Implementing newborn screening for sickle cell disease in Korle Bu Teaching Hospital, Accra: Results and lessons learned.

BACKGROUND: Early diagnosis of sickle cell disease (SCD) through newborn screening (NBS) is a cost-effective intervention, which reduces morbidity and mortality. In sub-Saharan Africa (SSA) where disease burden is greatest, there are no universal NBS programs and few institutions have the capacity to conduct NBS. We determined the feasibility and challenges of implementing NBS for SCD in Ghana's largest public hospital. PROCEDURE: The SCD NBS program at Korle Bu Teaching Hospital (KBTH) is a multiyear partnership between the hospital and the SickKids Center for Global Child Health, Toronto, being implemented in phases. The 13-month demonstration phase (June 2017-July 2018) and phase one (November 2018-December 2019) focused on staff training and the feasibility of universal screening of babies born in KBTH. RESULTS: During the demonstration phase, 115 public health nurses and midwives acquired competency in heel stick for dried blood spot sampling. Out of 9990 newborns, 4427 babies (44.3%) were screened, of which 79 (1.8%) were identified with presumptive SCD (P-SCD). Major challenges identified included inadequate nursing staff to perform screening, shortage of screening supplies, and delays in receiving screening results. Strategies to overcome some of the challenges were incorporated into phase one, resulting in increased screening coverage to 83.7%. CONCLUSIONS: Implementing NBS for SCD in KBTH presented challenges with implications on achieving and sustaining universal NBS in KBTH and other settings in SSA. Specific steps addressing these challenges comprehensively will help build on the modest initial gains, moving closer toward a sustainable national NBS program.

Utilization of Pneumococcal Vaccine and Penicillin Prophylaxis in Sickle Cell Disease in Three African Countries: Assessment among Healthcare Providers in SickleInAfrica.

Sickle cell disease is a genetic disease with a predisposition to infections caused by encapsulated organisms, especially Streptococcus pneumoniae. Pneumococcal vaccines and prophylactic penicillin have reduced the rate of this infection and mortality in sickle cell disease. However, implementation of these interventions is limited in Africa. The objectives of the study were to assess health care providers' behaviors with the implementation of pneumococcal vaccination and penicillin prophylaxis and to identify barriers to their use. A 25-item online questionnaire was administered through SickleinAfrica: a network of researchers, and healthcare providers, in Ghana, Nigeria, and Tanzania, working to improve health outcomes of sickle cell disease in Africa. Data was collected and managed using the Research Electronic Data Capture (REDCap), tools and data analysis was done using STATA version 13 and R statistical software. Eighty-two medical practitioners responded to the questionnaire. Only 54.0 and 48.7% of respondents indicated the availability of published guidelines on sickle cell disease management and pneumococcal vaccine use, respectively, at their facilities. The majority (54.0%) perceived that the vaccines are effective but over 20.0% were uncertain of their usefulness. All respondents from Ghana and Tanzania affirmed the availability of guidelines for penicillin prophylaxis in contrast to 44.1% in Nigeria. Eighty-five percent of respondents affirmed the need for penicillin prophylaxis but 15.0% had a contrary opinion for reasons including the rarity of isolation of Streptococcus pneumoniae in African studies, and therefore, the uncertainty of its benefit. Lack of published guidelines on the management of sickle cell disease and doubts about the necessity of prophylactic measures are potential barriers to the implementation of effective interventions.

Newborn screening for sickle cell disease in Europe: recommendations from a Pan-European Consensus Conference.

Sickle Cell Disease (SCD) is an increasing global health problem and presents significant challenges to European health care systems. Newborn screening (NBS) for SCD enables early initiation of preventive measures and has contributed to a reduction in childhood mortality from SCD. Policies and methodologies for NBS vary in different countries, and this might have consequences for the quality of care and clinical outcomes for SCD across Europe. A two-day Pan-European consensus conference was held in Berlin in April 2017 in order to appraise the current status of NBS for SCD and to develop consensus-based statements on indications and methodology for NBS for SCD in Europe. More than 50 SCD experts from 13 European countries participated in the conference. This paper aims to summarise the discussions and present consensus recommendations which can be used to support the development of NBS programmes in European countries where they do not yet exist, and to review existing programmes.

Relation Between Religious Perspectives and Views on Sickle Cell Disease Research and Associated Public Health Interventions in Ghana.

