Newborn sickle cell disease screening: the Jamaican experience (1995–2006)

Newborn Screening for Sickle Cell Disease in Catalonia between 2015 and 2022-Epidemiology and Impact on Clinical Events

In 2015, Catalonia introduced sickle cell disease (SCD) screening in its newborn screening (NBS) program along with standard-of-care treatments like penicillin, hydroxyurea, and anti-pneumococcal vaccination. Few studies have assessed the clinical impact of introducing NBS programs on SCD patients. We analyzed the incidence of SCD and related hemoglobinopathies in Catalonia and the change in clinical events occurring after introducing NBS. Screening 506,996 newborns from 2015 to 2022, we conducted a retrospective multicenter study including 100 screened (SG) and 95 unscreened (UG) SCD patients and analyzed SCD-related clinical events over the first six years of life. We diagnosed 160 cases of SCD, with an incidence of 1 in 3169 newborns. The SG had a significantly lower median age at diagnosis (0.1 y vs. 1.68 y, p < 0.0001), and initiated penicillin prophylaxis (0.12 y vs. 1.86 y, p < 0.0001) and hydroxyurea treatment earlier (1.42 y vs. 4.5 y, p < 0.0001). The SG experienced fewer median SCD-related clinical events (vaso-occlusive crisis, acute chest syndrome, infections of probable bacterial origin, acute anemia requiring transfusion, acute splenic sequestration, and pathological transcranial Doppler echography) per year of follow-up (0.19 vs. 0.77, p < 0.0001), a reduced number of annual emergency department visits (0.37 vs. 0.76, p < 0.0001), and fewer hospitalizations (0.33 vs. 0.72, p < 0.0001). SCD screening in Catalonia's NBS program has effectively reduced morbidity and improved affected children's quality of life.

Sickle Cell Disease

Background

Sickle cell disease (SCD) is among the most frequent hereditary disorders globally and its prevalence in Europe is increasing due to migration movements.

Summary

The basic pathophysiological event of SCD is polymerization of deoxygenated sickle hemoglobin, resulting in hemolysis, vasoocclusion, and multiorgan damage. While the pathophysiological cascade offers numerous targets for treatment, currently only two disease-modifying drugs have been approved in Europe and transfusion remains a mainstay of both preventing and treating severe complications of SCD. Allogeneic stem cell transplantation and gene therapy offer a curative option but are restricted to few patients due to costs and limited availability of donors.

Key Message

Further efforts are needed to grant patients access to approved treatments, to explore drug combinations and to establish new treatment options.

Factors Affecting Age of Initial Specialty Clinic Evaluation Among Infants with Sickle Cell Disease in Kingston, Jamaica

OBJECTIVES

To evaluate the effectiveness of newborn screening for sickle cell disease in eastern Jamaica by determining what proportion of screen-positive infants were registered with the Sickle Cell Unit (SCU) by two months (60 days) of age and identifying parents' perceptions of facilitators and barriers impacting age at registration.

STUDY DESIGN

This cross-sectional study used a mixed method approach. Ages at diagnosis confirmation and first clinic visit were recorded for screen-positive infants born between February 1, 2015, and November 15, 2017. All parents were invited to complete the survey and early and late attendees were invited to participate in the qualitative aspect of the study. A researcher-designed questionnaire and an interview guide based on the Capability, Opportunity, Motivation, Behavior (COM-B), and Health Belief Models examined factors that may affect time to registration. Quantitative data were analyzed to yield descriptive statistics using Stata®v14. All interview data were coded. Similar codes were grouped together into themes.

RESULTS

Most (97.7%) of the 133 screen-positive infants had their diagnosis confirmed. Only 40% had their first clinic visit by age 60 days. Denial of the diagnosis, poor communication, and the costs of treatment and transportation were perceived barriers to registration, whereas family support was a facilitator.

CONCLUSIONS

Diagnosis confirmation was almost universal, but most infants did not attend clinic by two months of age. In-depth interviews have identified several facilitators and barriers that can be targeted to improve early registration.

Social inequalities in the temporal trend of mortality from sickle cell disease in Brazil, 1996-2019

Contrary to international trends, the mortality rate of sickle cell disease increased in Brazil after the implementation of the neonatal screening program, probably due to improving access to diagnosis. This study aimed to assess differences in the temporal trend of the mortality rate and median age at death from sickle cell disease in Brazil, considering implemented measures to expand diagnosis, and improve health care access in-country and in the international scenario. Time series were extracted from the Brazilian Mortality Information System from 1996 to 2019. Changes in the mortality rate and median age at death were verified via segmented regression models, which were stratified by sex, region of residence, and age. Most deaths occurred in non-white people, young adults, and the Southeast and Northeast population. Sickle cell disease mortality rate increased until 2010 (13.31%; 95%CI: 6.37; 20.70), particularly in individuals aged 30 years or more (12.78%; 95%CI: 2.98; 23.53) and in the Northeast (12.27%; 95%CI: 8.92; 15.72). Most deaths occurred in the second decade of life (3.01 deaths/million), with a 59% increase in the median age of death in Brazil, from 27.6 to 30.3 years, more pronounced in females and the North Region. The observed gain in the survival of sickle cell disease in Brazil is still much lower than in developed countries and presents regional disparities, probably due to the lack of access to health care and recent treatments, such as hydroxyurea, still restricted to hematological referral centers in Brazilian capitals.

Diagnosis patterns of sickle cell disease in Ghana: a secondary analysis

BACKGROUND

Despite having the highest prevalence of sickle cell disease (SCD) in the world, no country in Sub-Saharan Africa has a universal screening program for the disease. We sought to capture the diagnosis patterns of SCD (age at SCD diagnosis, method of SCD diagnosis, and age of first pain crisis) in Accra, Ghana.

METHODS

We administered an in-person, voluntary survey to parents of offspring with SCD between 2009 and 2013 in Accra as a part of a larger study and conducted a secondary data analysis to determine diagnosis patterns. This was conducted at a single site: a large academic medical center in the region. Univariate analyses were performed on diagnosis patterns; bivariate analyses were conducted to determine whether patterns differed by participant's age (children: those < 18 years old whose parents completed a survey about them, compared to adults: those > = 18 years old whose parents completed a survey about them), or their disease severity based on SCD genotype. Pearson's chi-squared were calculated.

RESULTS

Data was collected on 354 unique participants from parents. Few were diagnosed via SCD testing in the newborn period. Only 44% were diagnosed with SCD by age four; 46% had experienced a pain crisis by the same age. Most (66%) were diagnosed during pain crisis, either in acute (49%) or primary care (17%) settings. Children were diagnosed with SCD at an earlier age (74% by four years old); among the adults, parents reflected that 30% were diagnosed by four years old (p < 0.001). Half with severe forms of SCD were diagnosed by age four, compared to 31% with mild forms of the disease (p = 0.009).

CONCLUSIONS

The lack of a robust newborn screening program for SCD in Accra, Ghana, leaves children at risk for disease complications and death. People in our sample were diagnosed with SCD in the acute care setting, and in their toddler or school-age years or thereafter, meaning they are likely being excluded from important preventive care. Understanding current SCD diagnosis patterns in the region can inform efforts to improve the timeliness of SCD diagnosis, and improve the mortality and morbidity caused by the disease in this high prevalence population.

