07 March 2005
More Bird Flu Appears in Humans in Vietnam
No evidence that cases transmitted from human to human
The Ministry of Health in Vietnam and the World Health Organization (WHO) verified on March 7 several more occurrences of humans getting ill from a lethal strain of bird flu that has circulated in Asia for more than a year.
The WHO has confirmed four new cases of human infection with H5N1 avian influenza, including one resulting in the death of a 69-year-old man. Health officials are not suggesting that the illnesses resulted from person-to-person transmission of the H5N1 virus that has infected hundreds of millions of birds in Southeast Asia over the last year.
If the H5N1 virus mutates into a form of the disease that can be passed through contact between persons, then global health authorities fear a pandemic could result. All but a couple of cases occurring in the region over the last year have been traced to a person’s direct contact with infected birds.
The new cases bring the total number of WHO-confirmed human cases in Vietnam, Thailand and Cambodia to 59 since January 2004. Of that total, 42 have resulted in death -- a fatality rate that health officials find alarming.
News services on March 7 report a fifth new case of the disease in Vietnam.
The text of the WHO situation report follows.
World Health Organization
Avian influenza -- situation in Viet Nam -- update 10 7 March 2005
The Ministry of Health in Viet Nam has confirmed an additional four cases of human infection with H5N1 avian influenza.
Details about these four cases are as follows:
· A 21-year-old man from Thai Binh Province. He developed symptoms on 14 February and was admitted to hospital on 20 February.
· His 14-year-old sister, also from Thai Binh Province. She developed symptoms on 21 February and was hospitalized the following day.
· A 69-year-old man, also from Thai Binh Province. He developed symptoms on 19 February, was admitted to hospital the same day, and died on 23 February.
· A 35-year-old woman from Hanoi. She developed symptoms on 18 February and was hospitalized on 24 February.
WHO continues to work closely with the Vietnamese Ministry of Health to further investigate additional cases which may have occurred since 2 February. WHO will update its cumulative list of confirmed cases accordingly.
Earlier this year, staff from WHO, Japan’s National Institute of Infectious Diseases in Tokyo, and Centers for Disease Control and Prevention, Atlanta, Georgia, USA, began working with health authorities in Viet Nam to improve the sensitivity and reliability of laboratory diagnostic tests. This activity, which aimed to upgrade laboratory capacity and included a training component, involved the retesting in Tokyo of specimens from several persons initially classified in Viet Nam in January as negative for H5N1 infection. Retesting detected H5N1 in specimens from seven persons. WHO is awaiting further details about these cases, including outcomes. Upon receipt of this information, WHO will also include these cases in the cumulative total for Viet Nam.
One additional case in Viet Nam, dating back to February 2004, has been identified retrospectively from specimens stored as part of a study of encephalitis (see the New England Journal of Medicine, 2005, 352:686-691). H5N1 infection, which was not considered in the diagnosis of this fatal case, was identified in November 2004 when specimens were submitted to a battery of tests. Specimens collected from other patients in this study are now being systematically tested for possible H5N1 infection.
Information on new cases is of greatest concern and WHO continues to gather as much data as possible on each new case. Such data are urgently needed at a time when many countries are intensifying their pandemic preparedness activities.