Oseltamivir resistance mutation N294S in human influenza A [H5N1] virus in Egypt

ABSTRACT

In December 2006, three human specimens were received that were suspected positive for influenza A[H5N1]. The specimens were tested using real time PCR. And the presence of A[H5N1] virus was confirmed in 2 patients [16F and 26M], The NA sequence from A[H5N1] positive specimens collected before and after antiviral therapy revealed a mutation [N294S] [N295S according to N1 numbering], previously associated with resistance to oseltamivir. When tested with NA inhibition assays, the two N294S viruses from Egypt exhibited from 57 to 138-fold reduction in susceptibility to oseltamivir, depending on the assay. To our knowledge, this is the first time oseltamivir resistance has been detected in A[H5N1] infecting a human prior to treatment