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

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

[Inflammatory rheumatic diseases in migrants]

The immigration of people from other countries or even from other continents represents new challenges even for rheumatologists. Although all inflammatory rheumatic diseases that occur in this country also exist in the countries of origin of immigrants, the frequencies are different. Diseases such as familial Mediterranean fever (FMF) or Behçet syndrome (BS) are rare in western Europe but are often more frequent than rheumatoid arthritis (RA) and spondylarthritis (SPA) in North Africa and Mediterranean countries. Furthermore, FMF is associated with the occurrence of spondyloarthritis, which is then frequently negative for the human leucocyte antigen B27 (HLA-B27). There is also an association with BS. Rheumatic fever also still occurs relatively frequently especially in African countries, whereas it is almost eradicated in Europe. Possible differential diagnoses such as rheumatic symptoms in genetically determined anemia or infections such as human immunodeficiency virus (HIV) infections, hepatitis, tuberculosis and parasitosis need to be considered as they are all much more frequent in the countries of origin of immigrants than in northwestern Europe. Last but not least, the treatment situation with modern diagnostic and treatment modalities is different in the countries of origin of the migrants, either because these possibilities are unavailable due to limited resources or because the situation has dramatically deteriorated due to acute events, such as the recent war in Ukraine.

Inverse Association between Iron Deficiency and Glycated Hemoglobin Levels in Ghanaian Adults-the RODAM Study

BACKGROUND

Glycated hemoglobin (HbA1c) is often used to diagnose type 2 diabetes (T2D), but studies show that iron deficiency (ID) is associated with elevated HbA1c in the absence of hyperglycemia. It is unknown whether ID prevalence varies between sub-Saharan African populations living in different locations and whether ID influences HbA1c levels in these populations.

OBJECTIVES

We assessed the prevalence of ID among Ghanaian migrants in Europe and nonmigrant Ghanaians, and the influence of ID on HbA1c categories among Ghanaians without T2D.

METHODS

We used the database from the cross-sectional RODAM (Research on Obesity and Diabetes among African Migrants) study. This contained data on 3377 Ghanaian men and women aged 25-70 y living in urban and rural Ghana and Ghanaian migrants living in Amsterdam, London, and Berlin. ID was defined as ferritin < 15 ng/mL or, if C-reactive protein was ≥5 mg/mL, as ferritin < 30 ng/mL according to the WHO. We used binary logistic regression to assess differences in ID between sites and its association with clinically defined HbA1c categories (<5.5%, ≥5.5% to <6.5%, ≥6.5%). Men and women were analyzed separately.

RESULTS

The prevalence of ID was higher in migrant [28.4%; adjusted OR (aOR): 3.08; 95% CI: 2.04, 4.65)] and urban (23.2%; aOR: 2.37; 95% CI: 1.56, 3.59) women than in rural women (11.9%). Among women, ID was associated with higher odds of HbA1c ≥ 5.5% to <6.5% in the absence of hyperglycemia (aOR: 1.43; 95% CI: 1.08, 1.87). This association was not found in men.

CONCLUSIONS

Further research is needed to identify factors underlying the high prevalence of ID among urban and migrant Ghanaian women, and the association of ID with HbA1c ≥ 5.5% to <6.5% in women. In addition, our study reinforces the need to consider iron concentrations if interpreting HbA1c among African populations.

Genetic structure of pharmacogenetic biomarkers in Brazil inferred from a systematic review and population-based cohorts: a RIBEF/EPIGEN-Brazil initiative

We present allele frequencies involving 39 pharmacogenetic biomarkers studied in Brazil, and their distribution on self-reported race/color categories that: (1) involve a mix of perceptions about ancestry, morphological traits, and cultural/identity issues, being social constructs pervasively used in Brazilian society and medical studies; (2) are associated with disparities in access to health services, as well as in their representation in genetic studies, and (3), as we report here, explain a larger portion of the variance of pharmaco-allele frequencies than geography. We integrated a systematic review of studies on healthy volunteers (years 1968-2017) and the analysis of allele frequencies on three population-based cohorts from northeast, southeast, and south, the most populated regions of Brazil. Cross-validation of results from these both approaches suggest that, despite methodological heterogeneity of the 120 studies conducted on 51,747 healthy volunteers, allele frequencies estimates from systematic review are reliable. We report differences in allele frequencies between color categories that persist despite the homogenizing effect of >500 years of admixture. Among clinically relevant variants: CYP2C9*2 (null), CYP3A5*3 (defective), SLCO1B1-rs4149056(C), and VKORC1-rs9923231(A) are more frequent in Whites than in Blacks. Brazilian Native Americans show lower frequencies of CYP2C9*2, CYP2C19*17 (increased activity), and higher of SLCO1B1-rs4149056(C) than other Brazilian populations. We present the most current and informative database of pharmaco-allele frequencies in Brazilian healthy volunteers.

