[1] Biyem Assi Dist Hosp, Yaounde, Cameroon
[2] Univ Yaounde I, Fac Med & Biomed Sci, Yaounde, Cameroon
[3] Yaounde Gen Hosp, Yaounde, Cameroon
[4] Chantal Biya Fdn, Mother & Child Ctr, Sickle Cell Dis Unit, Yaounde, Cameroon
[5] Natl Univ Teaching Hosp, Cotonou, Benin
[6] Univ Yaounde I, Fac Med & Biomed Sci, Dept Internal Med & Specialties, POB 8314, Yaounde, Cameroon