No highly pathogenic H5N1 avian influenza virus has turned up in any of the 13,000 wild migratory birds that federal and state officials have tested since Apr 26, the US government announced yesterday.

The US Department of Agriculture (USDA) said about 113 birds tested positive for other types of avian flu. Those results were expected, officials said, because there are 144 avian flu subtypes, most of which pose no threat to domestic poultry or humans and do not produce noticeable illness in wild birds.

"Although no high-path H5N1 virus has yet been detected, we must remain vigilant and thorough in this important detection and early warning program," said Interior Secretary Dirk Kempthorne, who is visiting a sampling camp near Barrow, Alaska, this week.

The Alaska sampling has targeted 26 species whose migratory patterns would have likely put them in contact with the H5N1 virus before arriving in Alaska, the USDA said.

The national wild bird surveillance plan is part of the administration´s National Strategy for Pandemic Flu. President Bush allocated $29 million in the fiscal year 2006 avian flu supplemental funding package for wild bird monitoring, which was recently expanded to the lower 48 states, Hawaii, and Pacific territories. The sampling program goal is to test 75,000 to 100,000 migratory birds and 50,000 bird feces samples this year.

In other avian flu news, an H5 avian flu virus was detected this week in a flock of ducks in a Hanoi suburb, according to an Agence France-Presse report today. The two ducks that tested positive were from a market; a total of five were tested, all in good health. The neuraminidase (N) component of the virus had not yet been identified.

"This discovery shows that the virus is still circulating among poultry, especially waterfowl," Agriculture Minister Hoang Van Nam told AFP. The geographic origin of the ducks could not be determined. Though live poultry trade in Hanoi´s inner district is prohibited, the ban is loosely enforced.

Vietnamese health officials said 2 days ago that the H5N1 virus was found on a small duck farm in the southern Ben Tre province, and an H5 virus resurfaced in ducks and storks in the past month. Though Vietnam has the highest number of human H5N1 cases (93), no human cases have been reported this year.

To help prevent avian flu in Latin America and the Caribbean, the United Nations Food and Agriculture Organization (FAO) announced today the release of a new handbook aimed at the region´s small-scale poultry farmers. The guide focuses on simple, inexpensive methods to ensure farm biosecurity and prevent contact between domestic poultry and wild birds, according to an FAO press release.

The guidebook, to be widely distributed and available free on the FAO´s Web site, is similar to a guide that was published for poultry farmers in Southeast Asia.

The threat to Latin American and Caribbean poultry from migratory birds is the same as for North America. The FAO said that if it reached North America, the H5N1 virus would follow north-south migration routes from the Arctic to Tierra del Fuego, the archipelago at the southern tip of South America. Domestic poultry smuggling, informal trading, and cockfighting contests could all contribute to the spread of avian flu, the agency said.

Though the Asian H5N1 strain has never been detected in the Americas, other strains (H5N2 and H7N3) have caused disease outbreaks in Canada, Chile, the United States, and Mexico in recent years, the FAO noted.

An appearance of  H5N1 avian flu in Latin America and the Caribbean would threaten the food security of the most vulnerable groups in the region, where poultry accounts for more than 70% of animal protein consumption, the FAO said.

In related news, media reports said today that seven more people in Indonesia have been hospitalized on suspicion of having avian flu. Two of the patients, a 17-year-old and a 39-year-old man, are from the Garut district of West Java, where health authorities recently investigated the possibility of human-to-human disease transmission, according to an AFP report today.

Five people from the Indonesian island of Sulawesi were hospitalized this week, according to a Reuters report today. An avian-flu information official told Reuters that samples from the patients were sent to a government lab for testing. No other details about the patients were available.

See also:

Aug 29 USDA press release on results of wild bird testing in Alaska

Aug 30 FAO press release on avian flu guidance for Latin American and Caribbean poultry farmers
http://www.fao.org/newsroom/en/news/2006/1000381/index.html

FAO guidebook on avian flu prevention for poultry farmers in Latin America and the Caribbean
http://www.fao.org/AG/AGAINFO/SUBJECTS/documents/ai/AI-Manual-spanish.pdf