Preoperative Anaemia and Associated Postoperative Outcomes in Noncardiac Surgery Patients in Central Region of Ghana

Introduction

Several studies suggest that preoperative anaemia (PA) is associated with adverse postoperative outcomes, but little is known about these outcomes in the Central Region of Ghana. This study aims to determine the prevalence of PA among noncardiac surgical patients and its implications for their postoperative outcomes.

Methods

This study was designed as an observational study; data including demographics and clinical and laboratory results were collected from the patients' records and through interviews.

Results

A total of 893 inpatient surgical cases undergoing elective and emergency operations, aged 15 years and above with mean age of 44.2 ± 17.0 yrs, were enrolled. The prevalence of PA was 54.3%, mostly microcytic with or without hypochromia (57.2%). The prevalence was higher in females than males (p ≤ 0.001). Preoperative anaemia was significantly associated with prolonged length of hospital stay (OR: 2.12 (95% CI: 1.49–3.10)). Allogeneic blood transfusion significantly prolonged the length of hospital stay (OR 4.48 (95% CI: 2.67–7.51)). 15.5% of the anaemic patients received oral iron supplements compared to 2.2% of nonanaemic patients (p ≤ 0.001).

Conclusion

Preoperative anaemia is common among noncardiac surgical patients. It is independently and significantly associated with prolonged hospital stay leading to the use of increased healthcare resources. It is also the main predictor for perioperative allogeneic blood transfusions and the use of haematinics.

[Increase in genetically determined anemia as a result of migration in Germany]

BACKGROUND

Due to the increasing numbers of migrants and asylum seekers, hemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency are no longer rare diseases in Germany. As a result of the current migration movements these genetically determined diseases will gain in importance.

METHODS

Following a literature search the prevalence of the original endemic regions was compiled and compared to the population composition based on statistical data on migrants, foreign residents and asylum seekers in Germany.

RESULTS

In the endemic regions a prevalence of 40 % and sometimes higher have been found for glucose-6-phosphate dehydrogenase deficiency and hemoglobinopathies. The number of people arriving in Germany from these endemic regions is rapidly increasing.

CONCLUSION

Due to the high number of asylum seekers arriving from Asian and African regions, genetic erythrocyte defects will gain importance in the differential diagnosis of anemia; therefore, medical education and training must incorporate heightened awareness of risks, diagnostics and therapy of these disease patterns.

Impact of fortified versus unfortified lipid-based supplements on morbidity and nutritional status: A randomised double-blind placebo-controlled trial in ill Gambian children

BACKGROUND

Multiple micronutrients (MMN) are commonly prescribed in pediatric primary healthcare in sub-Saharan Africa to improve nutritional status and appetite without evidence for their effectiveness or international clinical guidelines. Community-wide MMN supplementation has shown limited and heterogeneous impact on growth and morbidity. Short-term ready-to-use therapeutic foods in acutely sick children in a hospital setting also had limited efficacy regarding subsequent growth. The effectiveness of MMN in improving morbidity or growth in sick children presenting for primary care has not been assessed.

