Introduction: Oseltamivir (Tamiflu®) is an important pharmaceutical intervention against the influenza virus. The importance of surveillance for resistance to oseltamivir has been highlighted by two global events: the emergence of an oseltamivir-resistant seasonal influenza A(H1N1) virus in 2008, and emergence of the influenza A(H1N1)pdm09 virus in 2009. Oseltamivir is a prescription medicine in New Zealand, but more timely access has been provided since 2007 by allowing pharmacies to directly dispense oseltamivir to patients with influenza-like illness.
Objective: To determine the frequency of oseltamivir-resistance in the context of a medicine reclassification in 2007, the importation of an oseltamivir-resistant seasonal influenza virus in 2008, and the emergence of a pandemic in 2009.
Methods: A total of 1795 influenza viruses were tested for oseltamivir-resistance using a fluorometric neuraminidase inhibition assay. Viruses were collected as part of a sentinel influenza surveillance programme between the years 2006 and 2010.
Results: All influenza B, influenza A(H3N2) and influenza A(H1N1)pdm09 viruses tested between 2006 and 2010 were shown to be sensitive to oseltamivir. Seasonal influenza A(H1N1) viruses from 2008 and 2009 were resistant to oseltamivir. Sequencing of the neuraminidase gene showed that the resistant viruses contained an H275Y mutation, and S247N was also identified in the neuraminidase gene of one seasonal influenza A(H1N1) virus that exhibited enhanced resistance.
Discussion: No evidence was found to suggest that increased access to oseltamivir has promoted resistance. A probable importation event was documented for the global 2008 oseltamivir-resistant seasonal A(H1N1) virus nine months after it was first reported in Europe in January 2008.
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http://dx.doi.org/10.5365/WPSAR.2012.3.3.002 | DOI Listing |
Virus Evol
November 2024
Center for Viral Surveillance and Serological Assessment (CeVIVAS), Instituto Butantan, Avenida Vital Brasil, 1500, Butantã, São Paulo, São Paulo 05503-900, Brazil.
Influenza A and B viruses represent significant global health threats, contributing substantially to morbidity and mortality rates. However, a comprehensive understanding of the molecular epidemiology of these viruses in Brazil, a continental-size country and a crucial hub for the entry, circulation, and dissemination of influenza viruses within South America, still needs to be improved. This study addresses this gap by consolidating data and samples across all Brazilian macroregions, as part of the Center for Viral Surveillance and Serological Assessment project, together with an extensive number of other Brazilian sequences provided by a public database during the epidemic seasons spanning 2021-23.
View Article and Find Full Text PDFMethodsX
June 2025
Department of Statistics, Shahjalal University of Science and Technology, Sylhet, Bangladesh.
In infectious disease outbreak modeling, there remains a gap in addressing spatiotemporal challenges present in established models. This study addresses this gap by evaluating four established hybrid neural network models for predicting influenza outbreaks. These models were analyzed by employing time series data from eight different countries to challenge the models with imposed spatial difficulties, in a month-on-month structure.
View Article and Find Full Text PDFLancet Respir Med
January 2025
Netherlands Institute for Health Services Research, Utrecht, Netherlands. Electronic address:
Background: The majority of respiratory syncytial virus (RSV) infections in young children are managed in primary care, however, the disease burden in this setting remains poorly defined.
Methods: We did a prospective cohort study in primary care settings in Belgium, Italy, Spain, the Netherlands, and the UK during the RSV seasons of 2020-21 (UK only; from Jan 1, 2021), 2021-22, and 2022-23. Children aged younger than 5 years presenting to their general practitioner or primary care paediatrician with symptoms of an acute respiratory tract infection were eligible for RSV testing.
Vaccine
January 2025
Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
Introduction: While it remains impossible to predict the timing of the next influenza pandemic, novel avian influenza A viruses continue to be considered a significant threat.
Methods: A Phase II study was conducted in healthy adults aged 18-64 years to assess the safety and immunogenicity of two intramuscular doses of pre-pandemic 2017 influenza A(H7N9) inactivated vaccine administered 21 days apart. Participants were randomized (n = 105 in each of Arms 1-3) to receive 3.
Vaccine
January 2025
Vaxine Pty Ltd, Warradale, Adelaide, SA 5046, Australia; Australian Respiratory and Sleep Medicine Institute Ltd, Adelaide, SA 5042, Australia. Electronic address:
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