Work

Association between chlorine-treated drinking water, the gut microbiome, and enteric pathogen burden in young children in Haiti: An observational study

Year: 2024

Type: article

Abstract: Background: Safe drinking water is critical for prevention of enteric infection and diarrheal disease. However, the effect of safe household water, sanitation, and hygiene (WASH) interventions on the gut microbiome and enteric pathogen burden is not well understood. We measured the association between free chlorine residue (FCR) levels in drinking water, microbiome composition, and enteric pathogen burden in infants and young children in Haiti.Methods: We enrolled 131 children <1 month-59 months from 108 households in Mirebalais, Haiti as a subset of a larger cross-sectional study conducted in the setting of a public health campaign to eliminate of cholera transmission. We measured household-level WASH factors including a one-time FCR level in the household drinking water. Stool enteric pathogen burden was assessed using multiplex RT-PCR and the microbiome was profiled from rectal swabs using metagenomic sequencing.Findings: Most individuals lived in households with undetectable FCR measured in the drinking water (112/131, 86%). Detection of enteric pathogen DNA was common and did not correlate with household water FCR. Enteroaggregative Escherichia coli was detected in 88% and 71% of infants <12 months and young children 12-59 months, respectively. The infant microbiome in households with detectable FCR demonstrated reduced richness (Kruskall-Wallis test, Dunn's multiple comparisons, P=0·04) and less diversity than households with undetectable FCR (Inverse Simpson index, mean±SD=5·9±3·7 versus 13·0± 8·9, P=0·05). Infants in households with detectable FCR were more likely to have abundant Bifidobacterium, a genus commonly associated with gut health in infants. In vitro susceptibility testing of species from bacterial families representative of FCR-associated microbiome differences in infants revealed that some Bifidobacterium species, but not commensal strains, were resistant to chlorine.Interpretation: FCR in household drinking water did not correlate with enteric pathogen burden in our study. Infants in households with detectable FCR had reduced species richness and an increase in Bifidobacteria.Funding: This work was funded by the NIH (AI099243 and AI123494).Declaration of Interest: All authors declare no competing interests.Ethical Approval: Written informed consent was obtained from a parent or guardian for all the children participating in the study. The study protocol was approved by both the Partners Institutional Review Board in the US Protocol # 2016P002781 and the Haitian National Bioethics Committee (Port-au-Prince, Haiti).

Source: International Journal of Infectious Diseases

DOI: 10.1016/j.ijid.2024.107165