World Health Organization experts are studying what they say is the most significant development yet in the spread of the bird-flu virus -- the death of seven members of one family in Indonesia. Senior officials of the United Nations health agency say they are extremely concerned about the size and source of the outbreak in Indonesia. With seven deaths in the past three weeks and an eighth family member still infected with the H5N1 bird-flu virus, the case in northern Sumatra is the largest known human cluster of bird-flu infections.
WHO scientists who examined virus samples in Indonesia say they found no evidence of any mutation indicating that bird flu in Asia has changed to a form more dangerous to humans. However, a regional spokesman for the agency says it is almost certain there has been some limited form of human-to-human transmission of the disease. The spokesman says health experts can find no bird flu in animals or poultry in the village where the deaths occurred.