[1] Natl Inst Pharmaceut Res & Dev, Idu, Abuja, Nigeria
[2] Nigerian Inst Med Res, Lagos, Nigeria
[3] Univ Jos, Teaching Hosp, Jos, Nigeria
[4] Uthman Danfodio Univ, Teaching Hosp, Sokoto, Nigeria
[5] Univ Nigeria, Teaching Hosp, Enugu, Nigeria
[6] Univ Coll Ibadan Hosp, Ibadan, Nigeria
[7] Univ Maiduguri, Teaching Hosp, Maiduguri, Nigeria
[8] Univ Uyo, Teaching Hosp, Uyo, Nigeria
[9] Fed Minist Hlth, Abuja, Nigeria