Avian influenza

What is the difference between viruses causing human influenza and avian influenza?
Human influenza and avian influenza are both caused by influenza viruses. In Hong Kong, human influenza is commonly caused by influenza A (H3N2), influenza A (H1N1) and influenza B viruses, while avian influenza is commonly caused by influenza A (H5N1) and influenza A (H9N2) viruses.

What is the route of transmission of avian influenza?
Avian influenza is transmitted from infected live birds to humans. Transmission between humans is inefficient.

What are the symptoms of avian influenza?
The initial symptoms of avian influenza are similar to those caused by other human influenza viruses, including fever, headache, muscle pain, runny nose, cough and sore throat. However, it is more likely to result in high fever, chest infection, respiratory failure, multi-organ failure, and death.

Is the influenza vaccination effective against the avian influenza?
Influenza vaccine cannot prevent avian influenza as the vaccine is meant for human influenza. However, the vaccine can help reduce the chance of complications and hospitalization resulting from human influenza; hence it is recommended for the elderly and patients with chronic cardiac or respiratory diseases. Influenza vaccine can also reduce the chance of genetic re-assortment and subsequent emergence of influenza strain with pandemic potential. People should seek medical advice if they are considering getting the vaccination.

What can the general public do to prevent avian influenza?
The public can take the following measures to prevent avian influenza:

1. Avoid touching live poultry or their droppings, because they may carry the avian influenza virus.
2. Wash your hands thoroughly with liquid soap and water immediately after contact with live poultry, birds or their droppings.
3. Cook poultry and eggs thoroughly before eating.
4. Develop good body resistance and have a healthy lifestyle. This can be achieved through a balanced diet, regular exercise, adequate rest, reducing stress and no smoking.
5. Observe good personal and environmental hygiene.
6. Keep hands clean and wash hands properly.
7. Cover nose and mouth while sneezing or coughing. Dispose sputum or secretions wrapped in tissue paper into rubbish bins with lids. Wash hands afterwards.
8. Avoid crowded places with poor ventilation if you are feeling unwell.
9. Maintain good indoor ventilation
10. If you have flu symptoms, consult a doctor and wear a mask to prevent spread of disease. Tell your doctor your travel history if you have been to a country with avian influenza outbreak.
    

Source of references: Department of Health
Written by Dr. John Lau, Resident Medical Officer of Canossa Hospital (Caritas)
CT/wl/No.46(12-2005)