10 More H3N2v IN and OH Cases Match Novel WV Sub-Clade
August 16, 2012
The CDC has released sequences (at GISAID) from 10 more H3N2v cases in Indiana and Ohio which were collected between July 26 and July 30, 2012 (see list with collection dates below).
HA and NA sequences were available from all 10, while 9 MP sequences were released. PB2 sequences were released from 5, while sequences from the remaining 4 gene segments were released from 8.
All 10 N2 sequences were closely related to each other and matched (see realtionship to LaPorte County isolates here) the 2011 West Virginia cluster sub-clade. The H3 sequences had more diversity but all matched (see relationship to Jackson County isoalte here) the lineage for all human cases since 2011, which was true for the 9 MP sequences (see relationship to Butler County isolate here). Thus, all 10 cases, like all prior human cases from 2012 matched the novel sub-clade first reported in the West Virginia cluster, which had no swine exposure.
These sequences support human evolution and transmission of a novel sub-clade which is in all human 2012 sequences, and rarely detected in swine isolates collected prior to the current outbreak.