Avian influenza – situation in Viet Nam

18 August 2004

In the present outbreak in Viet Nam, first reported last week, three fatal human cases of avian influenza have now been laboratory confirmed, two in the north and one in the south. For two of these cases, further testing has identified the H5N1 strain as the causative agent. The most recent case died on 6 August and no new cases have been identified since then.

With support from the Ministry of Health in Viet Nam, arrangements are under way to send specimens from these cases to a laboratory in the WHO Global Influenza Surveillance Network. The laboratory will perform gene sequencing and other analyses of the virus in order to yield information immediately relevant to assessment of the public health risk.

Studies will determine whether the virus responsible for these cases has mutated. It is particularly important to learn whether the H5N1 virus strain remains entirely of avian origin.

Following a meeting held earlier this week, health officials in Viet Nam have called for close cooperation between WHO and the country’s two institutes equipped to test specimens for avian influenza. These are the National Institute of Hygiene and Epidemiology in Hanoi and the Pasteur Institute in Ho Chi Minh City. This cooperation is expected to expedite the sharing of test results on any additional cases that might require investigation.

A small team of WHO staff will be traveling to Viet Nam over the weekend. The team will be working closely with the Ministry of Health to assess the present risk to public health and to work out plans to strengthen surveillance capacity for the detection of human cases.