title: Clinical findings in 10 children with H275Y influenza A(H1N1)pdm09 virus infection.
abstract: BACKGROUND
  Little is known about the clinical effectiveness of neuraminidase inhibitors against H275Y influenza A(H1N1)pdm09 virus. A cluster of H275Y influenza A(H1N1)pdm09 virus with cross-resistance to oseltamivir and peramivir was detected among untreated community patients in Hokkaido, Japan, during the 2013-2014 influenza season.
  
  
  METHODS
  This was a retrospective observational study. Specimens from nasopharyngeal swabs underwent rapid testing and single-nucleotide polymorphism identification on real-time polymerase chain reaction. We collected clinical data from the H275Y group and a 275H wild-type comparison group. All children were given one of four neuraminidase inhibitors.
  
  
  RESULTS
  Twenty-eight children infected with influenza A(H1N1)pdm09 virus were analyzed. Ten viruses had the H275Y substitution, while the other 18 had wild-type 275H. Mean fever duration after treatment and after onset was 25.3 h (95%CI: 14.1-36.5) and 48.9 h (95%CI: 34.4-63.3) in the H275Y group, respectively, and 26.1 h (95%CI: 18.7-33.6) and 46.3 h (95%CI: 35.7-56.8) in the 275H group, respectively. In the H275Y group, three patients were treated with oseltamivir, one with peramivir, five with zanamivir, and one with laninamivir. All of them had mild symptoms and received only outpatient care. Fever duration was 7.5-21.0 h and 18.0-66.0 h after treatment and after onset, respectively, in the patients treated with oseltamivir and peramivir, and 20.5-42.0 h and 42.0-88.0 h, respectively, in those treated with zanamivir and laninamivir.
  
  
  CONCLUSIONS
  Fever in the H275Y children treated with oseltamivir and peramivir resolved rapidly during the 2013-2014 influenza season.
authors: Department of Pediatrics, Furano Kyokai Hospital, Furano, Hokkaido, Japan.
authors: Fujio
authors: F
authors: Kakuya
authors: Clinical Laboratory, Furano Kyokai Hospital, Furano, Hokkaido, Japan.
authors: Takahiro
authors: T
authors: Kinebuchi
authors: Department of Pediatrics, Furano Kyokai Hospital, Furano, Hokkaido, Japan.
authors: Hiroaki
authors: H
authors: Fujiyasu
authors: Department of Pediatrics, Furano Kyokai Hospital, Furano, Hokkaido, Japan.
authors: Ryosuke
authors: R
authors: Tanaka
authors: Department of Pediatrics, Furano Kyokai Hospital, Furano, Hokkaido, Japan.
authors: Hitoshi
authors: H
authors: Okubo
authors: Clinical Laboratory, Furano Kyokai Hospital, Furano, Hokkaido, Japan.
authors: Hiroki
authors: H
authors: Kano
mesh_terms: D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D015994:Incidence; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics*; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D012621:Seasons
chemical_list: D004279:DNA, Viral
keywords: H275Y substitution; antiviral resistance; clinical effectiveness; influenza A(H1N1)pdm09; neuraminidase inhibitor