Giuseppe
Emeritus
Oseltamivir-resistant influenza viruses circulating during the first year of the influenza A(H1N1)2009 pandemic in the Asia-Pacific region, March 2009 to March 2010 (Euro Surveill., abstract, edited)
[Source: Eurosurveillance, full text: (LINK). Abstract, edited.]
Eurosurveillance, Volume 16, Issue 3, 20 January 2011
Surveillance and outbreak reports
Oseltamivir-resistant influenza viruses circulating during the first year of the influenza A(H1N1)2009 pandemic in the Asia-Pacific region, March 2009 to March 2010
A C Hurt 1, Y M Deng 1, J Ernest 1, N Caldwell 1, L Leang 1, P Iannello 1, N Komadina 1, R Shaw 1, D Smith 2, D E Dwyer 3, A R Tramontana 4, R T Lin 5, K Freeman 6, A Kelso 1, I G Barr 1
1. WHO Collaborating Centre for Reference and Research on Influenza, North Melbourne, Victoria, Australia
2. PathWest Laboratories, Perth, Western Australia, Australia
3. Centre for Infectious Diseases and Microbiology, ICPMR, Westmead Hospital, New South Wales, Australia
4. Peter MacCallum Cancer Centre, Melbourne, Australia
5. National Public Health Laboratory, Communicable Diseases Division Ministry of Health, Singapore
6. Centre for Disease Control, Darwin, Australia
Citation style for this article: Hurt AC, Deng YM, Ernest J, Caldwell N, Leang L, Iannello P, Komadina N, Shaw R, Smith D, Dwyer DE, Tramontana AR, Lin RT, Freeman K, Kelso A, Barr IG. Oseltamivir-resistant influenza viruses circulating during the first year of the influenza A(H1N1)2009 pandemic in the Asia-Pacific region, March 2009 to March 2010. Euro Surveill. 2011;16(3)
ii=19770. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19770
Date of submission: 30 July 2010
During the first year of the influenza A(H1N1)2009 pandemic, unprecedented amounts of the neuraminidase inhibitors, predominantly oseltamivir, were used in economically developed countries for the treatment and prophylaxis of patients prior to the availability of a pandemic vaccine. Due to concerns about the development of resistance, over 1,400 influenza A(H1N1)2009 viruses isolated from the Asia-Pacific region during the first year of the pandemic (March 2009 to March 2010) were analysed by phenotypic and genotypic assays to determine their susceptibility to the neuraminidase inhibitors. Amongst viruses submitted to the World Health Organization Collaborating Centre for Reference and Research in Melbourne, Australia, oseltamivir resistance was detected in 1.3% of influenza A(H1N1)2009 strains from Australia and 3.1% of strains from Singapore, but none was detected in specimens received from other countries in Oceania or south-east Asia, or in east Asia. The overall frequency of oseltamivir resistance in the Asia-Pacific region was 16 of 1,488 (1.1%). No zanamivir-resistant viruses were detected. Of the 16 oseltamivir-resistant isolates detected, nine were from immunocompromised individuals undergoing oseltamivir treatment and three were from immunocompetent individuals undergoing oseltamivir treatment. Importantly, four oseltamivir-resistant strains were from immunocompetent individuals who had not been treated with oseltamivir, demonstrating limited low-level community transmission of oseltamivir-resistant strains. Even with increased use of oseltamivir during the pandemic, the frequency of resistance has been low, with little evidence of community-wide spread of the resistant strains. Nevertheless, prudent use of the neuraminidase inhibitors remains necessary, as does continued monitoring for drug-resistant influenza viruses.
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[Source: Eurosurveillance, full text: (LINK). Abstract, edited.]
Eurosurveillance, Volume 16, Issue 3, 20 January 2011
Surveillance and outbreak reports
Oseltamivir-resistant influenza viruses circulating during the first year of the influenza A(H1N1)2009 pandemic in the Asia-Pacific region, March 2009 to March 2010
A C Hurt 1, Y M Deng 1, J Ernest 1, N Caldwell 1, L Leang 1, P Iannello 1, N Komadina 1, R Shaw 1, D Smith 2, D E Dwyer 3, A R Tramontana 4, R T Lin 5, K Freeman 6, A Kelso 1, I G Barr 1
1. WHO Collaborating Centre for Reference and Research on Influenza, North Melbourne, Victoria, Australia
2. PathWest Laboratories, Perth, Western Australia, Australia
3. Centre for Infectious Diseases and Microbiology, ICPMR, Westmead Hospital, New South Wales, Australia
4. Peter MacCallum Cancer Centre, Melbourne, Australia
5. National Public Health Laboratory, Communicable Diseases Division Ministry of Health, Singapore
6. Centre for Disease Control, Darwin, Australia
Citation style for this article: Hurt AC, Deng YM, Ernest J, Caldwell N, Leang L, Iannello P, Komadina N, Shaw R, Smith D, Dwyer DE, Tramontana AR, Lin RT, Freeman K, Kelso A, Barr IG. Oseltamivir-resistant influenza viruses circulating during the first year of the influenza A(H1N1)2009 pandemic in the Asia-Pacific region, March 2009 to March 2010. Euro Surveill. 2011;16(3)
ii=19770. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19770Date of submission: 30 July 2010
During the first year of the influenza A(H1N1)2009 pandemic, unprecedented amounts of the neuraminidase inhibitors, predominantly oseltamivir, were used in economically developed countries for the treatment and prophylaxis of patients prior to the availability of a pandemic vaccine. Due to concerns about the development of resistance, over 1,400 influenza A(H1N1)2009 viruses isolated from the Asia-Pacific region during the first year of the pandemic (March 2009 to March 2010) were analysed by phenotypic and genotypic assays to determine their susceptibility to the neuraminidase inhibitors. Amongst viruses submitted to the World Health Organization Collaborating Centre for Reference and Research in Melbourne, Australia, oseltamivir resistance was detected in 1.3% of influenza A(H1N1)2009 strains from Australia and 3.1% of strains from Singapore, but none was detected in specimens received from other countries in Oceania or south-east Asia, or in east Asia. The overall frequency of oseltamivir resistance in the Asia-Pacific region was 16 of 1,488 (1.1%). No zanamivir-resistant viruses were detected. Of the 16 oseltamivir-resistant isolates detected, nine were from immunocompromised individuals undergoing oseltamivir treatment and three were from immunocompetent individuals undergoing oseltamivir treatment. Importantly, four oseltamivir-resistant strains were from immunocompetent individuals who had not been treated with oseltamivir, demonstrating limited low-level community transmission of oseltamivir-resistant strains. Even with increased use of oseltamivir during the pandemic, the frequency of resistance has been low, with little evidence of community-wide spread of the resistant strains. Nevertheless, prudent use of the neuraminidase inhibitors remains necessary, as does continued monitoring for drug-resistant influenza viruses.
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