Wastewater profiling of illicit drugs, an estimation of community consumption: a case study of eThekwini Metropolitan Municipality, South Africa

 

Introduction: Estimating community-wide illicit drug consumption through wastewater analysis is a novel approach in Africa, despite its widespread use in developed nations under wastewater-based epidemiology (WBE). This method is valuable for understanding the supply and demand patterns of illicit drug use on different scales—local, national, and international. 

Problem: Illicit drug use is a serious global issue affecting social behaviour and public health. In Africa, obtaining up-to-date data on illicit drug use remains challenging due to insufficient government monitoring structures and financial constraints. In South Africa, the prevalence of illicit drug use has steadily increased in recent years. For instance, in 2002, fewer than 2% of surveyed individuals reported using illicit drugs in the past three months; by 2017, this figure had risen to 10%. Access to accurate data on illicit drug use enables effective responses from relevant agencies and institutions, thereby enhancing understanding and management of drug-related issues.  

The study: Ten illicit drugs were assessed from samples collected at four major wastewater treatment plants (WWTPs) in the eThekwini Metropolitan Municipality of KwaZulu-Natal Province. The results indicated that cocaine was the most consumed illicit drug in the catchment area, followed by amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyamphetamine (MDA). Per capita usage ranged as follows: cocaine, 360–3,000 mg/day/1,000 inhabitants; amphetamine, 47–800 mg/day/1,000 inhabitants; methamphetamine, 19–120 mg/day/1,000 inhabitants; MDMA, not detected (ND) to 4.9 mg/day/1,000 inhabitants; and MDA, ND to 410 mg/day/1,000 inhabitants. Weekly usage patterns varied among the four WWTPs, likely reflecting differences in the lifestyles of the populations served by each plant. These findings provide valuable data on illicit drug use in eThekwini, which can be utilised by public health agencies to implement appropriate response strategies. 

Conclusions: This study utilising WBE identified cocaine as the most consumed illicit drug in the province among the monitored targets, followed by amphetamine. It also successfully established the origin of these substances. Consumption patterns varied across WWTPs, indicating area-specific differences and suggesting that drug use is influenced by local demographics. The findings underscore the effectiveness of WBE as a rapid, cost-effective, and non-intrusive method for monitoring community health and drug use trends, providing valuable data that can complement traditional epidemiological approaches. Implementing WBE in African countries could address the current lack of comprehensive data on illicit drug use, aiding in the development of targeted public health interventions. 

Paper(s): 

Wastewater profiling of illicit drugs, an estimation of community consumption: A case study of eThekwini Metropolitan Municipality, South Africa    

Partners: University of Bath, University of KwaZulu-Natal 

Funders: USAID-Partnerships for Enhanced Engagement in Research (PEER) program (Grant number: AID-OAA-A-11-00012) and the European Union’s Horizon 2020 research and innovation programme (INTERWASTE project) under the Marie Skłodowska-Curie grant (Grant number: 734522).