METHODS AND FINDINGS

We undertook a double-blind randomised controlled trial of small-quantity lipid-based nutrient supplements (SQ-LNS) fortified with 23 micronutrients in children aged 6 months (mo) to 5 years (y) presenting with an illness at a rural primary healthcare centre in The Gambia. Primary outcomes were repeat clinic presentations and growth over 24 wk. Participants were randomly assigned to receive 1 of 3 interventions: (1) supplementation with micronutrient-fortified SQ-LNS for 12 wk (MMN-12), (2) supplementation with micronutrient-fortified SQ-LNS for 6 wk followed by unfortified SQ-LNS for 6 wk (MMN-6), or (3) supplementation with unfortified SQ-LNS for 12 wk (MMN-0) to be consumed in daily portions. Treatment masking used 16 letters per 6-wk block in the randomisation process. Blinded intention-to-treat analysis based on a prespecified statistical analysis plan included all participants eligible and correctly enrolled. Between December 2009 and June 2011, 1,101 children (age 6-60 mo, mean 25.5 mo) were enrolled, and 1,085 were assessed (MMN-0 = 361, MMN-6 = 362, MMN-12 = 362). MMN supplementation was associated with a small increase in height-for-age z-scores 24 wk after recruitment (effect size for MMN groups combined: 0.084 SD/24 wk, 95% CI: 0.005, 0.168; p = 0.037; equivalent to 2-5 mm depending on age). No significant difference in frequency of morbidity measured by the number of visits to the clinic within 24 wk follow-up was detected with 0.09 presentations per wk for all groups (MMN-0 versus MMN-6: adjusted incidence rate ratio [IRR] 1.03, 95% CI: 0.92, 1.16; MMN-0 versus MMN-12: 1.05, 95% CI: 0.93, 1.18). In post hoc analysis, clinic visits significantly increased by 43% over the first 3 wk of fortified versus unfortified SQ-LNS (adjusted IRR 1.43; 95% CI: 1.07, 1.92; p = 0.016), with respiratory presentations increasing by 52% with fortified SQ-LNS (adjusted IRR 1.52; 95% CI: 1.01, 2.30; p = 0.046). The number of severe adverse events during supplementation were similar between groups (MMN-0 = 20 [1 death]; MMN-6 = 21 [1 death]; MMN-12 = 20 [0 death]). No participant withdrew due to adverse effects. Study limitations included the lack of supervision of daily supplementation.

CONCLUSION

Prescribing micronutrient-fortified SQ-LNS to ill children presenting for primary care in rural Gambia had a very small effect on linear growth and did not reduce morbidity compared to unfortified SQ-LNS. An early increase in repeat visits indicates a need for the establishment of evidence-based guidelines and caution with systematic prescribing of MMN. Future research should be directed at understanding the mechanisms behind the lack of effect of MMN supplementation on morbidity measures and limited effect on growth.

TRIAL REGISTRATION

ISRCTN 73571031.

Validation of the rapid test Carestart(tm) G6PD among malaria vivax-infected subjects in the Brazilian Amazon

INTRODUCTION

In the Brazilian Amazon, malaria infections are primarily caused by Plasmodium vivax. The only drug that kills the hypnozoite form of P. vivax is primaquine, thereby preventing relapse. However, treating glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals with primaquine can lead to severe hemolysis. G6PD deficiency (G6PDd) affects approximately 400 million people worldwide, most of whom live in malaria-endemic areas. Therefore, clinicians need tools that can easily and reliably identify individuals with G6PDd. This study estimated the accuracy of the Carestart(tm) G6PD rapid test (Access Bio) in the diagnosis of G6PDd in male participants with and without P. vivax acute malaria.

METHODS

Male participants were recruited in Manaus. Malaria diagnosis was determined by thick blood smear. G6PD quantitative analysis was performed spectro photometrically at a wave length of 340nm. The Carestart(tm) G6PD test was performed using venous blood. Genotyping was performed for individuals whose samples had an enzyme activity less than 70% of the normal value.

RESULTS

Six hundred and seventy-four male participants were included in this study, of whom 320 had a diagnosis of P. vivax malaria. In individuals with enzyme activity lower than 30% (n=13), the sensitivity, specificity, positive predictive value, and negative predictive value of the Carestart(tm) G6PD test were as follows: 61.5% (95%CI: 35.5%-82.3%), 98.3% (95%CI: 97.0%-99.1%), 42.1% (95%CI: 23.1%-63.7%), and 99.2% (95%CI: 98.2%-82.3%), 98.3% (95%CI: 97.0%-99.1%), 42.1% (95%CI: 23.1%-63.7%), and 99.2% (95%CI: 98.2%-99.7%), respectively. Increases in sensitivity were observed when increasing the cut-off value.

CONCLUSIONS

Despite low sensitivity, Carestart(tm) G6PD remains a good alternative for rapid diagnosis of G6PDd in malaria-endemic regions.