Sickle cell disease (SCD) is highly prevalent in Africa with a significant public health burden for under-resourced countries. We employed qualitative research methods to understand the ethical, legal, and social implications of conducting genomic research in SCD under the Human Heredity and Health in Africa (H3Africa) initiative. The present study focused on religious and cultural aspects of SCD with the view to identifying beliefs and attitudes relevant to public health interventions in Ghana. Thematic analyses from individual and group interviews revealed six key areas of importance, namely, reliance on a supreme being; religion as a disruptive influence on health behaviors; role of religious leaders in information sharing and decision-making; social, religious, and customary norms; health and religious/supernatural beliefs; and need for social education and support through church and community. Findings suggest that public health programs in Ghana should not only aim at increasing knowledge and awareness about SCD and its management but also create an understanding of the relevance of genomics and alternative technological advancement to diagnosis and ethical decision-making around available options for health seeking. Future research should engage communities to help address the ethical and social implications of a persuasive religious influence on SCD-related health decisions.

Newborn Screening for Sickle Cell Disease in Liberia: A Pilot Study.

BACKGROUND: In malaria-endemic countries in West Africa, sickle cell disease (SCD) contributes to childhood mortality. Historically, Liberia had regions wherein hemoglobin S and beta-thalassemia trait were mutually exclusive. Data on hemoglobinopathies in the Monrovia, the capital, are outdated and do not reflect urban migration. Updating the epidemiology of SCD is necessary to plan a public health and clinical agenda. Neither newborn screening (NBS) nor screening tools were available in country. This pilot study aimed to determine the feasibility of NBS using a South-South partnership and define the incidence of sickle cell trait (SCT) and SCD in Monrovia. PROCEDURE: This descriptive epidemiologic feasibility study collected dried blood spots from 2,785 consecutive newborns delivered at a hospital in Monrovia. Samples were analyzed by isoelectric focusing at a regional reference laboratory. Infants with SCD were referred for preventive care. RESULTS: SCT occurred in 10.31% of infants screened. SCD occurred in 33 infants screened [1.19% (95% confidence interval [CI]: 0.79-1.59%)] (FS: 28/33, FSB: 2/33, FSA: 2/33, FSX: 1/33). There were no infants with FSC phenotype observed. Nonsickling hemoglobin phenotypes "FC" and "F" were each present in three infants screened. Seventy-six percent of infants with SCD were brought to care, demonstrating the feasibility of our approach. CONCLUSIONS: The incidence of SCD and other hemoglobinopathies remains high in Liberia. Additional studies are needed to clarify sickle genotypes and identify the contribution of silent beta-thalassemia alleles. By developing regional partnerships, countries similar to Liberia can acquire current data to inform NBS as an important public health initiative toward improving child health.

Filterability of freshly-collected sickle erythrocytes under venous oxygen pressure without exposure to air.

We previously found that blood samples collected from steady-state patients with sickle cell disease (SCD) without exposure to air contain a new type of reversibly sickled cells (RSCs) with blunt edges at a level of as high as 78%. Since partial oxygenation of once-deoxygenated sickled cells with pointy edges to near venous oxygen pressure generates similar sickled cells with blunt edges in vitro, we named them as partially oxygenated sickled cells (POSCs). On the other hand, partial deoxygenation of once-oxygenated SS cells to venous oxygen pressure generates partially deoxygenated sickled cells (PDSCs) with pointy edges. In this study, we obtained blood samples from 6 steady-state patients with SCD under venous oxygen pressure without exposure to air, subjected them to various oxygenation/deoxygenation/reoxygenation cycles, and studied their filterability through a membrane filter with pore diameter of 3µm, the theoretical minimum diameter of a capillary. Our results indicated that discocytes, POSCs with blunt edges, and irreversibly sickled cells could deform and pass through the filter, while PDSCs with pointy edges were rigid and could not. The filterability of SS cells seems to be related to the length and amount of deoxy-hemoglobin S fibers in the cells.

Using formative research to develop a counselor training program for newborn screening in Ghana.

Sickle cell disease (SCD), sickle cell trait (SCT) and related conditions are highly prevalent in sub-Saharan Africa. Despite the public health implications, there is limited understanding of the unique needs regarding establishing and implementing extensive screening for newborns and appropriate family counseling. We sought to gain understanding of community attitudes and beliefs about SCD/SCT from counselors and potential counselors in Ghana; obtain their input about goals for counseling following newborn screening; and obtain guidance about developing effective counselor education. Five focus groups with 32 health care providers and health educators from 9 of 10 regions in Ghana were conducted by trained facilitators according to a structured protocol. Qualitative data were coded and categorized to reflect common themes. Saturation was achieved in themes related to genetics/inheritance; common complications of SCD; potential for stigmatization; marital strain; and emotional stress. Misconceptions about SCT as a form of SCD were prevalent as were cultural and spiritual beliefs about the causes of SCD/SCT. Potential positive aspects included affected children's academic achievement as compensation for physical limitations, and family cohesion. This data informed recommendations for content and structure of a counselor training program that was provided to the Ministry of Health in Ghana.

