Recombinomics Commentary 02:13 January 2, 2010 The Ivanosky Virology Institute has released sequences at Genbank from trachea (A/Orenburg/IIV2974/2009 ) and lung (A/Bryansk/IIV2971/2009) samples suggesting these are from fatal cases. The trachea sample yielded an HA sequence with D225N, while the lung had D225G. The sequences followed three sequences released yesterday, which were also from Russia lung samples and all three had D225G. It is unclear if these recent release represent an increased detection of these changes, but they are the first receptor binding domain chnages from Russia and now there are five such sequences. Some match the clade in Ukraine, which also had samples with D225G and D225N. It is unclear if these sequences indicate one or the other change is in the patient, or detection is based on tissue source or isolation procedures. Both polymorphisms have been reported in the same patient in the United States, Mexico, and Sweden. In all cases the signals were mixed, suggesting these samples had similar levels of each polymorphism.
These additional isolates further discount the WHO working hypothesis that these sequences are generated independently by random mutations. The finding of a position 225 change (D225G or D225N) on six of six fatal cases in Ukraine supports transmission of both changes, which have been appended onto the same genetic background which appears to be spilling over into Russia, based on the latest sequences.
In Ukraine, 94 fatalities have been reported in the past 96 hours, raising concerns that these changes will continue to spread. One of the western Ukraine isolates with D225G was tested for reactivity with ferret reference sera and was characterized as a low reactor, raising concerns that these changes will evade host immune responses and become dominant.
Thus far only partial sequences have been released by Mill Hill and the CDC for the initial cases. Full sequences from these and additional early cases as well as those in the current wave, which has spread across the country, including regions adjacent to Russia, would be useful.
