The Impact of Water Chlorination on Faecal Carriage Rates of Antimicrobial Resistant Bacteria in Bangladeshi Children

Sammanfattning: Can drinking water chlorination reduce the spread of antimicrobial resistant bacteria? Antimicrobial resistance (AMR) is one of today’s most pressing global health threats, accounting for an estimated 700,000 deaths per year (WHO, 2019). The WHO has emphasized the need for effective sanitation and hygiene measures in order to reduce the incidence of infections caused by antimicrobial resistant bacteria (WHO, 2015). This interdisciplinary study aims to quantify the impact of the chlorination of drinking water using a passive dosing device, on the gut microbiota of Bangladeshi children. It focuses on testing the hypothesis: consuming chlorinated water reduces the amount of antimicrobial resistant bacteria in children’s stools. A reduction in antimicrobial resistant bacteria in children’s stools could potentially reduce the spread of antimicrobial resistant bacteria and consequently decrease incidences of antibiotic resistant infections. The study is based on a double-blind randomized clinical trial conducted by researchers from Stanford University, Tufts University and the International Center for Diarrhoeal Disease Research, Bangladesh, between July 2015 and December 2016 (Pickering et al., 2019). The participants in the trial were Bangladeshi children under the age of five, living in the urban slums of Dhaka and Tongi. They were randomly assigned to either a treatment or a control group. Children in the treatment group used chlorinated water as a primary drinking water source. Children in the control group used non-chlorinated water dosed with vitamin C (Pickering et al., 2019). Stool samples from the participants were collected during the trial, frozen and sent to laboratories at Stanford University and EAWAG (Swiss Federal Institute of Aquatic Science and Technology). In the scope of this study, antimicrobial resistant bacteria in the stool samples were detected and quantified by means of a culture-based method. Furthermore, the results of the samples taken from the treatment group were compared in a preliminary analysis to the results of samples from the control group. An observational analysis of supplementary information on the children was also conducted in order to identify risk factors associated with the prevalence of antimicrobial resistant bacteria in the stool samples. Our findings show high faecal carriage rates of antimicrobial resistant bacteria among children in Dhaka and Tongi, with more than 64% of the samples containing E. coli resistant to multiple beta-lactam antibiotics. The outcome of the study sheds light on the importance of understanding the major drivers influencing faecal carriage in children to develop and implement viable interventions which effectively reduce the spread of AMR.