Retrospective Identification of Another Familial Cluster in Iraq
Recombinomics Commentary
September 21, 2006
"The spokesperson noted that a member of the same family of the patient died with suspicions of bird flu disease, while another family member had symptoms of the disease in the area of Kamaliya in Baghdad.
Meanwhile, the source said that three-year-old Haydar Razzaq Hussein fully recovered from the disease and is living a normal life,"
The Ministry of Health in Iraq has retrospectively confirmed the country’s third case of human infection with the H5N1 avian influenza virus. The case, a 3-year-old boy, was hospitalized in Baghdad on 15 March 2006. His illness was mild and he fully recovered.
The above comments, from a March 29 media report followed by comments in the latest WHO update suggest that the most recently confirmed case was part of a family cluster. Disease onset dates are not given for the fatal case, but it is likely that the fatal case infected the 3 year old, and one of the two then infected the third case. The mild case (3M) was confirmed because he was a contact of a fatal case.
The data indicate that H5N1 in birds and people was widespread in Iraq. The index case for the country, and her uncle were from northern Iraq. There was another cluster in southern Iraq, but only the associated pigeons were reported to be H5N1 infected. There were also reports of birds falling out of the sky just north of Baghdad in Sumatra. Thus, although there are only three WHO confirmed cases in Iraq, it is likely that the number of cases has significantly higher.
The detection of mild H5N1 in a contact is similar to the third confirmed cases in Indonesia. The 9 year old nephew was tested because he was a contact of his aunt, who was the second confirmed case in Indonesia. He also had a mild case and quickly recovered.
The failure to isolate H5N1 from either of these confirmed mild cases may indicate that the mild cases were due to a low initial dose from a fatally infected relative. The initial inconclusive result for the 3M in Iraq raises questions about negative data for contacts in other cases. If these contacts were infected with a low dose of H5N1, then testing them for H5N1 neutralizing antibodies may yield positive results. Antibodies can be detected in recovered patients for decades.
The level of testing of contacts remains unclear. In Turkey, the four siblings initially tested negative for H5N1. Three siblings died and were subsequently positive for H5N1 (and sequences for H5N1 from the first two have been released). However, the fourth sibling recovered and remains a negative on the official WHO list, strongly suggesting that there was no follow-up test. Similarly, 8 relatives hospitalized with symptom remain negative, even though 2 members of that family were placed I the ICU and subsequently tested positive while the fourth fatality in Turkey was from a third related family, and a sibling of the fourth fatality also was hospitalized and was H5N1 positive.
Thus, there is strong clinical evidence for much larger clusters in Turkey and elsewhere, suggesting WHO follow-up testing on these recovered cases is limited.
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