June 29, 2004

Asian Bird Flu Becoming More Dangerous To Mammals
 

Asian bird flu strains that have circulated in ducks and other aquatic birds since 1996 are becoming more dangerous to mammals, and should be monitored to prevent transmission to humans, a study from China revealed.

According to researchers led by Hualan Chen, a virologist at the Chinese Ministry of Agriculture in Harbin, the duck viruses have grown steadily more lethal to mice, capable of infecting the animals' lungs and other organs.

The concern is that the strain may spread to animals such as pigs, chickens and rabbits, which live in close proximity to humans in places such as Thailand and China. More than 100 million fowl were slaughtered in Asia this year in order to halt a bird flu outbreak in chickens that infected 34 people, killing 23 in Vietnam and Thailand, according to the World Health Organization.

"These viruses in aquatic birds are ticking away and becoming more and more pathogenic,'' Robert Webster, a virologist at St. Jude Children's Research Hospital in Memphis, Tennessee, said. "We need surveillance across a variety of species to see which mammals it has made its way into.'' Webster assisted in the writing of the study.

Chinese officials should test animals regularly to look for signs of bird flu infection, Webster said. The Ministry's study suggests that the Chinese government is prepared to do more to prevent outbreaks, he said.