Sickle Cell Disease in the Islands of Zanzibar: Patients’ Characteristics, Management, and Clinical Outcomes

BACKGROUND: This study aimed to describe Sickle Cell Disease (SCD) phenotypes, sociodemographic characteristics, healthcare, and clinical outcomes of patients with SCD attending Mnazi Mmoja Hospital (MMH) in Zanzibar. METHODS: Individuals who visited MMH between September 2021 and December 2022 and were known or suspected to have SCD were enrolled in the clinic. Sociodemographic characteristics and clinical features were documented, and laboratory tests were performed. A two-sample test of proportions was used to ascertain the significance of differences in the distribution of clinical outcomes between the follow-up visits. RESULTS: A total of 724 patients with SCD were enrolled: 367 (50.7%) were male, and 357 (49.3%) were female. Most patients-713 (98.5%) in total-were homozygous (Hb SS), 9 (1.2%) had the Hb SC phenotype, and 2 (0.3%) had HbS β+ thalassemia. The majority of patients were aged 13 years and below-520 (71.8%) in total-and most did not have health insurance-582 (80.4%) in total. While all patients received folic acid, only a quarter received pneumococcal prophylaxis and hydroxyurea. Attendance at the third visit was associated with a reduced frequency of self-reported episodes of pain (24 patients [4.3%] vs. 11 patients [1.9%]). CONCLUSION: The population of patients with SCD in Zanzibar mostly comprised children who were Hb SS. Basic care services are still suboptimal, although they are associated with better outcomes when present. Thorough evaluation of SCD prevalence in Zanzibar through newborn screening programs is warranted.