To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: Oseltamivir-Resistant Strains of Seasonal Influenza Found in North America and Europe URL: http://www.pslgroup.com/dg/21D98A.htm Doctor's Guide February 22, 2008
NEW YORK -- February 22, 2008 -- The World Health Organization (WHO) has reported higher rates of seasonal influenza A(H1N1) resistant to oseltamivir (Tamiflu) compared to previous seasons in various areas of four European countries, Canada, and the United States. The initial report comes after Norway notified the WHO, under the International Health Regulations, that a high rate of A(H1N1) virus isolates had tested positive for oseltamivir resistance. Norwegian officials reported that the mutation was present in 12 of 16, or 75 percent of viruses isolated in that country from patients in November and December. Among Britain, Denmark, France, and Norway, the four European countries reporting cases of the mutant virus known as influenza A(H1N1 H274Y), the Norwegian rate was the highest. Overall, the mutant form was found in 19 of the viruses isolated from 148 patients, or 13 percent, in a monitoring system that the European Center for Disease Prevention and Control runs in 10 European countries. Excluding Norway, that percentage fell to 5 percent. In January, Alicia Fry, MD, MPH, Centers for Disease Control and Prevention (CDC), Atlanta, told The New York Times that the oseltamivir-resistant strain was found in 9 of 237, or 3.8 percent of US patients from whom influenza type A and B viruses were isolated. All 9 cases were in the A(H1N1) category. As of February 9, 2008, 4.6% of all influenza viruses analysed by CDC this season have been found to be resistant to oseltamivir. Of those, 8.1% of A(H1N1) viruses have been resistant to oseltamivir. No oseltamivir-resistant influenza A(H3N2) or B viruses have been found in the United States this season. The limited information currently available does not show clustering in particular age groups nor does it suggest that infections caused by the resistant strain are more severe. The WHO is compiling information to determine the public health impact of this data. Despite the findings, officials from the WHO and the United States confirmed that there are no immediate plans to recommend changes in the use of oseltamivir because the incidence of the mutant virus is still small. CDC and the Advisory Committee on Immunization Practices (ACIP) recommend that oseltamivir or another antiviral, zanamivir (Relenza) can be used for the treatment and prevention of influenza in the United States this season. In addition, officials stated that immunization with this season's influenza vaccine remains effective, including for the prevention of illness due to the oseltamivir-resistant A(H1N1) virus. SOURCE: World Health Organization, The New York Times, Centers for Disease Control and Prevention --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.