Prevalence of hemoglobin S trait among blood donors: a cross-sectional study

Sickle cell trait (SCT) or Hemoglobin S (HbS) trait which is due to inheritance of an abnormal hemoglobin (Hb) gene from one parent and a normal gene from the other has been known to be common among people of African descent. Individuals with SCT may find themselves in the blood donor population without knowing their 'carrier' status and this may have severe consequences on their health as well as that of a recipient, particularly if they happen to be a sickle cell disease patient. The aim of the study was to determine the prevalence of HbS trait among blood donors.

This cross-sectional study employed convenience sampling method to recruit subjects. A total of 150 prospective and healthy blood donors comprising 138 males and 12 females were involved in the study. Two (2) ml of venous blood was collected from each donor into K(3)EDTA tubes and analyzed using the sodium metabisulphite slide test and cellulose acetate Hb electrophoresis at alkaline pH (8.6) for Hb genotypes. Statistical Package for Social Sciences version 20.0 (SPSS 20.0) and Chi square were used to analyse the data obtained. Out of the 150 blood donors, 133 (88.7 %) tested negative for sickling (131 were genotype AA and 2 were AC) and 17 (11.3 %) tested positive for sickling, all of whom were genotype AS.

The results of the study showed the existence of SCT among the blood donor population sampled. Taking blood from such people can harm their health as well as that of the recipient if they happen to be sickle cell disease (SCD) patients. It is therefore recommended that blood donors as well as donated blood units should be screened for SCT to avoid causing any harm to both the donor and recipient.