Due: Thursday, March 1, 2012
Avian Influenza A: H5N1
Avian Influenza, also known as bird flu, is a zoonotic disease with several different subtypes that affect mostly other birds, but few can be transmitted to humans. The most prevalent avian influenza virus in humans is the highly pathogenic Avian Influenza A (H5N1) virus, which has caused over 380 confirmed cases in 15 countries (Rabinowitz, 2010). Majority of cases have been transmitted via bird-to-human, with rare cases of human-to-human transmission. Continued exposure to the virus not only poses the threat of ongoing morbidity and mortality, but also the threat of H5N1 being able to adapt and change allowing sustained human-to-human transmission. (Rabinowitz, 2010).
Human exposure to H5N1 begins with the natural host for the virus, wild birds, which is then transmitted to domestic birds, and then finally reaching humans as a host. Starting with wild birds, most commonly waterfowl, the virus lives in the intestines and is shed through fecal matter, saliva, and nasal secretions. Most wild birds are resistant to infections associated with avian influenza A. Wild birds are exposed to the virus when they come into contact with contaminated nasal, respiratory, or fecal material from infected birds, most commonly fecal to oral transmission (Korteweg & Gu, 2010). Transmission to domestic birds, mainly poultry, can occur with direct contact with infected birds or indirect exposure through contaminated dirt, cages, water, and feed. Domestic birds have little to no resistance to the virus and suffer serious health issues, often resulting in death (Influenza Viruses, 2005). In the case a human is infected with H5N1, transmission routes are either through direct contact or indirect contact. Direct contact consists of people holding, catching, hunting, or playing with unknowingly infected birds. Slaughtering, defeathering, processing and preparing poultry for...