Prevalence Of Sickle Cell Trait Research Articles

Community based screening for sickle haemoglobin among pregnant women in Benue State, Nigeria: I-Care-to-Know, a Healthy Beginning Initiative

BackgroundHaemoglobin genotype screening at prenatal care offers women an opportunity to be aware of their genotype, receive education on sickle cell disease (SCD) and may increase maternal demand for SCD newborn screening. In developed countries, most pregnant women who access prenatal care and deliver at the hospital receive haemoglobin genotype screening. In settings with low prenatal care attendance and low hospital deliveries, community-based screening may provide similar opportunity for pregnant women. We assessed the feasibility and acceptability of integrating haemoglobin genotype screening into an existing community-based HIV program.MethodsOnsite community-based integrated testing for HIV, hepatitis B virus and haemoglobin electrophoresis, were conducted for pregnant women and their male partners. Community Health Advisors implementing the NIH and PEPFAR-supported Healthy Beginning Initiative (HBI) program provided education on SCD, collected blood sample for haemoglobin electrophoresis and provided test results to participants enrolled into the HBI program. We concurrently conducted a cross-sectional study using a pretested, semi-structured, interviewer administered questionnaire to collect demographic data and assess awareness of individual haemoglobin “genotype” among HBI pregnant women participants.ResultsIn this study, 99.9% (10,167/10,168) of pregnant women who received education on SCD accepted and completed the survey, had blood drawn for haemoglobin electrophoresis and received their results. A majority of participating pregnant women (97.0%) were not aware of their haemoglobin “genotype”. Among the participants who were incorrect about their haemoglobin “genotype”, 41.1% (23/56) of women who reported their haemoglobin “genotype” as AA were actually AS. The odds of haemoglobin “genotype” awareness was higher among participants who were in younger age group, completed tertiary education, had less number of pregnancies, and attended antenatal care. Overall prevalence of sickle cell trait (AS) was 18.7%.ConclusionsIt is feasible to integrate haemoglobin “genotype” testing into an existing community-based maternal-child program. Most pregnant women who were unaware of their haemoglobin “genotype” accepted and had haemoglobin genotype testing, and received their test results. Increasing parental awareness of their own haemoglobin “genotype” could increase their likelihood of accepting newborn screening for SCD.

Hemoglobin S identification in blood donors: A cross section of prevalence

IntroductionIn Brazil, the sickle cell trait (SCT) has an average prevalence of 4% in the general population and 6–10% among Afro-descendants. Although SCT is highly prevalent, a large segment of the population ignores their status. The Therapeutic Guidelines prohibit the transfusion of SCT red blood cells into patients with hemoglobin disorders or severe acidosis and newborns. MethodsThis was a cross-sectional study with data from 37,310 blood donation candidates. The study included only eligible first-time donors qualified to be tested for the presence of hemoglobin S (HbS) at the Fundação Hemominas Juiz de Fora, Brazil. The variables studied were gender, skin color, age, type of donation, place of birth, blood type, result of the solubility test for hemoglobin S (HbST) and hemoglobin electrophoresis (HbEF). Statistical analysis was performed using the Q square test and the Kappa index of agreement for comparing biochemical methods. This project was approved by the National Research Ethics Committee. ResultsThe analysis of first-time donor data showed that 7166 were considered eligible. A total of 127 of the 7166 donors were carriers of SCT (1.77%). Among the blood donors, 73.23% were from the local area. The HbST and HbEF were found to be 100% in concordance. Sensitivity was not tested in the present study. ConclusionsThe HbST is highly specific for identifying the HbS, but sensitivity was not tested in this study. The screening of blood donors for abnormal hemoglobins is useful, helping to detect and counsel heterozygous people. The study seeks to identify the prevalence of SCT in a region of Brazil.

Effect of health education on knowledge and awareness of sickle cell disease among adolescents

Introduction: Majority of Nigerians are not aware of their personal genotype, and the knowledge about sickle cell disease is quite low. We hypothesize that health education will improve the knowledge and awareness of sickle cell genotype among adolescents. This study aimed to determine the effect of health education on knowledge and awareness of sickle cell genotype among adolescents. Materials and Methods: Adolescent students of Federal Government College were recruited, and necessary data on sociodemography, knowledge, and awareness of sickle cell were obtained through a pretested sickle cell knowledge assessment questionnaire. Following health education, the same questionnaire was re-administered to the participants for assessment of any change in knowledge. Results: Majority (58.1%) of the respondents heard about sickle cell during lessons in class, while mass media was the next common source (16.5%) of knowledge and awareness. Following health education, there was an improvement in all the specific knowledge questions, especially the prevalence of sickle cell trait in Nigeria (28.1% vs. 75.2%) and the probability of carrier couple having a child with sickle cell anemia (SCA) (10.3% vs. 48.2%). There was a statistically significant increase in mean knowledge score (t = −14.203, P < 0.001), as well as a significant increase in high knowledge level (χ2 = 105.13, P < 0.001) after education. Conclusion: Health education improved the knowledge and awareness of sickle cell among adolescents in secondary schools, especially the chances of having children with SCA in carrier couples. Inculcating health education on sickle cell in secondary school curriculum will help in informed decision on marriage and birth, ultimately reducing the birth of children with SCA.

