[1] Univ Liverpool, Liverpool Sch Trop Med, Dept Clin Sci, Liverpool L3 5QA, Merseyside, England
[2] Malawi Liverpool Wellcome Trust Clin Res Programm, TB & HIV Grp, Blantyre, Malawi
[3] London Sch Hyg & Trop Med, Dept Clin Res, London WC1, England
[4] Univ Malawi, Coll Med, Dept Pathol & Lab Med Sci, Blantyre, Malawi
[5] Univ Liverpool, Liverpool Sch Trop Med, Dept Int Publ Hlth, Liverpool L3 5QA, Merseyside, England
[6] Minist Hlth, HIV Dept, Lilongwe, Malawi