Bird flu H5N8: What do H and N stand for?
There are three types of flu viruses, A, B and C. In humans, flu is usually caused by types A and B. The bird rib belongs to the type A pathogen group. We explain the exact background.
The additional division into H and N is based on proteins found on the surface of viruses, H for hemagglutinin and N for neuraminidase. There are a total of 16 H subtypes and 9 N subtypes. Depending on the combination of the subtypes, the type designations such as H5N8 are created. According to a report by the Friedrich Löffler Institute (FLI), the main reservoir of virus carriers in nature is aquatic wild birds such as ducks. However, they are usually only carriers of the virus and do not develop any symptoms of avian flu. However, you can spread the virus to domestic poultry, mammals and humans. The viruses can mutate into highly pathogenic variants such as H5 and H7, the course of which can be fatal to humans.
Hunting practitioners who are also poultry farmers are therefore particularly at risk. The risk of indirect transmission of the pathogen is particularly high for you, especially if game birds that have been shot are further processed in poultry operation (plucking, gutting, etc.). Carrying over contaminated clothing or footwear is also an option.
In chicken and turkey populations, these viruses, known as classic avian influenza, can even lead to high loss rates, which is why they are of great economic importance.
The virus H5N8, which has appeared in Europe, e.g. was previously known to wild birds from Asia.
Exact transmission path unknown
The specific entry source for the H5N8 virus has so far not been identified according to the FLI. In general, the transmission of influenza viruses in poultry occurs primarily through direct contact with infected animals or through contact with virus-contaminated materials such as bedding, equipment, footwear, protective clothing and the like. So far, airborne transmission has not emerged as an important form of distribution. The federally regulated avian influenza regulation serves to prevent and combat classic avian influenza. The main focus is on biosecurity measures to prevent the development and spread of the pathogens in poultry farming. This also includes monitoring examinations in wild birds and domestic poultry, with infectiological, specific diagnostics being of crucial importance. (sb)
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