Avian influenza or avian flu is a strain of the flu virus that is usually transmitted among birds but has on occasion infected humans, according to the World Health Organization. H5N1 in particular is a virulent strain of avian flu that has been transmitted between birds and humans. Understanding how the virus is transmitted is vital in preventing or restricting its spread.
Airborne Infected Droplets
Avian flu can spread via contact with infected droplets of body fluid, notes the World Health Organization. The infected droplets are usually suspended in the air after being expelled from the body. Contamination may occur when the infected droplets come in contact with the eyes, mouth, or nose of a potential new host.
Air and Dust Particles
Avian flu may also survive on dust particles suspended in the air. These infected particles may then be inhaled or ingested via the mouth area, explains the World Health Organization.
Contact with Inanimate Objects
The avian influenza virus may survive on inanimate objects such as bank notes and coins, clothes, door handles, and other miscellaneous items for as little as two hours to as much as two days, notes the World Health Organization. The duration of survival time depends on the material composition of the inanimate object, as well as temperature and humidity levels. The more humid the environment, the less likely the virus could survive.
Direct Contact with Infected Organism
Avian flu may also spread through direct contact with an infected bird or through an intermediary such as pigs, notes the Centers for Disease Control and Prevention. Direct exposure to infected poultry may spread the virus to humans. However current data indicates that avian flu transmission between humans remains relatively rare, according to X-Plain.com.
Exposure to Contaminated Water
Avian flu can survive in water for at least 32 days, notes the World Health Organization. Water temperature affects the duration of survival. Data collected from a study indicates that avian flu survived in water for up to 207 days when the water temperature was approximately 63 degrees Fahrenheit. In addition to temperature, the viral strain can also affect the duration of survival in water. The virus can thus spread when the infected water is ingested or makes contact with the eyes or nose.
Exposure to Infected Excrement
Avian flu can spread through contact with infected excrement, explains the World Health Organization. The infected excrement may spread the virus via direct contact or through an intermediate medium such as water or air. Infected water fowl might contaminate water via defecating infected excrement in a body of water. However the infected excrement could be used as fertilizer and thus spread avian flu via direct contact.
References
- "Avian Influenza or Bird Flu Reference Summary"; X-Plain.com; 2008 April 30
- Centers for Disease Control and Prevention: Avian Influenza Transmission of Influenza A Viruses Between Animals and People
- "Review of latest available evidence on potential transmission of avian influenza (H5N1) through water and sewage and ways to reduce the risks to human health"; World Health Organization; 2007 October 10