The promise and role of point of care testing to reduce the global burden of sickle cell disease through early diagnosis and linkage to care

Sickle cell disease (SCD) is a devastating and under-recognised global child health issue affecting over 300,000 infants annually, with the highest prevalence in India and sub-Saharan Africa. Most affected infants born in low- and middle-income countries (LMIC) lack access to SCD testing and die from complications in the first years of life without a formal diagnosis. The majority of deaths are preventable with early diagnosis and provision of inexpensive interventions. Despite global recognition of the urgent need, expansion of SCD newborn screening (NBS) programmes beyond the pilot stage has been obstructed by a dependence on an expensive and logistically challenging centralised laboratory testing model. Recently, several point-of-care tests (POCT) for SCD have been developed with promising field validation studies. Here, we summarise the state of POCT for SCD, review barriers and unanswered questions, and discuss optimal strategies for utilising POCT to address the growing global burden of SCD. There is an urgent need to prospectively evaluate the ability of POCT to reduce the morbidity and high early mortality of SCD. To impact a sustainable reduction to this end, it is essential to link a diagnosis with comprehensive SCD care, including wide and affordable access to affordable hydroxycarbamide therapy.

Hydroxycarbamide treatment reduces transcranial Doppler velocity in the absence of transfusion support in children with sickle cell anaemia, elevated transcranial Doppler velocity, and cerebral vasculopathy: the EXTEND trial

EXpanding Treatment for Existing Neurological Disease (EXTEND) investigated whether hydroxycarbamide lowers transcranial Doppler (TCD) velocities in Jamaican children with sickle cell anaemia (SCA) and elevated TCD velocity with or without previous stroke. Forty-three children (age 2-17 years) with baseline maximum time-averaged mean velocity (TAMV) ≥ 170 cm/s were stratified into three risk categories based on treatment status and stroke history: Group 1 (no history of stroke, on hydroxycarbamide, n = 12); and Groups 2 (no stroke, no hydroxycarbamide, n = 21) and 3 (previous stroke, no hydroxycarbamide, n = 10). Open-label hydroxycarbamide at 20 mg/kg/day was commenced, with escalation to maximum tolerated dose (MTD) based on mild marrow suppression (average dose 25·4 ± 4·5 mg/kg/day). TCD was performed every six months with brain magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) at baseline and after 18-months of hydroxycarbamide. The maximum TAMV decreased significantly compared to baseline (24 ± 30 cm/s, P < 0·0001), with similar declines in all groups. Clinical stroke occurred in five children, one in Group 1, none in Group 2, and four in Group 3, P = 0·0032, comparing group incidence rates. Brain MRI/MRA was stable in children without clinical stroke. EXTEND documents the feasibility and benefits of hydroxycarbamide at MTD to lower TCD velocities and reduce stroke risk in children with SCA and no history of primary stroke in low-resource settings without transfusion management.

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.

How Free Is Free Health Care? An Assessment of Universal Health Coverage Among Jamaicans with Sickle Cell Disease

Purpose: In an effort to transition toward universal health coverage (UHC), Jamaica abolished user fees at all public health facilities in 2008. We aimed to determine the extent of out-of-pocket payments (OPPs) and the other cost barriers to UHC among patients with sickle cell disease (SCD). Methods: Patients presenting to the Sickle Cell Unit in Kingston, Jamaica, for routine care between October 2019 and August 2020 were consecutively recruited and interviewed about their latest hospitalization within the previous 4 weeks. Parents or guardians completed the questionnaire on behalf of pediatric patients. The questionnaire included the Patient Satisfaction Questionnaire Short Form (PSQ)-18 and the health module of the Jamaica Survey of Living Conditions. Results: There were 103 patients with ages ranging from 7 months to 56 years (51.5% female, 60.2% public hospitalizations, and 54.4% pediatric). The modal income (J$6200-$11,999 per week) was similar to the minimum wage and 48.5% lived in overcrowded households. Government drug-subsidy cards were owned by 39.8%. OPPs were made by 19.4% of persons for items and tests that were unavailable at public facilities. There were no costs reported by 69.6%, who visited public pharmacies. Similarly, the cost of admission to public hospitals was free for 95.4% of subjects. Using public transportation, private hospitalization, and having more disease complications were predictive of a perception that health care is unaffordable. Conclusion: Most SCD subjects reported no expense with public hospitalizations; however, approximately one in five reported OPPs. Efforts are needed to increase the availability of subsidized items, and the use of drug-subsidy cards, to improve UHC.

Screening for sickle cell disease in newborns: a systematic review

BACKGROUND

Sickle cell disease (SCD) is an inherited autosomal recessive disorder caused by the replacement of normal haemoglobin (HbA) by mutant Hb (sickle Hb, HbS). The sickle-shaped red blood cells lead to haemolysis and vaso-occlusion. Especially in the first years of life, patients with SCD are at high risk of life-threatening complications. SCD prevalence shows large regional variations; the disease predominantly occurs in sub-Saharan Africa. We aimed to systematically assess the evidence on the benefit of newborn screening for SCD followed by an earlier treatment start.

METHODS

We systematically searched bibliographic databases (MEDLINE, EMBASE, Cochrane Databases, and the Health Technology Assessment Database), trial registries, and other sources to identify systematic reviews and randomised controlled trials (RCTs) or non-randomised trials on newborn screening for SCD. The last search was in 07/2020. Two reviewers independently reviewed abstracts and full-text articles and assessed the risk of bias of the studies included. Data were extracted by one person and checked by another. As meta-analyses were not possible, a qualitative summary of results was performed.

RESULTS

We identified 1 eligible study with direct evidence: a Jamaican retrospective study evaluating newborn screening for SCD followed by preventive measures (prevention of infections and education of parents). The study included 500 patients with SCD (intervention group, 395; historical control group, 105). Although the results showed a high risk of bias, the difference between the intervention and the control group was very large: mortality in children decreased by a factor of about 10 in the first 5 years of life (0.02% in the intervention group vs. 0.19% in the control group, odds ratio 0.09; 95% confidence interval [0.04; 0.22], p < 0.001).

CONCLUSION

The results are based on a single retrospective study including historical controls. However, the decrease of mortality by a factor of 10 is unlikely to be explained by bias alone. Therefore, in terms of mortality, data from this single retrospective study included in our systematic review suggest a benefit of newborn screening for SCD (followed by preventive measures) versus no newborn screening for SCD (weak certainty of conclusions).

The risk of acute events among patients with sickle cell disease in relation to early or late initiation of care at a specialist center: evidence from a retrospective cohort study

BACKGROUND

The greatest disease burden of sickle cell disease occurs early in life. Understanding factors that reduce disease related events in this period is therefore important. Hence, we assessed the impact of early care at a specialist center on the incidence of acute events during the first five years.

METHODS

This was a retrospective cohort study among Jamaican children with sickle cell disease. Medical records of patients born January, 2004 to December, 2009, who were registered at the Sickle Cell Unit, a specialist care facility, were abstracted for dates of initiation to care, first occurrence and frequency of the outcomes of interest (vaso-occlusive crises, acute splenic sequestration, acute chest syndrome, and infection). Patients were classified according to whether initiation of care was before (early) or after 5 months of age (late). Using standardized t-tests, χ2 tests, and a multiple-failure survival analysis the rates of acute events between groups were compared.

