A 2004 study in Japan found that 9 of 50 children with influenza A (H3N2) virus infection who had been treated with oseltamivir (18 percent) had a virus with a drug-resistance mutation in the ...

In adults with influenza A (H1N1) or (H3N2) virus infection, the development of resistance to oseltamivir is rare, but resistant viral variants have been detected in up to 18 percent of children ...

Resistance to oseltamivir was identified among 142 of 1,155 U.S. influenza A(H1N1) viruses (12 percent) tested during the 2007-2008 influenza season.

Oseltamivir resistance can be conferred by a single point missense mutation from histidine to tyrosine at position 275 (H275Y) of the neuraminidase gene, which is the most commonly reported mutation.

Resistance to oseltamivir was identified among 142 of 1,155 U.S. influenza A(H1N1) viruses (12 percent) tested during the 2007-2008 influenza season.

To date, all but one of these oseltamivir-resistant strains of pandemic H1N1 have been found to have the H275Y mutation. Resistance is infrequent and detected sporadically in pandemic H1N1, although ...

Their lab experiments, published in March, found the two mutations appeared to raise H1N1's resistance to the flu treatment oseltamivir, commonly sold under the brand Tamiflu by drugmaker Roche.

Transmissibility and pathogenicity of resistant strains appear similar to those of susceptible strains. In 2006, the circulating influenza A virus rapidly became resistant to the adamantanes ...

Three cases of drug-resistant H1N1 swine flu worry some experts. TORONTO, July 8, 2009— -- Public health authorities are reporting three cases of the pandemic H1N1 influenza in which the ...

Clinical evidence of oseltamivir (Tamiflu, Roche) resistance has been confirmed in patients infected with the novel avian H7N9 flu, as published online in The Lancet.

New findings indicate the emergence of oseltamivir-resistant 2009 H1N1 virus in England and Scotland — particularly among immunocompromised patients. Laurence Calatayud, MD,trainee of the ...

For some patients, replication of avian influenza virus is suppressed incompletely enough by oseltamivir that drug resistance develops. What about zanamivir? New antiviral agents desperately needed.