title: [Disease caused by the new influenza A(H1N1) virus].
abstract: BACKGROUND
  A new A(H1N1) influenza virus was detected in April 2009. The virus is now causing a pandemic of influenza. The article presents an overview of symptoms, complications, vulnerable groups, diagnosis and treatment.
  
  
  METHODS
  The overview is based on literature identified through a search in PubMed (using PubMed's own search strategy) and on official reports from WHO and the disease control centres of EU and the USA.
  
  
  RESULTS
  The new influenza A(H1N1) has so far mainly affected young people, only few people over 60 years. The clinical presentation is similar to that of ordinary influenza; but nausea, vomiting and diarrhoea seem to be more common. The reported risk of complications and case fatality are low, but hospitalisation, pneumonia and deaths have occurred, also in previously healthy young individuals. Antiviral treatment with oseltamivir or zanamivir is likely to be as effective as in ordinary influenza.
  
  
  CONCLUSIONS
  Mild cases may be underrepresented in the published literature. It is important to keep up-to-date on international reports on the nature of the disease in order to best prepare clinicians to diagnose and treat patients when the epidemic hits Norway with full force.
authors.affiliation: Norwegian Field Epidemiology Training Programme (Nor-FETP) og Divisjon for smittevern, Nasjonalt folkehelseinstitutt, Postboks 4404 Nydalen, 0403 Oslo, Norway. siri.helene.hauge@fhi.no
authors.forename: Siri Helene
authors.initials: SH
authors.lastname: Hauge
authors.forename: Susanne Gjeruldsen
authors.initials: SG
authors.lastname: Dudman
authors.forename: Katrine
authors.initials: K
authors.lastname: Borgen
authors.forename: Olav
authors.initials: O
authors.lastname: Hungnes
authors.forename: Arne
authors.initials: A
authors.lastname: Brantsaeter
authors.forename: Bjørn
authors.initials: B
authors.lastname: Iversen
authors.forename: Preben
authors.initials: P
authors.lastname: Aavitsland
mesh_terms: D000367:Age Factors; D000998:Antiviral Agents / Q000627:therapeutic use; D004196:Disease Outbreaks; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology; D011379:Prognosis; D012307:Risk Factors
chemical_list: D000998:Antiviral Agents