Abstract
BACKGROUND: Whoonga is a smoked heroin-based street drug that first emerged in South Africa a decade ago. While previous scientific reports suggest that use is growing and youth are particularly vulnerable, trajectories of initiation are not well characterized. METHODS: In 2015, 30 men undergoing residential addiction treatment for this smoked heroin drug in KwaZulu-Natal, South Africa participated in semi-structured interviews about their experiences using the drug. Interview data were coded using qualitative content analysis. RESULTS: Participant trajectories to initiating smoked heroin were "vertical" in the context of marijuana use or "horizontal" in the context of other hard drug use. Participants reporting vertical trajectories began smoking heroin as youth at school or in other settings where people were smoking marijuana. Several participants with horizontal trajectories started smoking heroin to address symptoms of other drug or alcohol addiction. Social influences on initiation emerged as an overarching theme. Members of participants' social networks who were smoking or distributing heroin figured prominently in initiation narratives. Surprisingly, references to injection drug use were absent from initiation narratives. Participants reported people who smoke heroin differ from those who inject heroin by race. CONCLUSION: Consistent with theories implicating social and structural influences on substance use initiation, people who started smoking heroin had social contacts who smoked heroin and frequented places where substance use was common. Smoked heroin initiation for several participants with horizontal trajectories may have been averted if they accessed evidence-based treatments for stimulant or alcohol use disorders. With increasing reports of heroin use across Africa, a coordinated approach to address this growing epidemic is needed. However, because smoked heroin and injection heroin use occur in distinct risk environments, interventions tailored to people who use smoked heroin will be needed to prevent smoked heroin use, prevent transition to injection use, and mitigate other social harms.