Recombining H5N1 High CFR and Transmission in Egypt
Recombinomics Commentary 22:44
December 31, 2007
Later, health officials said another women, Hanim Ibrahim Attwa, 44, also died today from bird flu at Al-Abbasiya Hospital in Cairo. Ms Attaw was from the Nile delta province of Dimayt, some 200 km north of the Egyptian capital.
The above comments confirm that the fourth H5N1 fatality was one of the patients (listed as 50F in WHO update) who was H5N1 confirmed last week. Thus, four of the five cases confirmed in the past week have died (see satellite map).
This high case fatality rate (CFR) is similar to the rate twelve months ago, at the beginning of last season. However, the frequency of reported infections is much higher, and comparable to the rate in the spring last season, when mild H5N1 cases were reported. Only one of seventeen cases from the spring until the end of last season died. The cases were most frequently reported in March and early April, when no fatalities were reported.
Thus, the current outbreak has combined the high case fatality rate from the beginning of last season, when reported cases were infrequent, with the low case fatality rate in the spring when the reported cases were frequent.
One of the concerns of the frequent mild cases was the creation of conditions leading to recombination which would create a more efficiently transmitted H5N1 with an H5N1 with a high case fatality rate.
Such recombination in Egypt would be likely because of the high concentration of H5N1 (see the mapping of the 922 OIE reported cases here here here here here) which lead to the increased complexity of H5N1 last season.
The release of the sequences from the current avian and human cases remains critical.
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