Neonatal Screening for Sickle Cell Disease in Congo

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

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

Bridging the gaps in newborn screening programmes: Challenges and opportunities to detect haemoglobinopathies in Africa

Background

Haemoglobinopathies, including sickle cell disease and β-thalassaemia, are monogenic disorders with a relatively higher prevalence among malaria-endemic areas in Africa. Despite this prevalence, most African countries lack the necessary resources for diagnosing and managing these debilitating conditions.

Aim

This study provides a critical review of newborn screening for detecting haemoglobinopathies in Africa, highlighting challenges and proposing strategies for improved diagnosis and management.

Methods

A literature search on haemoglobinopathies in Africa was conducted in PubMed, Google Scholar and ScienceDirect, using specific keywords and Boolean operators, including articles published from January 1981 to December 2022.

Results

The data show that sickle cell disease is prevalent among populations in Central and West Africa; however, β-thalassaemia is prevalent among people in the northern parts of Africa. Newborn screening pilot initiatives for haemoglobinopathies were being implemented in Angola, Nigeria, Ghana, the Democratic Republic of Congo and the Republic of Benin. The cost of testing, lack of sufficient and accessible medical records, and inadequacy in healthcare infrastructure pose significant challenges in bridging the gaps in newborn screening. Furthermore, the stigmatisation and lack of awareness of haemoglobinopathies and access to newborn screening programmes pose additional challenges.

Conclusion

This review highlights the challenges associated with haemoglobinopathy testing, effective strategies for mitigating these challenges, and future perspectives for expanding efforts toward detecting and managing these disorders across Africa. Providing affordable diagnostic tools, mobile clinics, government subsidies, education campaigns, and the implementation of electronic medical records systems could help bridge the gaps in newborn screening in Africa.

What this study adds

The study presents a comprehensive view of newborn screening of haemoglobinopathies in Africa, provides a detailed outline of the challenges faced by newborn screening for haemoglobinopathies in Africa, and offers strategies for better diagnosis and care.

Newborn screening for sickle cell disease in Kisangani, Democratic Republic of the Congo: an update

BACKGROUND

Neonatal screening is the first action necessary to identify children with sickle cell disease (SCD) and thus ensure their care. Using rapid tests to give an immediate result to families is a new resilient approach of great interest. These two aspects are essential for establishing an adequate health policy for this disease. This study was undertaken in Kisangani to update the current incidence of neonatal SCD.

METHODS

Heel prick blood samples of 1432 babies born from different racial groups of parents living in Kisangani were collected at birth and screened using a point of care test, i.e. the HemoTypeSC^TM.

RESULTS

The incidence at birth was 2.2% (n = 31; 95% CI: [1.5%-3.1%]) for HbSS homozygosity and 21% (n = 303; 95% CI: [19%-23%]) for HbAS heterozygosity. Compared to a previous study in 2010; the incidence at the birth of the HbSS form has doubled, while that of the heterozygous form HbAS remained almost unchanged. The inter-ethnic incidence of HbSS among the five top-represented ethnic groups was significant (<0.001).

CONCLUSION

The prevalence of homozygote form has doubled compared to the 0.96% reported in 2010. Setting up a neonatal screening program and an awareness unit is necessary to assess the need for care services correctly.

Associated Factors of Cholelithiasis among Younger Children with Sickle Cell Disease at the National Reference Center for Sickle Cell Disease in Brazzaville, Congo

Introduction

Chronic hemolysis predisposes sickle cell patients to the development of gallstones. Their frequency increases with age, but they may appear early in young children. In the absence of management, they expose the patient to complications that can hinder the quality of life and sometimes even death. This survey aimed to identify the associated factors of the occurrence of cholelithiasis.

Materials and Methods

It was a case-control study carried out between January 2017 and June 2022 at the National Reference Center for Sickle Cell Disease (SCD) "Antoinette Sassou N'guesso" in Brazzaville. It concerned 37 children with cholelithiasis. Sociodemographic (socioeconomic status and diet) and clinical (body mass index, frequency of vasoocclusive crises and hospitalization for vasoocclusive crises, number of blood transfusion, and chronic complications) as well as hematological examination (type of SCD and blood count in the intercritical period) and hydroxyurea treatment were compared with those of 74 children with no clinical and radiographic signs of cholelithiasis. The chi-squared statistical test and the odds ratio were used for the comparison (p  <  0.05).

Results

The average age was 9.70 ± 1.73 years. The 10-12 age group was the most represented (22 cases or 59.45%), followed by 7- to 9-year-olds (12 cases or 32.43%). Three children (8.10%) were 6  years old. The sex ratio was 0.68 vs. 1.38. Factors associated with cholelithiasis were low socioeconomic status (83.78% vs. 45.95%; IC 95% 1.46-3.89; p ≤ 0.001), a higher number of blood transfusions (5.54 ± 1.22 vs. 2.46 ± 1.13; IC 95% 1.55-6.70; p ≤ 0.001), and irregular systematic monitoring (5.54 ± 1.22 vs. 2.46 ± 1.13; IC 95% 1.55-6.70; p ≤ 0.001).

Conclusion

A national strategy to facilitate access to care for patients living with sickle cell disease is imperative. Moreover, emphasis should be placed on the prevention and early management of acute complications of SCD.

Systematic Literature Review Shows Gaps in Data on Global Prevalence and Birth Prevalence of Sickle Cell Disease and Sickle Cell Trait: Call for Action to Scale Up and Harmonize Data Collection

Sickle cell disease (SCD) is an inherited monogenic disorder with high prevalence throughout sub-Saharan Africa, the Mediterranean basin, the Middle East, and India. Sources of SCD epidemiology remain scarce and fragmented. A systematic literature review (SLR) to identify peer-reviewed studies on SCD epidemiology was performed, with a search of bibliographic databases and key conference proceedings from 1 January 2010 to 25 March 2022 (congress abstracts after 2018). The SLR followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Meta-analyses, using a binomial normal random-effects model, were performed to estimate global and regional prevalence and birth prevalence. Of 1770 journal articles and 468 abstracts screened, 115 publications met the inclusion criteria. Prevalence was highest in Africa (~800/100,000), followed by the Middle East (~200/100,000) and India (~100/100,000), in contrast to ~30/100,000 in Europe. Birth prevalence was highest in Africa (~1000/100,000) and lowest in North America (~50/100,000) and Europe (~30/100,000). This SLR confirmed that sub-Saharan and North-East Africa, India, the Middle East, and the Caribbean islands are global SCD hotspots. Publications including mortality data were sparse, and no conclusions could be drawn about mortality. The identified data were limited due to gaps in the published literature for large parts of the world population; the inconsistent reporting of SCD genotypes, diagnostic criteria, and settings; and a sparsity of peer-reviewed publications from countries with assumed high prevalence. This SLR demonstrated a lack of systematic knowledge and a need to provide uniform data collection on SCD prevalence and mortality.