RESULTS

Of the total study group (n= 290), homozygous sickle cell disease accounted for 97% and 95% of the early (n=113) and late groups (n=177) respectively. The mean age of presentation in the early and late group was 0.2 and 2.3 years (p<0.01), with a mean length of follow-up of 5.2 and 3.2 years respectively (p<0.01). Vaso-occlusive crisis (n=880) and acute chest syndrome (n= 571) together accounted for 91.6% of the total number of events (n=1584). The risk of vaso-occlusive crisis and acute chest syndrome (among patients who presented with these acute events) was significantly higher in the "late" group, by 43% (Incidence rate ratio, (IRR) = 1.43, p<0.001); 95% CI (1.18-1.72) and 40% (IRR=1.40. p=0.002), 95% CI (1.12-1.75) respectively compared to "early" group. There was no difference in risk between groups for acute splenic sequestration and infection among persons presenting with these events.

CONCLUSION

The risk of acute events in children with sickle cell disease exposed to early care at a specialist care is significantly less. Therefore, widespread screening with rapid referral to a specialist center stands to reduce substantial morbidity in Jamaica and other regions with high prevalence of sickle cell disease.

The clinical characteristics of Congolese children and adolescents suffering from sickle-cell anemia are marked by the high frequencies of epistaxis compared to Western series

Background: Sickle cell anaemia (SCA) is the most common genetic diseases in the Democratic Republic of Congo (DRC). It is estimated 30,000 to 40,000 neonates with SCA are born annually. Despite this high incidence rate, and the severity of the Bantu haplotype found in Congolese patients, major clinical characteristics remain poorly defined. The objective of this study was to assess the clinical and haematological profile of the SCA in patients less than 24 years of age. Methods: A cross-sectional study was conducted in Kinshasa, the large city of the DRC. Patients were consecutively selected in three health institutions. Results: The study includes 256 sickle cell patients. The mean age of 8.4 (SD = 4.9) years. The Hand-foot syndrome was most common (52.7%) first presentation revealing the disease in our series. The most prevalent crises found in our series were vaso-occlusive crises (VOC) in 170 cases (66.4%) and severe hemolysis in 136 cases (53.1%). Splenic sequestration was noted in 19 cases (7.4%). The age at the first pain crisis was 18.2±15.2 months-of-age and the age at the first transfusions was 29.2±27.6 months-of -age. The most common signs associated with sickle cell disease in our series were hepatomegaly (53.9%), splenomegaly (41.7%), and adenotonsillar hypertrophy (34.8%). Epistaxis was reported in 9.4%. Conclusion: The clinical course of patients in DRC was comparable to reports from Western countries, with the notable exception of epistaxis which was significantly higher in patients in the DRC.

Newborn Screening for Sickle Cell Disease in the Caribbean: An Update of the Present Situation and of the Disease Prevalence

The region surrounding the Caribbean Sea is predominantly composed of island nations for its Eastern part and the American continental coast on its Western part. A large proportion of the population, particularly in the Caribbean islands, traces its ancestry to Africa as a consequence of the Atlantic slave trade during the XVI-XVIII centuries. As a result, sickle cell disease has been largely introduced in the region. Some Caribbean countries and/or territories, such as Jamaica and the French territories, initiated newborn screening (NBS) programs for sickle cell disease more than 20 years ago. They have demonstrated the major beneficial impact on mortality and morbidity resulting from early childhood care. However, similar programs have not been implemented in much of the region. This paper presents an update of the existing NBS programs and the prevalence of sickle cell disease in the Caribbean. It demonstrates the impact of the Caribbean Network of Researchers on Sickle Cell Disease and Thalassemia (CAREST) on the extension of these programs. The presented data illustrate the importance of advocacy in convincing policy makers of the feasibility and benefit of NBS for sickle cell disease when coupled to early care.

Knowledge, beliefs and practices regarding sickle cell eye disease of patients at the sickle cell unit, Jamaica

Introduction

Sickle cell disease can result in visually threatening eye disease (proliferative sickle cell retinopathy). This can be prevented with timely eye screening. It is important for patients to understand their role. Our research is to determine the knowledge, beliefs and practices (KBP) regarding eye disease of Sickle Cell patients and the impact of genotype, demographic and socio-economic status.

Methods

Cross-sectional study at the Sickle Cell Unit, Jamaica during May 2016. Consecutive non-pregnant adults (>18 years of age) attendees, who were not acutely unwell, were invited to participate. A 26-item single interviewer administered questionnaire was used to obtain socio-demographic data, highest level of education completed, employment status, sickle cell genotype, if known, frequency of clinic attendance and patients' knowledge, beliefs and practices. Ten of these were yes/no questions, whereas eight required that they choose correct answers from four choices.

Results

One hundred subjects were recruited, 72% had homozygous SS disease. Their ages ranged from 18-63 years (mean 34.1 years, SD11.3). Fifty six percent were female. Most (75%) had achieved at least secondary education. The majority (62%) were unemployed. The mean belief score was 3.6/6(60%) and the mean knowledge and practice scores were 3.3/7(47%) and 2.2/5(44%) respectively. Milder genotypes had higher knowledge scores vs the more severe genotypes (4.0 vs 3.2, P=0.013). Only 28% had regular eye examinations; less than 50% had seen an ophthalmologist in the past year. Practice scores were higher in employed than in unemployed patients (2.6 vs 1.9, (P=0.04)). Employed patients were more likely than the unemployed to see their eye doctor for regular eye “examinations” (42.1% vs 19.4%, χ2=6.0, P=0.02). The practice and knowledge scores correlated (r²=0.363, P<0.001) and belief score (r²=0.304, P =0.002), except where 98% believed they should see an ophthalmologist annually, but only 42% did, and 21% had never.

Conclusion

Knowledge scores were fair, however, the practice was not always in keeping with knowledge.

The Use of HPLC as a Tool for Neonatal Cord Blood Screening of haemoglobinopathy: A Validation Study

Background

Newborn cord blood screening identifies infants with underlying haemoglobinopathies before they develop the characteristic symptoms or sequelae.

Aims

This study was performed to validate the interpretation high-performance chromatography (HPLC) along with complete blood count (CBC) results as a tool for universal neonatal screening of hemoglobin disorders in Oman.

Methods

HPLC and CBC data on subjects who participated in the National Neonatal screening program at birth were obtained from archival records. The results recorded at birth were compared with a second study performed on the same subjects, after approval from the local medical research and ethics committee.

Results

Only 290 subjects from amongst the original cohort of 3740 newborns could be recalled between April 2010 to March 2011, to repeat HPLC and CBC, as well as perform confirmatory DNA studies, wherever necessary. All these subjects had been documented to show an initial abnormal result. 31 cases who had no HbA at birth on HPLC were confirmed as either homozygous β-thalassaemia major (n=5 subjects) or homozygous sickle cell anemia (n=26 subjects) by appropriate DNA analysis. Additionally, amongst 151 subjects, 72 subjects were studied in the initial study by Hb Bart’s quantitation using the alpha thalassaemia short program at birth. In this cohort, 42 subjects with Hb Bart’s >1% at birth could be confirmed as having either deletional or non-deletional thalassaemia by GAP PCR studies. No case of HbH was detected in this cohort. Further, carrier status for structural hemoglobin variants (HbS, HbC, HbD, HbE) (n=67) and beta thalassaemia allele with low HbA at birth (n=29 out of 41) were confirmed by relevant molecular studies.

Conclusions

The study validated the earlier observation by 100% concordance with the results of CBC and HPLC. Presence of Hb Bart’s at birth does not always mean the presence of alpha thalassemia, as subjects with Hb Bart’s below 1% by quantitation, were shown to be normal by molecular studies.

