Avian Flu Virus Specifics

Occurrence

Avian flu viruses cause influenza in birds, which is how they got their name (avian). The viruses can cause mild to severe illness in domestic birds (for example, chickens and turkeys). Migratory waterfowl, like wild ducks, have some resistant to avian flu- however, they can still harbor the virus even though they do not get sick.

Even though avian flu viruses primarily affect birds, these viruses have been observed to jump from birds to other animals, causing disease in tigers, pigs, cats, and even humans.

 

H5N1

The most well-known subtype of avian flu virus is H5N1. In fact, in recent times, “avian flu” has come to refer to the flu caused by highly pathogenic H5N1 viruses. H5N1 is a very dangerous virus, and has caused fatal disease and epidemics in bird populations. There have recently been many cases of H5N1 jumping from birds to humans, causing very severe influenza in humans. This has concerned scientists, because H5N1 could be extremely deadly if there was an epidemic.

 

Classification

The avian flu virus is part of the orthomyxoviridae family of flu viruses. The virus is classified as a type A influenza virus, meaning that it can cause serious disease, and has the potential to cause epidemics.

 

Structure

The avian flu virus can be round or oval shaped. The surface of the virus is covered with spike-shaped neuraminidase (N) and hemagglutinin (H) surface proteins.

The virus uses hemagglutinin surface proteins to break through the cell membrane to infect the cell. After a host cell is infected, the copies of the virus within the cell use the neuraminidase surface proteins to escape from the cell, so they can continue to go infect other cells.

The virus’s genetic material is made up of RNA. The RNA is divided into 8 segments, which each range from about 800 to 2300 nucleotides in length. The whole virus genome is about 13000 nucleotides long.