Respiratory muscle force and lung volume changes in a population of children with sickle cell disease.

Sickle cell disease (SCD) is a disorder known to impact the respiratory system. We sought to identify respiratory muscle force and lung volume relationships in a paediatric SCD population. Thirty-four SCD-SS subjects underwent pulmonary function testing. Height, weight, age, and gender-adjusted percent predicted maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) values were compared to spirometry and lung volumes. Statistical analyses were performed using Pearson's correlation coefficient and paired two-tailed t-test. The mean ± standard deviation (SD) MIP and MEP was 69·6 ± 31·6 cm H2 O and 66·9 ± 22·9 cm H2 O, respectively, and mean ± SD percent predicted MIP (101·3 ± 45·9) exceeded MEP (72·1 ± 26·0) (P = 0·002). MIP correlated with forced vital capacity (FVC; r = 0·51, P = 0·001) and TLC (r = 0·54, P < 0·0001). MEP also correlated with FVC (r = 0·43, P = 0·011) and total lung capacity (TLC; r = 0·42, P = 0·013). Pearson's correlation coefficient testing yielded relationships between MIP and MEP (r = 0·64, P < 0·0001). SCD-SS patients showed correlations between respiratory muscle force and lung volume, and reduced percent predicted expiratory muscle force compared to inspiratory muscle force. Respiratory muscle strength may affect lung volumes in these patients, and expiratory muscles may be more susceptible than the diaphragm to SCD-induced vaso-occlusive damage.

Access to essential therapy for sickle cell disease in Africa: Experience from a national program in Ghana.

Novartis, a global medicines company, and the Sickle Cell Foundation of Ghana (SCFG), an advocacy organization, have endeavored to support the implementation of global best practices in the care of people living with sickle cell disease (SCD) in Africa, and to address unmet needs relating to this condition on the continent. Beginning in 2019, a multifaceted SCD program was implemented in Ghana through a public-private partnership involving the government of Ghana, the SCFG, Novartis, and other partners. A key component of the program involved expanding the reach of hydroxyurea (HU), the only approved disease-modifying generic treatment for SCD, in ways that would promote sustainable access. The program helped to raise the profile of SCD in Ghana and, in 2022, the government adopted HU into its National Health Insurance Scheme. Features of the effort in Ghana are now being expanded to other countries in Africa through cocreated programs with in-country partners. This article reviews the program's history, progress, challenges, and lessons learned.

Enablers and barriers to newborn screening for sickle cell disease in Africa: results from a qualitative study involving programmes in six countries.

OBJECTIVES: Given the fundamental role of newborn bloodspot screening (NBS) to enable prompt diagnosis and optimal clinical management of individuals with sickle cell disease (SCD), we sought to systematically assess enablers and barriers to implementation of NBS programmes for SCD in Africa using established qualitative research methods. SETTING: Childbirth centres and NBS laboratories from six countries in East, West and Southern Africa. PARTICIPANTS: Eight programme leaders involved with establishing and operating NBS programmes for SCD in Angola, Democratic Republic of Congo, Ghana, Liberia, Nigeria and Tanzania. PRIMARY AND SECONDARY OUTCOME MEASURES: Data obtained through a structured, phased interview approach were analysed using a combination of inductive and deductive codes and used to determine primary themes related to the implementation and sustainability of SCD NBS programmes. RESULTS: Four primary themes emerged from the analysis relating to governance (eg, pragmatic considerations when deploying overcommitted clinical staff to perform NBS), technical (eg, design and execution of operational processes), cultural (eg, variability of knowledge and perceptions of community-based staff) and financial (eg, issues that can arise when external funding may effectively preclude government inputs) aspects. Key learnings included perceived factors that contribute to long-term NBS programme sustainability. CONCLUSIONS: The establishment of enduring NBS programmes is a proven approach to improving the health of populations with SCD. Organising such programmes in Africa is feasible, but initial implementation does not assure sustainability. Our analysis suggests that future programmes should prioritise government partner participation and funding from the earliest stages of programme development.

