Risk factors for childhood enteric infection in urban Maputo, Mozambique: A cross-sectional study

Abstract

Background

Enteric infections are common where public health infrastructure is lacking. This study assesses risk factors for a range of enteric infections among children living in low-income, unplanned communities of urban Maputo, Mozambique.

Methods & findings

We conducted a cross-sectional survey in 17 neighborhoods of Maputo to assess the prevalence of reported diarrheal illness and laboratory-confirmed enteric infections in children. We collected stool from children aged 1–48 months, independent of reported symptoms, for molecular detection of 15 common enteric pathogens by multiplex RT-PCR. We also collected survey and observational data related to water, sanitation, and hygiene (WASH) characteristics; other environmental factors; and social, economic, and demographic covariates.

We analyzed stool from 759 children living in 425 household clusters (compounds) representing a range of environmental conditions. We detected ≥1 enteric pathogens in stool from most children (86%, 95% confidence interval (CI): 84–89%) though diarrheal symptoms were only reported for 16% (95% CI: 13–19%) of children with enteric infections and 13% (95% CI: 11–15%) of all children. Prevalence of any enteric infection was positively associated with age and ranged from 71% (95% CI: 64–77%) in children 1–11 months to 96% (95% CI: 93–98%) in children 24–48 months. We found poor sanitary conditions, such as presence of feces or soiled diapers around the compound, to be associated with higher risk of protozoan infections. Certain latrine features, including drop-hole covers and latrine walls, and presence of a water tap on the compound grounds were associated with a lower risk of bacterial and protozoan infections. Any breastfeeding was also associated with reduced risk of infection.

Conclusions

We found a high prevalence of enteric infections, primarily among children without diarrhea, and weak associations between bacterial and protozoan infections and environmental risk factors including WASH. Findings suggest that environmental health interventions to limit infections would need to be transformative given the high prevalence of enteric pathogen shedding and poor sanitary conditions observed.

Trial registration

ClinicalTrials.gov NCT02362932

Author summary

Enteric pathogens such as bacteria, protozoa, and viruses can cause diarrhea and other longer-term health problems. Poor sanitary conditions, including inadequate sanitation facilities, can lead to contamination of the living environment and higher risk of exposure to and transmission of enteric pathogens. Young children, who are vulnerable to both the short- and long-term health effects of enteric infections, interact with their environment in different ways than older children or adults. In order to limit enteric pathogen transmission among this vulnerable group, we must understand the infection burden and the environmental or sanitation-related factors that are associated with infection. Among a group of children younger than four years old living in low-income neighborhoods of Maputo, Mozambique, we found over 85% tested had ≥1 enteric infection. Children living in environments visibly contaminated with feces were more likely to have an infection than children whose living environments were not visibly contaminated. In contrast, children living in compounds with certain latrine features, including walls and pit covers (potential indicators of build quality), had reduced infection risk. Understanding that these risk factors may play important roles in exposure and transmission in this setting is key to planning effective interventions.