Fever: One of the first symptoms of bird flu in humans is a fever higher than 100 °F, that is 38 °C.
Cough: Cough similar to regular flu symptoms. Coughing patients emit droplets laden with virus, and for this reason, a protective face mask is recommended for both patients and caretakers. A surgical mask is sufficient for patients, while caretakers should wear a face mask that is N95 certified or better.
Shortness of Breath: Difficulties breathing.
Sore throat: Similar to regular flu.
Diarrhea and Abdominal Pain: Diarrhea and abdominal pain has been a symptom in some patients, but not all of them. Watery diarrhea may be a symptom in bird flu cases, but is not a common symptom in regular flu. Diarrhea comes before respiratory symptoms. Two young patients had encephalitis and diarrhea without any respiratory symptoms.
Bleeding of nose and gums: A symptom reported in some patients.
Muscle Aches: Similar aches as for regular flu.
Vomitting: Nausea and vomiting has been a symptom in some patients.
Conjunctivitis: Conjunctivitis is not a usual symptom of people with H5N1 avian flu, but is common in people infected with other subtypes of avian flu.
Flu-like Symptoms With a Few Differences:
In general, bird flu symptoms in humans are similar to regular flu symptoms. High fever, muscle aches, cough, and sore throat are common. Humans ill with avian flu subtype H5N1 rarely have conjunctivitis, a common symptom in people infected with other subtypes of avian flu.
Most people have suffered respiratory distress, but a couple of young children did not show any signs of respiratory distress, but had diarrhea and symptoms of encephalitis.
Sources:
- Infectious Diseases Society of America, Avian Influenza (Bird Flu): Implications for Human Disease (Updated Jne 2, 2006) For text, see http://content.nejm.org/cgi/content/full/353/13/1374
- The Writing Committee of the World Health Organization (WHO) Consultation on Human Influenza A/H5, Avian influenza A (H5N1) infection in humans. N Engl J Med 2005 Sep 29;353(13):1374-85. For full text, see http://content.nejm.org/cgi/content/full/353/13/1374