Definition

Avian influenza is a strain of influenza virus that primarily infects birds. It is often called the bird flu.

In Asia and Africa, there have been cases of avian influenza that have the ability to infect humans. The most significant of these avian influenza strains is called H5N1. This strain can cause serious illness and death.

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Causes

Avian influenza is caused by a specific influenza type A virus. The virus is common among wild and domestic birds, but rarely infects humans. Occasionally, the virus can mutate which allows it to infect humans.

The virus is passed through contact with an infected bird's:

• Saliva or blood
• Nasal secretions
• Droppings

Avian influenza is not contracted through eating well-cooked poultry or eggs. The virus rarely passes from one human to another. When it does, it is usually a weakened version of the virus. Infections are being monitored to see if the virus mutates in a way that allows it to easily pass between humans.

Risk Factors

Close contact with infected poultry increases your chance of avian influenza. This may include domestic or wild ducks, geese, chickens, or turkeys.

Your chance of infection is also increased with recent travel to an area known to have avian influenza. Avian influenza outbreaks are most common in Asia, the Middle East, and northeast Africa.

Symptoms

Symptoms of avian influenza may include:

• Fever
• Chills
• Cough
• Sore throat
• Body aches
• Diarrhea and/or vomiting
• Abdominal and chest pain

More severe infections can lead to pneumonia or serious organ failure.

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. You will be asked if you have had close contact with infected poultry or have recently traveled to an area known to have avian influenza.

Nasal or respiratory secretions or blood can be tested for the presence of the virus.

Treatment

Antiviral medications can help decrease your symptoms and the length of time you are sick. They do not cure the flu. The sooner the medication is started the more effective it can be. Ideally, the medication should be started within 48 hours of the first symptoms.

Prevention

The overall risk of getting avian influenza is small. To help reduce your chances of avian influenza:

• Get a yearly flu vaccine. This is the best step to prevent an infection with influenza virus.
• Avoid traveling to areas where there are avian influenza outbreaks. For the latest travel information, visit the CDC's Traveler's Health page.
• Avoid contact with potentially infected poultry. This includes farms or open-air markets.
• Wash your hands often if you are in an area where exposure to the influenza virus is possible. Be sure that hands are washed before preparing food. Use a hand sanitizer if clean water is not available for washing.

The US Food and Drug Administration has licensed a vaccine to protect against H5N1 in adults aged 18-64. It will be made available in the event of an outbreak. Vaccinations can protect the individual and may control the spread of the infection.