How does bird flu effect humans?

Avian influenza (bird flu) viruses do not normally infect humans. However, rare cases of human infection with avian influenza viruses have been reported. When such infections occur, most of these cases have had direct or indirect contact with infected live or dead poultry or environments contaminated with the virus.

Depending on the type and severity of the infection, symptoms of human infections have ranged from mild (e.g. conjunctivitis, upper respiratory illness, influenza-like symptoms) to severe (e.g. severe pneumonia, respiratory distress syndrome requiring intensive care, multi-organ failure, fatal disease) and even death.

The most common symptoms of human infections with avian influenza viruses have included fever, cough, sore throat, muscle aches and malaise, which can be accompanied by diarrhoea and vomiting. Human cases have occurred sporadically and no efficient or sustained human-to-human transmission of avian influenza viruses has occurred yet.