Hematological and Biochemical Profile of Sickle Cell Patients in Critical and Inter-Critical Periods in Brazzaville, Republic of Congo

Introduction: Sickle cell disease is a public health problem in the Republic of Congo where the prevalence of sickle cell trait is estimated at 1.25%. The objective of this study is to describe the variations of hematological and biochemical parameters of hemolysis in sickle cell patients in critical and inter-critical periods. Methods: This is a descriptive cross-sectional study including sickle cell patients followed regularly at the National Reference Center for Sickle Cell Disease (CNRDr) from November 2019 to March 2020. A sample of 167 patients (sickle cell subjects in crisis and in steady state as well as control subjects) was randomly selected during the study period. The blood count was performed using a Sysmex-XN 350 automated system and the biochemical parameters were determined using the Cobas e 311 automated system. Statistical analysis was performed with SPSS version 22 software. Results: The study showed that the mean cholesterol level in controls was 4.16 ± 0.77 ul compared with 9.64 ± 4.34 ul in sickle cell crisis subjects. Hb and HCT levels were significantly higher in controls compared with sickle cell subjects in crisis. During crisis, total bilirubin, direct bilirubin, triglycerides, LDH, AST, and CRP were significantly elevated. Hematological parameters such as Hb and HCT were elevated in controls, while the mean WBC value and RET were higher in sickle cell patients in steady state. The mean values of the biochemical parameters were higher in sickle cell patients in steady state. Conclusion: Evaluation of the influence of sickle cell trait on biochemical and hematological parameters showed significant differences between sickle cell and control subjects.

Attitudes and impact among people with abnormal premarital screening test results in Muscat governorate's primary healthcare centers in 2018.

Hereditary hemoglobin disorders are among the most common inherited diseases globally. In Oman, the burden of hereditary hemoglobin disorders has long been recognized as a major public health problem. In Oman, the prevalence of SCD ranges between 0.2 and 0.3% and of homozygous B-thalassemia was 0.07-0.08% while the prevalence of sickle cell trait and B-thalassemia trait reached up to 4.8-6% and 2-2.6% respectively. Glucose-6-phosphate dehydrogenase (G6PD) had a high prevalence in Oman, being 25% in males and 10% in females. The premarital screening and counseling (PMSC) program is an important preventative service for the most common hereditary hemoglobin disorders in Oman. The aim of this research is to study the attitude of those with abnormal premarital screening results and the impact of these results. This cross-sectional study was carried out in all primary healthcare centers in the Muscat governorate in 2018 to analyze abnormal premarital screening (PMS) tests results which mainly include sickle cell disease, thalassemia, and G6PD deficiency. Data were collected through telephone questionnaires with those with abnormal PMS test results. The questionnaire consisted of 3 parts investigating sociodemographic characteristics, attitudes toward PMS, and impact of the screening on participants. Of the 159 participants, 72.3% were between 20 and 29years of age. Over two-thirds (71.5%) took PMS test while engaged. Consanguineous marriage was reported in 38.4% of married participants. The majority (94.3%) of participants believed PMSC to be important and (90%) agreed PMS should be obligatory before marriage. Half took the test as a personal decision while 17% complied with their spouse. Healthcare worker advice accounted for 21.4% of participants' decisions. Participant response to positive PMS results showed that 23% canceled their engagement, while 13.8% continued with marriage. Overall, 57.9% believed that PMS affected their lives positively. There is a relatively high favorable attitude toward PMSC. More effort is needed to raise public awareness regarding early PMS. Additionally, further genetic counseling before and after PMS testing is essential for the program's success.

