1. Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland1;
2. Surveillance and Epidemiology, Division of HIV/AIDS Prevention, National Center for HIV, STD, and TB Prevention,2 and
3. Uganda Virus Research Institute, Entebbe, Uganda3;
4. HIV/AIDS Collaboration, Nonthaburi, Thailand4;
5. Projet RETRO-CI, Abidjan, Côte d'Ivoire5; and
6. Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases,6 Centers for Disease Control and Prevention, Atlanta, Georgia;
7. Laboratorio Central y Seccion de Infectiologia, Hospital de Italiano de Buenos Aires, Buenos Aires, Argentina7