Mapping and size estimation of people who inject drugs: an innovative approach for targeted harm reduction program in Iran

Background Hotspot mapping of People Who Inject Drugs (PWIDs) is important for harm reduction program planning. The aim of this study is to estimate the numbers of PWIDs and their geographic distribution in Iran. Methods We used the hotspot mapping and size estimation method to estimate the number of drug users in four cities of Iran from December 2017 to January 2019. We calculated three estimates in each hotspot: a) Key Affected Population Key Informant (KAP-KI) estimate (drug users met in the hotspot), b) Non-KAP KI estimate (e.g., taxi drivers, shopkeepers nearby the hotspot); c) estimation made by field observers. Locations of hotspots were recorded by the field team and ArcGIS software was used for mapping. Results A total number of 335 hotspots were identified in four cities and 1524 key informants were interviewed. The forty four per cent of identified hotspots received harm reduction services. Ahvaz had the highest estimated number of PWIDs (843, range: 703-887), followed by Sari (346, range: 307-666), Yazd (228, range: 221-471) and district 2 of Tehran (18, range: 18-34). Conclusion Findings highlight the need to use hotspot mapping to identify new PWIDs hotspots and best location for drop-in centers (DIC) and to provide targeted harm reduction programs.