Neonatal Screening for Sickle Cell Disease in Belgium for More than 20 Years: An Experience for Comprehensive Care Improvement

Our previous results reported that compared to sickle cell patients who were not screened at birth, those who benefited from it had a lower incidence of a first bacteremia and a reduced number and days of hospitalizations. In this context, this article reviews the Belgian experience on neonatal screening for sickle cell disease (SCD). It gives an update on the two regional neonatal screening programs for SCD in Belgium and their impact on initiatives to improve clinical care for sickle cell patients. Neonatal screening in Brussels and Liège Regions began in 1994 and 2002, respectively. Compiled results for the 2009 to 2017 period demonstrated a birth prevalence of sickle cell disorder above 1:2000. In parallel, to improve clinical care, (1) a committee of health care providers dedicated to non-malignant hematological diseases has been created within the Belgian Haematology Society; (2) a clinical registry was implemented in 2008 and has been updated in 2018; (3) a plan of action has been proposed to the Belgian national health authority. To date, neonatal screening is not integrated into the respective Belgian regional neonatal screening programs, the ongoing initiatives in Brussels and Liège Regions are not any further funded and better management of the disease through the implementation of specific actions is not yet perceived as a public health priority in Belgium.

Causes of death and early life determinants of survival in homozygous sickle cell disease: The Jamaican cohort study from birth

Globally, the majority of persons born with sickle cell disease do not have access to hydroxyurea or more expensive interventions. The objectives were to estimate the survival in homozygous sickle cell disease, unbiased by symptomatic selection and to ascertain the causes of death in a pre-hydroxyurea population. The utility of early life biomarkers and genetically determined phenotypes to predict survival was assessed. A cohort study based on neonatal diagnosis was undertaken at the Sickle Cell Unit, a specialist clinic delivering care to persons with sickle cell disease in Jamaica. Screening of 100,000 deliveries detected 315 babies with homozygous sickle cell disease of whom 311 have been followed from birth for periods up to 43 years. Pneumococcal prophylaxis and teaching mothers splenic palpation were important, inexpensive interventions. Anticipatory guidance, routine care and out-patient acute care were provided. Each participant was classified as alive, dead, or defaulted (usually emigration). Causes of death were ascertained from clinical records and/or post-mortem reports. Survival was assessed using the Kaplan-Meier function. Sex-adjusted Cox semi-parametric proportional hazards and Weibull modelling were used to assess the effects on survival of biomarkers.

Survival to 40 years was 55.5% (95% CI 48.7% to 61.7%). Acute Chest Syndrome (n = 31) and septicemia (n = 14) were significant causes of death at all ages. Acute splenic sequestration (n = 12) was the most common cause of early deaths. Survival was significantly shorter in those with lower hemoglobin at 1 year, high total nucleated count at 1 year, and a history of dactylitis ever.

In these hydroxyurea naïve patients, survival into midlife was common. Causes of death were often age specific and some may be preventable. Early life biomarkers predictive of decreased survival in SS disease identify a patient group likely to benefit from close clinical supervision and potentially high risk therapies.

The Use of Dried Blood Spots: A Potential Tool for the Introduction of a Neonatal Screening Program for Sickle Cell Anemia in Zambia

Context

Sickle cell disease is a group of hemoglobin (Hb) disorders resulting from the inheritance of the sickle β-globin gene. It is the most common pathological Hb mutation worldwide with 75% being born in Sub-Saharan Africa.

Aims

This study aims to determine if dried blood spots (DBSs) can be used for diagnosis of sickle cell in newborns. In Zambia, there is no neonatal screening program for sickle cell anemia (SCA), yet it has been proved that early diagnosis by newborn screening (NBS) using DBSs and access to comprehensive care results in survival to adulthood of over 96% of sickle cell patients.

Settings and Design

A cross-sectional study was carried out at the University Teaching Hospital to determine whether DBSs can be used to diagnose sickle cell using Hb electrophoresis.

Subjects and Methods

Results from DBSs stored for 2 weeks were then compared to those obtained using freshly collected whole blood.

Statistical Analysis Used

To evaluate performance characteristics, the following values were used: true positive, false positive, true negative, and false negative.

Results

Ninety-seven participants were included in this study. DBSs had a sensitivity of 100%, a specificity of 94.7%, positive predictive value of 96.7%, negative predictive value of 100%, overall efficiency of 97.9%, and a Kappa r², P < 0.0001 in comparison to fresh whole blood which we used as the gold standard.

Conclusions

The use of DBSs can be recommended for NBS of SCA in Zambia due to its high sensitivity, specificity, and stability of hemoglobin.

Prevalence of sickle cell disease among Grenadian newborns

Objective To establish the birth prevalence of sickle cell disease in Grenada, with a view to assess the requirement for a population-based neonatal screening programme. Methods A two-year pilot neonatal screening programme, involving the Ministry of Health of Grenada, the Sickle Cell Association of Grenada, and the diagnostic laboratory of hemoglobinopathies of the University Hospital of Guadeloupe, was implemented in 2014-2015 under the auspices of the Caribbean Network of Researchers on Sickle Cell Disease and Thalassemia. Results Analysis of 1914 samples processed identified the following abnormal phenotypes: 10 FS, 2 FSC, 183 FAS, 63 FAC. These data indicate β^s and β^c allele frequencies of 0.054 and 0.018, respectively. Conclusion Neonatal screening conducted in the framework of this Caribbean cooperation can allow rapid detection and earlier management of affected children.

Simultaneous point-of-care detection of anemia and sickle cell disease in Tanzania: the RAPID study

Both anemia and sickle cell disease (SCD) are highly prevalent across sub-Saharan Africa, and limited resources exist to diagnose these conditions quickly and accurately. The development of simple, inexpensive, and accurate point-of-care (POC) assays represents an important advance for global hematology, one that could facilitate timely and life-saving medical interventions. In this prospective study, Robust Assays for Point-of-care Identification of Disease (RAPID), we simultaneously evaluated a POC immunoassay (Sickle SCAN™) to diagnose SCD and a first-generation POC color-based assay to detect anemia. Performed at Bugando Medical Center in Mwanza, Tanzania, RAPID tested 752 participants (age 1 day to 20 years) in four busy clinical locations. With minimally trained medical staff, the SCD POC assay diagnosed SCD with 98.1% sensitivity and 91.1% specificity. The hemoglobin POC assay had 83.2% sensitivity and 74.5% specificity for detection of severe anemia (Hb ≤ 7 g/dL). Interobserver agreement was excellent for both POC assays (r = 0.95-0.96). Results for the hemoglobin POC assay have informed the second-generation assay design to be more suitable for low-resource settings. RAPID provides practical feasibility data regarding two novel POC assays for the diagnosis of anemia and SCD in real-world field evaluations and documents the utility and potential impact of these POC assays for sub-Saharan Africa.

