An Indonesian who died after catching the virus from his son represents the first confirmed case of human-to-human transmission of the disease.

The W.H.O. investigators also discovered that the virus had mutated slightly when the son had the disease, although not in any way that would allow the virus to pass more readily among people.

The article on the New York Times website Quotes Dick Thompson from the W.H.O as saying that the flu ‘ is slightly altered, but in a way that viruses commonly mutate’

More than 200 people have contracted bird flu worldwide, almost all of them after very close contact with infected birds.

The international health officials had been in Indonesia for much of the past month, investigating the family outbreak that affected seven relatives in Kubu Sembilang, a remote village in the mountainous Karo district of Sumatra.

So far, six of the seven have died, and one is still hospitalized.

Although the H5N1 virus of bird flu mutated slightly in this Indonesian family, experts insist that this mutation doesn’t increase the possibility of a human pandemic.

An official for the CDC says it’s the first evidence of possible human-to-human transmission, but that the virus didn’t pass outside the family and died out with the father.