1. Hanoi Medical University Hospital , Hanoi, Vietnam
2. Center for Training and Research on Substance abuse – HIV, Hanoi Medical University , 01 Ton That Tung street, Dong Da District, Hanoi, Vietnam
3. Supporting Community Development Initiative , Hanoi, Vietnam
4. School of Public Health, University of Alberta , Edmonton, Canada
5. CESP/Inserm 1018, Centre Pierre Nicole, French Red Cross , Paris, France