[1] Soroti Univ, Sch Hlth Sci, Dept Internal Med, Soroti, Uganda
[2] Makerere Univ, Coll Hlth Sci, Dept Med, POB 7072, Kampala, Uganda
[3] Makerere Univ, Coll Hlth Sci, Dept Microbiol, POB 7072, Kampala, Uganda
[4] MRC, Uganda Virus Res Inst, Entebbe, Uganda
[5] London Sch Hyg & Trop Med, Uganda Res Unit, Entebbe, Uganda
[6] Mengo Hosp, Dept Med, Sir Albert Cook Rd, POB 7161, Kampala, Uganda