New H5N1 Cases in Egypt Raise Pandemic Concerns
Recombinomics Commentary 11:38
December 31, 2007
The fourth confirmed H5N1 case in Egypt raises pandemic concerns. The four cases are in separate governorates (see satellite map). Two of the four have died (25F, 25F) while the remaining two are either in critical condition (50F) or in the ICU (22F). Three additional suspect cases have been identified (two of the suspect cases are in the same governorate, Al Minufiyah, as one of the confirmed cases).
New confirmed H5N1 outbreaks in poultry are reported daily. These bird flu outbreaks are on commercial farms as well as small holdings and are also widespread and have raised questions about the effectiveness of a vaccination campaign. The human and poultry outbreaks have led to an alert followed by the distribution of Tamiflu, and increased surveillance. However, the condition of the four confirmed cases has suggested a more virulent strain of H5N1 is in circulation. This possibility is supported by the outbreaks on commercial farms. Last season, most outbreaks were on small holdings.
Increased activity in Egypt was expected, due to the widespread outbreaks of H5N1 in Europe this fall. In the past no EU country reported H5N1 in the fall even though H5N1 was reported in eastern Europe in the fall of 2005 and 2006.
In addition to the European outbreaks, a reported 38 outbreaks in Saudi Arabia have been noted and a suspect case at Kuwait airport has been described. Similarly, the first H5N1 cases have been reported in Pakistan, including the most sustained transmission chain reported to date.
In the past, reported outbreaks in Egypt have been limited to H5N1 with regional markers found in Israel, Gaza, and Djibouti. However, the recent outbreaks in Europe have been a distinct clade 2.2 sub-clade tracing back to Uva Lake. Last season, the H5N1 in Egypt was more genetically complex. This was due in part because of recombination due to the high concentration of cases. This increased complexity was in both human and avian influenza isolates.
Egypt lies at the intersection of two major flyways, and cases have been reported throughout the Nile Delta. Migration of the Uva Lake strain into Egypt would accelerate H5N1 evolution in the region.
Sequence data on the recent human and avian outbreaks would be useful.
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