Participants were people aged 18 years or older who had at some point in their lives been drug users (injecting and non-injecting).
It included individuals who had been diagnosed with HIV for the first time in the five years prior to recruitment, or HIV-negative people who had their last HIV test in the 12 months prior to the interview date.
All participants were recruited from Treatment Teams (TEs) in the North and Centre regions of Portugal and from two Hospitals in the city of Porto: São João Hospital and Joaquim Urbano Hospital.
In the initial assessment, 303 patients were interviewed, 80 (26%) were diagnosed with HIV infection less than five years ago and 223 were (74%) seronegative.
This cohort aimed to identify the epidemiological factors that continue to drive the HIV epidemic and how they differ between HIV positive and HIV negative drug users.
The results obtained from the study aim to provide information which has the potential of modifying Public Health strategies and policies.