KUBU SIMBELANG, Indonesia -- The biggest case yet of humans infecting others with bird flu prompted the World Health Organization to put the maker of the anti-viral drug Tamiflu on alert for possible shipment of the global stockpile for the first time, officials said Saturday.
No further action on the emergency supply was expected for now, according to the U.N. health agency, which called the alert part of its standard operating procedure when a case arises like that in Indonesia.
"We have no intention of shipping that stockpile," WHO spokesman Dick Thompson cautioned. "We see this as a practice run."
Meanwhile, Indonesia confirmed three more bird flu deaths as the country grapples with a spike in human cases. Bird flu is known to have infected 48 people in Indonesia, with 36 deaths -- second highest after Vietnam's 42 deaths.
A precautionary 9,500 treatment doses of Tamiflu from a separate WHO stockpile, along with protective gear, were flown into Indonesia on Friday. The tablets will likely be handed over to the Indonesian government, WHO spokeswoman Maria Cheng said in Geneva.
Officials revealed the stockpile alert came last Monday as experts puzzled over why six Indonesians from a family in a North Sumatra village died after being infected by the H5N1 virus. A seventh was buried before tests could be done, but she is believed to have been infected.
Despite the cluster of deaths, the virus has not mutated into a form easily passed among humans, experts said. Scientists have seen examples of bird flu passing between family members in a handful of smaller cases.
"If this virus had evolved into a form that is more easily passed between people, you would have seen some other cases (outside the family) by now," Cheng said. "The virus hasn't passed beyond the family."
No health workers could be seen Saturday in the family's village of Kubu Simbelang, where dozens of chickens ran among houses and through backyards framed by high mountains and surrounded by rich fields of chilis, oranges and limes.
The family infected by the virus lived in three houses near the church in the Christian village.
Indonesia's number of human bird flu cases has jumped this year, but public awareness of the disease remains low and government efforts have not equaled that of other countries. Indonesia's reaction has raised concerns it is moving slowly and ineffectively in containing the disease.
Vietnam, the country hit hardest by bird flu, has been hailed for controlling the virus through mass poultry vaccination, among other measures. No human cases have been reported there since November.
Indonesia, a sprawling nation of 17,000 islands, has refused to carry out mass slaughters of poultry in all infected areas -- a basic containment guideline -- saying it cannot afford to compensate farmers. And bio-security measures are virtually nonexistent in the densely populated countryside, with its hundreds of millions of backyard chickens.
WHO officials in Jakarta received word about the Kubu Simbelang cluster from the Indonesian Health Ministry on Monday. That led the Geneva-based agency to alert the Swiss pharmaceutical company Roche Holding AG within hours about possible Tamiflu shipments, said Jules Pieters, director of WHO's rapid response and containment group.
"We were quite keen to inform Roche quite timely," Pieters said. "We knew Thursday would be a holiday in Europe and wanted to make sure Roche warehouses would be open."
He said Roche would remain on alert for approximately the next two weeks, or twice the incubation period of the last reported H5N1 case.
Roche spokesman Baschi Duerr said the emergency stockpile, which consists of 3 million treatment courses, is ready to be shipped wherever it is needed.
"We are in very close contact with WHO, even today, and our readiness is geared to be able to deliver," Duerr said.
Meanwhile, Nyoman Kandun, a senior official at Indonesia's health ministry, said a WHO laboratory in Hong Kong had confirmed five more cases of human bird flu, three of which were fatal. All five had earlier tested positive for the virus in a local laboratory.
The latest confirmed deaths were a 39-year-old man from Jakarta, a 10-year-old girl from West Java and a 32-year-old man, who on Monday became the last to die in the Kubu Simbelang cluster.
Experts have been unable to link the cluster family members to contact with infected birds, and tests on poultry in their village have come back negative. No one else in the village has fallen ill.
So far, most human cases have been traced to contact with infected poultry. But there is evidence of isolated cases of limited transmission between people in very close contact with each other.
Scientists are unsure how this occurred, but they theorize the virus may pass from one person to another through droplets sneezed or coughed into the air or onto food or other surfaces.
It has been suggested some people may have a genetic susceptibility to the disease. In all, WHO has recorded four family clusters of bird flu so far and only direct blood relatives -- not spouses -- have become ill.
Experts are exploring whether the first woman sickened in the Kubu Simbelang family may have had contact with sick or dead chickens. She worked at a market where chickens are sold and may have used chicken feces as a garden fertilizer, WHO officials said.
Bird flu has killed at least 124 people worldwide since the virus began ravaging Asian poultry stocks in late 2003.
Associated Press writers Zakki Hakim in Jakarta and Sam Cage in Geneva contributed to this report.