Robert Roos  News Editor

Feb 27, 2004 (CIDRAP News) – The World Health Organization (WHO) today reported Thailand"e;s 10th confirmed human case of H5N1 avian influenza, marking the first new case confirmation anywhere since Feb 23.

The case involved a 47-year-old woman who has already recovered, the WHO said. She became ill Feb 3 after exposure to diseased and dead chickens at her home and was discharged from a hospital Feb 25, the agency said.

A total of 33 human cases of H5N1 flu have been reported so far. Thailand has had seven deaths among its 10 cases, while Vietnam has had 23 cases with 15 deaths, according to the WHO.

New outbreak reported in Japan
Meanwhile, a new avian flu outbreak was reported in Japan, and South Korea said tests had shown that the avian flu strain there is harmless to humans.

Preliminary tests have pointed to avian flu as the cause of death of about 28,000 chickens at a farm near Kyoto in western Japan, according to an online report by Japan Today. But the virus subtype was not reported in that sotry or in a Reuters report yesterday. Japan has had two previous poultry outbreaks of H5N1 flu in recent weeks.

The Reuters report said about 1,000 chickens had been dying at the farm each day since around Feb 20. The farm had shipped 15,000 live chickens to a nearby meat-packing firm Feb 25 and 26, according to Japan Today.

In South Korea, health officials said tests by the US Centers for Disease Control and Prevention (CDC) showed that the virus blamed for the country"e;s avian flu outbreaks, though listed as H5N1, is harmless to humans, according to an online report yesterday by the Korea Times.

Kim Moon-shik, head of the Korea Center for Disease Control and Prevention, was quoted as saying, "Korea"e;s bird flu virus is harmless to humans, as it has a different genetic sequence than those found in Thailand, Vietnam and Laos." Blood samples from infected chickens were sent to the US CDC for analysis in December, the report said.

In Vietnam, officials have voiced optimism this week about bringing the disease under control soon. An animal health official said yesterday that avian flu "is nearly under control because the disease has not spread to any other provinces," according to an Agence France-Presse report.

The state-controlled Vietnam News Agency said today that 10 of the country"e;s 57 affected provinces and cities had no new outbreaks from Feb 5 through 26.

No more poultry outbreaks in Texas
In the United States, the US Department of Agriculture (USDA) said today that no further avian flu cases have turned up in connection with an outbreak of highly pathogenic H5N2 avian flu in a chicken flock near San Antonio. The 6,600-bird flock was sacrificed Feb 21. Testing of samples from 200 farms within 10 miles of the affected flock has revealed no other cases so far, the USDA"e;s Animal and Plant Health Inspection Service (APHIS) said.

As reported previously, the H5N2 virus was found at two live-bird markets in Houston that had received poultry from the affected flock. Birds in those markets were destroyed Feb 23. As a precaution, three other Houston live-bird markets were emptied and cleaned, according to the APHIS report. A total of 2,300 birds were removed from the five markets.

APHIS also reported that a total of 426 farms in Delaware have been tested and found free of avian flu. Outbreaks attributed to an H7 virus were reported at two Delaware farms early in February.

In other recent developments, the Associated Press reported this week that WHO scientists were planning a variety of studies on the current H5N1 virus to try to assess how it might behave in humans and how likely it is to combine with human flu viruses.