Bird Flu Familial Cluster of Five in Haiphong Vietnam
Recombinomics Commentary
March 25, 2005
>> In Vietnam, the afternoon edition of the state-run Hanoi Moi (New Hanoi) daily said five members of one family were hospitalized on Wednesday in the northern port city of Haiphong with coughing and breathing difficulties.
Doctors suspected they had bird flu, the paper said. It quoted Nguyen Van Vy, director of Haiphong's Health Department, as saying poultry at the family's house had been slaughtered earlier to stop bird flu outbreaks.
Bird flu tests on the five were under way, Vy said. <<
The hospitalization of five members of one family would represent the largest familial cluster reported to date. Although many of the index cases in the clusters are exposed to sick poultry, transmission to other family members is limited to one or two. Similarly, there is usually just one index case. The onset dates are bimodal, indicating human-to-human transmission, but such transmissions are limited.
The longest transmission was the Thai Binh cluster that involved two family members and two nurses, although the second nurse was not confirmed. A third family member had antibodies to H5N1, but a rising antibody titer was not reported, so the cause of the antibodies remains uncertain. However, the grandfather, who tested positive, did not have symptoms.
The description of the cluster in Haiphong indicates all five family members have symptoms and were hospitalized at the same time. This would signal a major difference with previous clusters, because even though most have initially been tied to poultry, transmission from poultry- to-humans has been much less efficient than human-to-human transmission.
Because of the large number of infected birds throughout southeast Asia, efficient transmission of H5N1 from birds to humans would be a major cause for concern.
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