Multispectral imaging for MicroChip electrophoresis enables point-of-care newborn hemoglobin variant screening.

Hemoglobin (Hb) disorders affect nearly 7% of the world's population. Globally, around 400,000 babies are born annually with sickle cell disease (SCD), primarily in sub-Saharan Africa where morbidity and mortality rates are high. Screening, early diagnosis, and monitoring are not widely accessible due to technical challenges and cost. We hypothesized that multispectral imaging will allow sensitive hemoglobin variant identification in existing affordable paper-based Hb electrophoresis. To test this hypothesis, we developed the first integrated point-of-care multispectral Hb variant test: Gazelle-Multispectral. Here, we evaluated the accuracy of Gazelle-Multispectral for Hb variant newborn screening in 265 newborns with known hemoglobin variants including hemoglobin A (Hb A), hemoglobin F (Hb F), hemoglobin S (Hb S) and hemoglobin C (Hb C). Gazelle-Multispectral detected levels of Hb A, Hb F, Hb S, and Hb C/E/A2, demonstrated high correlations with the results reported by laboratory gold standard high performance liquid chromatography (HPLC) at Pearson Correlation Coefficient = 0.97, 0.97, 0.93, and 0.95. Gazelle-Multispectral demonstrated accuracy of 96.8% in subjects of 0-3 days, and 96.9% in newborns. The ability to obtain accurate results on newborn samples suggest that Gazelle-Multispectral can be suitable for large-scale newborn screening and for diagnosis of SCD in low resource settings.

Development of multi-level standards of care recommendations for sickle cell disease: Experience from SickleInAfrica.

Introduction: Sickle Cell Disease (SCD) causes significant morbidity and mortality particularly in sub-Saharan Africa (SSA) where it contributes to early childhood deaths. There is need to standardize treatment guidelines to help improve overall SCD patient health outcomes. We set out to review existing guidelines on SCD and to set minimum standards for management of SCD for the different referral levels of healthcare. Methods: A standards of care working group (SoC-WG) was established to develop the SoC recommendations. About 15 available SCD management guidelines and protocols were reviewed and themes extracted from them. The first draft was on chosen themes with 64 major headings and subtopics. Using a summarised WHO levels of referral document, we were able to get six different referral levels of healthcare. The highest referral level was the tertiary facilities whilst the lowest level was the home setting. Recommendations for SCD management for the regional, district, sub-districts, health posts and CHPs compounds were also drafted. Results: The results from this review yielded a guidelines document which had recommendations for management of SCD on 64 topics and subtopic for all the six (6) different referral levels. Discussions: Every child with SCD need to receive comprehensive care that is coordinated at each level. This recommendation is unique in terms of the availability of recommendations for different levels of care as compared to the traditional guidelines which is more focused at the tertiary levels. Patients can access care at any of the other lower referral hospitals and be managed with recommendations that are in keeping with institutional resources at that level. When such patients need care that requires expertise that is not available at that level, the recommendations will be to refer to the appropriate referral level where those expertise are available. This encourages patients to have good clinical care nearer their homes but also having access to specialist screening modalities and expertise at the tertiary hospitals if need be. With this, patient are not limited to a specific referral level when interventions cannot be instituted for them. Conclusion: This SoC recommendations document is a useful material that can be used for consistent standards of treatment in SSA.

Establishing a Sickle Cell Disease Registry in Africa: Experience From the Sickle Pan-African Research Consortium, Kumasi-Ghana.

Sickle cell disease (SCD) is the most common clinically significant hemoglobinopathy, characterized by painful episodes, anemia, high risk of infection, and other acute and chronic complications. In Africa, where the disease is most prevalent, large longitudinal data on patients and their outcomes are lacking. This article describes the experiences of the Kumasi Center for SCD at the Komfo Anokye Teaching Hospital (KCSCD-KATH), a Sickle Pan-African Research Consortium (SPARCO) site and a SickleInAfrica Consortium member, in establishing a SCD registry for the evaluation of the outcomes of patients. It also provides a report of a preliminary analysis of the data. The process of developing the registry database involved comprehensive review of the center's SCD patient medical records, incorporating data elements developed by the SickleInAfrica Consortium and obtaining ethical clearance from the local Institutional Review Board. From December 2017 to March 2020, 3,148 SCD patients were enrolled into the SCD registry. Enrollment was during the SCD outpatient clinic visits or through home visits. A significant proportion of the patients was from the newborn screening cohort (50.3%) and was males (52.9%). SCD-SS, SCD-SC, and Sß +thalassemia were seen in 67.2, 32.5, and 0.3% patients, respectively. The majority of the patients were in a steady state at enrollment; however, some were enrolled after discharge for an acute illness admission. The top two clinical diagnoses for SCD-SS patients were sickle cell painful events and acute anemia secondary to hyperhemolysis with incidence rates of 141.86 per 10,000 person months of observation (PMO) and 32.74 per 10,000 PMO, respectively. In SCD-SC patients, the top two diagnoses were sickle cell painful events and avascular necrosis with incidence rates of 203.09 per 10,000 PMO and 21.19 per 10,000 PMO, respectively. The SPARCO Kumasi site has developed skills and infrastructure to design, manage, and analyze data in the SCD registry. The newborn screening program and alternative recruitment methods such as radio announcement and home visits for defaulting patients were the key steps taken in enrolling patients into the registry. The registry will provide longitudinal data that will help improve knowledge of SCD in Ghana and Africa through research.

