H5N1 Avian Influenza Virus

Effects of Bird Flu on Infected Birds and the Threat to Human Health

May 1, 2009

Avian influenza viruses are also known as bird flu viruses and can infect all types of birds, including wild birds, commercially raised poultry and pet birds of all types

Influenza viruses are ubiquitous and can be found almost anywhere. Scientists break influenza viruses down into three types: A, B and C. The avian influenza, or bird flu, virus belongs to the influenza A group.

Influenza viruses are further divided into strains. For instance, the H5N1 strain of avian influenza virus caused some public concern in 2005 when several human cases appeared in Asia and in Europe and the H5N1 strain of bird flu virus caused some human deaths.

Avian Influenza in Birds

Avian influenza, or bird flu, is classified as low-pathogenicity strains or high-pathogenicity strains. Strains which are classified as low-pathogenicity often produce very mild signs and infected birds may not show symptoms at all or may show mild flu-like respiratory symptoms.

In the more virulent high-pathogenicity strains, serious respiratory symptoms can occur quite quickly and these flu viruses can be fatal in as little as 1-2 days when birds become infected.

Often, poultry and pet birds are infected with avian influenza by wild birds. The avian influenza,or bird flu, virus is spread through contact with body fluids from infected birds. Body fluids may include respiratory secretions or feces.

Avian influenza virus, the H5N1 strain and the threat to people

Many strains of avian influenza virus exist and infect birds regularly. Many of these strains are also transmissible to people through contact with infected birds. Most often, outbreaks of avian influenza cause mild flu-like symptoms in people.

However, there are some strains of avian influenza virus which can cause serious and even fatal disease in people. The H5N1 strain of avian influenza is one of these strains. In fact, in Asia and Europe in 2005, there were numerous cases of avian influenza. In actuality, the H5N1 strain of avian influenza was first recognized in 1997 when it was responsible for the deaths of several people in Hong Kong, according to the US Center for Disease Control (CDC).

In almost all human cases of avian influenza or bird flu, transmission occurred through contact with infected birds. Very rarely is transmission of the avian influenza virus accomplished from person to person. However, avian influenza viruses can mutate rapidly and the major concern among health experts at this time is that the H5N1 strain of avian influenza virus may eventually mutate so that it can be transmitted easily from person to person.

To date, the H5N1 avian influenza (or bird flu) virus has not mutated to allow person to person transmission. However, should this mutation ever occur, there is a concern that this particular avian influenza virus could cause a global pandemic of bird flu.

In summary, avian influenza or bird flu is a common disease of pet birds as well as commercially raised poultry. Disease symptoms seen with avian influenza in birds can range from mild and self-limiting to quite severe with the risk of high mortality. On occasion, avian influenza viruses can also be transmitted to people through contact with pet birds, wild birds, or poultry.

The copyright of the article H5N1 Avian Influenza Virus in Pet Diseases is owned by Lorie Huston. Permission to republish H5N1 Avian Influenza Virus in print or online must be granted by the author in writing.