Understanding Avian Influenza
What is avian influenza, normal influenza and pandemic influenza?
Avian influenza is a disease affecting birds that is caused by several types of Influenza viruses. Highly Pathogenic Avian Influenza (HPAI) is a highly contagious disease affecting wild birds and poultry, and has been responsible for recent human outbreaks and deaths in Asian countries.
Avian influenza spreads to humans mainly through contact with infected birds, which shed the virus in their saliva, nasal secretions and faeces. Very rarely, inefficient and limited human-to-human transmission may occur. (MOH website)
Influenza is an infection caused by a virus called the influenza virus. It is usually a more severe illness than the common cold which is caused by other respiratory viruses. There are 3 main types of influenza: influenza A, influenza B and influenza C. Influenza A and influenza B are associated with annual outbreaks and epidemics.
Influenza A usually causes more severe illness than influenza B and can result in pneumonia, hospitalization or even death, especially in the elderly and those with chronic illnesses. Influenza A has also been responsible for all previous pandemics (worldwide epidemics of influenza). Influenza C is very rarely seen and is associated with only mild sporadic illness. (MOH website)
Pandemic influenza occurs when a new influenza virus emerges and starts spreading as easily as normal influenza (ie efficient human-to-human transmission) - by coughing and sneezing. The new virus must be able to replicate in humans and cause serious illness. As the virus is new, the human immune system will have no pre-existing immunity. This makes it likely that that people who contract pandemic influenza will experience more serious disease than that caused by normal influenza. (WHO website)Understanding Avian Influenza