Reduced Case Fatality Rate for Bird Flu Secondary Cases
Recombinomics Commentary
January 25, 2005
>>Meanwhile, two brothers from northern Vietnam were expected to be released from the hospital after recovering from bird flu, said their doctor, Nguyen Thi Tuong Van.
Their older brother also contracted the virus and died Jan. 10. All three siblings ate raw duck blood pudding before testing positive for the disease, officials have said. However, the youngest brother didn't show any symptoms.
The World Health Organization hasn't ruled out human-to-human transmission among the brothers, but experts say isolated cases have occurred in the past and shouldn't increase alarm that the virus has mutated.<<
The discharge of the two younger brothers will bring the case fatality rate down to approximately 80% for this season in Vietnam, similar to the rate over the summer for Thailand cases. In the latest cases, the only three survivors have been secondary or tertiary H5N1 avian influenza infections. In the case of the youngest brother in Vietnam, early intervention was associated with a lack of symptoms. This may have been due to treatment (including anti-viral Tamiflu) or to a lower initial exposure (from one of the older brothers).
Thus, although the number of human to human transmissions is on the rise in Vietnam, the ability to successfully treat 2nd or 3rd generations of H5N1 infections may reduce the fatality rate. In the four reported clusters, there are only six confirmed or suspect cases. Two have died (25F, 26F) three have recovered (32F, 42M, 36M), and the suspect case is hospitalized in critical condition (22F). All four index cases (19M, 11F, 47M, 17M) have died.
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