1. School of Nursing, University of California, San Francisco, CA, USA
2. Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
3. Gladstone Institute of Virology and Immunology, San Francisco, CA, USA
4. Center for AIDS Prevention Studies, University of California, San Francisco, CA, USA
5. School of Public Health, University of Michigan, Ann Arbor, MI, USA
6. School of Nursing, Yale University, New Haven, CT
7. Research Institute for Health Sciences, Chang Mai, Thailand
8. Investigaciones Medicas en Salud, Lima, Peru
9. School of Medicine, University of California, San Francisco