[1] Univ Maryland, Sch Med, Div Epidemiol & Prevent, Inst Human Virol, Baltimore, MD 21201 USA
[2] Nigerian Fed Minist Hlth, Abuja, Federal Capital, Nigeria
[3] Reach Care Fdn, Abuja, Federal Capital, Nigeria
[4] Ctr Dis Control & Prevent, Div HIV AIDS Prevent, Atlanta, GA USA
[5] Ctr Dis Control & Prevent, Global AIDS Program, Natl Ctr HIV AIDS Hepatitis STD & TB Prevent, Atlanta, GA USA