Oseltamivir-Resistant Pandemic (H1N1) 2009 Virus Infections, United States, 2010–11

Abstract

During October 2010-July 2011, 1.0% of pandemic (H1N1) 2009 viruses in the United States were oseltamivir resistant, compared with 0.5% during the 2009-10 influenza season. Of resistant viruses from 2010-11 and 2009-10, 26% and 89%, respectively, were from persons exposed to oseltamivir before specimen collection. Findings suggest limited community transmission of oseltamivir-resistant virus.