title: Influenza A (H1N1) 2009 pandemic calm down the prevalence of acute hepatitis A in the latter half of 2009: Korean population study.
abstract: OBJECTIVE
  There was a spiking incidence of acute hepatitis A (AHA) in 2009 summer, but it went down drastically after an outbreak of influenza A (H1N1). We assessed the relationship between 2009 H1N1 pandemic and AHA prevalence from August to December 2009.
  
  
  METHODS
  We compared AHA cases nationwide and in our hospital for the period from the latter half of 2008 to the end of 2010. H1N1 cases in our hospital from August 2009 to December 2009 were included in the study and the correlation between 2009 H1N1 pandemic and AHA prevalence was assessed.
  
  
  RESULTS
  The national surveillance system reported 2,233, 7,895, 15,231 and 7,660 AHA cases from 2007 to 2010, respectively. A similar trend was noted in our hospital in the same periods. Although the national total incidence was increased in 2009, it showed steep decreasing trend line in the final 21 weeks of 2009 (weeks 32-52), as compared with 2008 and 2010. The mean weekly incidence percentage (AHA cases in a week/total in a year) in weeks 32-52 of 2009 was 1.17±0.55%, significantly lower than that in 2008 and 2010 (1.61±0.43% and 1.56±0.51%; p<0.001). Furthermore, we found a significant negative correlation between 2009 H1N1 pandemic and AHA in our hospital for weeks 32-52 of 2009 (r=-0.597; p<0.001).
  
  
  CONCLUSIONS
  The widespread occurrence of 2009 H1N1 pandemic highlighted the benefits of health care and good hygiene, such as effective hand washing and wearing of masks, which may have also interrupted hepatitis A virus transmission.
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, 1174 Jung-dong, Wonmi-gu, Bucheon 420-767, Korea.
authors.forename: Jin Myung
authors.initials: JM
authors.lastname: Byun
authors.forename: Sang Gyune
authors.initials: SG
authors.lastname: Kim
authors.forename: Yuan Yuan
authors.initials: YY
authors.lastname: Zhang
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Kim
authors.forename: Soung Won
authors.initials: SW
authors.lastname: Jeong
authors.forename: Sae Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Jang
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Hong
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Moon
authors.forename: Hong Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Moon Sung
authors.initials: MS
authors.lastname: Lee
authors.forename: Boo Sung
authors.initials: BS
authors.lastname: Kim
mesh_terms: D000208:Acute Disease; D006506:Hepatitis A / Q000453:epidemiology*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D058873:Pandemics; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012621:Seasons