruses.
To better assess the public health risks associated with fur farming and other types of animal production, more extensive and regular monitoring of these animals is necessary, according to the researchers.
"This time the study was carried out in China, where animal husbandry and handling may be different from Sweden and other countries. But the findings are highly relevant for other countries as well, and I hope that this will contribute to an increased focus on animal husbandry and its importance for the emergence of new viral zoonoses," continues Pettersson.
10.1038/s41586-024-07901-3
https://www.nature.com/articles/s41586-024-07901-3
