Avian Influenza is an infectious viral disease of birds caused by type 'A' strains of the influenza virus. The flu virus appears naturally among birds. Wild migratory birds such as ducks, geese, gulls and shorebirds are natural carriers of the virus, but are resistant to severe infection from the virus. However, the virus is contagious among domesticated poultry birds and can cause very severe consequences.
AI is diagnosed in humans by isolating the virus from nasal secretions by rapid testing methods.
Ai is usually treated symptomatically including administration of plenty of fluids. Sometimes newer antiviral medications such as ostelmavir (Tamiflu) and zanamavir (Relenza) are used, which however may only be partially effective. People at risk should receive the current season's influenza vaccine only to reduce the possibility of infection with both avian and human influenza.
Avian Influenza is transmitted by contact with infected birds or surfaces contaminated with nasal secretions or excretions from infected birds.
There are many different serotypes of the Avian Influenza virus depending on the hemagglutinin [HA] and neuraminidase [NA] surface proteins. There are 15 different types of HA and 9 different NA. Based on the combination of these proteins, certain AI are more pathogenic than the rest.
Highly Pathogenic Avian Influenza (HPAI) infections are characterized by a severe and highly contagious illness, affecting most vital organs with mortality rates in domestic flocks approaching 100%.
Low Pathogenicity Avian Influenza (LPAI) on the other hand is the form which is commonly found in the wild bird population. Illness with LPAI is characterized by mild respiratory symptoms and has a low mortality rate in domesticated flocks. However, LPAI like all other influenza viruses has the ability to mutate and become Highly Pathogenic Avian Influenza.
Most cases of AI develop within 3-7 days of exposure to infected birds or contaminated surfaces.
People infected with AI manifest with typical flu like symptoms such as fever, cough, sore throat and muscle aches, to eye infections, acute respiratory distress, and pneumonia amongst others.