Quantifying community-wide antimicrobials usage via wastewater-based epidemiology

Increasing usage of antimicrobials is a significant contributor to the emergence and dissemination of antimicrobial resistance. Wastewater-based epidemiology is a useful tool for evaluating public health, via the monitoring of chemical and biological markers in wastewater influent, such as antibiotics. Sixteen antimicrobials and their metabolites were studied: sulfonamides, trimethoprim, metronidazole, quinolones, nitrofurantoin, cyclines, and antiretrovirals. Correction factors (CFs) for human drug excretion, for various drug forms, were determined via a systematic literature review of pharmacokinetic research. Analyte stability was examined over a 24 h study. The estimation of community-wide drug intake was evaluated using the corresponding catchment prescription data. Overall, antimicrobials excreted in an unchanged form were often observed to over-estimate daily intake. This could be attributed to biotransformation, e.g., via glucuronide cleavage, or direct disposal of unused drugs. Acetyl-sulfonamides, trimethoprim, hydroxy-metronidazole, clarithromycin, ciprofloxacin, ofloxacin, tetracycline, and oxytetracycline generally performed well in the estimation of drug intake, relative to prescription records. The low prevalence of quinolone and trimethoprim metabolites, and the low stability of nitrofurantoin, limited the ability to evaluate these metabolites and their respective CFs.

Automated summary

Increasing usage of antimicrobials contributes to the emergence and spread of antimicrobial resistance. Wastewater-based epidemiology is a tool to evaluate public health by monitoring chemical and biological markers in wastewater influent, including antibiotics. The study investigated 16 antimicrobials and their metabolites, examining their stability and estimating drug intake using catchment prescription data. Unchanged antimicrobials often overestimated daily intake, attributed to biotransformation or direct disposal of unused drugs. Certain antimicrobials and metabolites performed well in estimating drug intake, while others had limitations due to low prevalence or stability.