• 1
    Infectious disease Surveillance Center. Weekly reports of influenza virus isolation/detection. Available at
  • 2
    Kawai N, Ikematsu H, Tanaka O et al. Comparison of the clinical symptoms and the effectiveness of neuraminidase inhibitors for patients with pandemic influenza H1N1 2009 or seasonal H1N1 influenza in the 2007–2008 and 2008–2009 seasons. J Infect Chemother2011; 17:375381.
  • 3
    WHO. Summary review of the 2010–2011 northern hemisphere winter influenza season. Distribution of virus subtypes by influenza transmission zone (October 2010-April 2011). Available at
  • 4
    Ikematsu H, Kawai N, Kashiwagi S. In vitro neuraminidase inhibitory activities of four neuraminidase inhibitors against influenza viruses isolated in the 2010-2011 season in Japan. J Infect Chemother. 2012 Feb 28.
  • 5
    Kawai N, Ikematsu H, Iwaki N et al. Factors influencing the effectiveness of oseltamivir and amantadine for the treatment of influenza: a multicenter study from Japan of the 2002–2003 influenza season. Clin Infect Dis2005; 40:13091316.
  • 6
    Kawai N, Ikematsu H, Iwaki N et al. A Comparison of the effectiveness of oseltamivir for the treatment of influenza A and influenza B: a Japanese multicenter study of the 2003–2004 and 2004–2005 influenza seasons. Clin Infect Dis2006; 43:439444.
  • 7
    Kawai N, Ikematsu H, Iwaki N et al. Longer virus shedding in influenza B than in influenza A among outpatients treated with oseltamivir. J Infect2007; 55:267272.
  • 8
    Kawai N, Ikematsu H, Iwaki N et al. A comparison of the effectiveness of zanamivir and oseltamivir for the treatment of influenza A and B. J Infect2008; 56:5157.
  • 9
    Kawai N, Ikematsu H, Iwaki N et al. Clinical effectiveness of oseltamivir for influenza A(H1N1) virus with H274Y neuraminidase mutation. J Infect2009; 59:207212.
  • 10
    Kawai N, Ikematsu H, Hirotsu N et al. Clinical effectiveness of oseltamivir and zanamivir for treatment of influenza A virus subtype H1N1 with the H274Y mutation. A Japanese multicenter study of the 2007–2008 and 2008–2009 Influenza Seasons. Clin Infect Dis2009; 49:18251835.
  • 11
    Kawai N, Ikematsu H, Iwaki N et al. Persistence of pandemic influenza H1N1 virus in young patients after oseltamivir therapy in the 2009-2010 season: a comparison with seasonal H1N1 with or without H275Y mutation. J Infect Chemother2012; 18:180186, DOI 10.1007/s10156-011-0314-2.
  • 12
    Watanabe A, Chang SC, Kim MJ, Chu DW, Ohashi Y, MARVEL Study Group. Long-acting neuraminidase inhibitor laninamivir octanoate versus oseltamivir for treatment of influenza: A double-blind, randomized, noninferiority clinical trial. Clin Infect Dis2010; 51:11671175.
  • 13
    Ikematsu H, Kawai N. Laninamivir octanoate: a new long-acting neuraminidase inhibitor for the treatment of influenza. Expert Rev Anti Infect Ther2011; 9:851857.
  • 14
    Boivin G, Goyette N. Susceptibility of recent Canadian influenza A and B virus isolates to different neuraminidase inhibitors. Antiviral Res2002; 54:143147.
  • 15
    Kawai N, Ikematsu H, Iwaki N et al. A prospective, Internet-based study of the effectiveness and safety of influenza vaccination in the 2001–2002 influenza season. Vaccine2003; 21:45074513.
  • 16
    Stockton J, Ellis JS, Saville M, Clewley JP, Zambon MC. Multiplex PCR for typing and subtyping influenza and respiratory syncytial viruses. J Clin Microbiol1998; 36:29902995.
  • 17
    CDC protocol of realtime RT-PCR for influenza A (H1N1). Available at
  • 18
    Yamashita M, Tomozawa T, Kakuta M, Tokumitsu A, Nasu H, Kubo S. CS-8958, a prodrug of the new neuraminidase inhibitor R-125489, shows long-acting anti-influenza virus activity. Antimicrob Agents Chemother2008; 53:186192.
  • 19
    Cao B, Li XW, Mao Y et al. Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in China. N Engl J Med2009; 361:25072517.
  • 20
    Ikematsu H, Takeuchi Y, Rosenlund M et al. The post-infection outcomes of influenza and acute respiratory infection in patients above 50 years of age in Japan: an observational study. Influenza Other Respi Viruses2012; 6:211217.
  • 21
    Keramarou M, Cottrell S, Evans MR et al. Two waves of pandemic influenza A(H1N1) 2009 in Wales--the possible impact of media coverage on consultation rates, April-December 2009. Euro Surveill2011; 16:pii: 19772.
  • 22
    Presanis AM, Pebody RG, Paterson BJ et al. Changes in severity of 2009 pandemic A/H1N1 influenza in England: a Bayesian evidence synthesis. BMJ2011; 343:d5408, doi: 10.1136/bmj.d5408.
  • 23
    Mytton OT, Rutter PD, Mak M, Stanton EA, Sachedina N, Donaldson LJ. Mortality due to pandemic (H1N1) 2009 influenza in England: a comparison of the first and second waves. Epidemiol Infect2012; 140:153341.
  • 24
    Kubo S, Tokumitsu A, Tomozawa T, Kakuta M, Yamashita M. High and continuous exposure of laninamivir, an anti-influenza drug, may work suppressively to generate low-susceptibility mutants in animals. J Infect Chemother2012; 18:6974.