[1] Med Sans Frontieres, Cape Town, Western Cape, South Africa
[2] Univ Stellenbosch, Dept Med, Cape Town, Western Cape, South Africa
[3] Univ Stellenbosch, Ctr Infect Dis, Fac Hlth Sci, Cape Town, Western Cape, South Africa
[4] Johns Hopkins Univ, Johns Hopkins Bloomberg Sch Publ Hlth, Dept Int Hlth, Baltimore, MD USA
[5] Johns Hopkins Univ, Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[6] Univ Cape Town, Dept Med, ZA-7925 Cape Town, Western Cape, South Africa
[7] Univ Ottawa, Fac Hlth Sci, Ottawa, ON, Canada