Scientists find 'likely' human-human H5N1 spread

A new study by Chinese scientists suggests a highly possible human-to-human transmission of H5N1 bird flu virus.

Publishing their study this week (8 April) in The Lancet, lead author Wang Yu, director of the Chinese Center for Disease Control and Prevention (China CDC) and colleagues analysed two human cases of bird flu that occurred within the same family in eastern China's Jiangsu Province in December 2007.

The 24-year-old son died of H5N1 infection on 2 December, the fifth day of his hospitalisation. Two days after his death, his 52-year-old father developed typical flu symptoms such as fever, chill and cough. He was diagnosed with H5N1 infection, and survived only after receiving early antiviral treatment.

The researchers investigated the men's exposure to both poultry and people, and found the son's only plausible exposure to H5N1 was a visit to a poultry market six days before the onset of illness.

The father had substantial unprotected exposure to his ill son, and the researchers could find no evidence of him coming into contact with live poultry or being exposed to H5N1 by any other transmission channel.

The H5N1 viruses isolated from father and son were also found to have virtually the same genetic structures.