Elevated Levels of Environmental Enteric Dysfunction Biomarkers Among Rural Indonesian Infants: Associations with Water, Sanitation, Hygiene and Linear Growth

Abstract Objective To investigate the burden of environmental enteric dysfunction (EED) and its association with water, sanitation, and hygiene (WASH) and linear growth amongst infants in rural Central Java, Indonesia. Study design A longitudinal study of 119 infants aged between 5-19 months was conducted in five villages of Wonosobo District, Central Java, Indonesia. Anthropometric measurements of infants and their mothers were performed at baseline and 5-month follow-up alongside a quantitative questionnaire on household, socio-economic, WASH and caregiving variables and stool sample collection for the investigation of alpha-1-antitrypsin (AAT), neopterin (NEO), and myeloperoxidase (MPO) levels. Linear mixed-effects regression models estimated the associations between WASH and height-for-age z-score (HAZ) on log-transformed EED biomarkers. Results Biomarkers increased from baseline to follow-up despite a declining trend with age and 68.7%, 79.0%, and 71.4% of infants experienced elevated AAT, NEO, and MPO respectively follow-up. Infants had higher AAT if they averaged > 30 minutes playing on soiled surfaces per day (β = 0.11, p<0.05). NEO was elevated in infants with diarrhoea (β = 1.04, p<0.05), municipal water source ( = β 0.71, p<0.05), and in infants who mouthed soiled fomites weekly (β = 0.55, p<0.05). Infants in houses with municipal water source had higher MPO (β = 0.56, p<0.05) and higher MPO if mouthing soil weekly (β = 0.41, p<0.05). Compared to infants at risk of stunting, stunted infants at baseline had lower AAT at follow-up (β = −0.39, p<0.05) while infants with HAZ > −1 had lower AAT at baseline ( = −0.43, p<0.05). HAZ at baseline was positively associated with NEO at follow-up (β = 0.36, p<0.05). MPO was higher in infants with HAZ > −1 at follow-up (β = 0.59, p<0.05) and stunted infants (β = −0.54, p<0.05) compared to infants at risk of stunting. Conclusion Elevated EED biomarker levels were frequent and associated weakly with WASH and HAZ with bi-directionality, highlighting the need for quality birth cohort studies to improve understanding of EED and develop interventions.