Early diagnosis of sickle cell disease at birth hospitals and vaccination centers in Angola using point-of-care tests

Abstract

AbstractSickle cell disease (SCD) is a life-threatening blood disorder affecting >500 000 infants annually, mostly in sub-Saharan Africa. Most infants do not have access to an early diagnosis and die early from treatable complications of SCD. Universal newborn screening (NBS) is not yet available in any African country for a variety of reasons, including lack of laboratory capacity, difficulty in tracking affected infants, and the relatively short stay of mothers and newborns at maternity hospitals. Several point-of-care (POC) tests for SCD have been recently developed and validated, but the 2 most well-established tests (Sickle SCAN and HemoTypeSC) have not been rigorously compared with one another. In this study, we aimed to evaluate and compare these 2 POC tests to screen infants aged ≤6 months in Luanda, Angola. Challenging the traditional NBS paradigm, we performed testing not only at maternity centers, but also at vaccination centers across Luanda. We enrolled 2000 babies and performed 1000 tests with each POC test. Both tests demonstrated diagnostic accuracy, with 98.3% of Sickle SCAN results and 95.3% of HemoTypeSC results aligning with the gold standard isoelectric focusing hemoglobin pattern. When the result was provided at the POC, 92% of infants were linked to SCD care compared with 56% in the pilot Angolan NBS program, which used centralized laboratory testing. This study demonstrates the real-world feasibility and accuracy of POC tests to screen infants for SCD in Angola. This study also suggests that including vaccination centers may improve the capture rate for early infant SCD screening programs.