Newborn Screening for Sickle Cell Disease in St. Vincent and the Grenadines: Results of a Pilot Newborn Screening Program

Objective: To pilot a newborn screening program for sickle cell disease (SCD) in St. Vincent and the Grenadines using a novel partnership method to determine the feasibility of a universal newborn screening program in this country. Methods: A prospective study of mothers and their newborns was conducted between January 1, 2015, and November 1, 2015, at the country's main hospital. Mothers of infants born at this hospital were offered screening for SCD for their infants. If accepted, the newborn's heel-stick blood specimen was obtained and mailed to the South Carolina Department of Health and Environmental Control Newborn Screening Laboratory for testing. Samples were analyzed for variant hemoglobins using standard laboratory techniques and results were communicated to local physicians. Feasibility was determined by a benchmark of having >50% of SCD patients receive the diagnosis and initiate disease-specific care by 3 months of age. Descriptive statistics were completed using SAS 9.4. Results: There were 1147 newborn infants screened for SCD. Of these, 123 (10.7%) had results indicative of sickle trait and 3 patients (0.3%) were diagnosed with SCD: 1 with HbSS and 2 with HbSC. All 3 patients with SCD received treatment before 3 months of age. Conclusions: A newborn screening program is feasible in this population when partnered with an established newborn screening laboratory.

The pressing need for point-of-care diagnostics for sickle cell disease: A review of current and future technologies

Sickle cell disease (SCD) is a common and life threatening inherited blood disorder, affecting over 300,000 newborns per year. Over 75% of SCD births occur in sub-Saharan Africa, where the lack of timely and accurate diagnosis results in premature death within the first few years of life for a majority of affected infants. Current methods to diagnosis SCD require expensive laboratory equipment and reagents, and adequately trained laboratory personnel. In addition, test results are often delayed due to transport and batching of samples in a central laboratory. Financial and technical limitations often preclude any form of SCD laboratory testing at the local level in regions where SCD is most prevalent. There has been a recent surge of interest in addressing the global burden of SCD, including improving and optimizing diagnostic capacities. Largely stimulated by a funding opportunity from the NIH, several point-of-care diagnostics have been developed for SCD with a focus on developing devices that are inexpensive, simple, and practical in limited resource settings. In this manuscript, we review the global burden of SCA, including the rationale for the development of POC assays, and carefully review the POC devices currently in development.

Impact of prematurity and immigration on neonatal screening for sickle cell disease

Background

Others have described a relationship between hemoglobin A levels and gestational age, gender and ethnicity. However, studies are needed to determine normal cut-off points considering these factors. To address this issue we designed a study to determine the percentiles of normality of neonatal hemoglobin A levels taking these factors into account.

Methods

This cross-sectional study involved 16,025 samples for sickle cell disease screening in the province of Alicante, Spain, which has a high immigration rate. The primary variable was hemoglobin A, and the secondary variables were gender, gestational age (preterm and full term) and maternal origin (Spain, the rest of Europe, North Africa, Sub-Saharan Africa, Latin America and Asia). Percentiles of normality (1 and 99) were obtained by origin, gender and gestational age using quantile regression models and bootstrap samples. The association between these percentiles of normality and altered levels (≥1%) of hemoglobin E was analyzed. We obtained the percentiles of normality (1 and 99) for each maternal origin, gender and gestational age.

Results

Of a total of 88 possible E carriers, 65 had above-normal hemoglobin A levels (74%). The levels of normality for hemoglobin A varied greatly according to the maternal origin and gestational age.

Conclusion

With the levels of normality that we established it is possible to discard samples with unrecorded blood transfusions. Our methodology could be applied to other diseases in the neonatal screening.

Newborn screening for sickle cell disease in Jamaica: logistics and experience with umbilical cord samples

The study aims to describe the logistics and results of a programme for newborn screening for sickle cell disease based on samples from the umbilical cord. Samples were dried on Guthrie cards and analysed by high pressure liquid chromatography. All suspected clinically significant abnormal genotypes were confirmed by age 4-6 weeks with family studies and then recruited to local sickle cell clinics. The programme has screened 66,833 samples with the sickle cell trait in 9.8 % and the HbC trait in 3.8 %. Sickle cell syndromes occurred in 407 babies (204 SS, 148 SC, 35 Sbeta⁺ thalassaemia, 6 Sbeta^o thalassaemia, 6 sickle cell-variants, 8 sickle cell-hereditary persistence of fetal haemoglobin) and HbC syndromes in 42 (22 CC, 14 Cbeta⁺ thalassaemia, 1 Cbeta^o thalassaemia, 5 HbC- hereditary persistence of fetal haemoglobin). Focusing on the year 2015, screening was performed in 15,408, compliance with sample collection was 98.1 %, and maternal contamination occurred in 335 (2.6 %) but in only 0.05 % did diagnostic confusion require patient recall and further tests. This model of newborn screening for sickle cell disease is accurate, robust and economic. It is hoped that it may be helpful for other societies with high prevalence of abnormal haemoglobins and limited resources, who are planning to embark on newborn screening for sickle cell disease.

Family, Community, and Health System Considerations for Reducing the Burden of Pediatric Sickle Cell Disease in Uganda Through Newborn Screening

Sickle cell disease (SCD) is associated with high mortality for children under 5 years of age in sub-Saharan Africa. Newborn sickle screening program and enhanced capacity for SCD treatment are under development to reduce disease burden in Uganda and elsewhere in the region. Based on an international stakeholder meeting and a family-directed conference on SCD in Kampala in 2015, and interviews with parents, multinational experts, and other key informants, we describe health care, community, and family perspectives in support of these initiatives. Key stakeholder meetings, discussions, and interviews were held to understand perspectives of public health and multinational leadership, patients and families, as well as national progress, resource needs, medical and social barriers to program success, and resources leveraged from HIV/AIDS. Partnering with program leadership, professionals, patients and families, multinational stakeholders, and leveraging resources from existing programs are needed for building successful programs in Uganda and elsewhere in sub-Saharan Africa.

CAREST--Multilingual Regional Integration for Health Promotion and Research on Sickle Cell Disease and Thalassemia

Sickle cell disease (SCD) is a significant problem in the Caribbean, where many individuals have African and Asian forebears. However, reliable prevalence data and specific health care programs for SCD are often missing in this region. Closer collaboration between Caribbean territories initiated in 2006 to set up strategies to promote better equity in the health care system for SCD patients led to the formation of CAREST: the Caribbean Network of Researchers on Sickle Cell Disease and Thalassemia. We present the effectiveness of collaborations established by CAREST to promote SCD newborn screening programs and early childhood care, to facilitate health worker training and approaches for prevention and treatment of SCD complications, and to carry out inter-Caribbean research studies.

Characteristics of a rapid, point-of-care lateral flow immunoassay for the diagnosis of sickle cell disease

Sickle cell disease (SCD) is a common and life-threatening hematological disorder, affecting approximately 400,000 newborns annually worldwide. Most SCD births occur in low-resource countries, particularly in sub-Saharan Africa, where limited access to accurate diagnostics results in early mortality. We evaluated a prototype immunoassay as a novel, rapid, and low-cost point-of-care (POC) diagnostic device (Sickle SCAN) designed to identify HbA, HbS, and HbC. A total of 139 blood samples were scored by three masked observers and compared to results using capillary zone electrophoresis. The sensitivity (98.3-100%) and specificity (92.5-100%) to detect the presence of HbA, HbS, and HbS were excellent. The test demonstrated 98.4% sensitivity and 98.6% specificity for the diagnosis of HbSS disease and 100% sensitivity and specificity for the diagnosis of HbSC disease. Most variant hemoglobins, including samples with high concentrations of HbF, did not interfere with the ability to detect HbS or HbC. Additionally, HbS and HbC were accurately detected at concentrations as low as 1-2%. Dried blood spot samples yielded clear positive bands, without loss of sensitivity or specificity, and devices stored at 37°C gave reliable results. These analyses indicate that the Sickle SCAN POC device is simple, rapid, and robust with high sensitivity and specificity for the detection of HbA, HbS, and HbC. The ability to obtain rapid and accurate results with both liquid blood and dried blood spots, including those with newborn high-HbF phenotypes, suggests that this POC device is suitable for large-scale screening and potentially for accurate diagnosis of SCD in limited resource settings.

