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.
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.
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.
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.