Researchers from the Faculties of Veterinary Medicine and Health Sciences of the CEU Cardenal Herrera University (CEU UCH) of Valencia have published in the journal Animals the detection of two positive cases of SARS-CoV-2 in wild american mink (Neovison vison), in two rivers of the province of Castellon.
These two cases are the first in Europe in which the virus has been detected in wild animals that have not been in direct contact with infected people. The article, which has just been published after its peer review, raises the possible origin of contagion by contact of these aquatic animals with polluted sewage.
In both cases they were wild animals without contact with farm animals: the closest facility, more than 20 kilometers away, has not reported the escape of specimens since 2007
“Minks are animals that have shown susceptibility to the spread of the SARS-CoV-2 coronavirus by contact with infected people on fur farms in several countries in Europe and North America. However, the virus had not been detected so far in wild specimens of this species ”, highlights the professor from CEU UCH Jordi Aguiló.
The two positive specimens analyzed in this study were captured, along with eleven more, during the invasive alien species control campaign in the rivers. Palancia Y Mijares, where there is evidence of stable populations since the late 1980s.
In both cases they were wild animals without contact with animals of farm: the closest facility, more than 20 kilometers away, has not reported the escape of specimens since 2007, nor have cases of SARS-CoV-2 been detected in the periodic analyzes carried out by agricultural technicians.
Wastewater, possible cause of contagion
Although the origin of the infection of these animals cannot be determined with total certainty, the CEU UCH researchers suggest as the most probable cause the contact of these two wild American mink with contaminated wastewater in the rivers they inhabit, in the upper reaches of the river. Mijares and the Palancia, separated from each other by the Sierra de Espadán.
These animals were captured on January 14 and 28, dates that coincide with the third wave of the virus, whose incidence was especially high in the Valencian Community
“These animals were captured on January 14 and 28, dates that coincide with the third wave of the virus, whose incidence was especially high in the Valencian Community. This could explain the contagion of wild mink ”, Aguiló points out.
After the first necropsy of the captured specimens, which was carried out at the El Saler Fauna Recovery Center, the researchers detected the SARS-CoV-2 coronavirus “in tissue from the mesenteric lymph node, by means of a two-step RT-PCR and, subsequently, we proceeded to the sequencing of the virus RNA ”, as explained by the professor of the Department of Pharmacy of the CEU UCH and principal investigator of the Molecular Virology Group Consuelo Rubio.
According to the scientists, these positives could not be confirmed in the subsequent analyzes carried out at the Central Veterinary Laboratory of Algete, probably due to the fragility of the RNA and the new thawing the samples had to be subjected to.
Wild mink, bioindicators of the virus
The study raises for the first time the possible indirect transmission of SARS CoV-2 to the wildlife, without coming into contact with the human being. This pathway could mean that wild species susceptible to infection, such as American mink, act as reservoirs for the SARS-CoV-2 coronavirus, transmitting it to other animal species and humans.
The study raises for the first time the possible indirect transmission of SARS CoV-2 to wildlife, without coming into contact with humans
Therefore, the authors emphasize the need for an approach One Health, taking into account the interconnectedness of human, animal and environmental health to avoid the transmission of the virus not only between people, but also to wild animals.
The study authors also suggest that minks, due to their susceptibility to SARS-CoV-2 infection, could constitute a bioindicator of the presence of the virus in the environment, if studies are carried out to analyze more specimens of this and other species along the banks of the rivers they inhabit, while analyzing the presence of the virus in the waters fluvial.
The characterization of the variant of the virus in these animals, through its complete sequencing, would allow better identification of the possible routes of contagion, as well as maintaining a close surveillance before potentials mutations of the virus in its leap between species.
Fountain: CEU UCH
Rights: Creative Commons.