Are non-injecting opioid users at risk of transition to injecting drug use? A multi-site study from India

Most people who inject drugs (PWID) start their drug use careers by using non-injecting opioid drugs. A variety of interconnected factors may influence the risk of transition from non-injecting to injecting drug use (IDU). However, such factors have not been studied well in India. As almost all non-injecting opioid users (NIOU) are at potential risk of switching to IDU in future, it is important to understand the phenomenon of transition.

In this multi-site, cross-sectional observational study, we compared injecting and non-injecting opioid users on the pattern of progression of drug use and their knowledge, attitude and belief about IDU/HIV. Data were collected from people who use drugs coming in contact with Non-Governmental Organizations providing drug treatment or HIV prevention services, in ten cities of six states located in North/North-West India. Following informed consent, a total of 1987 male participants (n = 1234 PWID and n = 753 NIOU) were interviewed using a semi-structured questionnaire. Factors associated with risk of transition were analyzed using logistic regression analysis.

The age of onset of heroin and other opiates as well as other substances was not different between two groups. Among PWID, a majority (n = 713; 57.77%) reported using opioids through non-injecting route before switching to injecting route. The mean duration between first use of non-injecting opioid and first use of injecting opioid was 1.80 ± 3.32 years (range 0-26 years). Awareness and exposure to the act of injecting were amongst factors associated with perceived risk of transition to injecting (p < 0.01). On a univariate logistic regression analysis, less education was associated with increased likelihood while being employed was associated with less likelihood of being offered injection (p < 0.001).

Though, NIOU are almost indistinguishable from PWID in many respects, there may be certain factors putting them at risk of transition to injecting route. As the majority of PWID start their injecting career by non-injecting route, interventions targeted atrisk NIOU (as suggested by our study) could interrupt the HIV transmission.