Screening for sickle cell anemia in two populations of eastern Gabon using alkaline electrophoresis and hemoglobin level combined with leukocyte count.

Abstract

Background: Sickle cell anemia remains a major public health problem in Gabon, with high mortality. However, its prevalence is mainly documented in the capital city of Libreville, with few data for other areas.

Methods: We performed diagnostic testing by electrophoresis on 1534 individuals from two sites in eastern Gabon: Franceville and Koula-Moutou. We also screened 791 individuals from Koula-Moutou using a method that combines hemoglobin levels with leukocyte counts.

Results: The allelic frequency of the hemoglobin S and C genes were 18.5% and 0.07%, respectively, in areas of eastern Gabon. Also 3.7% of individuals had sickle cell disease, 29.8% had sickle cell trait and 0.1% was heterozygous for hemoglobin AC. The diagnostic orientation method used in our study showed a sensitivity of 100%, a specificity of 97.4%, and a negative predictive value of 100%.

Conclusion: This method using hemogram data has proved to be valuable in areas with high resource constraints, and could be used in other areas to aid diagnostic orientation. It would be interesting to similarly evaluate the frequency of sickle cell anaemia in the northern and southern regions of Gabon.