Avian influenza

Avian influenza viruses normally spread between birds. However, some viruses have been found to infect humans.

When avian influenza infects humans, symptoms may range from mild upper respiratory infection (fever and cough) to severe pneumonia, acute respiratory distress syndrome (difficulty breathing), shock and even death.

The primary risk factor for humans is exposure to infected live or dead poultry or contaminated environments, such as live bird markets. Slaughtering, defeathering, handling carcasses and preparing poultry for consumption, especially in household settings, are also risk factors.

Although human-to-human transmission of avian influenza is thought to have occurred in some instances when there had been close or prolonged contact with a patient, no sustained human-to-human transmission has been identified to date.

As much as possible, residents and travellers in countries with known outbreaks of avian influenza in birds should avoid:

• poultry farms
• contact with animals in live poultry markets
• entering areas where poultry may be slaughtered
• contact with any surfaces that appear to be contaminated with faeces from poultry or other animals
• consumption of raw or incompletely cooked meat or eggs.

Good food safety and hand hygiene practices should also be followed, including regular handwashing with soap and water.

Seek medical care immediately if you live in or have recently visited an area experiencing an outbreak and you are suffering flu-like symptoms such as fever, cough and difficulty breathing.

If you or someone close is experiencing flu-like symptoms, take protective measures:

• Regular handwashing with proper drying of the hands
• Good respiratory hygiene – covering mouth and nose when coughing or sneezing, using tissues and disposing of them correctly
• Early self-isolation of those feeling unwell, feverish and having other symptoms
• Avoid close contact with people with respiratory symptoms

Meat products and eggs can be safely consumed, provided they are properly prepared because influenza viruses are inactivated by thorough cooking. Please see "How can meat and eggs be safely prepared?” for detailed information.

Consuming raw or incompletely cooked meat and eggs from areas experiencing outbreaks of avian influenza is high-risk and should be avoided. Likewise, animals that are sick or have died unexpectedly should not be eaten.

To avoid contamination, always keep raw meat and eggs separate from cooked or ready-to-eat foods. Do not use the same chopping board or the same knife for raw meat and other foods, and do not place cooked meat back on the same plate or surface it was on before cooking. After handling raw meat, wash your hands thoroughly with soap and water. Do not eat raw or soft-boiled eggs. Wash and disinfect all surfaces and utensils that have been in contact with raw meat.

To avoid contamination, always keep raw meat and eggs separate from cooked or ready-to-eat foods. Do not use the same chopping board or the same knife for raw meat and other foods, and do not place cooked meat back on the same plate or surface it was on before cooking. After handling raw meat, wash your hands thoroughly with soap and water. Do not eat raw or soft-boiled eggs. Wash and disinfect all surfaces and utensils that have been in contact with raw meat.

No vaccine for the prevention of avian influenza infections in humans is commercially available. WHO is working with partners on vaccine development. Some products are already being tested for efficacy and safety.

The seasonal influenza vaccine does not prevent avian influenza, but it may reduce the likelihood of being simultaneously infected with both avian and seasonal influenza viruses (dual infections). Reducing dual infections decreases the likelihood of viruses gaining the ability to spread easily from person to person.

WHO does not recommend travel restrictions related to avian influenza. However, travellers can take certain measures to reduce the risk of infection. Please see "How can human infections with avian influenza be prevented?"