Human-to-human transmission of bird flu might have occurred in an Indonesian family and health experts are tracing anyone who might have had contact with them, the World Health Organisation said.
Financial markets, however, were spooked on fears the Indonesia cluster could be the start of a pandemic. Currencies in Asia, where most bird flu cases have occurred, fell. U.S. commodity prices came under pressure while European markets slipped as investors turned jittery.
Concern has been growing about the case in north Sumatra in which seven family members from Kubu Sembilang village died this month. The case is the largest family cluster known to date. Clusters are looked on with far more suspicion than isolated infections because they raise the possibility the virus might have mutated to transmit efficiently among humans. That could spark a pandemic, killing millions of people. The WHO statement came after one of the family members, a 32-year-old father, died on Monday after caring for his ailing son, who had died earlier. The agency said such close contact was considered a possible source of infection.
Limited transmissions between people are caused by close and prolonged contact when the sick person is coughing and probably infectious. Experts in Kubu Sembilang were acting to contain any further spread. "We are going wide, contacting the various contacts, putting on (anti-viral) Tamiflu whoever has had close contact, basically putting family members who have not been affected on Tamiflu as a precaution," Mehta told Reuters in an interview in Jakarta.
"There is active surveillance in the village, fever surveillance to look for any more cases that are occurring outside this immediate family cluster," he said. But another WHO spokesman said the agency was worried. "This is the most significant development so far in terms of public health," Peter Cordingley, spokesman for the West Pacific region of the WHO, said in the Philippine capital on Wednesday. "We have never had a cluster as large as this. We have not had in the past what we have here, which is no explanation as to how these people became infected." "We can't find sick animals in this community and that worries us," he added.
Markets are also nervous about a suspected cluster in Iran. An Iranian medical official told Reuters on Monday that a 41-year-old man and his 26-year-old sister from the northwestern city of Kermanshah had tested positive for bird flu. The two siblings were among five members of a family who became sick and the other three remain in hospital.