Decline in Rotavirus Hospitalizations and Health Care Visits for Childhood Diarrhea Following Rotavirus Vaccination in El Salvador

Background: A recent postlicensure study from El Salvador showed that the monovalent rotavirus vaccine conferred 76% protection against rotavirus hospitalizations. We further examined the impact of rotavirus vaccination on the national burden of childhood diarrhea to help assess the total public health benefits of vaccination. Methods: We compared all-cause diarrhea and rotavirus-specific hospitalization rates during prevaccine year 2006, with postvaccine years 2008 and 2009 in children <5 years of age from 7 sentinel surveillance hospitals. We also compared annual rates of diarrhea-related healthcare events during prevaccine years 2005 and 2006 with postvaccine years 2008 and 2009 to examine the national burden of healthcare utilization for all-cause diarrhea. Results: Among sentinel surveillance hospitals, rotavirus hospitalization rates among children <5 years of age declined by 81% (95% confidence interval [CI]: 78%-84%) in 2008 when 2-dose rotavirus vaccine coverage was 50% among infants <1 year; the decline was 69% (95% Cl: 65%-73%) in 2009 when 2-dose vaccine coverage was 61% among infants <1 year, compared with 2006. The greatest declines were observed in children <= 1 year of age, although sizeable reductions were also observed among children >= 2 years in 2008. National diarrhea-related healthcare visits during rotavirus season decreased by 48% (95% Cl: 47%-48%) in 2008 and by 35% (95% Cl: 34%-35%) in 2009 compared with the mean rate from the 2005 and 2006 rotavirus seasons. Conclusions: Rotavirus vaccination had a substantial public health impact on rotavirus disease and overall diarrhea events in El Salvador. Important age-related changes in diarrheal incidence emphasize the need for ongoing rotavirus surveillance after vaccine introduction.