title: [Epidemiology of influenza A/California/07/09 (H1N1) in foreign countries in 2009 - 2010 season].
abstract: OBJECTIVE
  Study of spread ofa new influenza variant A(H1N1) in the world in 2009.
  
  
  METHODS
  Analysis of WHO weekly situation reports on influenza epidemic in the countries of the Northern and Southern hemisphere.
  
  
  RESULTS
  The first laboratory confirmed cases ofA/California/07/09 (H1N1) were registered in the countries of the Northern hemisphere in 10 days, and in other continents--in 1 month after the increase of morbidity. In the countries of Northern hemisphere 2 increases of A/California/07/09 (H1N1) morbidity were present--spring and autumn, and in the autumn period an increase of population morbidity, rate of hospitalization and number of lethal outcomes was noted. Only in Canada autumn increase of morbidity was not accompanied by an increase in severe influenza cases. In the Southern hemisphere a single but longer increase of morbidity was registered during the summer period. In the South-eastern Asia 2 increases were mostly present with a higher level during the first one.
  
  
  CONCLUSIONS
  A significant increase in morbidity in the autumn periodand its decrease at the same time in the Southern hemisphere are determined by varying seasonality of influenza in the countries of Northern and Southern hemisphere. Spring increase of morbidity was of mixed etiology; and in the autumn period influenza A/ California/07/09 (H1N1) virus dominated in the etiology of diseases.
authors.forename: L S
authors.initials: LS
authors.lastname: Karpova
authors.forename: M Iu
authors.initials: MIu
authors.lastname: Pelikh
authors.forename: I G
authors.initials: IG
authors.lastname: Marinich
mesh_terms: D000328:Adult; D002140:California / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D058872:Epidemics; D005060:Europe / Q000453:epidemiology; D005202:Asia, Eastern / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality / Q000821:virology*; D008297:Male; D012621:Seasons; D013020:South America / Q000453:epidemiology; D014944:World Health Organization