[1] Inst Trop Med, HIV & Retrovirol Res Unit, Dept Microbiol, B-2000 Antwerp, Belgium
[2] Case Western Reserve Univ, Dept Med, Div Infect Dis, Cleveland, OH 44106 USA
[3] Inst Trop Med, Dept Clin Sci, B-2000 Antwerp, Belgium
[4] Univ Antwerp, Dept Biomed Sci, Fac Pharmaceut Vet & Biomed Sci, B-2020 Antwerp, Belgium