Symptoms:

Symptoms of avian flu infection in humans depend on the particular strain of virus. In case of the H5N1 virus, infection in humans causes more classic flu-like symptoms, which might include:

• Cough (dry or productive)
• Sore throat
• Fever greater than 100.4°F (38°C)
• Difficulty breathing
• Diarrhea
• Runny nose
• Headache
• Malaise
• Muscle aches

Signs and tests:

If you think you have been exposed to avian influenza, call your health care provider before your visit. This will give the staff a chance to take proper precautions that will protect them and other patients.

In February 2006, the U.S. Food & Drug Administration approved a new, faster test for diagnosing strains of bird flu in people suspected of having the virus. The test is called the Influenza A/H5 (Asian lineage) Virus Real-time RT-PCR Primer and Probe Set. The test gives preliminary results within 4 hours. Older tests required 2 to 3 days.

Your doctor might also perform the following tests:

• Chest x-ray  
• Nasopharyngeal culture  
• Blood differential
• Auscultation (to detect abnormal breath sounds)

Other tests may be done to look at the functions of your heart, kidneys, and liver.