Neonatal Screening and the Clinical Outcome in Children with Sickle Cell Disease in Central India

BACKGROUND

Sickle cell disease (SCD) is a major health burden in India. The objective of the study was to establish a neonatal screening program and to understand the clinical course of children with SCD in central India.

METHODS AND FINDINGS

Pregnant mothers were screened for sickle hemoglobin using the solubility test. Babies were screened by high performance liquid chromatography if the mother was positive for sickle hemoglobin. The diagnosis was confirmed by molecular analysis. They received early prophylactic treatment and vaccination. Of 2134 newborns screened, 104 were sickle homozygous (SS), seven had sickle β-thalassemia (S-β thal) and 978 were sickle heterozygous (AS). The other hemoglobin abnormalities detected included HbS-δβ thalassemia-1, HbSD disease-2, HbE traits-5, β-thalassemia traits-4, alpha chain variants-3 and HbH disease-1.These babies were followed up regularly for hematological and clinical evaluation. Pain, severe anemia requiring blood transfusions and acute febrile illness were the major complications with 59.7, 45.1 and 42.6 cases per 100 person years. Fetal hemoglobin (HbF) levels were inversely associated with vaso-oclussive crisis (VOC) and severe anemia while presence of alpha thalassemia increased the rate of painful events and sepsis. Six early deaths occurred among the SS babies.

CONCLUSION

A systematic follow up of this first newborn SCD cohort in central India showed that 47% of babies presented within 1 year of age. In spite of the presence of the Arab-Indian haplotype many babies had severe manifestations.

A Cost-Effectiveness Analysis of a Pilot Neonatal Screening Program for Sickle Cell Anemia in the Republic of Angola

OBJECTIVE

To assess the cost-effectiveness of a pilot newborn screening (NBS) and treatment program for sickle cell anemia (SCA) in Luanda, Angola.

STUDY DESIGN

In July 2011, a pilot NBS and treatment program was implemented in Luanda, Angola. Infants identified with SCA were enrolled in a specialized SCA clinic in which they received preventive care and sickle cell education. In this analysis, the World Health Organization (WHO) and generalized cost-effectiveness analysis methods were used to estimate gross intervention costs of the NBS and treatment program. To determine healthy life-years (HLYs) gained by screening and treatment, we assumed NBS reduced mortality to that of the Angolan population during the first 5 years based upon WHO and Global Burden of Diseases Study 2010 estimates, but provided no significant survival benefit for children who survive through age 5 years. A secondary sensitivity analysis with more conservative estimates of mortality benefits also was performed. The costs of downstream medical costs, including acute care, were not included.

RESULTS

Based upon the costs of screening 36,453 infants and treating the 236 infants with SCA followed after NBS in the pilot project, NBS and treatment program is projected to result in the gain of 452-1105 HLYs, depending upon the discounting rate and survival assumptions used. The corresponding estimated cost per HLY gained is $1380-$3565, less than the gross domestic product per capita in Angola.

CONCLUSIONS

These data demonstrate that NBS and treatment for SCA appear to be highly cost-effective across all scenarios for Angola by the WHO criteria.

The lived experiences of adolescents with sickle cell disease in Kingston, Jamaica

Aim

To explore the lived experiences of adolescents with sickle cell disease, in Kingston, Jamaica.

Method

A descriptive qualitative design was used for this research. In-depth interviews were conducted with six adolescents with sickle cell disease at a Sickle Cell Unit operated by the University of the West Indies. Interviews were audiotaped, transcribed, and thematically analyzed.

Results

The majority of the adolescents demonstrated a positive self-concept. They reported strong family, school, and peer support which made them feel accepted. All were actively engaged in social activities such as parties, but had challenges participating in sporting activities. Various coping strategies were utilized to address challenges of the disease including praying, watching television, and surfing the Internet.

Conclusion

Sickle cell disease can be very challenging for the adolescent, but with positive self-concept and increased social support, especially from family and peers, these adolescents were able to effectively cope with their condition and live productive lives.

Impact of a Comprehensive Sickle Cell Center on Early Childhood Mortality in a Developing Country: The Jamaican Experience

OBJECTIVE

To compare mortality in children <5 years of age with sickle cell disease (SCD) in Jamaica, a resource-limited country, diagnosed by newborn screening and managed in a comprehensive care facility, to that of the general population.

STUDY DESIGN

The study was carried out at the Sickle Cell Unit in Kingston, Jamaica. We determined the status (dead/alive) at age 5 years in a cohort of 548 children with SCD diagnosed by newborn screening and managed at the Sickle Cell Unit during the period November 1995 to December 2009. The standardized mortality ratio was calculated using World Health Organization life tables for reference mortality.

RESULTS

Eight deaths (1.5%) occurred in children <5 years of age during the study period. The mean age at death was 2.0 ± 1.5 years. The overall mortality incidence in children <5 years of age was 3.1 (95% CI 1.6, 6.2) per 1000 person-years with a standardized mortality ratio of 0.52 (95% CI 0.3, 1.0).

CONCLUSIONS

Mortality in children <5 years of age with SCD diagnosed at birth and managed at a comprehensive care clinic in Jamaica is equivalent to that of the general population. Children with SCD, a highly vulnerable population, can be effectively managed, even in resource-limited environments.

Improving survival for children with sickle cell disease: newborn screening is only the first step

Invited commentary on 'Survival of children with sickle cell disease in the comprehensive newborn screening programme in Minas Gerais, Brazil', Sabarense et al.

A Survey of the Pain Management of Acute Painful Crisis among Patients with Sickle Cell Disease at Two Centres in Jamaica

OBJECTIVES

The aim of this survey was to establish the pain management approaches to acute painful crisis (APC) in sickle cell patients at two healthcare facilities and to compare with available guidelines.

METHODS

A multi-centre observational survey of the management of APC in sickle cell patients was conducted. Data were collected at the Sickle Cell Unit (SCU), Tropical Medicine Research Institute (TMRI) and Accident and Emergency Department (A&E), University Hospital of the West Indies.

RESULTS

One hundred episodes of uncomplicated APC involving 81 patients managed at the SCU clinic and 64 episodes at the A&E in a total of 28 patients were included in the data set. Drugs used at the SCU included oral morphine, codeine and paracetamol and intramuscular diclofenac. At the A&E, parenteral morphine and pethidine were most commonly used. At the SCU, the mean time to initiation of analgesics was 38 minutes (IQR 25 to 50 minutes); at the A&E, this was 111 minutes (IQR 50 to 150 minutes). At the SCU, the mean duration of stay (DOS) was 2.9 hours (IQR 1.9 to 3.8 hours) with 94% of the patients being discharged home. At the A&E, the mean DOS was 13.0 hours (IQR 8.3 to 16.9 hours) with 93% of the patients being discharged home. The A&E patient group contained multiple high frequency presenters. Documentation of pain severity scores was inconsistent.

CONCLUSION

The findings of the survey indicate that the management of APC at the two centres is substantially different. Further study is required to investigate patient satisfaction, centre preference and analgesic therapy efficacy.

