Several mink have tested positive with COVID-19 at four mink farms in the Netherlands. The mink showed various symptoms including respiratory problems. Some employees had symptoms of the coronavirus at both companies. Research shows that mink on the farm have transmitted the virus to each other. It is also plausible that one of the employees has been infected by mink.
The Animal Health Service (GD), Utrecht University (UU), Erasmus MC (EMC) and Wageningen Bioveterinary Research (WBVR) are conducting research to gain more insight into the virus, the spread of the virus and the spread in the environment. Samples of sick and healthy animals have been collected and air and dust samples have also been taken in the vicinity of the farms. GGD is involved in sampling and research into contamination of employees.
Spread of the virus between mink
Previous research has shown that ferrets are susceptible to SARS-CoV2. Therefore it was already assumed that mink might be susceptible too. Pneumonia was seen in sections on mink and SARS-CoV-2 was detected in organs and throat swabs. Based on the variations in the genetic codes of the virus, it could be concluded that mink farms have transmitted the virus to each other.
Possible spread from mink to an employee
Minister Schouten of Agriculture, Nature and Food Quality (LNV) reports in a letter to parliament dated 19 May that it is plausible that one of the employees was infected with the coronavirus by mink. Additional measures have been announced for mink farms. All Dutch mink farms will be screened and visitors are banned from visiting the stables. A reporting obligation had already been introduced and employees were already required to wear protective clothing.
Virus in dust particles in the stables
Virus RNA has been detected in dust particles in the stables, which indicates that people in the stables with infected minks can be exposed to coronavirus.
No virus found in outside air samples
The first results show that no virus was found in the air samples outside the farms. However, virus has been found in the immediate vicinity of mink on dust particles within the farms. It is not unknown if people can become infected with COVID-19 through these dust particles. Minister Schouten reported this in a letter to parliament dated 8 May. The National Institute for Public Health and the Environment (RIVM) indicates that the risk of exposure of people to the virus outside the farms is negligible.
Precautionary measures in the area withdrawn
In the second sampling series, the virus was no longer found in dust particles in the air inside or outside the farms. The previous advice not to walk or cycle in a 400 meter radius around an infected mink farm has therefore been withdrawn by Minister Schouten on 15 May.
Three cats infected
Eleven cats at one of the infected farms were involved in the study. Antibodies to COVID-19 have been demonstrated in three of these cats. This means these cats were infected with the coronavirus.
WBVR tested the animals
Wageningen Bioveterinary Research has performed confirmation tests on samples from the mink. In addition, further research is being done in collaboration with GD, UU and EMC.