[1] Africa Ctr Hlth & Populat Studies, Mtubatuba, South Africa
[2] Univ British Columbia, Div Infect Dis, Dept Med, Vancouver, BC V5Z 1M9, Canada
[3] Univ Manitoba, Nairobi STD HIV Control Project, Winnipeg, MB R3T 2N2, Canada
[4] Univ Nairobi, Nairobi, Kenya