Association between type of primary water source and prevalence of diarrheal disease in Bolivia

Diarrheal diseases cause 75% of pediatric morbidity and mortality in Bolivia, leading to 500,000 cases and 7,900 deaths annually. Clean water and sewer access are fundamental to prevention, yet international creditors have pressured Bolivia to privatize municipal water networks. Two programs ended by popular protests when after 8 years >200,000 people found themselves unable to afford privatized water. Proponents argue that cleaner water improves public health, but if privatized water is unaffordable, people may rely on contaminated water sources, increasing pediatric diarrheal disease prevalence.

From June-August 2006, we surveyed an urban cohort of 596 homes with children 3-6 years old in two Bolivian cities: Cochabamba and El Alto. Surveys studied the child's diarrheal disease history, household water usage, and sanitation practices from 2/12/03-6/30/06. We compared prevalence rates between and within each city, stratified by water utilization.

Most participants utilized city water networks (89.4%), with few changes (16.3%) and only 5.0% drinking water from multiple sources. Annual diarrheal disease prevalence in 2003, 2004, and 2005 were 27.4, 36.9, and 38.6% in Cochabamba and 29.0, 31.5, and 38.6% in El Alto, respectively. Higher prevalence was found with indoor compared to outdoor faucets in Cochabamba, with the opposite observed in El Alto. Recurrent episodes were more common in Cochabamba. Homes buying off-network water from cistern trucks had the highest prevalence in both cities.

We observed increased prevalence of diarrhea over time. In addition, rates were higher among indoor faucet users in Cochabamba. Our findings may guide water policy decisions in Bolivia and globally.