1. Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
2. Ivagen SA, 62 RN 113, Bernis, France.
3. Department of Medicine, Feinberg School of Medicine, Northwestern University and Howard Brown Health Center, Chicago, Illinois.
4. Department of Medicine, Geffen School of Medicine, University of California, Los Angeles, California.
5. University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania.