Father caught bird flu from son, international study claims

A man who was diagnosed with bird flu in China caught the infection from his son, a new study claims today.

The report raises further concerns about person-to-person transmission of the virus.

A team of international researchers studied the two family members, who were diagnosed within a week of each other in December 2007 in China's Jiansu Province.

The 24-year-old son died and his father survived after receiving early antiviral treatment,

Writing in the Lancet journal, the researchers say the son's only plausible exposure to the highly pathogenic avian influenza (H5N1) virus was a poultry market visit six days before the onset of illness.

His father had substantial exposure to his ill son.

The viruses isolated from the father and son were found to be genetically identical except for one small change in part of the H5N1 genetic structure.

"Limited, non-sustained person-to-person transmission of H5N1 virus probably occurred in this family cluster," the researchers conclude.