[1] Kamuzu Univ Hlth Sci, Dept Pathol, Blantyre, Malawi
[2] Univ Malawi, Coll Med, Blantyre, Malawi
[3] Africa Ctr Excellence Publ Hlth & Herbal Med ACEP, Blantyre, Malawi
[4] Malawi Liverpool Wellcome Trust Clin Res Programm, Blantyre, Malawi
[5] Univ Catholique Graben, Fac Med, Dept Infect Dis, Butembo, DEM REP CONGO
[6] Univ Liverpool Liverpool Sch Trop Med, Pembroke Pl, Liverpool L3 5QA, Merseyside, England
[7] Kamuzu Univ Hlth Sci, Dept Publ Hlth, Blantyre, Malawi
[8] Queen Elizabeth Cent Hosp, Dept Surg, Blantyre, Malawi