Three Fatal Human Cases of Avian Influenza Confirmed in Vietnam

MANILA, Philippines -- The Ministry of Health

in Vietnam has informed the World Health Organization (WHO) that three recent deaths from influenza-like illness in Vietnam were caused by infection with avian influenza.  These are the first officially reported cases of avian influenza in Vietnam since late February.

The three cases are among a group of patients, admitted to hospitals in Vietnam between July 19, 2004 and August 8, 2004 that have been under investigation by health authorities.

Initial tests have identified the virus as belonging to the H5 subtype.

Further testing is needed to determine whether the virus belongs to the same

H5N1 strain that caused 22 cases, with 15 deaths in Vietnam, and 12 cases,

with eight deaths, in Thailand earlier this year.

To date, H5N1 is the only strain of the H5 subtype known to jump directly

from infected poultry to cause illness in humans.

Two of the fatal cases occurred in the northern Ha Tay province.  The

third case occurred in the southern province of Hau Giang.  Staff from the WHO

country office in Vietnam will be meeting with the Ministry of Health this

afternoon to gather further details about these cases and work out plans for

addressing the situation.  The government has today announced an initial

series of measures aimed at controlling the disease in poultry and preventing

further cases in humans.

 WHO regards it as particularly important that viruses from these cases be

made available for further analysis by laboratories in the WHO Global

Influenza Surveillance Network.  Further studies can help determine whether

the virus has mutated and thus yield valuable information about the further

evolution of the outbreak, the risks to humans, and the best preventive

measures.  Studies of the virus are also important in the further development,

presently under way, of an effective human vaccine.

Thorough epidemiological and clinical investigation of these cases and

their contacts is needed to improve understanding of the risks to humans.

Earlier this year, Vietnam reported outbreaks of highly pathogenic H5N1

avian influenza in poultry in 57 of the country's 64 provinces, resulting in

the death or destruction of more than 43 million poultry.  After a period of

quiescence, Vietnam reported fresh outbreaks in poultry in July in provinces

in northern, central, and southern parts of the country.  Outbreaks were also

reported in July in China, Indonesia, and Thailand.

The confirmation of these latest human cases underscores the risk of virus

transmission to humans from infected poultry.  This risk will continue as long

as outbreaks are occurring in poultry.  Of greatest concern is the risk that

continuing transmission of the virus to humans will give avian and influenza

viruses an opportunity to exchange genes, potentially giving rise to a new

virus with pandemic potential.

Source: World Health Organization