[1] UNIV CAPE TOWN, DEPT MED, CAPE TOWN, SOUTH AFRICA
[2] GROOTE SCHUUR HOSP, CAPE TOWN 7925, SOUTH AFRICA
[3] UNIV STELLENBOSCH, DEPT MED, STELLENBOSCH, SOUTH AFRICA
[4] UNIV STELLENBOSCH, DEPT VIROL, STELLENBOSCH, SOUTH AFRICA
[5] UNIV STELLENBOSCH, DEPT MED, TYGERBERG 7505, SOUTH AFRICA
[6] UNIV STELLENBOSCH, DEPT VIROL, TYGERBERG 7505, SOUTH AFRICA
[7] UNIV CAPE TOWN, DEPT MED, CAPE TOWN, SOUTH AFRICA
[8] UNIV CAPE TOWN, DEPT VIROL, CAPE TOWN, SOUTH AFRICA