Impact of Sickle Cell Trait on Morbidity and Mortality from Sars-Cov-2 Infection

Introduction: The high morbidity and mortality of SARS-CoV-2 in Blacks or African American in the United States is well established. Individuals with sickle cell trait (SCT), who are mostly Black or African American, have adverse health outcomes in situations of increased physiologic stress. The novel corona virus SARS-CoV-2 causes a severe multi-systemic viral infection that induces intense inflammation and metabolic derangements that can exacerbate RBC sickling and organ damage. The purpose of this study is to evaluate the impact of SCT status on the outcome of patients hospitalized for SARS-CoV-2.Methods: We conducted a multi-center, IRB-approved, retrospective analysis of Black/African American patients who were admitted for management of SARS-CoV-2 infection from March 24, 2020 to June 2, 2020. Patients were identified using an electronic medical record (EMR) report that selected for race as “Black or African American” and a positive SARS-CoV-2 PCR test during that admission. We excluded patients admitted for reasons other than SARS-CoV-2 infection and reviewed only the in-hospital experience. Patient demographics, co-morbidities, admission laboratory values, complications of SARS-CoV-2 infection, and status on discharge were abstracted by manual chart review. High performance liquid chromatography (HPLC) was performed on discarded blood of patients to test for sickle cell trait. The primary objective was to evaluate the impact of SCT status on morbidity outcomes of Blacks/African Americans hospitalized with SARS-CoV-2 infection. Categorical data were tested using the Fisher exact test, and quantitative data were tested using the Wilcoxon rank sum test. Testing was done at the nominal 0.05 two-sided significance level.Results: One hundred and sixty-six Black or African American patients admitted for SARS-CoV-2 infection are included in the analysis. Twenty patients had SCT, 143 had normal hemoglobin (AA) and 3 had hemoglobin C trait (AC). The 146 patients with AA and AC hemoglobin were pooled together. Patient demographics, comorbidities, and lab values on admission by SCT status are shown in Table 1. Complications of SARS-CoV-2 by SCT status is shown in Table 2. Among Black or African American patients admitted for SARS-CoV-2 in this study, SCT represented 12.0% of the total. At the time of admission, individuals with SCT had significantly higher creatinine (p=0.004) but were less likely to present with a history of chronic lung disease (p=0.004). However, a history of chronic lung disease was not in itself associated with death in hospital, p=0.056, and creatinine at admission was not associated with death, p=0.483. Correspondingly, a total of 19 of the 146 patients without SCT died in the hospital (13%), compared to 3 of 20 SCT patients (15%), Fisher exact test p-value = 0.732, despite the difference in the groups at admission.Discussion: The higher morbidity and mortality from SARS-CoV-2 infection in Black or African Americans is well-documented. This study showed equivalent outcomes in patients admitted for SARS-CoV-2 infection whether, or not they had SCT. There was a lower rate of chronic lung disease in patients with SCT, but no difference in respiratory outcome from SARS-CoV-2 between the groups. Patients with SCT also had worse creatinine at presentation but there was no difference in hospital death or end organ complications at discharge. Notably, individuals with SCT made up 12% of Black patients admitted for SARS-CoV-2 in this study which is higher than the reported prevalence of SCT of 7.31% in the African American population (p=0.025), but this is of unclear significance. Our study is limited by the restriction to one metropolitan area and by being retrospective in nature, but the initial data suggests that those with SCT may be more frequently admitted to hospital when infected by SARS-CoV-2 than individuals without SCT. A larger prospective study across multiple regions of the United States should be considered to further assess the prevalence of SARS-CoV-2 in the African American community and the apparent increased rate of hospitalizations for SARS-CoV-2 infection in individuals with SCT.DisclosuresNeuberg:Madrigak Pharmaceuticals: Current equity holder in publicly-traded company; Celgene: Research Funding; Pharmacyclics: Research Funding. Achebe:Global Blood Therapeutics: Other: Advisory Board; Fulcrum Pharmaceuticals: Consultancy; Pharmacosmos: Other: Advisory Board.

High Prevalence of Anemia and Inherited Hemoglobin Disorders in Tribal Populations of Madhya Pradesh State, India

Despite estimated high prevalence of inherited hemoglobin (Hb) disorders among tribal populations in Madhya Pradesh State, India, the burden of disease is unknown, leading to high morbidity and associated mortality. Our aim was to screen tribal populations in designated tribal districts of Madhya Pradesh State for various hemoglobinopathies and to estimate the prevalence and plausible cause of anemia. The present study screened a total of 3992 tribal individuals comprised of students of Tribal schools, ashrams of Dindori, Mandla, and Chhindwara districts of Madhya Pradesh State. Screening of hemoglobinopathies was done using Hb electrophoresis and or high performance liquid chromatography (HPLC), α-thalassemia (α-thal) was detected using polymerase chain reaction (PCR). The median age of the studied cohort was 15 years (interquartile range 13–16 years). High prevalence (76.7%) of anemia was observed among the studied cohort. The prevalence of sickle cell trait and sickle cell disease varies from 10.7 to 15.6% and 0.4 to 0.8%, respectively. The allele frequency of sickle cell gene was highest in the Pradhan tribe followed by the Panika tribe. Dindori district had the highest prevalence of sickle cell trait. β-Thalassemia (β-thal) trait was observed in only 1.4% of the screened population. α Gene deletions were observed in 84.7% individuals. Significant association of α gene deletion mutations with mean Hb, mean corpuscular volume (MCV), and mean corpuscular Hb (MCH) was observed. The Bharia tribe showed the highest prevalence for α-thal. For comprehensive health care, effective intervention programs are needed to reduce the high prevalence of anemia and hemoglobinopathies among tribes.

