Mixed scenario seen behind Pakistan birdflu spread

By Stephanie Nebehay

GENEVA (Reuters) - The eight individuals in Pakistan who are suspected to have bird flu probably have a combination of infections from poultry and limited person-to-person transmission from close contact, a top World Health Organization expert said on Tuesday. Keiji Fukuda, coordinator of WHO's global influenza program, said while unconfirmed, any human-to-human spread seemed similar to previous outbreaks in Thailand and Indonesia -- affecting close family members caring for sick loved ones.

There was no immediate cause for alarm and the United Nations agency was not raising its level of pandemic alert for the time being, he said, adding it was very reassuring that "we are not seeing large increases in the number of cases".

"Right now it doesn't look like pure human to human transmission. It looks like the veterinarian, who was the index case, and a number of other suspect cases had poultry exposure," Fukuda told Reuters in an interview.

"It is definitely possible that we have a mixed scenario where we have poultry to human infection and possible human to human transmission within a family, which is not yet verified."

But human to human transmission "would not be particularly surprising or unprecedented," he added.

Eight people have tested positive for the H5N1 bird flu virus in North West Frontier Province since late October, and one of the confirmed cases has died. A brother of the dead man also died, but was never tested, so is not counted among them.

H5N1 is mainly an animal disease, but experts fear it could mutate into a form that could spread easily between people, causing a pandemic which could kill millions of people. In Thailand, a mother was killed by the virus in 2004 after cradling her dying infected daughter all night. The largest known cluster of human bird flu cases worldwide occurred in May 2006 in Indonesia's North Sumatra province, where as many as seven people in an extended family died.

Three WHO experts, led by Hassan El-Bushra of its regional Cairo office, is in Pakistan helping to investigate the outbreak.