The first case of human-to-human transmission of the bird flu virus has been confirmed in laboratory tests of samples taken from a 10-year-old Indonesian boy who died last month from the H5N1 avian influenza strain, a World Health Organization official said Friday.
Genetic sequencing of a virus sample taken from the boy showed a minute change that was also found in a sample taken from his father, who also later died, said Dick Thompson, a spokesman for the United Nations health agency in Geneva, Switzerland. Human-to-human transmission had been suspected as the cause of the infection in seven members of a family of eight from the island of Sumatra.
"We have seen a genetic change that confirms in a laboratory that the virus has moved from one human to another," Thompson told Bloomberg News. 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.
The Sumatran cluster attracted international attention because it represented the largest reported instance of bird-flu spread among people and the first evidence of a three-person chain of infection.
A 37-year-old woman suspected of being the first family member to die was buried before samples were taken. She reportedly mixed fowl manure with soil with her bare hands to fertilize her garden.
The woman's 10-year-old nephew, an 18-month-old niece, two teenage sons and a 29-year-old sister became sick between May 2 and May 4, and later died after having close contact with the woman during her illness, Bloomberg said. A 25-year-old brother was also infected but survived.
Virus mutated slightly
The New York Times reported that the first five family members to fall ill had identical strains of H5N1, but the virus had mutated slightly in the sixth victim, the 10-year-old boy, who passed it to his father. That mutation allowed the lab to confirm the route of transmission.
World health officials said there was no evidence that the mutated virus is any better adapted to human infection than before. In fact, the WHO has been following 54 neighbours and family members who lived near the family for a month, and none has contracted the virus, the newspaper said.
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. – (HealthDayNews)