Progressive emergence of an oseltamivir-resistant A (H3N2) virus over two courses of oseltamivir treatment in an immunocompromised paediatric patient
Aeron C Hurt, Sook Kwan Leang, Karin Tiedemann, Jeff Butler, Francoise Mechinaud, Anne Kelso, Peter Downie, Ian G Barr
INFLUENZA AND OTHER RESPIRATORY VIRUSES | WILEY-BLACKWELL | Published : 2013
A minor viral population of oseltamivir-resistant A(H3N2) viruses (E119V neuraminidase mutation) was selected and maintained in a continually infected immunocompromised child following initial oseltamivir treatment. A subsequent course of oseltamivir given 7 weeks later rapidly selected for the E119V variant resulting in a near-pure population of the resistant virus. The study highlights the challenges of oseltamivir treatment of immunocompromised patients that are continually shedding virus and demonstrates the ability of the E119V oseltamivir-resistant virus to be maintained for prolonged periods even in the absence of drug-selective pressure.
For susceptibility testing, the NAI oseltamivir carboxylate was kindly provided by Hoffmann-La Roche Ltd, Switzerland; zanamivir was kindly provided by GlaxoSmithKline, Australia; peramivir was kindly provided by BioCryst Pharmaceuticals; and laninamivir was kindly provided by Daiichi-Sankyo, Japan. The Melbourne WHO Collaborating Centre for Reference and Research on Influenza is supported by the Australian Government Department of Health and Ageing.