[1] Univ Cape Town, Lung Infect & Immun Unit, Div Pulmonol, Lung Inst, ZA-7925 Cape Town, South Africa
[2] Univ Cape Town, Dept Med, ZA-7925 Cape Town, South Africa
[3] Univ Cape Town, Inst Infect Dis & Mol Med, ZA-7925 Cape Town, South Africa
[4] UCL, Sch Med, Ctr Infect Dis & Int Hlth, Dept Infect, London W1N 8AA, England