High temporal-spatial resolution profiling of antibiotic consumption in Guangzhou revealed by wastewater-based epidemiology and evaluation of uncertainties for different sampling strategies

Abstract

Wastewater-based epidemiology (WBE) has been used for the monitoring of substance consumption for more than a decade. It enhanced the understanding of temporal and spatial variations of substance consumption in the population which is useful for the development of public health strategies. However, the limited number of samples analysed compromised the representativeness and statistical power of patterns observed in previous studies. This study analysed 23 antibiotics in wastewater samples collected weekly from 18 treatment plants across Guangzhou for a year. Results indicated that 10 antibiotics were quantified in more than half of the samples collected. Concentration ranged from several ng/L to several μg/L for different analytes. Some antibiotics had higher consumption in the urban population than in the suburban population except sulfapyridine, sulfamethazine and trimethoprim. Lincomycin, sulfadiazine had large intra-city variations with much higher mass loads in certain WWTPs. Sulfamethoxazole had higher consumption in cooler months, while clindamycin and clarithromycin had lower consumption during the same period. Bi-monthly sampling of the 8 largest WWTPs or one sample per season from the 12 largest WWTPs can achieve a relatively accurate estimation of annual consumption with a restricted budget. Suburban catchments have a limited impact on the overall annual consumption in the whole city, but should be considered for health equity. By integrating the routine WBE monitoring results and prescription/sales statistics, better management of antibiotic consumption can be achieved.