Surveillance for sickle cell disease, United Republic of Tanzania

ObjectiveTo determine the regional- and district-level newborn prevalence of sickle cell trait and disease, and the prevalence of haemoglobin variants and genetic modifiers of sickle cell disease, in the nine regions of north-western United Republic of Tanzania.MethodsWe repurposed dried blood spot samples from children (aged 0–24 months) born to mothers living with human immunodeficiency virus (HIV), collected as part of the HIV Early Infant Diagnosis programme, for sickle cell diagnosis. We performed isoelectric focusing to determine whether samples had normal haemoglobin, sickle cell trait, sickle cell disease or a rare haemoglobin variant. We shipped samples diagnosed as disease or variant to Cincinnati Children’s Hospital in the United States of America for deoxyribonucleic-acid-based analyses to determine the prevalence of α-thalassaemia, glucose-6-phosphate dehydrogenase (G6PD) deficiency or fetal haemoglobin genetic modifiers.FindingsWe analysed a total of 17 200 specimens during February 2017–May 2018. We observed a prevalence of sickle cell trait and disease of 20.3% (3492/17 200) and 1.2% (210/17 200), respectively. District-level trait varied from 8.6% (5/58) to 28.1% (77/274). Among confirmed sickle cell disease specimens, we noted 42.7% (61/143) had 1-gene deletion and 14.7% (21/143) had 2-gene deletion α-thalassaemia trait. We documented G6PD A– deficiency in 19.2% (14/73) of males.ConclusionOur calculated prevalence is twice as high as previously reported and reinforces the need for enhanced sickle cell diagnostic services. Our district-level data will inform public health policy, allowing screening and disease-modifying hydroxyurea therapy to be focused on high-prevalence areas, until universal newborn screening is available.

Current modalities of sickle cell disease management.

Sickle cell disease (SCD) affects nearly 100,000 people in the United States of America and the sickle gene is present in approximately 8% of black Americans. Among Africans, the prevalence of sickle cell trait (heterozygosity) is as high as 30%. While SCD occurs among varying racial and ethnic groups, it is more commonly prevalent in individuals of African or African-American descent. This inherited blood disorder causes varying symptoms and complications among affected children and adults and early diagnosis and treatment are essential to help reduce mortality rates. Because there is no cure for SCD, management is vital to survival. Hence, there are different approaches in use to aid those living with SCD; thus, this paper provides insight into the current methods that are implemented in the management and maintenance of this disease.

Knowledge and awareness of individual sickle cell genotype among adolescents in a unity school in Southeast, Nigeria: a cross-sectional study.

Our study sought to assesses the knowledge and awareness of individual sickle cell genotype among adolescents. Participants were recruited from a large school in Southeast Nigeria where adult prevalence of sickle cell trait is 25%. Data was collected through a 50-item survey with previously pretested questions that assessed awareness of individual genotype, general knowledge of sickle cell disease, perception of sickle cell trait and sickle cell anaemia (SCA). Additionally, self-reported genotype was compared to the school's admission records to determine accuracy of self-reported genotype. The knowledge scores were summed on a binary basis with one point assigned for a correct answer while zero was given for an incorrect response. Four hundred and nine (409) students were approached and enrolled in the study. A vast majority (94%) of the respondents reported being aware of their genotype and two-thirds had the awareness during school admission. However, in specific knowledge of sickle cell, majority (89.7%) of the participants miscalculated the probability of having a child with SCA in married carrier couple and 71.9% misidentified the proportion of Nigerians with sickle cell trait. Assessing level of knowledge of sickle cell, only very few of the adolescents (7.3%) were found with the expected high knowledge scores of 7-8. Although a significant proportion of respondents were aware of their genotype, most were unaware of the implications of sickle cell trait and thought that people with sickle cell trait also have symptoms of sickle cell disease. Also, only a few of the respondents have the expected level of sickle cell knowledge. A focused educational intervention among this age group is crucial as they embark on making reproductive health decisions.

Comorbidity of sickle cell trait and albinism: a cross-sectional survey in the Democratic Republic of the Congo.

