Sickle Cell Screening in Children in a Resource Constrained Environment: Diagnosis and Follow up

Introduction: Sickle cell disease (SCD) is the most common hemoglobinopathy in the world and it disproportionately affects population in tropical, resource-constrained regions where there is a high prevalence of malaria. Efforts to screen for SCD have been highly prioritized in these areas despite limited resources. However, follow up after diagnosis remains a challenge. Counterintuitively, many of those diagnosed with SCD are lost to follow up after screening while others lack access to treatment that would otherwise prevent them from developing adverse health effects of SCD which is the primary reason for screening for the disease.

Objectives: To determine the rate of enrollment of children with sickle cell disease into comprehensive sickle cell clinic and initiation of sickle cell treatment after screening positive for SCD.

Methodology: This is a cross sectional study. Families of children aged 5 years and below who screened positive for SCD as part of a validation of point of care test between 2017 and 2018 in Homabay County Referral Hospital in Kenya were contacted by phone and an inquiry was made on their health status, clinic visits and treatment for SCD. Five attempts were made at reaching the families within a period of one week. Data were analyzed using frequency tables.

Results: Seven hundred children under 5 years were screened for SCD between 2017 and 2018 at Homabay County Referral Hospital and 34 were found to have sickle cell disease by screening and confirmatory testing. The mean age at the time of testing was 24 months (range 4 to 59 months). Mean follow up time was 33 months after diagnosis(range 32-35 months). Twenty-seven participants were reachable on phone and 8 could not be traced. Out of those contacted three had died from possible infectious diseases and one had stopped attending sickle cell clinic for unclear reasons. Twenty-three children were consistent with clinic attendance and were taking folic acid, and proguanil for malaria prophylaxis. Eight had not been started on hydroxyurea because they were asymptomatic for sickle cell. Fifteen patients who had been started on hydroxyurea had already experienced at least 3 or more painful crises, hospitalizations, febrile illness, or more than 1 blood transfusions within a year. These criteria are used to initiate hydroxyurea because of limited supply. In a setting where typically more than 50% of children screened for SCD are lost to follow up, 77% of the children were traceable and of those alive 96% were enrolled to comprehensive sickle cell clinic. Preliminary results from screening with point of care test permitted intensive education of families with a child highly likely to have SCD. This likely contributed to the high proportion of children attending SCD clinic. Relocation of families and unreliable phone contacts may have contributed to cases of lost to follow up.

Conclusion: While screening for SCD is crucial for timely diagnosis and prevention of life-threatening complication of SCD, establishing consistent follow-up of patients is challenging. Timely screening results and education based on these results is an effective strategy to increase SCD clinic attendance, treatment adherence, and improve outcomes in children with SCD.