Sickle Cell Disease in Africa: SickleInAfrica Registry in Ghana, Nigeria and Tanzania

Abstract

Introduction: Sickle cell disease (SCD) is most prevalent in Sub-Saharan Africa (SSA), where incomplete patient profiles and limited management strategies hinder research and healthcare standards.

Methods: We describe the first large-scale and multinational assessment of 13,403 SCD patients enrolled from 2017-2021 across 31 facilities in Ghana, Nigeria, and Tanzania into the SickleInAfrica consortium registry. We used hierarchical regression models to estimate and analyze the demographics, adoption levels of SCD diagnosis and therapies.

Results: The average age at diagnosis was 3 months, 19 months and 3 years in Ghana, Nigeria and Tanzania respectively, reflecting differences in country-specific newborn screening programs and policies. Hydroxyurea (HU) use was highest in Ghana (21%), followed by Nigeria (12%) and Tanzania (6%), with significant variability across facilities. Sex differences in SCD management were observed, with males more likely to receive HU and blood transfusions. At the consortium level, HU initiation correlated with enrolment age rather than age at diagnosis, highlighting the need for earlier intervention.

Conclusions: Our findings highlight the potential of the SickleInAfrica registry toward enhancing understanding of regional disparities in SCD care and potential gender inequalities, emphasizing the need for enabling policies toward strengthened SCD research and improved quality of life and care of patients in Africa.

Keywords: SickleInAfrica; disease management; meta‐analysis; registry; regression models; sickle cell disease.

FIGURE 1

Spatial distribution of the registry enrolment facilities for the 3 consortium countries. Each black dot marks the location of an enrolment facility. Due to the high density of facilities in some regions, several black dots overlap. Specific location information of the facilities is available in Table S2.

FIGURE 2

Predicted median age at diagnosis across healthcare facilities in the registry. This figure shows the median age at diagnosis for patients at different healthcare facilities, grouped by age at enrolment. Each panel represents a fixed age at enrolment: 5 years (top left), 10 years (top right), 20 years (bottom left), and 40 years (bottom right). Points indicate the median age at diagnosis for each facility, with bars representing 95% confidence intervals (CIs). Different colors represent different countries.

FIGURE 3

Influence of sex on SCD management. This figure presents age‐adjusted odds ratios for SCD treatment regimens among patients with the HbSS genotype (see Table S3). Females serve as the reference group, and dots represent the estimated odds ratios for males compared to females, with horizontal bars indicating 95% confidence intervals (CIs). An odds ratio greater than 1 suggests higher treatment uptake in males, while an odds ratio below 1 suggests lower uptake in males relative to females. The dashed vertical line at 1.0 represents no difference in treatment uptake between sexes.

FIGURE 4

Prevalence of hydroxyurea (HU) use for each healthcare facility in Nigeria, with 95% confidence intervals (CIs). On the Y axis is the Human Development Index (HDI) of the state that a given facility is located in. The facility at the top of the plot is in a state with the highest HDI, and the facility at the bottom is in a state with the lowest HDI.

FIGURE 5

Relationship between age at hydroxyurea (HU) initiation, enrolment, and diagnosis at Muhimbili Hospital, Tanzania. This figure shows that at Muhimbili Hospital, patients on HU (blue dots and line) had a lower age at diagnosis than those not on HU (orange dots and line), suggesting that HU initiation was more closely linked to diagnosis in this setting.