IntroductionSickle Cell Disease (SCD) and albinism are both recessive hereditary diseases in human kind with a high prevalence in sub-Saharan Africa. This study aimed to determinate the prevalence of sickle cell trait in people living with albinism (PLA).Methodsa cross-sectional descriptive survey was conducted in PLA attending the "Hôpital du Cinquantenaire de Kisangani". In total, by non-probabilistic convenience sampling, 82 albinos and 139 non-albinos and without any antecedents of albinism in their family were included, selected from students in the Faculty of Medicine and Pharmacy at the University of Kisangani. Blood samples were collected on "dried blood spot" and analyzed by mass spectrometry at CHU of Liège. Data were entered into an Excel file and analysed on SPSS 20.0 (Chicago, IL).Resultsforty-six of the 82 albinos (56.1%) were female and 43.9% male with a sex ratio of 1.28. Among albinos, 18.3% had hemoglobin AS (HbAS) and 81.7% hemoglobin AA (HbAA) compared to 18% of subjects with hemoglobin AS and 82% hemoglobin AA in the control group. The difference was not statistically significant (Chi-square=0.003, ddl=1, p=0.9544).Conclusionthis study highlighted that the prevalence of the sickle cell trait is high among people living with albinism, but does not differ from that observed in non-albinos in the Democratic Republic of the Congo. It is therefore important to raise awareness among this category of people about sickle cell disease and the importance of its premarital screening.

The prevalence of sickle cell trait in Division I university athletics programs

ABSTRACT Objectives: To determine the prevalence of student-athletes with sickle cell trait (SCT) and describe their demographics, prior knowledge of status, and hemoglobin (Hb) profile. Methods: A retrospective chart review was conducted at two National Collegiate Athletic Association Division I universities. Participants were student-athletes during the 2010/11-2018/19 academic years. The independent variable was SCT status. Main outcome measures included actual prevalence of SCT positive student-athletes, sex, race, sport, prior knowledge of personal and family history SCT status, and Hb profile (HbA, HbA2, HbS, HbF, HbC) proportions. Results: Fifty-three SCT positive student-athletes (13.2 ± 2.0 per academic year) were identified, accounting for ~1% of the student-athlete population annually. The majority were Black/African-American (n = 49, 100.0%; 4 missing) and males (n = 44, 83.0%). Football had the majority (n = 28, 52.8%) of SCT student-athletes. Most student-athletes were unaware of their SCT status (n = 33, 62.3%). There was no difference between actual and expected prevalence of SCT student-athletes overall and by race in any academic year (p > 0.05). Results of Hb electrophoresis testing were available for 44 (83.0%) student-athletes. Average values for HbA, HbA2, HbS, HbF and HbC were 58.54 ± 4.26%, 3.42 ± 0.53%, 37.99 ± 4.60%, 0.17 ± 0.68% and 0.00 ± 0.00%, respectively. Conclusions: Student-athletes with SCT were a small proportion of the student-athlete population. The majority of SCT student-athletes had no prior knowledge of personal or family history; therefore, it is insufficient to rely on self-reported history. No difference was found between actual and expected prevalence of SCT student-athletes. Due to high proportion of student-athletes who are unaware of their SCT status, institutions should facilitate SCT screening with confirmatory testing for all student-athletes to prevent missed identification of those with SCT.

Pregnancy in sickle cell trait: what we do and don't know.

Sickle cell trait (SCT) is the carrier state for sickle cell disease that results from the HBB rs334 missense mutation (p.Glu6Val) in the β-globin chain of haemoglobin. While not associated with any impact on life expectancy, it has been established that SCT is associated with an increased risk of both venous thromboembolism (and in particular, pulmonary embolism) and chronic kidney disease. It is largely unknown what short- or long-term effect, if any, pregnancy has upon the risk or outcomes of these disorders. In addition, SCT has been linked with various adverse outcomes in pregnancy, ranging from maternal complications such as elevated risk of bacteriuria to potentially life-threatening entities such as pre-eclampsia and prematurity. In these scenarios also, no clear association with SCT has been established. Given the high worldwide prevalence of SCT, further studies addressing these issues are warranted.