Newborn screening for sickle cell disease in Jamaica: a review - past, present and future

Newborn screening (NBS) for sickle cell disease (SCD) has occurred in Jamaica since 1973 in two periods, the most recent being since 1995. As a result of NBS, significant lessons have been learnt about management of the disease. Additionally, significant improvements in morbidity and mortality of children affected with the disease have occurred because of the implementation of simple interventions. Unfortunately, in a country where the burden of disease is high compared to other countries, only approximately 40% of children born in Jamaica currently benefit from NBS. As such, the future of NBS for SCD in Jamaica lies in island-wide screening. There are challenges including the lack of appropriate governance and policy structures, the technology for high-volume processing and comprehensive care clinics throughout the island. On the other hand, the significant strides made in disease management, the strength and model of care of the Sickle Cell Unit, delicately balancing limited resources and increased survival cannot be disparaged. Therefore, consistent with the World Health Organization's recommendation, we are working toward achieving island-wide screening for SCD, to ensure equitable access to continued improvements in morbidity, mortality and quality of life.

Global migration and the changing distribution of sickle haemoglobin: a quantitative study of temporal trends between 1960 and 2000

BACKGROUND

Changes in the geographical distribution of genetic disorders are often thought to happen slowly, especially when compared with infectious diseases. Whereas mutations, genetic drift, and natural selection take place over many generations, epidemics can spread through large populations within a few days or weeks. Nevertheless, population movements can interfere with these processes, and few studies have been done of their eff ect on genetic disorders. We aimed to investigate the eff ect of global migration on the distribution of the sickle-cell gene-the most common and clinically significant haemoglobin structural variant.

METHODS

For each country, we extracted data from the World Bank’s Global Bilateral Migration Database about international human migrations between 1960 and 2000. We combined this information with evidence-based estimates of national HbS allele frequencies, generated within a Bayesian geostatistical framework, to analyse temporal changes in the net numbers of migrants, and classified countries with an index summarising these temporal trends.

FINDINGS

The number of international migrants increased from 92.6 million in 1960, to 165.2 million in 2000. The estimated global number of migrants with HbS increased from about 1.6 million in 1960, to 3.6 million in 2000. This increase was largely due to an increase in the number of migrants from countries with HbS allele frequencies higher than 10%, from 3.1 million in 1960, to 14.2 million in 2000. Additionally, the mean number of countries of origin for each destination country increased from 70 (SE 46) in 1960, to 98 (48) in 2000, showing an increasing diversity in the network of international migrations between countries. Our index of change map shows a patchy distribution of the magnitude of temporal changes, with the highest positive and negative values scattered across all continents.

INTERPRETATION

Global human population movements have had a substantial eff ect on the distribution of the HbS gene. Population movements can create a long-term burden on health-care systems. Our findings, which emphasise countries in which migration fluxes are changing the most, should increase awareness about the global burden of haemoglobinopathies and encourage policy makers to implement specific public health interventions, such as screening programmes and genetic counselling.

FUNDING

Wellcome Trust, European Research Council, Bill & Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases-National Institutes of Health, the Research and Policy for Infectious Disease Dynamics program, Fogarty International Center.

A prospective newborn screening and treatment program for sickle cell anemia in Luanda, Angola

Over 300,000 infants are born annually with sickle cell anemia (SCA) in sub-Saharan Africa, and >50% die young from infection or anemia, usually without diagnosis of SCA. Early identification by newborn screening (NBS), followed by simple interventions dramatically reduced the mortality of SCA in the United States, but this strategy is not yet established in Africa. We designed and implemented a proof-of-principle NBS and treatment program for SCA in Angola, with focus on capacity building and local ownership. Dried bloodspots from newborns were collected from five birthing centers. Hemoglobin identification was performed using isoelectric focusing; samples with abnormal hemoglobin patterns were analyzed by capillary electrophoresis. Infants with abnormal FS or FSC patterns were enrolled in a newborn clinic to initiate penicillin prophylaxis and receive education, pneumococcal immunization, and insecticide-treated bed nets. A total of 36,453 infants were screened with 77.31% FA, 21.03% FAS, 1.51% FS, and 0.019% FSC. A majority (54.3%) of affected infants were successfully contacted and brought to clinical care. Compliance in the newborn clinic was excellent (96.6%). Calculated first-year mortality rate for babies with SCA compares favorably to the national infant mortality rate (6.8 vs. 9.8%). The SCA burden is extremely high in Angola, but NBS is feasible. Capacity building and training provide local healthcare workers with skills needed for a functional screening program and clinic. Contact and retrieval of all affected SCA infants remains a challenge, but families are compliant with clinic appointments and treatment. Early mortality data suggest screening and early preventive care saves lives.

Universal newborn screening for haemoglobinopathies in Guadeloupe (French West Indies): A 27-year experience

Objectives

In Guadeloupe, an island in the French West Indies, a universal newborn screening programme for sickle cell disease and other abnormal haemoglobins was initiated in 1984. In 1990, a comprehensive sickle cell centre was established to carry on the management programme. We here report the main results from the newborn screening programme from 1984 to 2010, and consider how the establishment of the sickle cell centre affected the programme.

Methods

All blood samples were screened for the haemoglobinopathies using two reference methods in a single reference diagnosis laboratory. DNA analyses were also performed for confirmatory tests and analysis of the globin gene status.

Results

Between 1 January 1984 and 31 December 2010, 178,428 newborns were screened at birth, and 585 children were diagnosed with major sickle cell syndromes (ie. an overall incidence of 1 in 304 births). Sickle cell anaemia (haemoglobin SS disease) was the most frequently observed (1 in 575 births), followed by haemoglobin SC disease (1 in 771 births) and haemoglobin Sβ-thalassemia disease (1 in 4,243 births). Some other rare haemoglobin variants were also detected, the most common being HbDPunjab. The establishment of a comprehensive sickle cell centre resulted in a significant improvement in the screening coverage ( p < 0.001) and a significant reduction of the delay between diagnosis and the first medical visit ( p < 0.001).

Conclusion

The universal screening programme has made it possible to establish the incidence of the major sickle cell syndromes in Guadeloupe, and the management centre has improved its efficiency.

Global burden of sickle cell anaemia in children under five, 2010-2050: modelling based on demographics, excess mortality, and interventions

BACKGROUND

The global burden of sickle cell anaemia (SCA) is set to rise as a consequence of improved survival in high-prevalence low- and middle-income countries and population migration to higher-income countries. The host of quantitative evidence documenting these changes has not been assembled at the global level. The purpose of this study is to estimate trends in the future number of newborns with SCA and the number of lives that could be saved in under-five children with SCA by the implementation of different levels of health interventions.

METHODS AND FINDINGS

First, we calculated projected numbers of newborns with SCA for each 5-y interval between 2010 and 2050 by combining estimates of national SCA frequencies with projected demographic data. We then accounted for under-five mortality (U5m) projections and tested different levels of excess mortality for children with SCA, reflecting the benefits of implementing specific health interventions for under-five patients in 2015, to assess the number of lives that could be saved with appropriate health care services. The estimated number of newborns with SCA globally will increase from 305,800 (confidence interval [CI]: 238,400-398,800) in 2010 to 404,200 (CI: 242,500-657,600) in 2050. It is likely that Nigeria (2010: 91,000 newborns with SCA [CI: 77,900-106,100]; 2050: 140,800 [CI: 95,500-200,600]) and the Democratic Republic of the Congo (2010: 39,700 [CI: 32,600-48,800]; 2050: 44,700 [CI: 27,100-70,500]) will remain the countries most in need of policies for the prevention and management of SCA. We predict a decrease in the annual number of newborns with SCA in India (2010: 44,400 [CI: 33,700-59,100]; 2050: 33,900 [CI: 15,900-64,700]). The implementation of basic health interventions (e.g., prenatal diagnosis, penicillin prophylaxis, and vaccination) for SCA in 2015, leading to significant reductions in excess mortality among under-five children with SCA, could, by 2050, prolong the lives of 5,302,900 [CI: 3,174,800-6,699,100] newborns with SCA. Similarly, large-scale universal screening could save the lives of up to 9,806,000 (CI: 6,745,800-14,232,700) newborns with SCA globally, 85% (CI: 81%-88%) of whom will be born in sub-Saharan Africa. The study findings are limited by the uncertainty in the estimates and the assumptions around mortality reductions associated with interventions.

