Thursday, November 30, 2023

Finland: Food Safety Authority Statement On H5N1 In Fur Farms


According to the Finnish Food Safety Authority (Ruokavirasto), more than half of the fur farms in Finland have now been tested for avian H5N1, with 32 farms testing positive in the month of November. In all, 65 farms have tested positive since July.

This is the first statement we've seen since November 10th, although we've seen the infected farm list updated several times. 

First today's statement, after which I'll has a postscript.

The bird flu survey of foxes and raccoons has progressed rapidly

November 30, 2023

The avian flu survey for domesticated foxes and raccoons has progressed more than halfway. The Food Agency's laboratory has examined samples from 182 fur farms, of which bird flu has been found in 32 farms. The infected fur farms are located in the five provinces where bird flu infections have occurred before.

The bird flu survey of the fox and raccoon kennels really started in week 45, and more bird flu has been found in the survey than in the mink kennels. In the first carried out survey of mink farms, bird flu was found in only three farms out of more than a hundred examined. Possibly foxes are more sensitive than minks to getting infected with bird flu, or the bird protection in fox farms has not been as good as in mink farms.

In the survey, blood samples were taken from foxes and sable dogs in fur farms. The Regional Administrative Agency of Western and Central Finland has been responsible for organizing the sampling and coordinating the mapping for the whole of Finland. The samplers are mainly municipal control veterinarians, who have performed their work effectively. Samples have already been taken from 216 shelters and there are still around 80 shelters left. Sampling has been carried out in the nurseries in good agreement with the producers.

In the Food Agency's laboratory, the blood samples are first tested for antibodies caused by the Influenza A virus 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.

A total of 65 fur farms have been diagnosed with bird flu. So far, the Food Agency has ordered the culling of fur animals from 53 shelters. The total number of animals ordered to be killed is about 425,000, of which there are about 121,000 minks, about 287,000 foxes and about 17,000 raccoons. The preparation of termination decisions is in progress for 12 shelters. The basis for termination decisions is the protection of people's health.

While Finland initially concentrated their efforts on testing for H5N1 in mink - which are regarded as particularly susceptible to influenza A viruses - the surprise has been the high seropositivity among foxes and raccoons. 

 Finland's Institute for Health and Welfare (THL warned of this possibility last August, writing:

Although mink is considered to be the most problematic animal species in terms of avian influenza virus infections, there are also risks associated with bird flu epidemics in dense, large animal populations of foxes and other fur-bearing animals, that the virus becomes more adaptable to mammals.

With the detection of H5N1 in 65 mixed species fur farms in Finland, it begs the question, how many other fur farms around the world are similarly infected?

Unfortunately, unless unusual mortality events are reported to local authorities, it is highly likely that no one is looking.