Prevalence of sickle cell trait in blood donors at the regional blood transfusion center in the Haute Matsiatra Region, Madagascar

Introductionle trait drépanocytaire correspond à la forme hétérozygote de la drépanocytose. Les porteurs du trait drépanocytaire sont capables de synthétiser de l´hémoglobine A normale et de l´hémoglobine S. Cette affection est cliniquement inapparente de telle sorte que des porteurs du trait drépanocytaire, ignorant leurs statuts génétiques, peuvent se retrouver parmi les donneurs de sang. Cette situation peut avoir des conséquences sévères sur leurs propres états de santé ainsi qu´aux receveurs, particulièrement si ces derniers sont drépanocytaires. L´objectif de notre étude est de déterminer la prévalence du trait drépanocytaire chez les donneurs de sang.Méthodesnous avons réalisé une étude prospective descriptive sur 4 mois (de janvier à mai 2017) au Centre Régional de Transfusion Sanguine (CRTS) Haute Matsiatra. Tous les donneurs ont été dépistés par test d´Emmel et confirmation des cas positifs par électrophorèse de l´hémoglobine.Résultatsnous avons recruté 427 donneurs dont 332 hommes et 95 femmes avec un sex-ratio de 3,4. L´âge moyen des donneurs était de 32,72 ans allant de 18 à 64 ans. Le test d´Emmel s´est révélé positif chez 5 donneurs (1,17%), tous confirmés de génotype AS à l´électrophorèse de l´hémoglobine.Conclusionles résultats de cette étude révèlent l´existence de porteurs de trait drépanocytaire parmi les donneurs de sang du CRTS dont la plupart ignore leur statut drépanocytaire avant le don de sang. Afin d´assurer la sécurité transfusionnelle et la qualité des produits sanguins, le dépistage de la drépanocytose chez les donneurs de sang est désormais une question pertinente et d´actualité.

Distribution of haemoglobin genotypes, knowledge, attitude and practices towards sickle cell disease among unmarried youths in the Buea Health District, Cameroon.

Introductionsickle cell disease (SCD) is one of the commonest genetic causes of morbidity and mortality in the world. In resource-limited settings, SCD prevention through public education and screening could be a significant strategy to curb its prevalence. The study aimed at determining the distribution of haemoglobin genotypes among unmarried youths in Buea, Cameroon as well as their knowledge, attitude and practices towards SCD.Methodsa community-based, analytic, cross-sectional study was conducted within the city of Buea. Data was collected from 410 youths using self-administered questionnaires. Of the 410 youths, 100 were selected by purposive random sampling and their haemoglobin genotyping was done using haemoglobin electrophoresis. The data was analysed using the statistical software Epi Info Version 7.Resultsthe majority (51.5%) of the 410 respondents were females. The modal age range was 18- 21 years (46.8%) and 60.4% had tertiary education. Less than one quarter (20.5%) had good knowledge of SCD. Only 13.2% knew their genotype and 59.3% were willing to avoid carrier marriages. Out of the 100 participants for genotyping, 84.0% had normal haemoglobin (HbAA) and 16.0% had the sickle cell trait (HbAS).Conclusionmost of the respondents had moderate knowledge of SCD. Only a few knew their haemoglobin genotype and more than half were willing to avoid carrier marriages. The prevalence of sickle cell trait is high in Buea. The promotion of preventive methods like public education and genetic screening is recommended to reduce the burden of SCD in Cameroon.

Prevalence of Sickle Cell Trait and Rare Hemoglobin Variants in the Metropolitan Washington DC Area.

Prevalence of Sickle Cell Trait and Rare Hemoglobin Variants in the Metropolitan Washington DC Area.

Prevalence of sickle cell trait in blood donors: A systematic review

Introduction: The sickle cell trait is a genetic mutation characterizedby the presence of hemoglobin S (HbS) in heterozygosisin which patients are asymptomatic, which makesthem suitable for blood donation. Aim: Systematizing datarelated to the prevalence of the sickle cell trait among blooddonors. Materials and methods: A search of the literature wasconducted in May 2019 to seek articles published from 1990and which had available online abstracts, in four electronicdatabases. Studies were selected with the following characteristics:(1) original work; (2) observational; (3) developed withblood donors; and (4) showing prevalence of sickle cell trait.Two independent reviewers identified the articles for inclusionin this systematic review of the literature (SRL), extractedthe pre-determined data and carried out the evaluation of theworks’ methodological quality. Results: Eight studies publishedin the last 12 years in different countries were selected totake part in this SRL. With variable sample size, all presented across-sectional methodology. For the detection of the presenceof HbS, electrophoresis in alkaline pH was commonly used.The statistical analysis developed involved simple techniques,showing that the prevalence of blood donors with sickle celltrait ranged from 0.4% to 20.8%. The majority of studies wasconsidered of high methodological quality. Conclusion: Theprevalence of sickle cell trait among blood donors varies widely,although it may not be moderate, given that the screeningof HbS has important clinical significance for the proper useof this blood component.Keywords: Sickle cell trait; Blood donor; Blood transfusion.

