The aims of this study were to describe illegal drug abuse patterns in relation to the migration process and use of drug treatment centers among immigrant injected drug users (IDUs) involved in harm reduction programs, and to compare the characteristics of immigrant and native IDUs. Cross-sectional study of 748 IDUs aged ≥18 years attending harm reduction centers between 2008 and 2009. We explored differences in socio-economic status, illegal drug consumption, health status and use of treatment centers in native versus immigrant IDUs. We also described whether immigrant IDUs started using injected drugs before or after entering the host country. Immigrant IDUs tend to live alone more frequently, start injection at later ages, use heroin and inject it more frequently and use drug treatment centers less frequently than native IDUs. Seventy-six percent of immigrants began using illegal drugs before arriving at the host country. Those who started in other countries were residing in the host country for 5 years or less (63.9%). Overall, immigrant IDUs attended drug treatment centers (36.9%) less frequently than native IDUs (71.8%). In conclusion, migration could be a risk factor for illegal drug abuse initiation or increase in consumption, often with the adoption of local consumption patterns and aggravated due to a lower access to drug treatment centers.
