Oseltamivir-Resistant Pandemic (H1N1) 2009 Treated with Nebulized Zanamivir

摘要

To the Editor: In late November 2009, a 3-year-old immunocompro-mised boy experienced an upper respi-ratory tract infection caused by in. u-enza A pandemic (H1N1) 2009 virus, as demonstrated by a positive result for real-time PCR on a nasal swab speci-men. His medical history was notable for a congenital intracardiac tumor; an ABO–incompatible heart transplant at 2 months of age; and an Epstein-Barr virus–related humoral rejection 20 months later that was treated with anti-CD20 and plasmapheresis and continuous immunosuppressive ther-apy with tacrolimus and everolimus. Thus, a 5-day regimen of oseltamivir treatment was undertaken, and the pa-tient's clinical signs improved.However, 3 days after drug treat-ment was suspended, the child had a relapse and exhibited fever, cough, and mild respiratory distress. The patient had fi ne crackles in the left posterior basal lung, normal oxygen saturation, and an infi ltrate in the left basal lung, observed on chest radiograph. Infection with pandemic (H1N1) 2009 virus was confi rmed. He was then transferred to an isolated ward of the pediatric department, and oseltamivir treatment was again initi-ated and dosages of immunosuppres-sive drugs were reduced. However, no clinical or virologic responses were observed during the 3 weeks of drug administration