title: [How have we understood and responded clinically to pandemic H1N1 2009?].
abstract: Pandemic H1N1 2009 (pdmH1) has a broad clinical spectrum. Although many cases are mild, its pathogenesis is not necessarily low as it often causes serious respiratory disorder in children, and thus early treatment is necessary. As the positive rate as determined by rapid diagnostic kit is low, and false negative results can occur when the test is conducted too early following symptomatic onset, patients suspected of pdmH1 influenza warrant initiation of treatment even before establishment of a definite diagnosis. For therapeutic drugs, oseltamivir, zanamivir, and peramivir can be similarly efficacious, but intravenous administration is required in patients suffering symptoms of respiratory disorder and/or vomiting. As for the infectiousness, based on higher household transmission from parents to children in comparison to seasonal influenza A (FluA), as well as a high prevalence among primary school children, pdmH1 appears more likely to affect children, especially school children. In addition, since pdmH1 has a long incubation period, which can facilitate latent viral transmission, wearing a mask is useful during the epidemic period. A judgment of recovery should be carefully made especially in children, because the virus remains for a long time even after resolution of fever.
authors.affiliation: Japan Physicians Association.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hirotsu
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hatori
authors.forename: Kouichi
authors.initials: K
authors.lastname: Miyakawa
mesh_terms: D017677:Age Distribution; D000998:Antiviral Agents / Q000008:administration & dosage; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000635:transmission; D007564:Japan / Q000453:epidemiology; D058873:Pandemics / Q000517:prevention & control*; D012574:Schools / Q000706:statistics & numerical data; D013997:Time Factors
chemical_list: D000998:Antiviral Agents