title: Diarrhea-associated hospitalizations among US children over 2 rotavirus seasons after vaccine introduction.
abstract: OBJECTIVE
  After implementation of rotavirus vaccination in 2006, large decreases in rates of severe diarrhea among US children occurred in 2007-2008. We ascertained whether these decreases were sustained in 2008-2009.
  
  
  METHODS
  We examined hospital discharge data from a national network of pediatric hospitals and compared all-cause diarrhea-related and rotavirus-specific hospitalizations in 3 prevaccine rotavirus seasons (2003-2006) with those in 2 postvaccine seasons (2007-2008 and 2008-2009) among children <5 years of age. We defined rotavirus seasons using data from a national laboratory surveillance network.
  
  
  RESULTS
  At 62 consistently reporting hospitals, a median of 15 645 diarrhea-related hospitalizations (range: 14 881-16 884 hospitalizations) occurred each rotavirus season among children <5 years of age in 2003-2006. Compared with this median, all-cause diarrhea-related hospitalizations decreased by 50% (n = 7760) in 2007-2008 and by 29% (n = 11 039) in 2008-2009. In 2007-2008, reductions of 47% to 55% were seen for all age groups, including vaccine-ineligible children ≥2 years of age (48%). In 2008-2009, these reductions decreased in magnitude, especially among children ≥2 years of age (17%). Decreases in 2007-2008 and 2008-2009 were similar in the Northeast and West, but decreases were smaller in 2008-2009, compared with 2007-2008, in the Midwest and South.
  
  
  CONCLUSIONS
  Compared with prevaccine seasons, decreases in diarrhea- and rotavirus-associated hospitalizations seen in 2007-2008 were sustained in 2008-2009 but were somewhat smaller. Given the variability in diarrhea-related hospitalization trends over the 2 postvaccine seasons according to age group and region, continued surveillance is required for full assessment of the impact of rotavirus vaccination.
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS A-47, Atlanta, GA 30333, USA. cyen@cdc.gov
authors.forename: Catherine
authors.initials: C
authors.lastname: Yen
authors.forename: Jacqueline E
authors.initials: JE
authors.lastname: Tate
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Wenk
authors.forename: J Mitchell
authors.initials: JM
authors.lastname: Harris
authors.forename: Umesh D
authors.initials: UD
authors.lastname: Parashar
mesh_terms: D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology* / Q000821:virology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D012400:Rotavirus Infections / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control*; D022243:Rotavirus Vaccines; D012621:Seasons; D014481:United States
chemical_list: D022243:Rotavirus Vaccines