ASIA: The bird flu virus, which has killed 31 people in Thailand and Vietnam this year, is adaptable and has the ability to jump to many species, a Hong Kong expert on the disease has warned.
The H5N1 swept through much of Asia this year and millions of fowl were slaughtered in an effort contain the virus. The avian influenza virus was first seen in humans in 1997 in Hong Kong, where it infected 18 people, killing a third of them.
Guan Yi, a microbiologist at the University of Hong Kong who has studied the virus since 1997, said it was prone to mutate in search of suitable hosts across different species. "The virus is easily transmitted from one species to another. It can jump to many different species," he said in an interview.
Guan said the H5N1 virus carried a genotype which could be extremely unstable and generate many variants capable of jumping and latching on to different species.
"When it jumps from one species to another, it doesn't know if the new species likes it or not, so it becomes very unstable and generates many variants to allow the host to select the best one . . . so as to increase its own chances of survival.
"It doesn't want to kill the host because that way, it kills itself too, so it has to change itself," Guan said. "It generates many variants that can even invade neighbours of the host."
Migratory waterfowl are reservoirs for the H5N1 and are not taken ill by it, but there is no vaccine to protect poultry, which is susceptible to the virulent virus. It can wipe out entire flocks within 24 hours.
Last month, Dutch researchers reported that domestic cats could catch the virus, which means pets may spread the disease.
The virus has been found in the past in pigs, which are susceptible to human flu viruses. The biggest fear of experts is that the H5N1 and a human flu virus will marry in swine and become easily transmissible among humans, setting off a pandemic.
So far, it has only been established that human victims of the virus were infected directly by contaminated birds.
Guan called on governments around the region to address the problem at its root - by reducing human exposure to domestic flocks through tightly regulated farming and shielding domestic flocks from migratory waterfowl.