An update on recent developments involving the H5N1 virus.

This is the VOA Special English Health Report.

Researchers in China have reported on a rare human-to-human case of bird flu. They say it is likely that a twenty-four year old man in the eastern province of Jiangsu infected his father last December.

They believe it happened while the father cared for the son in a hospital. The son died. The father lived.

Government researchers say genetic tests showed almost identical forms of the H5N1 virus in the two men. Ninety-one other people came in close contact with them but did not get infected.

The report appeared last week in the Lancet medical journal.

On April third, the World Health Organization said a family in Pakistan showed a high probability of human-to-human infection in a case last year. In that case, an animal doctor was infected with the avian flu virus when he helped destroy diseased birds in Peshawar. His three brothers became infected later although they had no contact with diseased birds.

Gregory Hartl is a project leader in the W.H.O.