CONCLUSIONS

Our quantitative approach confirms that the global burden of SCA is increasing, and highlights the need to develop specific national policies for appropriate public health planning, particularly in low- and middle-income countries. Further empirical collaborative epidemiological studies are vital to assess current and future health care needs, especially in Nigeria, the Democratic Republic of the Congo, and India.

Sickle cell disease incidence among newborns in New York State by maternal race/ethnicity and nativity

PURPOSE

Sickle cell disease is estimated to occur in 1:300-400 African-American births, with higher rates among immigrants from Africa and the Caribbean, and is less common among Hispanic births. This study determined sickle cell disease incidence among New York State newborns stratified by maternal race/ethnicity and nativity.

METHODS

Newborns with confirmed sickle cell disease born to New York State residents were identified by the New York State newborn screening program for the years 2000-2008 and matched to birth records to obtain birth and maternal information. Annual incidence rates were computed and bivariate analyses were conducted to examine associations with maternal race/ethnicity and nativity.

RESULTS

From 2000 to 2008, 1,911 New York State newborns were diagnosed with sickle cell disease and matched to the birth certificate files. One in every 1,146 live births was diagnosed with sickle cell disease. Newborns of non-Hispanic black mothers accounted for 86% of sickle cell disease cases whereas newborns of Hispanic mothers accounted for 12% of cases. The estimated incidence was 1:230 live births for non-Hispanic black mothers, 1:2,320 births for Hispanic mothers, and 1:41,647 births for non-Hispanic white mothers. Newborns of foreign-born non-Hispanic black mothers had a twofold higher incidence of sickle cell disease than those born to US-born non-Hispanic black mothers (P < 0.001).

CONCLUSION

This study provides the first US estimates of sickle cell disease incidence by maternal nativity. Women born outside the United States account for the majority of children with sickle cell disease born in New York State. Such findings identify at-risk populations and inform outreach activities that promote ongoing, high-quality medical management to affected children.

A global perspective on sickle cell disease

The global burden of sickle cell disease (SCD) is now being increasingly realized. SCD poses a significant public health problem in sub-Saharan Africa, the Middle East, some regions of India, the Caribbean, and Brazil. In many of these regions, progress in the management of SCD has been slow. Long-term North-South and South-South partnerships between SCD professionals, funding agencies, governments, and industry are needed to help reduce the high disease burden in developing countries, through widespread SCD education, relevant research and implementation of evidence-based cost-effective interventions. A group of SCD professionals have responded with action by forming a global network.

Effectiveness of antenatal screening for sickle cell trait: the impact on women's self-report of sickle cell trait status

OBJECTIVES

The sickle gene frequency in the Jamaican population has not changed over a generation. It is unknown whether routine antenatal screening for sickle cell trait (SCT) has affected women's knowledge of their SCT status. The aim of this study was to compare the prevalence of self-reported SCT in parous women to the prevalence in nulliparous women, men and to the observed prevalence of SCT measured in an antenatal clinic.

METHODS

All participants in the nationally representative Jamaica Health and Lifestyle Survey 2008 were asked whether they had the SCT. The impact of gender, age, educational attainment, geographical location, and pregnancy on self-reported SCT were assessed. The prevalence of SCT in women attending a large antenatal clinic concurrently was compared to that reported by women of child-bearing age in the lifestyle survey.

RESULTS

Self-report significantly underestimated the prevalence of SCT (2·9% versus 10·1%, P<0·001). Those with secondary education were more likely than those with presecondary education (P = 0·01) and women more likely than men (3·2% versus 1·1%, P = 0·001) to report having SCT. Women who had been pregnant were no more likely than other women to report having SCT (3·1% versus 4·1%, P = 0·4).

CONCLUSIONS

Attendance at antenatal clinic where SCT screening is routine, is not associated with increased self-report of SCT. Screening programs must ensure that, as well as technically accurate screening, there is effective communication of the results of screening for SCT to those tested to help reduce the public health burden of sickle cell disease in tropical countries.

First case of Hb Fontainebleau with sickle haemoglobin and other non-deletional α gene variants identified in neonates during newborn screening for sickle cell disorders

OBJECTIVE

To evaluate the significance of non-deletional α gene variants identified in neonates during newborn screening for sickle cell disorders.

METHODS

1534 newborn babies were screened in the last 2 years for sickle cell disease using a targeted screening approach. Investigations included a complete blood count, high performance liquid chromatography analysis, cellulose acetate electrophoresis (pH 8.9), heat stability test, restriction digestion and Amplified Refractory Mutation System for confirmation of sickle haemoglobin (Hb S), α genotyping by multiplex PCR and DNA sequencing.

RESULTS

Three non-deletional α gene variants, Hb Fontainebleau, Hb O Indonesia and Hb Koya Dora, were identified in heterozygous condition in newborns. This is the first report of Hb Fontainebleau in association with Hb S. The baby had anaemia at birth (Hb 11.4 g/dl) with no cyanosis, icterus or need for transfusion. She had occipital encephalocoele and was operated on day 24 to remove the mass. The baby diagnosed with Hb O Indonesia in combination with Hb S also had a low haemoglobin level of 12.7 g/dl.

CONCLUSION

Newborn screening for sickle cell disorders also enabled us to identify three α globin chain variants. Two babies who inherited Hb Fontainebleau and Hb O Indonesia along with Hb S had reduced Hb levels at birth and need to be followed up.

Sickle cell disease in Africa: a neglected cause of early childhood mortality

Sickle cell disease (SCD) is common throughout much of sub-Saharan Africa, affecting up to 3% of births in some parts of the continent. Nevertheless, it remains a low priority for many health ministries. The most common form of SCD is caused by homozygosity for the β-globin S gene mutation (SS disease). It is widely believed that this condition is associated with very high child mortality, but reliable contemporary data are lacking. We have reviewed available African data on mortality associated with SS disease from published and unpublished sources, with an emphasis on two types of studies: cross-sectional population surveys and cohort studies. We have concluded that, although current data are inadequate to support definitive statements, they are consistent with an early-life mortality of 50%-90% among children born in Africa with SS disease. Inclusion of SCD interventions in child survival policies and programs in Africa could benefit from more precise estimates of numbers of deaths among children with SCD. A simple, representative, and affordable approach to estimate SCD child mortality is to test blood specimens already collected through large population surveys targeting conditions such as HIV, malaria, and malnutrition, and covering children of varying ages. Thus, although there is enough evidence to justify investments in screening, prophylaxis, and treatment for African children with SCD, better data are needed to estimate the numbers of child deaths preventable by such interventions and their cost effectiveness.