Surveillance for neuraminidase inhibitor resistance among human influenza A and B viruses circulating worldwide from 2004 to 2008.

ABSTRACT: The surveillance of seasonal influenza virus susceptibility to neuraminidase (NA) inhibitors was conducted using an NA inhibition assay. The 50% inhibitory concentration values (IC(50)s) of 4,570 viruses collected globally from October 2004 to March 2008 were determined. Based on mean IC(50)s, A(H3N2) viruses (0.44 nM) were more sensitive to oseltamivir than A(H1N1) viruses (0.91 nM). The opposite trend was observed with zanamivir: 1.06 nM for A(H1N1) and 2.54 nM for A(H3N2). Influenza B viruses exhibited the least susceptibility to oseltamivir (3.42 nM) and to zanamivir (3.87 nM). To identify potentially resistant viruses (outliers), a threshold of a mean IC(50) value + 3 standard deviations was defined for type/subtype and drug. Sequence analysis of outliers was performed to identify NA

SUBMITTER: Sheu TG 

PROVIDER: S-EPMC2533500 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature