Two previously suspected outbreaks of the H5N1 strain of bird flu have been confirmed by the National Avian Influenza Reference Laboratory, with no new suspected cases reported since Tuesday, China's Ministry of Agriculture said on Friday.

The new infected regions are Huayin City, in Shaanxi, and Anning City, in Yunnan, two provinces in the west China area.

Local governments have taken measures against the disease by culling poultry in the affected areas and imposing prompt quarantine restrictions, said the ministry.

To date, the deadly H5N1 strain of bird flu has been confirmed in 16 provinces, municipalities and autonomous regions on the Chinese mainland.

While in Thailand, two domestic cats have died of the same bird flu that has killed at least 22 people in Asia, a veterinarian said on Friday, a day after Canada announced its first case of a different strain of the virus.

The discoveries have alarmed scientists who now fear the disease can spread as easily between species as it has between countries.

"We found H5N1 in two of the three cats," said Teerapol Sirinaruemit, a veterinarian at Kasetsart University's animal hospital who conducted autopsies on three animals.

"They might have caught the virus from eating chicken carcasses or from live chickens that had bird flu," he said.

The three were among 15 cats living in a house located near an infected chicken farm in Nakorn Pathom, 60 kilometers west of Bangkok, Teerapol said.

Fourteen cats died, but it was unclear if all had been infected with the H5N1 virus. One cat was still alive.

"We are going to bring the live one, which is quite sick, to the hospital today to check its health," Teerapol said.

Besides killing humans and millions of wild and farmed birds across Asia, the H5N1 strain showed earlier this week it can jump to other species after a rare clouded leopard at a zoo near Bangkok was confirmed to be dying of bird flu.

Reports earlier this month that the virus had spread to pigs, with an immune system similar to the human one, turned out to be false.

"Clearly the more animal species that are infected with the avian flu virus, the bigger is the risk humans may catch the virus from animals," said Bjorn Melgaard, the World Health Organization's Thailand representative.

"We need to be very, very watchful."

Scientists writing in the medical journal the Lancet said on Friday that developing human vaccines against the H5N1 strain must be a priority to prevent a pandemic like the one in 1918 that killed up to 50 million people worldwide.

"Developing a vaccine is one of the steps in preventing the generation of a new pandemic strain," said Dr Marion Koopmans, of the National Institute of Public Health and the Environment in the Netherlands.

Meanwhile the Canadian Food Inspection Agency was still conducting laboratory tests but officials said they had identified the H7 strain of avian influenza in British Columbia - the same type found recently in Delaware in the United States.

And in Manila, the head of the UN Food and Agriculture Organization on Friday urged international co-operation in fighting the spread of bird flu, saying the disease could spread to more animals.

FAO Director General Jacques Diouf said his agency has committed US$5.5 million to help co-ordinate the fight against bird flu and support individual countries. He said he has also written to leaders of developed countries for assistance.

Meanwhile, an Australian-made drug is effective in treating the bird flu, a government research body said on Friday.

It could also be taken as a preventative by people working in high-risk areas, lasting for up to 24 hours at a time, the Commonwealth Scientific and Industrial Research Organization (CSIRO) said.

Laboratory tests showed the flu drug Relenza was effective against a sample of an H5N1 influenza virus that has also killed millions of wild and farmed birds in Asia, CSIRO said.

(China Daily February 21, 2004)