title: Prevalence of Oseltamivir-Resistant 2009 H1N1 Influenza Virus among Patients with Pandemic 2009 H1N1 Influenza infection in NRITLD, Tehran, Iran.
abstract: BACKGROUND
  Oseltamivir-resistant cases were reported during the 2009 pandemic influenza outbreak and therefore, widespread emergence of oseltamivir-resistant 2009 H1N1 virus is imaginable. Underlying medical conditions like immunosuppression increase the chance of oseltamivir resistance.
  
  
  METHODS
  In a retrospective cross-sectional study, respiratory tract specimens of confirmed cases of 2009 H1N1 influenza referred to the Masih Daneshvari Hospital were analyzed for presence of H275Y mutation.
  
  
  RESULTS
  From November 2009 through March 2010, oseltamivir-resistant 2009 H1N1 infection was observed and confirmed in 4 patients (including 2 immunocompromised patients) by performing H275Y mutation molecular testing.
  
  
  CONCLUSIONS
  Close monitoring of resistance to neuraminidase inhibitors is essential in tertiary care centers. The H275Y mutation (oseltamivir-resistant genotype) could appear in the absence or presence of selective drug pressure.
authors.affiliation: Virology Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Ahmadreza
authors.initials: A
authors.lastname: Moradi
authors.affiliation: Virology Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Seyed Alireza
authors.initials: SA
authors.lastname: Nadji
authors.affiliation: Mycobacteriology Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Payam
authors.initials: P
authors.lastname: Tabarsi
authors.affiliation: Nursing and Respiratory Health Management Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Seyed Mohammadreza
authors.initials: SM
authors.lastname: Hashemian
authors.affiliation: Mycobacteriology Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Majid
authors.initials: M
authors.lastname: Marjani
authors.affiliation: Virology Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Sigaroodi
authors.affiliation: Clinical Tuberculosis and Epidemiology Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Davood
authors.initials: D
authors.lastname: Mansouri
authors.affiliation: Chronic Respiratory Disease Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Masjedi
authors.affiliation: Pediatric Respiratory Disease Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, TEHRAN-IRAN.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Velayati
keywords: H275Y mutation; Oseltamivir-resistance; Pandemic 2009 H1N1 virus