Extremely high birth prevalence of sickle cell disease in rural Tanzania

Abstract

Background/objectives: Sickle cell disease (SCD) is an important, hidden cause of childhood mortality worldwide. It is most prevalent in sub-Saharan Africa where national newborn screening programs remain unavailable and most children in rural areas are never diagnosed. We conducted a study at a rural district hospital in northern Tanzania to determine the birth prevalence and community awareness of SCD and to determine the feasibility of using point-of-care testing to enroll newborns in a new SCD clinic for ongoing treatment. Design/methods: We screened infants at Shirati KMT hospital for SCD using Hemo-TypeSC, an inexpensive point-of-care test. Infants who screened positive were enrolled in the SCD clinic and instructed to return at 6-12 weeks for confirmatory testing, counseling, and preventive care. Results: A total of 999 newborns were screened from February to September 2019. Among these, 31.6% (315/999) had sickle cell trait and 3.9% (39/999) had SCD. No hemoglobin C was detected. Very few parents knew their own sickle cell status (0.3%). At 5 months after completion, 12 infants from the screening study and 30 additional children had been seen at the SCD clinic for ongoing counseling and care. Conclusions: Birth prevalence of SCD in rural Tanzania is extremely high and community awareness is low. Newborn point-of-care testing enhances case finding and enables early enrollment in preventive care for SCD, even in rural sub-Saharan Africa with minimal laboratory capacity. SCD-specific clinical services implemented at the district hospital level could expand access to many children and significantly reduce early SCD morbidity and mortality. K E Y W O R D S linkage-to-care, newborn screening, prevalence, sickle cell disease, sub-Saharan Africa 1 INTRODUCTION Sickle cell disease (SCD) is an extremely important cause of childhood mortality in low-resource settings, where lack of diagnosis obscures Abbreviations: BMC, Bugando Medical Centre; DBS, dried blood spot; IEF, isoelectric focusing; POC, point-of-care; SCD, sickle cell disease; SCT, sickle cell trait its significant contribution to under-5 years mortality. 1 Sub-Saharan Africa is estimated to account for 75% of the approximately 400 000 infants born globally with SCD each year. 2,3 Unfortunately, most children with SCD in sub-Saharan Africa will die before the age of 5, 4 making SCD responsible for at least 6-16% of under-5 mortality in Africa. 5,6

Determination of birth prevalence of sickle cell disease using point of care test HemoTypeSC TM at Rundu hospital, Namibia

“…Similar studies which used HemoTypeSC as the primary screening method in some parts of Africa had sickle cell disease prevalence ranging from 1.1 to 3.9%, with the prevalence of sickle cell trait of 20.6 to as high as 31.6% (26, 43,44). In these studies con rmatory test were laboratory based and they showed a high sensitivity of HemoType SC, point of care test.…”

Determination of birth prevalence of sickle cell disease using point of care test HemotypeSC™ at Rundu Hospital, Namibia

“…Similar studies that used HemoTypeSC as the primary screening method in some parts of Africa reported sickle cell disease incidences ranging from 1.1 to 3.9%, with a prevalence of sickle cell traits ranging from 20.6 to as high as 31.6% [27,50,51]. In these studies, laboratorybased confirmatory tests were performed, and Hemo-Type SC, a point-of-care test, was highly sensitive.…”

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

“…High prevalence results (SCD ~4%) were also obtained at a hospital in Shirati (rural northern Tanzania) in a separate study undertaken from February to September 2019. In addition to birth prevalence data, this study also demonstrated the value of POC testing (HemoTypeSC TM ) and the need to improve community awareness [ 1575 ].…”