Recombinomics: Fatal H5N1 Cluster in Thanh Hoa Vietnam Raises Concerns

Commentary

Fatal H5N1 Cluster in Thanh Hoa Vietnam Raises Concerns
Recombinomics Commentary 07:33
January 8, 2009

said on 25-12-2008 daughter of his family he is BTTh. (13 years old, her daughter's baby BTT - 8 years old, infected with influenza A H5N1) have symptoms of fever, cough, difficulty breathing should be brought to the family clinic in, and then onto Hospital Ba Thuoc treatment. But due to the serious illness, the child of morning 2-1-2009. has died at the hospital district.

A third child -- a five-year-old boy living next door to the girls' family who hadalso eaten chicken and duck dishes -- was being treated for respiratory symptoms in the district hospital, said Mau.

"However, he had only normal pneumonia and we received an answer from the provincial level that he is negative for bird flu," she added. "He will be discharged from hospital today as he is OK now."

The above translation and comments describe two additional patients associated with the confirmed H5N1 case (8F) in Thanh Hoa, Vietnam (see satellite map) and suggest the fatally infected index (13F) case infected her sister and neighbor (5M).

The index case was taken to the family clinic on December 25, suggesting disease onset was several days earlier. Her sister (8F) developed symptoms on December 27, but was not hospitalized until her sister (13F) died on January 2. The disease onset date for the neighbor is not known, but since he is still hospitalized, his history is likely to be similar to the confirmed case, who is also recovering and will likely be discharged soon. Although he tested negative, false negatives are common and a test of convalescent antibodies, which should be from a serum sample collected a week or two after discharge, is warranted.

This cluster is cause for concern. The index case was not tested, even though her sister developed symptoms a week before the index case died. The neighbor tested negative, but was likely on Tamiflu because one neighbor died with bird flu symptoms and another tested positive for H5N1. The collection date of the negative sample, relative to the start of Tamiflu treatment is not described.

This cluster in Vietnam follows a cluster in Beijing. In that cluster the index case died and was H5N1 confirmed. A nurse developed symptoms and one media report indicated she had bird flu, but recovered. It is likely that the cluster was associated with clade 7, which was confirmed in Jiangsu outbreaks last month. The OIE report on the bird outbreaks indicated the infected birds were asymptomatic.

In August, clade 7 was also reported in Vietnam, raising concerns that the current cluster is also linked to clade 7. The proposed WHO vaccine target for clade 7 is from Vietnam and is likely from the August outbreak.

Sequence data from the clusters in China and Vietnam as well as poultry outbreaks would be useful.

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