Avian influenza – update: situation in Viet Nam

7 September 2004

WHO has received informal reports of a laboratory-confirmed fatal case of influenza A H5 infection in Viet Nam. The patient is thought to be a child who was hospitalized in Hanoi and who died over the weekend. Further details are awaited from official sources.

Detection of an H5 subtype of influenza A in a human should always arouse a very high level of suspicion that the case was caused by the H5N1 strain of avian influenza, particularly in a country with ongoing outbreaks of H5N1 in poultry. H5N1 is the only strain within the H5 subtype that has ever been shown to cause disease in humans.

Since August, Viet Nam has detected four human cases of H5 infection. These cases have occurred amidst recurring H5N1 outbreaks in poultry in several Asian countries.

Since January of this year, altogether 39 human cases have been reported from two countries, Viet Nam and Thailand. Of these cases, 28 have been fatal.

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