Potential for a large‐scale newborn screening strategy for sickle cell disease in Mali: A comparative diagnostic performance study of two rapid diagnostic tests (SickleScan® and HemotypeSC®) on cord blood

Abstract

SummarySickle cell disease (SCD) is a life‐threatening disease requiring reliable early diagnosis. We assessed the acceptability and diagnostic performances of two rapid diagnostic tests (RDTs) to identify SCD (HbSS, HbSC, HbS/β‐thalassaemia) or SCD carrier (HbS/HbC) in a pilot SCD newborn screening (NBS) strategy in Mali. All consenting delivering women were offered SCD NBS using cord blood sampling on two RDTs (SickleScan® and HemotypeSC®) compared to the high‐performance liquid chromatography (HPLC) gold standard to detect SCD states. From April 2021 to August 2021, 4333 delivering women were eligible of whom 96.1% were offered NBS: 1.6% refused, 13.8% delivered before consenting and 84.6% consented; 3648 newborns were diagnosed by HPLC; 1.64% had SCD (0.63% HbSS, 0.85% HbSC, 0.16 HbS/β‐plus‐thalassaemia); 21.79% were SCD carrier. To detect accurately SCD, SickleScan® had a sensitivity of 81.67% (95% confidence interval [CI]: 71.88–91.46) and a negative predictive value (NPV) of 99.69% (95% CI: 99.51–99.87); HemotypeSC® had a sensitivity of 78.33% (95% CI: 67.91–88.76) and a NPV of 99.64% (95% CI: 99.44–99.83). To detect SCD carrier: SickleScan® sensitivity was 96.10% (95% CI: 94.75–97.45) and NPV, 98.90% (95% CI: 98.51–99.29); HemotypeSC® sensitivity was 95.22% (95% CI: 93.74–96.70) and NPV, 98.66% (95% CI: 98.24–99.03). Routine SCD NBS was acceptable. Compared with HPLC, both RDTs had reliable diagnostic performances to exclude SCD‐free newborns and to identify SCD carriers to be further confirmed. This strategy could be implemented in large‐scale NBS programmes.

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020–2023)

“…The HemoTypeSC TM POC test kit, which only requires capillary blood samples and unfiltered tap water, was tested over a 2-year period in Koutiala hospital in rural Mali and found to be satisfactory for NBS [ 1530 ]. Similarly, the acceptability and diagnosis performances of two POC tests (SickleScan ® and H HemoTypeSC TM ) were evaluated against HPLC methodology in three maternity hospitals in Mali (two urban clinics in Bamako and one rural clinic in Kayes) using cord blood, and both tests were found to be acceptable NBS tests [ 1531 ]. A study of the Emmel test routinely used to test adults for SCA was found to be severely lacking when used for screening newborns in Bamako, and its use was NOT recommended despite its low cost and relative simplicity [ 1532 ].…”