[1] Univ Cape Town, Dept Med, Fac Hlth Sci, Cape Town, South Africa
[2] Groote Schuur Hosp, Cape Town, South Africa
[3] Walter Sisulu Univ, Fac Hlth Sci, Dept Internal Med, Mthatha, South Africa
[4] Nelson Mandela Acad Hosp, Mthatha, South Africa
[5] Univ Cape Town, Fac Hlth Sci, Dept Surg, Cape Town, South Africa
[6] Stellenbosch Univ, Fac Med & Hlth Sci, Cape Town, South Africa
[7] NIAID, Div Intramural Res, NIH, Bethesda, MD USA
[8] Johns Hopkins Univ, Sch Med, Dept Med, Baltimore, MD 21205 USA
[9] Univ Cape Town, Inst Infect Dis & Mol Med, Cape Town, South Africa
[10] Nelson Mandela Univ, Dept Med, Fac Hlth Sci, Gqeberha, South Africa
[11] Livingstone Hosp, Gqeberha, South Africa