1. Research, Epidemiology, and Evaluation Unit, Clinical Services and Research Branch, Substance Abuse Prevention and Control, Los Angeles County Department of Public Health, Alhambra, California;
2. Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California;
3. Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia;
4. TOMS Shoes, LLC, Los Angeles, California