Human Bird Flu Transmission Is Proven in Indonesia (Update2) June 23 (Bloomberg) -- Bird flu was spread directly between members of an Indonesian family in the first laboratory-confirmed case of human-to-human transmission of the lethal virus, a World Health Organization official said.
Genetic sequencing of a virus sample taken from a 10-year- old boy who died from the H5N1 avian influenza strain showed a minute change that was also found in a virus sample taken from his father, who later died from the virus, said Dick Thompson, a spokesman for the United Nations health agency in Geneva. ``We have seen a genetic change that confirms in a laboratory that the virus has moved from one human to another,'' Thompson said in an interview. The change in the virus ``doesn't seem to have any significance in terms of the pathology of the disease or how easily it's transmitted,'' he said. Human-to-human transmission had previously been suspected as the cause of infection in seven members of the Indonesian family from the island of Sumatra. The cases attracted international attention because they represent the largest reported instance in which avian flu is likely to have spread among people. They also provide the first evidence of a three-person chain of infection. At least 130 of the 228 people known to be infected with bird flu since 2003 have died, according to the WHO. World health officials are tracking the spread of the virus in the event it becomes more adept at infecting people. Clusters Clusters of human cases in which the virus was transmitted from person to person, including to health workers treating infected patients, may signal the emergence of a pandemic strain capable of killing millions of people. ``This was a more visible and a bigger cluster, but the concept and the mechanism behind it was what we've seen before'' in other cases where limited human-to-human transmission was suspected, Tom Grein, a senior WHO epidemiologist involved in the investigation, said in an interview yesterday. ``All H5N1 viruses were anti-genetically and genetically very closely related and similar to H5N1 viruses isolated from poultry and humans in Indonesia,'' Indonesia's Ministry of Health said in a summary of the investigation of the Sumatra patients. The document, obtained by Bloomberg News today, was prepared in conjunction with the WHO for a meeting this week of Indonesian officials and representatives from the United Nations health and agriculture agencies, the U.S. Centers for Disease Control and Prevention and other health organizations. International health experts submitted recommendations to the Indonesian government to further strengthen human disease surveillance and rapid response to outbreaks in poultry. `Transparency and Openness' ``Detection of human clusters is a priority,'' they said in a joint statement today. A report of the investigation of the Sumatran cases will be made as soon as possible to boost ``transparency and openness.'' A 37-year-old Sumatran woman suspected of being the first family member to die was buried before samples were taken, so her cause of death can't be determined. The woman, who sold fruit and vegetables in a local market, owned eight chickens, including three egg-laying hens that were reported to have died about two to seven days before she became ill on April 24, the summary said. She mixed fowl manure with soil with her bare hands to fertilize her garden, it said. The woman's 10-year-old nephew, 18-month-old niece, 19-year- old son, 18-year-old son and 29-year-old sister became sick between May 2 and 4, and subsequently died, after having close and prolonged contact with the woman during her illness, the summary said. A brother, 25, was also infected and survived. Chain of Infection A seventh patient, the father of the 10-year-old boy, contracted his fatal infection from close and unprotected contact with his son during the boy's hospitalization. The 37-year-old woman is the only one for whom exposure to sick or dead chickens or other animals was ascertained, the summary said. Before the Sumatran cases, disease trackers had found strong evidence of direct human-to-human transmission of H5N1 in Thailand in 2004. In that case, the virus probably spread from an 11-year-old girl to her aunt and mother, killing the mother and daughter, scientists reported in the Jan. 27, 2005, issue of the New England Journal of Medicine. People who had casual contact with the girl weren't infected.
