[1] Nelson Mandela Acad Hosp, Natl Hlth Lab Serv, Mthatha, South Africa
[2] Walter Sisulu Univ, Dept Lab Med & Pathol, Mthatha, South Africa
[3] Univ Cape Town, SAMRC UCT Gynaecol Canc Res Ctr, Cape Town, South Africa
[4] Univ Cape Town, Dept Pathol, Div Med Virol, Cape Town, South Africa
[5] South African Med Res Council, Burden Dis Res Unit, Cape Town, South Africa
[6] Univ New South Wales, George Inst Global Hlth, Sydney, NSW, Australia
[7] Univ Cape Town, Inst Infect Dis & Mol Med, Cape Town, South Africa