Editorial

Dear AllThe broad approach of the Brazilian Journal ofHealth and Biomedical Sciences shows itself again inthis issue. The papers are related to a variety of subjectscovering different populations. The current issuecontains a diversity of interesting and important studiesthat use practical and convenient techniques involvingboth young and elderly groups. This stimulatesthe reader to be in contact with a range of possibleinformation in the health and biomedical sciences areathat is highly relevant and current worldwide.In addition, several conditions related todiseases, such as type 2 diabetes mellitus (T2DM),chronic obstructive pulmonary disease (COPD), kneeosteoarthritis (KOA), and frailty are presented inthe studies. Findings are presented from the clinicalevaluation of induced sputum and pulmonary functionin patients with T2DM, racial/ethnic differences inbone mineral density, muscle function and fat mass inyoung women, land-based versus water-based walkingprograms in elderly women with KOA, processing speedduring attention and memory tasks as an indicator offrailty, use of the 6-minute walking test to evaluatepatients with respiratory disease, as well as an evaluationof the prevalence of sickle cell trait in blood donorsthrough a systematic review. An epidemiologicalanalysis of exogenous poisoning is also presented.The objectives of the papers published in thisissue include: (i) systematizing data related to theprevalence of sickle cell trait among blood donors;(ii) determination of racial/ethnic differences in bonemineral density, muscle function and fat mass inwomen of Caucasian, East-Asian, South-Asian, Hispanicand African-American backgrounds; (iii) investigationof effects of a walking program with a controlledprogressive workload in water compared to land withregard to pain, functional and physical performance,and quality of life in elderly women with KOA; (iv)characterization of the processing speed duringattention and memory tasks in a geriatric populationin different states of frailty in order to verify thefactors that most contribute to the frailty phenotype;(v) comparative cross-sectional study of the 6-minutewalking test data with inclusion of individuals withsystemic sclerosis, idiopathic pulmonary fibrosis andCOPD; (vi) evaluation of cellularity, albumin andinterleukin-1 levels in induced sputum to determinerespiratory function parameters in patients withT2DM; and (vii) observation of patterns in cases ofexogenous poisoning in a region of the State of MinasGerais, Brazil.Readers of the BJHBS may expect to access relevantdiscussions of subjects in Health and BiomedicalSciences.

Genetic Analysis in the Tanzania Sickle Surveillance Study (TS3): Modifiers of Sickle Cell Disease and Identification of Hemoglobin Variants

Introduction. Based on sparse historical data, Tanzania ranks fourth globally for the estimated number of annual births with sickle cell disease. Northwest Tanzania is projected to have an especially high burden of sickle cell disease, but no contemporary surveillance data exist to verify this projection. We designed a large prospective study to determine the prevalence of both sickle cell trait and sickle cell disease in northwest Tanzania. Additional objectives included an analysis of two known genetic modifiers of sickle cell disease [alpha thalassemia trait and glucose-6-phosphate dehydrogenase (G6PD) deficiency], as well as genetic variants affecting fetal hemoglobin (HbF) expression and characterization of hemoglobin variants. Methods. The Tanzania Sickle Surveillance Study (TS3) is a prospective cross-sectional study to determine the prevalence of sickle cell trait and disease in an area projected to be at high risk. Dried blood spots (DBS) from all children born to HIV-infected mothers in the 9 regions across northwest Tanzania were collected by the HIV Early Infant Diagnosis (EID) program and transported to a central laboratory at Bugando Medical Centre, a teaching and consultancy hospital in Mwanza. DBS were tested by isoelectric focusing and scored as normal, trait, disease, or variant. Samples scored as disease or variant were retested for confirmation, and then frozen for subsequent genetic analysis. In the US, genomic DNA was extracted from each DBS, and sickle cell disease status was confirmed by PCR and TaqMan genotyping. All confirmed samples were then analyzed for alpha thalassemia trait (rightward -3.7 gene deletion) using quantitative real time PCR, and for G6PD deficiency using three real time PCR probes to distinguish A and B G6PD isoforms, to identify the G6PD A- variant, and to confirm the sex, respectively. Single nucleotide polymorphisms within 3 quantitative trait loci [BCL11A, the HBS1L-MYB intergenic polymorphism (HMIP) region, and the gamma-globin promoter XmnI site] that modify baseline HbF were analyzed using TaqMan genotyping. DBS with hemoglobin variants were investigated for the presence of common variants found in East Africa. Results. Between February 2017 and May 2018, a total of 232 IEF gels were completed by local staff in Tanzania. Among EID samples from children <24 months of age, the median age was 52 days (IQR 41-93 days), and 17,278 unique DBS samples were scored. With 20 samples uninterpretable and 54 samples with missing results, the primary analysis was performed on 17,204 samples. The overall prevalence of sickle cell trait and disease in the entire cohort was 20.3% and 1.2%, respectively, for a sickle allele frequency of 0.114 with Hardy-Weinberg equilibrium. There was some geographical variation between individual districts in both sickle trait (15.2-27.8%) and disease (0.0-4.3%). Hemoglobin variants were rare (0.1%) and included 4 Hb G-Pest, 2 Hb Kenya, and 1 Hb P-Nilotic. Of 143 DBS confirmed to have sickle cell disease and available for further testing, 61 (43%) had one-gene deletion alpha thalassemia trait and 21 (15%) had two-gene deletion. A- G6PD deficiency was detected in 19.2% of males, and 25.7% of females were heterozygous carriers. The minor allelic frequency for known modifiers of HbF were 32.2% C at rs11886868 (BCL11A), 26.6% T at rs1427407 (BCL11A), 32.5% A at rs4671393 (BCL11A), 23.8% G at rs28384513 (HMIP), 4.5% C at rs9399137 (HMIP), and 0% A at rs7482144 (XmnI). Conclusion. The prevalence of sickle cell trait and disease among infants in northwest Tanzania is very high, exceeding 20% trait and 1.2% disease. Regional prevalence data paired with region-specific crude birth rates predict 10,055 births annually in the northwest regions, more than doubling previous estimates. Concomitant alpha thalassemia trait and G6PD deficiency are frequently co-inherited and may affect the phenotype, as well as common genetic modifiers of HbF expression. Our detailed genetic analysis of a geographically representative surveillance cohort provides a foundation for future targeted screening and the introduction of hydroxyurea for treatment of sickle cell disease in northwest Tanzania. Disclosures Ware: Bristol Myers Squibb: Other: Research Drug Donation; Addmedica: Other: Research Drug Donation; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Nova Laboratories: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: DSMB.

