Publication date: Jul 23, 2025

Illicit drug use causes great harm and economical loss to society, yet there is limited understanding of its prevalence in the population in low-income countries like Vietnam where survey resources are scarce. In this study, we used wastewater analysis as a cost-effective monitoring tool to measure illicit drug use in a population of Hanoi, Vietnam, a low-income country in Southeast Asia. This is a longitudinal observational study. Wastewater samples were collected at a sewage canal serving > 430 000 people, in Hanoi, Vietnam, over a six-year period (2018-2023). Drug biomarkers for amphetamine, methamphetamine, 3,4-Methylenedioxymethamphetamine (MDMA), ketamine, morphine, codeine and benzoylecgonine were measured using liquid chromatography-tandem mass spectrometry via direct injection. The results were used to back-estimate per capita drug consumption. Together with an evaluation of general temporal trend, an interrupted time series analysis using segmented linear regression was conducted to examine the potential changes in drug use associated with the post-COVID-19 restriction. There was a statistically significant decrease in methamphetamine use, with annual averages declining from a peak value of 359. 2 to 125. 6 mg/day/1000 people between 2018 and 2023 (P 

Semantics

Original Article