Bird flu: WHO does not exclude human-to-human transmission
Jakarta (AsiaNews/Agencies) The biggest cluster of bird flu deaths yet reported may have been caused by human-to-human transmission of the H5N1 virus, but that was not evidence it had mutated, the WHO said today.
Seven members of an extended family of eight died in Kubu Sembelang village in Indonesia's North Sumatra province. The first death occurred on May 13; the last, on May 22, when the father died after caring for his ailing son.
According to the WHO, "all confirmed cases in the cluster can be directly linked to close and prolonged exposure to a patient during a phase of severe illness. Although human-to-human transmission cannot be ruled out, the search for a possible alternative source of exposure is continuing."
Steven Bjorge, the WHO team leader in the village, said no poultry in the area had tested positive for the H5N1 virus.
The Sumatran cluster is the most important development in the spread of the virus since 2003, the WHO said. For the UN agency, its size and the difficulties in determining the source are reasons to worry.
Financial markets were spooked on fears the Indonesia cluster could be the start of a pandemic. Most Asian currencies fell.
"This is the first time that we've been completely stumped about possible single-source infection," Peter Cordingley, WHO spokesman for the Western Pacific region, said. "What we are looking out for is any sign of this virus going outside of this family cluster into the general community. [So far we] haven't seen any signs of that yet."
Isolated cases of limited human-to-human transmission have been previously documented. But for university of Hong Kong microbiologist Yuen Kwok-yung "there has never been such a large cluster in a household who got infected."
China. China's Agriculture minister reported new outbreaks in Tibet and, for a second time this month, in Guoluo (Qinghai), along the routes of migratory birds.
The WHO feared this might happen because in spring last year thousands of birds died during the migratory season.
Since 2003 there have been 124 known deaths from the bird flu in ten countries. (PB)