Year: 2009
Type: article
Abstract: To the Editor: The prevalence of oseltamivir-resistant influenza viruses A (H1N1) (ORVs) increased dramatically worldwide during the winter of 2007-08 (1).Recent reports indicated that by early 2009 most influenza virus (H1N1) strains were resistant to oseltamivir (2).Resistant viruses were transmitted readily and were as viable and pathogenic as oseltamivirsensitive viruses (OSVs) (3,4).The His275Tyr (N1 numbering) mutation in the neuraminidase (NA) genes of influenza virus A (H1N1) that confers resistance to oseltamivir has previously been associated with impaired virus replication, infectivity, and pathogenicity (5,6).We investigated the genetic diversity in all 8 gene segments of representative ORVs and OSVs collected during December 2007-March 2008 by the National Influenza Sentinel Surveillance System in Luxembourg (www.lns.public.lu/statistiques/grippe).Phylogenetic analyses were performed by using MEGA version 4.0 (7).Tree topology and posterior probabilities were calculated by using MrBayes version 3 (8).The sequences have been submitted to GenBank (accession nos.FM174406-60, FN401430-45, and FN401487-FN401518).Among 140 viruses, 34 strains (24.3%) had the oseltamivir-resistant genotype (Tyr275) in the NA gene.Bayesian analyses of NA genes showed that ORVs formed a distinct cluster supported by high posterior probability (1.00) on the common node (Figure).One resistant strain (LNS-365) was more closely related to OSVs (minimal Kimura distance 0.3%, 4 nt) than to ORVs (minimal
Source: Emerging infectious diseases
Institution: Laboratoire National de Santé
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W2015270682