Effect of rotavirus vaccination on death from childhood diarrhea in Mexico

Abstract

Background: A phased introduction of a monovalent rotavirus vaccine occurred in Mexico from February 2006 through May 2007. We assessed the effect of vaccination on deaths from diarrhea in Mexican children in 2008 and 2009.

Methods: We obtained data on deaths from diarrhea, regardless of cause, from January 2003 through May 2009 in Mexican children under 5 years of age. We compared diarrhea-related mortality in 2008 and during the 2008 and 2009 rotavirus seasons with the mortality at baseline (2003-2006), before the introduction of the rotavirus vaccine. Vaccine coverage was estimated from administrative data.

Results: By December 2007, an estimated 74% of children who were 11 months of age or younger had received one dose of rotavirus vaccine. In 2008, there were 1118 diarrhea-related deaths among children younger than 5 years of age, a reduction of 675 from the annual median of 1793 deaths during the 2003-2006 period. Diarrhea-related mortality fell from an annual median of 18.1 deaths per 100,000 children at baseline to 11.8 per 100,000 children in 2008 (rate reduction, 35%; 95% confidence interval [CI], 29 to 39; P<0.001). Among infants who were 11 months of age or younger, diarrhea-related mortality fell from 61.5 deaths per 100,000 children at baseline to 36.0 per 100,000 children in 2008 (rate reduction, 41%; 95% CI, 36 to 47; P<0.001). As compared with baseline, diarrhea-related mortality was 29% lower for children between the ages of 12 and 23 months, few of whom were age-eligible for vaccination. Mortality among unvaccinated children between the ages of 24 and 59 months was not significantly reduced. The reduction in the number of diarrhea-related deaths persisted through two full rotavirus seasons (2008 and 2009).

Conclusions: After the introduction of a rotavirus vaccine, a significant decline in diarrhea-related deaths among Mexican children was observed, suggesting a potential benefit from rotavirus vaccination.