|Home||Founder||What's New||In The News||Consulting|
Paradigm Shift Intervention Monitoring
H274Y Tamiflu Resistance Clonal Expansion - Newcastle Australia Recombinomics Commentary 21:40
Viruses from 25 of 184 (14 percent) A(H1N1)2009 cases from the Hunter
New England region exhibited highly reduced oseltamivir sensitivity
due to the H275Y substitution in the neuraminidase.
15 of the 1st 16 cases lived within a 50-km radius of the regional
centre of Newcastle. 16 of the 25 patients have been interviewed, and
none had received oseltamivir prior to influenza specimen collection.
The above comments describe the clonal expansion of H274Y in New South Wales province in Australia. The WHO regional center in Australia recently released three sequences (A/NEWCASTLE/14/2011, A/NEWCASTLE/47/2011, A/NEWCASTLE/58/20110 from Eleebana, Rutherford, and Cessnock, which are all within 30 km of Newcastle, and collected in June and July by John Hunter Hospital, Virology Unit, Clinical Microbiology in Lambton.
The HA from these sequences had S188T and all three sequence were identical, but none had H274Y. However, the identity of all three sequence from the region with H274Y suggests the resistant H1N1 matches the above sequences with H274Y appended to that genetic background.
These sequences are distinct of the clonal expansion of H274Y in Japan, or Delaware and Maryland, which involve additional S188T sub-clades. The expansion of multiple sub-clade with S188T and H274Y in three different continents indicates H274Y on an S188T is evolutionary fit and is rapidly spreading via hitchhiking and clonal expansion.