Decline in diarrhea mortality and admissions after routine childhood rotavirus immunization in Brazil: a time-series analysis

Background

In 2006, Brazil began routine immunization of infants <15 wk of age with asingle-strain rotavirus vaccine. We evaluated whether the rotavirusvaccination program was associated with declines in childhood diarrheadeaths and hospital admissions by monitoring disease trends before and aftervaccine introduction in all five regions of Brazil with varying diseaseburden and distinct socioeconomic and health indicators.

Methods and Findings

National data were analyzed with an interrupted time-series analysis thatused diarrhea-related mortality or hospitalization rates as the mainoutcomes. Monthly mortality and admission rates estimated for the yearsafter rotavirus vaccination (2007–2009) were compared with expectedrates calculated from pre-vaccine years (2002–2005), adjusting forsecular and seasonal trends. During the three years following rotavirusvaccination in Brazil, rates for diarrhea-related mortality and admissionsamong children <5 y of age were 22% (95% confidenceinterval 6%–44%) and 17% (95% confidenceinterval 5%–27%) lower than expected, respectively. Acumulative total of ∼1,500 fewer diarrhea deaths and 130,000 feweradmissions were observed among children <5 y during the three years afterrotavirus vaccination. The largest reductions in deaths(22%–28%) and admissions (21%–25%)were among children younger than 2 y, who had the highest rates ofvaccination. In contrast, lower reductions in deaths (4%) andadmissions (7%) were noted among children two years of age and older,who were not age-eligible for vaccination during the study period.

Conclusions

After the introduction of rotavirus vaccination for infants, significantdeclines for three full years were observed in under-5-y diarrhea-relatedmortality and hospital admissions for diarrhea in Brazil. The largestreductions in diarrhea-related mortality and hospital admissions fordiarrhea were among children younger than 2 y, who were eligible forvaccination as infants, which suggests that the reduced diarrhea burden inthis age group was associated with introduction of the rotavirus vaccine.These real-world data are consistent with evidence obtained from clinicaltrials and strengthen the evidence base for the introduction of rotavirusvaccination as an effective measure for controlling severe and fatalchildhood diarrhea.Please see later in the article for the Editors'' Summary