[1] Univ KwaZulu Natal, Sch Lab Med & Med Sci, Dept Virol, Natl Hlth Lab Serv, ZA-4058 Durban, South Africa
[2] Univ Zimbabwe, Fac Med & Hlth Sci, Dept Lab Med & Investigat Sci, Harare, Zimbabwe
[3] Ctr AIDS Programme Res South Africa CAPRISA, ZA-4013 Durban, South Africa
[4] South African Med Res Council SAMRC, CAPRISA HIV TB Pathogenesis & Treatment Res Unit, ZA-4013 Durban, South Africa