Send to

Choose Destination
J Infect Dis. 2012 Nov 15;206(10):1504-11. doi: 10.1093/infdis/jis571. Epub 2012 Sep 10.

Presence of oseltamivir-resistant pandemic A/H1N1 minor variants before drug therapy with subsequent selection and transmission.

Author information

Department of Computational & Systems Biology, Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.


A small proportion (1%-1.5%) of 2009 pandemic influenza A/H1N1 virus strains (A[H1N1]pdm09) are oseltamivir resistant, almost exclusively because of a H275Y mutation in the neuraminidase protein. However, many individuals infected with resistant strains had not received antivirals. Whether drug-resistant viruses are initially present as minor variants in untreated individuals before they emerge as the dominant strain in a virus population is of great importance for predicting the speed at which resistance will arise. To address this issue, we used ultra-deep sequencing of viral populations from serial nasopharyngeal specimens from an immunocompromised child and from 2 individuals in a household outbreak. We observed that the Y275 mutation was present as a minor variant in infected hosts before the onset of therapy. We also found evidence for the transmission of this drug-resistant variant with drug-susceptible viruses. These observations provide important information on the relative fitness of the Y275 mutation in the absence of oseltamivir treatment.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center