#17,747
Today the Finnish Food Safety Authority (Ruokavirasto) issued an update on their survey of all mink farms in the country for the H5N1 virus, a program which was announced last August and officially got underway in September.
Over the summer we saw 27 fur farms infected with H5N1 in Finland, and while most involved foxes and raccoons, 3 of those farms also raised mink.
In early October we saw the announcement of 2 additional infected mink farms, and today a 3rd case has been announced for the month of October.
Infected mink are are considered particularly problematic, with with past outbreaks of both H5N1 and SARS-CoV-2 linked to the development of mammalian adaptations in the virus. The concern over H5N1 in mink was well addressed a few of months ago by two well known UK virologists in an opinion piece published in the Journal PNAS.
Mink farming poses risks for future viral pandemics
Thomas P. Peacock and Wendy S. Barclay
July 19, 2023
120 (30) e2303408120
https://doi.org/10.1073/pnas.2303408120
Today's report finds the asymptomatic spread of H5N1 in 3 of the farms tested since the last report. While testing is centered on mink farms, there are plans to expand testing to hundreds of other fur farms later this month.
In the survey of minks, bird flu has been found in a few fur farms
November 3, 2023
In the bird flu mapping of mink farms, samples from 111 mink farms have been examined in the Food Agency's laboratory tests, of which minks from three farms have been found to be infected with bird flu. The latest infection was found in Merikarvia, a mink farm located in Satakunta. The results of the survey show that bird flu infection rarely occurs in mink farms where no symptoms have been detected in the animals.
After the bird flu epidemic that started in the summer in the fur farms in Ostrobothnia, the disease has been found in a total of 32 fur farms in the area of five provinces. Before the start of the survey, bird flu was found in five mink farms during an inspection and sampling based on the suspicion of an animal disease.
In order to map the bird flu situation, the Food Agency started monitoring all fur farms in mid-September. In the first phase of the survey, samples from shelters with minks have been examined, because bird flu infections in minks pose a greater health risk to human health than bird flu infections in other fur animals. The mapping of mink farms is missing samples from a few farms.
The bird flu survey of fox and raccoon kennels has already started in a few kennels. The mapping will begin at full capacity in week 45. The Regional Administrative Office of Western and Inner Finland is responsible for organizing the sampling and coordinating the mapping for the whole of Finland. Most of Finland's fur farms are in the area of the Regional Administration of Western and Inner Finland.
At the beginning of the survey, blood samples were taken from the shelters for antibody research and dead animals for virus detection (PCR research). From the beginning of week 40, the mapping was switched to taking only blood samples. The purpose of the change was to speed up the progress of the survey, so that potentially infected mink farms can be screened out before the human flu season begins.
Antibodies caused by the influenza A virus in fur animals are first examined using the ELISA method. Antibody-positive samples are confirmed by the HI method ( hemagglutination inhibition ). The method examines the binding of the antibodies in the sample to the HA protein of the influenza A virus, which is the same subtype as the virus isolated from fur farms. The test accurately identifies antibodies to the H5 virus.
The Food Agency will order animals to be euthanized from fur farms whose samples show antibodies to H5 bird flu.
