The World Health Organisation (WHO) said today the number of people who have caught the deadly bird flu virus in Turkey has risen to 18 from 15, mostly children.
Guenael Rodier, head of the WHO mission to Turkey, said that laboratory tests in Ankara showed that the third dead child from the same family had H5N1. Initial tests showed she did not have the bird flu virus.
"The (other) two new aditional cases are also children who lived in close proximity to poultry but they come from two geographical separate areas," he said.
The deadly H5N1 virus has been found in wild birds and poultry across Turkey.
The virus has been found in wild birds and poultry across large parts of Turkey, particularly in poor villages stretching from Istanbul at the gates of Europe to Van near the Iranian and Iraqi borders. It has killed at least two children.
The Health Ministry said tests showed that the virus was in the lungs of a third Turkish child who died last week, the sister of the two dead teenagers confirmed as bird flu victims.
Indonesia said today a 29-year-old woman who had bird flu, according to a local test result, had died.
Shigeru Omi, the WHO's regional director for the Western Pacific, said Asia remained the epicentre of the threat to global health but that a pandemic was not inevitable if countries and health bodies responded quickly.
"As the new cases of human infection with the H5N1 virus in Turkey show, the situation is worsening with each passing month and the threat of an influenza pandemic is continuing to grow every day," he told a two-day meeting of Asian countries and international organisations on bird flu in Tokyo.
Experts say the H5N1 virus could become more active in the colder months in affected regions, and spread in east Asia as people slaughter chickens for Lunar New Year celebrations.
The more it becomes entrenched in poultry flocks, the greater the risk that more humans will become infected. So far, the virus is reported to have infected about 150 people, killing at least 78 in six countries.
While it remains essentially a disease in birds, scientists fear the virus could mutate into a form that could spread easily between humans, causing a pandemic in which millions could die.
While there is no evidence of human-to-human transmission in Turkey, the large and rapid rise in the number of cases has worried experts.
Health experts are studying the outbreak in Turkey for clues as to how to combat the virus. The mortality rate in Turkey is lower than in east Asia where around one in every two victims has died.
"The pace of fatalities appears to have fallen off quickly. But it is as yet unclear whether this is because the virus has modified or Turkey's approach has been successful," said David Nabarro, the UN's senior coordinator for avian influenza.
The WHO says countries must do more to prepare for a pandemic and Dr Nabarro said it would cost donors about $1.4 billion to finance the next phase of the global campaign against the virus. This included gearing up veterinary services and preparing expert teams for quick deployment to outbreaks.
He was confident delegates to a bird flu conference in Beijing next week would pledge the needed amount.
European countries are raising their guard against the further spread of the virus. The Dutch government wants to vaccinate its huge poultry population against bird flu, the farm ministry said today.
Bird flu experts recommend preventive vaccination to be considered seriously in the small and densely populated Netherlands which has around 90 million poultry.