Dataset Information

Adamantane- and oseltamivir-resistant seasonal A (H1N1) and pandemic A (H1N1) 2009 influenza viruses in Guangdong, China, during 2008 and 2009.

ABSTRACT: Adamantane and oseltamivir resistance among influenza viruses is a major concern to public health officials. To determine the prevalence of antiviral-resistant influenza viruses in Guangdong, China, 244 seasonal A (H1N1) and 222 pandemic A (H1N1) 2009 viruses were screened for oseltamivir resistance by a fluorescence-based neuraminidase (NA) inhibition assay along with NA gene sequencing. Also, 147 seasonal A (H1N1) viruses were sequenced to detect adamantane resistance markers in M2. Adamantane-resistant seasonal A (H1N1) viruses clustering to clade 2C were dominant in 2008, followed by oseltamivir-resistant seasonal A (H1N1) viruses, clustering to clade 2B during January and May 2009. In June 2009, a lineage of double-resistant seasonal A (H1N1) viruses emerged, until it was replaced by the pandemic A (H1N1) 2009 viruses. The lineage most likely resulted from reassortment under the pressure of the overuse of adamantanes. As all viruses were resistant to at least one of the two types of antiviral agents, the need for close monitoring of the prevalence of antiviral resistance is stressed.

SUBMITTER: Zhou J

PROVIDER: S-EPMC3147846 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

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Adamantane- and oseltamivir-resistant seasonal A (H1N1) and pandemic A (H1N1) 2009 influenza viruses in Guangdong, China, during 2008 and 2009.

Zhou Jie J Zou Lirong L Zhang Xin X Liao Jiazheng J Ni Hanzhong H Hou Nianmei N Wang Yajing Y Li Hui H Wu Jie J Jonges Marcel M Meijer Adam A Koopmans Marion M Ke Changwen C

Journal of clinical microbiology 20110518 7

Adamantane and oseltamivir resistance among influenza viruses is a major concern to public health officials. To determine the prevalence of antiviral-resistant influenza viruses in Guangdong, China, 244 seasonal A (H1N1) and 222 pandemic A (H1N1) 2009 viruses were screened for oseltamivir resistance by a fluorescence-based neuraminidase (NA) inhibition assay along with NA gene sequencing. Also, 147 seasonal A (H1N1) viruses were sequenced to detect adamantane resistance markers in M2. Adamantane ...[more]

PMID: 21593267

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Project description:Pandemic (H1N1) 2009 influenza is affecting countries in all five continents, with most cases so far having been reported in North and South America and Europe, and children and young adults being the most susceptible age groups. To date, the clinical course of disease is typically mild, with low hospitalization and mortality rates. Pandemic (H1N1) 2009 is susceptible to oseltamivir and, although few clinical data are yet available, current information suggests that treatment with oseltamivir appears to be beneficial. Only isolated cases of resistance to the drug have been reported to date, in keeping with the low frequency observed in clinical studies involving patients infected with seasonal influenza viruses. Current health authority guidelines recommend the use of oseltamivir in infected adults and children who have or are at elevated risk for severe disease, including pregnant women; use during the pandemic in infants < 1 year has also been authorized in Europe and a number of other countries, including the USA and Canada. Before the onset of the current pandemic, F. Hoffmann-La Roche Ltd expanded annual production capacity for oseltamivir to 400 million treatment courses per year to meet anticipated demand. However, during an influenza pandemic, and despite increased production capabilities, resources are nonetheless likely to be initially in short supply. For this reason, Roche, in line with WHO recommendations, has advocated advance stockpiling of antivirals by governments as a pandemic preparedness measure. Between 2004 and December 2009, 350 million treatment courses were supplied to governments worldwide. Support for developing countries has been a priority. Roche has established a cluster of initiatives aimed at increasing access to Tamiflu for the world's developing economies, including, making donations to the WHO, establishing the Tamiflu Reserves Program (TRP) and sub-licensing and manufacturing contracts with local companies in Asia and Africa. Furthermore, Roche has published a document outlining how it would allocate limited supplies of Tamiflu during a pandemic, which are in line with WHO recommendations stating that 'resources should be used to provide the maximum possible health benefit'. Roche is also offering support such as reprocessing of expiring capsule stocks (in development) and shelf-life extension to support governments in the management of their stockpiles. Clinical studies, either sponsored by or supported by Roche, are in progress. These trials are designed to investigate the effectiveness of oseltamivir in patients infected with the pandemic virus in greater depth, and include high-dose studies, assessment of natural and drug-induced resistance, and response to treatment in high-risk populations such as young infants, immunocompromised patients and the severely ill.

Dataset Information

Adamantane- and oseltamivir-resistant seasonal A (H1N1) and pandemic A (H1N1) 2009 influenza viruses in Guangdong, China, during 2008 and 2009.

Publications

Adamantane- and oseltamivir-resistant seasonal A (H1N1) and pandemic A (H1N1) 2009 influenza viruses in Guangdong, China, during 2008 and 2009.

Similar Datasets

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