[1] Univ Maryland, Dept African Amer Studies, College Pk, MD 20742 USA
[2] Univ Missouri, Columbia, MO USA
[3] Univ Washington, Seattle, WA 98195 USA
[4] Univ Witwatersrand, MRC Wits Rural Publ Hlth & Hlth Transit Res Unit, Sch Publ Hlth, Johannesburg, South Africa
[5] Umea Univ, INDEPTH Network, Ctr Global Hlth, Umea, Sweden