The Consortium on Newborn Screening in Africa for sickle cell disease: study rationale and methodology.

Sickle cell disease (SCD) is a common condition within sub-Saharan Africa and associated with high under-5 mortality (U5M). The American Society of Hematology instituted the Consortium on Newborn Screening in Africa (CONSA) for SCD, a 7-country network of sites to implement standardized newborn hemoglobinopathy screening and early intervention for children with SCD in sub-Saharan Africa. CONSA's overall hypothesis is that early infant SCD screening and entry into standardized, continuous care will reduce U5M compared with historical estimates in the region. Primary trial objectives are to determine the population-based birth incidence of SCD and effectiveness of early standardized care for preventing early mortality consortium-wide at each country's site(s). Secondary objectives are to establish universal screening and early interventions for SCD within clinical networks of CONSA partners and assess trial implementation. Outcomes will be evaluated from data collected using a shared patient registry. Standardized trial procedures will be implemented among designated birth populations in 7 African countries whose programs met eligibility criteria. Treatment protocol includes administering antibacterial and antimalarial prophylaxis and standard childhood vaccinations against infections commonly affecting children with SCD. Infants with a positive screen and confirmation of SCD within the catchment areas defined by each consortium partner will be enrolled in the clinical intervention protocol and followed regularly until age of 5 years. Effectiveness of these early interventions, along with culturally appropriate family education and counseling, will be evaluated by comparing U5M in the enrolled cohort to estimated preprogram data. Here, we describe the methodology planned for this trial.

Sickle cell disease and transcranial Doppler imaging: inter-hemispheric differences in blood flow Doppler parameters.

BACKGROUND AND PURPOSE: to establish reference values of interhemispheric differences and ratios of blood flow Doppler parameters in the terminal internal carotid artery, middle cerebral artery, and anterior cerebral artery in children with sickle cell anemia. METHODS: fifty-seven out of 74 recruited children (mean age, 7.8 ± 3.4 years; range limits, 3-14 years), who were free of neurological deficits and intracranial narrowing detectable by MRA and had flow velocities <170 cm/s by conventional transcranial Doppler ultrasound, underwent transcranial color-coded duplex ultrasonography. Reference limits of flow parameters corrected and uncorrected for the angle of insonation were estimated using tolerance intervals, with P=0.90 for all possible data values from 95% of a population. RESULTS: reference limits for left-to-right differences in cm/s in the mean angle-corrected and uncorrected flow velocities were -56 to 53 and -72 to 75 for middle cerebral artery, -49 to 57 and -81 to 91 for anterior cerebral artery, and -55 to 64 and -73 to 78 for terminal internal carotid artery, respectively. Respective reference limits for left-to-right velocity ratios were 0.31 to 1.84 and 0.38 to 1.75 for middle cerebral artery, 0.48 to 2.99 and 0.46 to 2.89 for anterior cerebral artery, and 0.61 to 2.56 and 0.56 to 2.23 for terminal internal carotid artery. CONCLUSIONS: the study provides reference limits of interhemispheric differences and ratios of blood flow Doppler parameters that may be helpful in identification of intracranial arterial narrowing in children with sickle cell disease undergoing ultrasound screening for stroke prevention.

Approaches to transfusion therapy and iron overload in patients with sickle cell disease: results of an international survey.

