Impact of rotavirus vaccination and piped water access on childhood diarrhea rates in Peru, 2005-2015

Abstract

OPS 24: Drinking water contamination and children’s health, Room 411, Floor 4, August 27, 2019, 10:30 AM - 12:00 PM Background: Peru has undergone several health and infrastructure developments since 2005, including increased access to piped drinking water and national introduction of oral rotavirus vaccination. We examined whether these factors were associated with lower diarrhea rates in children under five. Methods: We fit a negative binomial model investigating the impact of rotavirus vaccination and piped water access on diarrhea rates in the 195 Peruvian provinces from 2005-2015, considering the interaction between these factors, and controlling for long-term and seasonal (El Niño) trends. We compared the “pre-(rotavirus) vaccine” (2005-2009) and “post-vaccine” (2010-2015) eras. Annual percentages of households in each province with access to piped water were analyzed in quartiles. Results: The 2005 childhood diarrhea rate was ~27 annual clinic visits per 100 children and decreased ~3% per year. Higher access to piped water was associated with significantly lower childhood diarrhea rates in the post-vaccine era only. We found no effect of the rotavirus vaccine in the lowest quartile of piped water access. Controlling for long-term trend, compared to the pre-vaccine era, the diarrhea rate was lower in the post-vaccine era by 7% (95% confidence interval (CI): 2-12%), 13% (95% CI: 7-19%), and 15% (95% CI: 10-20%) in the 2nd, 3rd, and 4th quartiles of piped water access, respectively. Diarrhea rates were significantly higher (6%, 95% CI: 4-8%) during moderate or strong El Niño events. Conclusions: Explanations for higher reductions in diarrhea rates from the pre- to post-vaccine era in provinces with better piped water access include: children without piped water may be predisposed to environmental enteric dysfunction, diminishing oral vaccine impact, and/or the etiologic patterns of diarrhea (and effectiveness of a vaccine targeting a viral pathogen) may differ by water source. Improved access to piped water and rotavirus vaccination may operate synergistically to reduce childhood clinic visits for diarrhea in Peru.