The potential transmission of bird flu between humans is the World Health Organization´s worst fear, said Francois Xavier Meslin, the group´s chief of animal diseases.

The ease of human-to-human transmission would make any bird flu pandemic worse than last year´s outbreak of severe acute respiratory syndrome, he told reporters today in Singapore. The group previously warned that bird flu may mutate into a form that could pass easily from human to human.

``If it happens, which is not yet proven, it´s going to be worse than SARS,´´ he said. ``SARS was mildly transmissible between humans. It was mild compared with a flu virus.´´

SARS infected more than 8,000 people and killed 774 after emerging in China in November 2002. An Asian outbreak of avian influenza, known as bird flu, killed at least 32 people this year. The H5N1 bird-flu strain, which is potentially fatal to humans, has been passed from infected poultry to people in contact with them, without any confirmed cases of human-to-human transmission.

The organization had earlier said the flu is endemic in Asia. No human vaccine is available, and so far reports of people catching bird flu from other humans have not been verified.

A task force made up of 10 Southeast Asian nations plus China, Hong Kong, Korea, the Netherlands and health officials from the United Nations met for the first time in Singapore today to develop a plan to cope with a future outbreak and to prevent human-to-human transmission.

``Avian influenza at the moment is a crisis of Asian dimension,´´ said Hans Wagner, senior animal production and health officer at the United Nations´ Food and Agriculture Organization. ``Asia is an area with very high poultry density, very high human density, and Asia has always been a center of the flu.´´

Malaysian Ban

Malaysia indefinitely extended a ban on moving poultry from its northern state of Kelantan, which borders Thailand, where bird flu was still being detected last month.

Southern neighbor Singapore, one of the biggest export markets for Malaysian poultry, has held off lifting an import ban on most of the country´s stock until the northern outbreak is cleared.

The city-state ended a six-week total ban on poultry imports from Malaysia in September, allowing the entry of eggs and chickens from two southern states of Johor and Malacca only, after authorities contained the disease in the north.

Malaysia supplies half of the poultry and two-thirds of the eggs consumed in Singapore. The earlier ban sent prices soaring and led to limits on consumption in the city-state, where most national dishes include chicken, duck or eggs.

``As long as we cannot control it or eradicate it, we´ll have a continuous negative impact on the supply of poultry and poultry meat,´´ Wagner said.