To gain an insight into current transfusion and chelation practice in patients with sickle cell disease (SCD), a survey of international experts has been conducted. The findings demonstrate that general utilization of transfusion therapy is low, the primary barrier to treatment being concerns over resultant iron overload and the subsequent need for iron chelation therapy. Where patients were transfused, many physicians indicated that a high proportion of patients had hemosiderosis. As evidence suggests more patients with SCD could benefit from regular transfusion therapy, it is apparent that greater awareness of the need to monitor and treat iron overload in transfused patients is required.

Transfusion and chelation practices in sickle cell disease: a regional perspective.

Although most common in tropical regions, population migration has meant that sickle cell disease is now one of the most prevalent genetic diseases worldwide. The issues and challenges faced by physicians and patients have been discussed by an international group of experts representing 4 key regions: the USA, Europe, Latin America, and the Middle East/Africa. Conclusive evidence to support the use of transfusion therapy for the prevention of stroke has resulted in key changes to patient management in all regions, and increasing numbers of patients are benefiting from this management approach. However, it is apparent that transfusion therapy is still under-utilized, largely due to concerns over iron overload, alloimmunization, limited blood supplies, and, sometimes, due to parental refusal. Once transfused, assessment and management of body iron levels can be poor, particularly in patients who are intermittently transfused. Compliance with chelation therapy regimens is a significant challenge, but new therapeutic options are likely to overcome some of the current barriers. Key requirements in all regions were considered to be the following: to provide greater physician, patient, and family education; to ensure effective transition from pediatric to adult care; and to establish national guidelines in order to ensure best practice is consistently applied.

Pulmonary, gonadal, and central nervous system status after bone marrow transplantation for sickle cell disease.

We conducted a prospective, multicenter investigation of human-leukocyte antigen (HLA) identical sibling bone marrow transplantation (BMT) in children with severe sickle cell disease (SCD) between 1991 and 2000. To determine if children were protected from complications of SCD after successful BMT, we extended our initial study of BMT for SCD to conduct assessments of the central nervous system (CNS) and of pulmonary function 2 or more years after transplantation. In addition, the impact on gonadal function was studied. After BMT, patients with stroke who had stable engraftment of donor cells experienced no subsequent stroke events after BMT, and brain magnetic resonance imaging (MRI) exams demonstrated stable or improved appearance. However, 2 patients with graft rejection had a second stroke after BMT. After transplantation, most patients also had unchanged or improved pulmonary function. Among the 11 patients who had restrictive lung changes at baseline, 5 were improved and 6 had persistent restrictive disease after BMT. Of the 2 patients who had obstructive changes at baseline, 1 improved and 1 had worsened obstructive disease after BMT. There was, however, significant gonadal toxicity after BMT, particularly among female recipients. In summary, individuals who had stable donor engraftment did not experience sickle-related complications after BMT, and were protected from progressive CNS and pulmonary disease.

Empowering newborn screening programs in African countries through establishment of an international collaborative effort.

In an effort to explore new knowledge and to develop meaningful collaborations for improving child health, the First Pan African Workshop on Newborn Screening was convened in June 2019 in Rabat, Morocco. Participants included an informal network of newborn screening stakeholders from across Africa and global experts in newborn screening and sickle cell disease. Over 150 attendees, representing 20 countries, were present including 11 African countries. The agenda focused on newborn screening rationale, techniques, system development, implementation barriers, ongoing research, and collaborations both globally and across Africa. We provide an overview of the workshop and a description of the newborn screening activities in the 11 African countries represented at the workshop, with a focus on sickle cell disease.

Silent infarcts in young children with sickle cell disease.

Silent infarcts have been reported most commonly in school-aged children with homozygous sickle cell disease (SCD-SS) and are associated with neurocognitive deficits. However, the prevalence of silent infarcts in younger children with SCD-SS is not well defined. In this retrospective study, brain magnetic resonance imaging and angiography (MRI/A) studies performed before 6 years of age in a cohort of children with SCD-SS were analysed and the prevalence of abnormalities was calculated. Clinical and laboratory parameters were compared between the groups with and without silent infarcts. Sixty-eight of 96 children in the cohort had brain MRI/A performed prior to age 6 years. Of the 65 who were neurologically asymptomatic, 18 (27.7%, 95% CI 17.3-40.2%) had silent infarcts (mean age 3.7 +/- 1.1 years, range 1.3-5.9 years). Factors associated with silent infarcts included cerebral vessel stensosis by magnetic resonance angiography, lower rates of vaso-occlusive pain and acute chest syndrome and lower haemoglobin levels. The prevalence of silent infarcts in young children with SCD-SS is similar to that of older children and anaemia and severe vasculopathy may be risk factors.