The Use of Dried Blood Spots: A Potential Tool for the Introduction of a Neonatal Screening Program for Sickle Cell Anemia in Zambia

CONTEXT: Sickle cell disease is a group of hemoglobin (Hb) disorders resulting from the inheritance of the sickle β-globin gene. It is the most common pathological Hb mutation worldwide with 75% being born in Sub-Saharan Africa. AIMS: This study aims to determine if dried blood spots (DBSs) can be used for diagnosis of sickle cell in newborns. In Zambia, there is no neonatal screening program for sickle cell anemia (SCA), yet it has been proved that early diagnosis by newborn screening (NBS) using DBSs and access to comprehensive care results in survival to adulthood of over 96% of sickle cell patients. SETTINGS AND DESIGN: A cross-sectional study was carried out at the University Teaching Hospital to determine whether DBSs can be used to diagnose sickle cell using Hb electrophoresis. SUBJECTS AND METHODS: Results from DBSs stored for 2 weeks were then compared to those obtained using freshly collected whole blood. STATISTICAL ANALYSIS USED: To evaluate performance characteristics, the following values were used: true positive, false positive, true negative, and false negative. RESULTS: Ninety-seven participants were included in this study. DBSs had a sensitivity of 100%, a specificity of 94.7%, positive predictive value of 96.7%, negative predictive value of 100%, overall efficiency of 97.9%, and a Kappa r(2), P < 0.0001 in comparison to fresh whole blood which we used as the gold standard. CONCLUSIONS: The use of DBSs can be recommended for NBS of SCA in Zambia due to its high sensitivity, specificity, and stability of hemoglobin.