Editor"e;s note: This story was revised Aug 13, 2004, to include additional information from the World Health Organization.

Aug 12, 2004 (CIDRAP News) – Three people in Vietnam died recently of the H5N1 strain of avian influenza, the Associated Press (AP) reported today.

If the report is accurate, the three are the first human victims of avian flu since March. In Asia"e;s widespread outbreaks earlier this year, the H5N1 virus infected 34 people and killed 23, according to World Health Organization (WHO) figures.

The latest victims, two of whom were small children, all tested positive for the H5N1 virus, according to Trinh Quan Huan, head of the Vietnamese Ministry of Health"e;s Department for Preventative Medicine and HIV/AIDS, as reported by the AP. The three people died between Jul 30 and Aug 1, Trinh said.

However, the World Health Organization (WHO) said the strain of virus in the three victims had not been fully identified. Initial tests have identified the virus as the H5 subtype, but further testing is needed to determine if it is H5N1, the WHO said in a statement dated Aug 12. The agency also said H5N1 is the only strain of the H5 subtype known to jump directly from poultry to humans and cause illness.

Trinh said a 4-year-old and a 1-year-old died in Ha Tay province about 30 miles west of Hanoi, while the other victim died in Hau Giang province in the Mekong Delta, about 110 miles south of Ho Chi Minh City, the AP reported. The story gave no other details about the third victim and did not say how the patients were infected.

Agence France-Presse (AFP) reported yesterday that Vietnamese health officials were investigating whether avian flu or SARS (severe acute respiratory syndrome) caused the recent deaths of four people who had respiratory infections. Those four died between Jul 29 and Aug 2, but all of them lived in Hau Giang province, according to the story.

The AFP report said a clinical sample from one of the four patients was being tested, but no samples were available from the other three deceased patients.

According to the AP report, Hans Troedsson, head of the WHO office in Hanoi, said he would ask the Vietnamese government for permission to send samples from the latest case-patients to a foreign laboratory for testing.

Avian flu killed 15 people in Vietnam and 8 in Thailand earlier this year, according to WHO figures. But reports attributed to the Vietnamese government have generally listed 16 deaths in Vietnam. Before the recent deaths, the last avian flu–related death in Vietnam was that of a 12-year-old boy in March, according to government sources.

All the human cases earlier this year were attributed to exposure to poultry, not to contact with other infected people. Disease experts are concerned that if the H5N1 virus infects a person already carrying a human flu virus, the two viruses could combine and produce a variant that could spread easily from person to person, potentially starting a pandemic.

Since late June, avian flu has resurfaced in Thailand, Indonesia, and China as well as Vietnam. Vietnam has had outbreaks in 12 provinces since Mar 30, when the government declared the country was free of the disease, according to AFP.

In related developments, South African officials were testing ostriches nationwide in the wake of the recent discovery of H5N2 avian flu on two ostrich farms in the Eastern Cape province, according to another AFP report today.

Culling of 6,000 ostriches on the two affected farms was under way, and up to 30,000 ostriches might be slaughtered in the surrounding area, the report said. The H5N2 virus has been described as harmless to humans.

The outbreak prompted the South African government to halt all poultry exports last week. The European Union and Switzerland have banned imports of ostrich meat from South Africa, the AFP report said.