J Virol Methods. Rapid molecular detection of the H275Y oseltamivir resistance gene mutation in circulating influenza A (H1N1) viruses.

[Giuseppe]

http://www.flutrackers.com/forum/showthread.php?t=77788

 

[HenryN]

Re: J Virol Methods. Rapid molecular detection of the H275Y oseltamivir resistance gene mutation in circulating influenza A (H1N1) viruses.

The five influenza A/H1N1 H275Y mutants described in this work
have been submitted to the influenza database as ISDN299176-​

ISDN299180 at http://www.flu.lanl.gov/.


doi:10.1016/j.jviromet.2008.07.011

 

[HenryN]

Re: J Virol Methods. Rapid molecular detection of the H275Y oseltamivir resistance gene mutation in circulating influenza A (H1N1) viruses.

Surveillance
in previous years have found <1% of circulating viruses to be resistant​

to oseltamivir and none to zanamivir (Monto et al., 2006). They

usually occurred following treatment, but had not been shown to
be readily transmissible and thiswas considered to be due possibly
to decreased virus fitness (​

​

Carr et al., 2002; Colacino et al., 1997;
Gubareva et al., 1997; Herlocher et al., 2004; Ives et al., 2002; Tai et​

al., 1998; Yen et al., 2005).

al., 1998; Yen et al., 2005​

​

​

).
The predominant influenza A viruses that have being circulating
in Europe during the 2007?2008 season are subtype H1N1 viruses,
antigenically similar to the A/Solomon Islands/3/2006 virus which
was included in the 2007?2008 northern hemisphere vaccine.
However recently, surveillance studies have shown that a significant
proportion of circulating viruses are presenting resistance
to oseltamivir (Euro Surveill, 2008). Analysis of 2813 influenza
A/H1N1 viruses from 24 European countries isolated between
November 2007 and June 2008 showed that 701 were resistant
to oseltamivir (mean 25%), but of those tested all samples analysed
retained sensitivity to the alternative NAI, zanamivir (the E119
residue in NA1) and the M2 proton pump blocker amantadine (S31
in the M2 protein) (Euro Surveill, 2008). The studies to date have
also shown considerable differences in the patterns of resistance
in different geographical regions. There is no evidence that these
influenza A/H1N1 viruses have arisen directly as a result of treatment
by oseltamivir, which is currently not prescribed widely in
most European countries. Global surveillance coordinated by the
WHO has also subsequently found evidence of resistant viruses in
North America and in the Far East. Clinical experience in Norway
has suggested that individuals who become ill with an oseltamivir
resistant strain of influenza A/H1N1 have a similar spectrum of illness
to those infected with the wild-type seasonal influenzaA(Euro​

Surveill, 2008).