Avian Influenza

Chest | Emergency Medicine | Avian Influenza (Disease)


Commonly known as bird flu, avian influenza is a highly infectious disease of birds, especially poultry, that can occasionally infect people who are in close contact with infected birds.

Symptoms of avian flu infection in humans depend on the strain of virus. Infection with the H5N1 virus in humans causes typical flu-like symptoms, which might include: cough (dry or productive); diarrhea; difficulty breathing; fever greater than 100. 4°F (38°C); headache; malaise; muscle aches; runny nose or sore throat.

Causes and Risk factors

It is caused by influenza A virus subtypes H5 and H7. All types of birds are susceptible to the virus but outbreaks occur most often in chickens and turkeys.

The following people have a higher risk for developing the bird flu: farmers and others who work with poultry; travelers visiting affected countries; those who touch an infected bird; those who eat raw or undercooked poultry meat, eggs, or blood from infected birds. Complication that can occur include: acute respiratory distress; organ failure; pneumonia; sepsis.

Diagnosis and Treatment

Tests to identify the avian flu exist but are not widely available. A test for diagnosing strains of bird flu in people suspected of having the virus gives preliminary results within 4 hours. Older tests took 2 to 3 days. Following tests can be performed: auscultation (to detect abnormal breath sounds); chest x-ray; nasopharyngeal culture; white blood cell differential.

Different types of avian flu virus may cause different symptoms. Therefore, treatment may vary. In general, treatment with the antiviral medication may make the disease less severe. People with severe infection may need to be placed on a breathing machine. Experts recommend that persons diagnosed with avian flu be put in isolation. ...