Validity of HbA1c in Diagnosing Diabetes Among People with Sickle Cell Trait in Tanzania

BACKGROUND: Hemoglobin A1c (HbA1c) measures the average of the past three month's glucose concentration and is recommended for diagnosing and monitoring diabetes. However in people with shorter red blood cells life spans like those with sickle cell trait (SCT), the test may underestimate the prevalence of diabetes. There are no data on the extent of this problem in East African region where the prevalence of SCT approaches 22%. OBJECTIVE: To compare diabetes diagnosis outcomes among adults with and without SCT by HbA1c and 2hrs oral glucose tolerance test (OGTT). METHODOLOGY: This was a cross sectional study conducted among patients who were previously recruited in the Chronic Infection, Cormobidities and Diabetes in Africa (CICADA) study, a cohort study investigating risk factors for diabetes in North western Tanzania during 2016 to 2021. Participants were included in this study if aged ≥18 years and were residents of Mwanza. After identification of eligible participants, stored blood samples were analyzed for SCT and other hemoglobinopathies i.e. thalassemia and G6PD deficiency through gene extraction, PCR and gel electrophoresis. Demographic, and anthropometric data as well as HbA1c and OGTT, hemoglobin, and lipids test results were available as part of CICADA study. Data were managed and analysed in stata. Student ttest was used for comparison of continuous variables while for categorical variables chi squire test was used. To investigate the validity of HbA1c, regression models were used to evaluate the association between SCT and diabetes diagnosis by HbA1c and OGTT separately. P< 0.05 indicated significant differences. RESULTS: 480 participants were included. Their mean age was 40.8 (±11.8) years, 292 (60.8%) were females, 128 (26.7%) had SCT and no sickle cell disease(SCD) which is homozygous trait observed. Those with SCT had lower body mass index (BMI) ((21.6(±4.3) vs. 22.5 (±5.0), P= 0.01) and lower HbA1c (5.2% vs. 5.9%, P<0.0001) compared to those without SCT. In multivariable logistic regression analysis adjusted for sex, age, BMI, another hemoglobinopathy which is thalassemia , G6PD deficiency , hemoglobin and lipids , participants with SCT were 88% less likely to be diagnosed with diabetes by HbA1c compared to those without SCT (OR=0.12, 95% CI (0.1,0.2), P <0.001). In contrast to logistic regression model adjusted for the same variables as above, SCT was not associated with diabetes diagnosis by OGTT (1.44, 95% CI (0.9, 2.3), P= 0.12). CONCLUSION: When compared with OGTT the findings shows that HbA1c systematically underestimate the prevalence of diabetes among people with SCT. The use of HbA1c for diabetes diagnosis should be done with caution especially in areas with high prevalence of SCT like in North Western Tanzania. Further research is needed to optimize the use of HbA1c in diagnosing and monitoring diabetes among people with SCT. Disclosures No relevant conflicts of interest to declare.