(AFP)
Updated: 2005-11-24 16:19

A mutated strain of bird flu has been found in samples taken in Cambodia, but it is not known if the new strain is more lethal than that which has killed four people here, health officials said.

Testing on the samples, which were collected in April, is continuing, said Philippe Buchy, head of the Virology Department at the Pasteur Institute office in the Cambodian capital Phnom Penh.

"We don't know yet if it has any significance for the transmission from humans to humans, or from birds to humans," Buchy said, adding that mutations of the H5 virus are common.

"I'm really not concerned about this. The strains have been seen by H5 experts from the (World Health Organisation's) networks and they didn't say anything."

Buchy said it was likely the strain found in Cambodia was similar, if not the same as a mutation reported earlier this month in southern Vietnam, where officials sought to ease fears that a deadlier form of bird flu had erupted.

No new cases of bird flu have been reported in either humans or animals in Cambodia since March, said Ly Sovann, head of the health ministry's infectious disease department.

But he also said the impoverished country does not have the means to test new strains of bird flu, making it more difficult to control future outbreaks.

Cambodia is located between Vietnam, where 42 bird flu deaths have occurred, and Thailand, which has seen 13 fatalities, according to the World Health Organisation's official figures since late 2003.

Two of the four bird flu victims from Cambodia, whose nationals regularly cross the porous border in the densely populated Mekong delta, died in southern Vietnam after being hospitalized in a Kien Giang hospital.

Scientists warn that the H5N1 virus, which has killed more than 60 people in Asia since late 2003, could mutate and combine with human flu variants, making it easily transmissible among humans and creating a global pandemic.