Bird Flu Case in Ha Tinh Vietnam
Recombinomics Commentary
April 4, 2005
>> A 27-year-old woman has tested positive for bird flu in central Vietnam, but she is recovering from the virus, a health official said Monday.
The woman was admitted to the general hospital in Ha Tinh province last Wednesday with a high fever, coughing and difficulty breathing, said Bui Bon, director of the Ha Tinh provincial health department, 350 kilometers south of Hanoi.
All the symptoms have since vanished and the woman is expected to be discharged soon, Bon said, adding that the National Institute of Hygiene and Epidemiology in Hanoi notified the hospital that the woman had contracted the H5N1 strain of the virus.
The woman had eaten duck with six other family members about two weeks ago at her in-laws' house, Bon said. The duck had been raised by the family and hadn't shown any signs of illness, he said. <<
The report above is a little more balanced than the duck blood headline. Although the duck blood has been a favorite of the media and someone at WHO, there has been little evidence tying a meal of duck blood to any confirmed case, including the one described above. Symptoms of H5N1 usually appear 2-4 days after exposure. So far no confirmed cases developed symptoms 2-4 days after such a meal. In all cases the ducks appeared healthy. Although asymptomatic ducks can shed H5N1, there is no evidence showing that the ducks linked to the blood pudding meals were infected.
Like the case above, at least one person who had the meal did not develop symptoms or show any evidence of exposure to H5N1. In the case above, five other family members ate the meal without ill effects.
Thus, even if the meal was the source, transmission was very inefficient, which is true for almost all H5N1 bird to human transmissions. In contrast, transmission from one family member to another is much more efficient. One third of reported H5N1 cases in Vietnam, Thailand, and Cambodia involve human-to-human transmission within a family.
The most efficient transmission to date was in a family of five in Haiphong. All five have been confirmed to be H5N1 positive and all entered the hospital on the same day.
Like the patient above, all are expected to recover. Moreover, like the patient above they had fever and breathing difficulties but had symptoms for a relatively short time of 1-2 weeks. In many respects the H5N1 infection was similar to an H3N2 infection by the aggressive California/7 strain. Thus, there could be thousands of similar cases that never produced a hospital visit.
The 27 year old from central Vietnam was admitted into the hospital on Wednesday and had H5N1 results from Hanoi by Monday. In contrast, the neighbors of the Haiphong family were admitted on March 25, but results have not been reported. Samples were collected in Quang Binh almost two weeks ago, and results have not been reported.
However, all the testing was being done at the same National Institute of Hygiene and Epidemiology in Hanoi.
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