Oct 19, 2004 (CIDRAP News) – A government official in Thailand said 23 tigers at a private zoo died of avian influenza after eating the carcasses of chickens believed to have had the disease, the Associated Press (AP) reported today.

Meanwhile, thousands of chickens have died in new outbreaks of avian flu in southern Vietnam this month, despite official statements that the disease was under control, according to news services.

In Thailand, tigers at the Sriracha Tiger Zoo in central Chonburi province began dying Sep 14, Charal Trinvuthipong, director of the nation"e;s Bird Flu Elimination and Prevention Center, told the AP. He said another 30 tigers, among more than 400 kept at the zoo, were sick.

"We believe that the tigers contracted bird flu because they ate chicken carcasses, and we believe the carcasses had bird flu," Charal was quoted as saying. He added that veterinarians were checking for avian flu at chicken farms in the province.

Last January avian flu killed a clouded leopard and infected a white tiger at a zoo near Bangkok, according to reports at the time. Today"e;s AP report said that zoo is also in Chonburi province and that the white tiger also died. Avian flu also killed at least two house cats in Thailand last February.

In Vietnam, an official said about 3,000 chickens on three farms in southern Tien Giang province died or were culled over suspicions they had the disease, according to an Oct 18 AP story.

Test results from samples of those birds are expected this week, Cao Van Hoa, deputy director of the provincial agriculture department, told the AP.

The villages near the outbreaks have been disinfected and transportation of poultry to or from the affected districts has been banned, officials told the news agency.

An Oct 16 Agence France-Presse (AFP) report said more than 20,000 chickens have sickened or died this month in Long An and Hau Giang provinces. It attributed the information to the daily newspaper Tuoi Tre, and quoted the story as saying, “The bird flu epidemic has returned quickly and caused big losses to farmers but no information about this has been released.”

But an agriculture ministry spokesman told AFP that the report could not be true. Vietnam officials earlier said they had brought the latest outbreak under control.

In northern Vietnam, the Oct 16 edition of the newspaper Tien Phong reported that police in Lan Son province last week seized and destroyed 3.5 tons of chickens smuggled from China, the AP reported. Avian flu has killed or led to the culling of more than 43 million poultry in Vietnam.

Those who look toward poultry vaccine as a possible solution were dealt a setback this week when an Australian company announced that an experimental avian flu vaccine for poultry had failed to protect chickens. Only a small percentage of the chickens inoculated in the initial Australian trial of the vaccine survived exposure to H5N1 virus, according to the Australian Associated Press (AAP).

Imugene Limited began the trial in August in Geelong, Victoria, announcing then that once developed, the vaccine could be used to protect the world’s poultry industry from further outbreaks.

Imugene managing director Dr. Warwick Lamb told the AAP Oct 18 that the company will develop a second avian influenza vaccine. “Although we only have very early data, we have identified ways to make the next trial vaccine candidate more effective,” Lamb said.

Avian influenza has killed 31 people in Vietnam and Thailand and sickened 12 more since Jan 28, according to the World Health Organization.