Avian influenza H5N8 What do H and N mean?

Avian influenza H5N8: What are H and N??

25/11/2014

There are three types of influenza viruses, A, B and C. In humans, the flu is usually caused by types A and B. The bird's rib belongs to the type A pathogen group. As the detailed backgrounds explain.

The additional classification into H and N is based on proteins found on the surface of viruses, H for hemagglutinin and N for neuraminidase. In total, there are 16 H subtypes and 9 N subtypes. Depending on the combination of subtypes, the type designations such as H5N8 are created. According to a statement of the Friedrich-Löffler-Institut (FLI), the essential reservoir of virus carriers in nature are aquatic live wild birds such as ducks. However, they are usually carriers of the virus and do not develop any avian influenza symptoms. However, they can spread the viruses to domestic poultry, mammals and humans. In the process, the viruses can mutate into highly pathogenic variants such as H5 and H7, whose disease process can also be fatal for humans.

Hunting practitioners, who are also poultry farmers, are particularly at risk. With you, the risk of indirect transmission of the pathogen is particularly high, especially when killed game birds in poultry farm is further processed (pluck, exclude, etc.). An introduction via soiled clothing or footwear is also possible.

In chicken and turkey stocks, these viruses, which are known as classical 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 among wild birds from Asia.

Exact transmission path unknown
The specific source of H5N8 virus entry has so far not been identified, according to FLI. In general, the transmission of influenza viruses in poultry is primarily by direct contact with infected animals or by contact with virus contaminated materials such as bedding, implements, footwear, protective clothing and the like. Transmission over the air has not yet emerged as an important pathway. The federally regulated avian influenza ordinance serves to prevent and combat classical avian influenza. The main focus is on biosafety measures to prevent the emergence and spread of the pathogens in poultry housing. This also includes monitoring studies in wild birds and domestic poultry, whereby the infectiological, specific diagnostics are of crucial importance. (Sb)