Exposure Assessment of Antimicrobial Resistant <i>E. coli</i> via Self-Supplied Drinking Water in Indonesia: Evaluating Boiling and Storage Practice Effectiveness

The rise of antimicrobial resistance is a rapidly worsening global health threat. Household water treatment and storage (HWTS) strategies are commonly employed in low-income settings to prevent the ingestion of unsafe drinking water. In order to evaluate the potential exposure to E. coli and cefotaxime-resistant E. coli via drinking water in Bekasi, Indonesia, we sampled drinking water sources (boreholes, protected/unprotected wells, bottled/refill) and point-of-use water from approximately 54 households during both wet season and dry season in 2020. Monte Carlo simulations were then used to estimate daily and annual exposure to both E. coli and cefotaxime-resistant E. coli. E. coli and cefotaxime-resistant E. coli were detected at 67.5% (77/114) and 28.1% (32/114) of source water samples, respectively. Median exposure estimates were reduced by approximately 1 order of magnitude for each log-removal of E. coli, and the proportion of the population exposed to E. coli that corresponds to a boiling efficiency of 0 (i.e., untreated), 2, and 4 log-removals was 68%, 54%, and 14%, respectively. Even when water boiling strategies achieve log-removal levels typically observed in practice or when they achieve “most protective” levels, fractions of the population may still be exposed to both E. coli and resistant E. coli.