Scientists in Hong Kong and the United States have detected a new strain of bird flu in China, and they say this variety of the virus could start a new wave of illness.
The discovery by researchers from the University of Hong Kong and St. Jude Children's Research Hospital in Memphis, in the southern U.S. state of Tennessee, appears in a scientific journal published by the U.S. National Academy of Sciences.
The scientists are calling the new bird-flu strain "the Fujian-like virus," because it was first discovered in that southern province of China.
They say the Fujian strain is now the dominant variety of bird-flu virus currently found by investigators in several Chinese provinces, and that the new poultry disease has already spread to Hong Kong, Laos, Malaysia and Thailand.
Bird-flu virus has persisted in Asia despite frequent mutations.
The variety that has proven deadly to infected humans, H5N1 virus, primarily infects poultry, but public-health authorities have long warned that a further mutation or alteration of the structure of the virus could produce a strain that could spread easily from human to human, and thus pose the potential threat of a worldwide pandemic.
The H5N1 strain of bird flu first appeared in 1997 in Hong Kong in poultry flocks, but quick action by public-health authorities there limited the spread of the virus.
The same deadly strain reappeared in China three years ago and began to spread through other countries in Asia.
Since then nearly 150 human deaths worldwide have been attributed to bird flu. Most victims contracted the virus from dead or sick birds.