TY - JOUR AU - Meijer, Adam AU - Lackenby, Angie AU - Hungnes, Olav AU - Lina, Bruno AU - van der Werf, Sylvie AU - Schweiger, Brunhilde AU - Opp, Matthias AU - Paget, John AU - van de Kassteele, Jan AU - Hay, Alan AU - Zambon, Maria T1 - Oseltamivir-Resistant Influenza Virus A (H1N1), Europe, 2007–08 Season T2 - Emerging Infectious Disease journal PY - 2009 VL - 15 IS - 4 SP - 552 SN - 1080-6059 AB - In Europe, the 2007–08 winter season was dominated by influenza virus A (H1N1) circulation through week 7, followed by influenza B virus from week 8 onward. Oseltamivir-resistant influenza viruses A (H1N1) (ORVs) with H275Y mutation in the neuraminidase emerged independently of drug use. By country, the proportion of ORVs ranged from 0% to 68%, with the highest proportion in Norway. The average weighted prevalence of ORVs across Europe increased gradually over time, from near 0 in week 40 of 2007 to 56% in week 19 of 2008 (mean 20%). Neuraminidase genes of ORVs possessing the H275Y substitution formed a homogeneous subgroup closely related to, but distinguishable from, those of oseltamivir-sensitive influenza viruses A (H1N1). Minor variants of ORVs emerged independently, indicating multiclonal ORVs. Overall, the clinical effect of ORVs in Europe, measured by influenza-like illness or acute respiratory infection, was unremarkable and consistent with normal seasonal activity. KW - viruses KW - antimicrobial resistance KW - influenza A virus KW - H1N1 KW - antiviral agents KW - oseltamivir KW - epidemiology KW - surveillance KW - Europe KW - research DO - 10.3201/eid1504.081280 UR - https://wwwnc.cdc.gov/eid/article/15/4/08-1280_article ER - End of Reference