[1] Levy Mwanawasa Med Univ, Inst Basic & Biomed Sci, Lusaka 10101, Zambia
[2] Lusaka Apex Med Univ, Dept Appl Sci, Lusaka 10101, Zambia
[3] Univ Teaching Hosp, Sch Med, Dept Pathol & Microbiol, Lusaka 10101, Zambia
[4] Univ Teaching Hosp, Trop Gastroenterol & Nutr Grp, Lusaka 10101, Zambia
[5] Univ Zambia, Sch Med, Dept Internal Med, Lusaka 10101, Zambia