1. Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, 503 Parran Hall, 130 DeSoto Street, Pittsburgh, PA 15261, United States of America (USA).
2. Warwick Centre for Applied Health Research and Delivery, University of Warwick, Coventry, England.
3. Department of Psychology, University of Limpopo, Turfloop, South Africa.
4. Department of Sociology, University of British Columbia, Vancouver, Canada.
5. Stanford Prevention Research Center, Stanford University, Stanford, USA.
6. HIV/AIDS and the World of Work Branch (ILOAIDS), International Labour Organization, Geneva, Switzerland.