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The clinical severity of sickle cell disease (SCD) is strongly influenced by the level of fetal haemoglobin (HbF) persistent in each patient. Three major HbF loci (BCL11A, HBS1L-MYB, and Xmn1-HBG2) have been reported, but a considerable hidden heritability remains. We conducted a genome-wide association study for HbF levels in 1006 Nigerian patients with SCD (HbSS/HbSß0), followed by a replication and meta-analysis exercise in four independent SCD cohorts (3,582 patients). To dissect association signals at the major loci, we performed stepwise conditional and haplotype association analyses and included public functional annotation datasets. Association signals were detected for BCL11A (lead SNP rs6706648, ß = -0.39, P = 4.96 × 10-34) and HBS1L-MYB (lead SNP rs61028892, ß = 0.73, P = 1.18 × 10-9), whereas the variant allele for Xmn1-HBG2 was found to be very rare. In addition, we detected three putative new trait-associated regions. Genetically, dissecting the two major loci BCL11A and HBS1L-MYB, we defined trait-increasing haplotypes (P < 0.0001) containing so far unidentified causal variants. At BCL11A, in addition to a haplotype harbouring the putative functional variant rs1427407-'T', we identified a second haplotype, tagged by the rs7565301-'A' allele, where a yet-to-be-discovered causal DNA variant may reside. Similarly, at HBS1L-MYB, one HbF-increasing haplotype contains the likely functional small indel rs66650371, and a second tagged by rs61028892-'C' is likely to harbour a presently unknown functional allele. Together, variants at BCL11A and HBS1L-MYB SNPs explained 24.1% of the trait variance. Our findings provide a path for further investigation of the causes of variable fetal haemoglobin persistence in sickle cell disease.
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Anemia de Células Falciformes , Proteínas de Unión al GTP , Estudio de Asociación del Genoma Completo , Haplotipos , Femenino , Humanos , Masculino , Alelos , Anemia de Células Falciformes/genética , Anemia de Células Falciformes/sangre , Predisposición Genética a la Enfermedad , Nigeria , Proteínas Nucleares/genética , Polimorfismo de Nucleótido Simple/genética , Proteínas Represoras/genéticaRESUMEN
Sickle cell disease (SCD) is a common genetic disorder in Africa. Some ongoing work in SCD research includes the analysis and comparisons of variation in phenotypic presentations and disease outcomes with the genotypic signatures. This has contributed to the observed growth of molecular and genetic data in SCD. However, while the "omics" data continues to pile, the capacity to interpret and turn the genetic findings into clinical practice is still underdeveloped, especially in the developing region. Building bioinformatics infrastructure and capacity in the region is key to bridging the gap. This paper seeks to illustrate how the Sickle Cell Programme (SCP) at the Muhimbili University of Health and Allied Sciences (MUHAS) in Tanzania, modeled the integration of infrastructure for bioinformatics and clinical research while running day-to-day clinical care for SCD in Tanzania.
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Anemia de Células Falciformes , Humanos , Tanzanía , Anemia de Células Falciformes/genética , Anemia de Células Falciformes/terapia , Encuestas y CuestionariosRESUMEN
Differentiated service delivery (DSD) models, such as adherence clubs (ACs), are client-centred approaches where clinically stable people living with HIV (PLHIV) meet to receive various services, including psychosocial support, brief symptoms screening, and refills of antiretroviral medications, among others. We conducted a review to assess the impact of DSD models, including ACs, on sustaining retention in care (RC) and achieving viral suppression (VS) among PLHIV in sub-Saharan Africa. The review protocol was registered in PROSPERO (CRD42023418988). We searched the literature from PubMed, Scopus, Web of Science, Embase and Google Scholar from their inception through May 2023. Eligible randomised controlled trials of adherence clubs were reviewed to assess impact on retention and viral suppression. Random effect models were used to estimate the risk ratios (RR) and 95% confidence intervals (CI). The literature search yielded a total of 1596 records of which 16 randomised clinical trials were determined to be eligible. The trials were conducted in diverse populations among adults and children with a total of 13,886 participants. The RR between any DSD models and standard of care (SoC) was 1.09 (95% CI: 1.08-1.11, I2 : 0%, p: <0.96) and 1.01 (95% CI: 1.00-1.02, I2 : 0%, p: <0.85) for RC and VS, respectively. The RR between ACs and SoC was 1.01 (95% CI: 0.96-1.07, I2 : 84%, p: <0.01) and 1.02 (95% CI: 0.98-1.07, I2 : 77%, p: <0.01) for RC and VS, respectively. DSD models, including ACs, show comparable effectiveness to SoC in maintaining care and achieving viral suppression for stable PLHIV. To maximise adoption, an implementation science approach is crucial for designing effective strategies and overcoming challenges.
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Fármacos Anti-VIH , Infecciones por VIH , Adulto , Niño , Humanos , Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/diagnóstico , África del Sur del Sahara/epidemiología , Carga Viral , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
INTRODUCTION: Urinary tract infection (UTI) is the second most common infectious disease affecting more than 150 million people globally annually. Uropathogenic E. coli (UPEC), the predominant cause of UTI, can occur as a biofilm associated with antimicrobial resistance (AMR). There is a data gap on global AMR patterns from low-income settings, including Tanzania. Data on antimicrobial susceptibility patterns in relation to biofilm formation will help in the proper selection of antibiotics and the fight against AMR. METHODS: This analytical cross-sectional study was conducted among consecutively selected outpatients (n = 344) from January to May 2022 at Morogoro Regional Referal Hospital. Mid-stream urine samples were collected aseptically from symptomatic patients. A significant UTI was defined when more than 105 colonies/ml of urine were recorded. Kirby Bauer's disc diffusion method was used for antibiotics susceptibility patterns and a Congo Red Agar method was used to determine biofilm formation. Two-sided χ2 test or Fisher's exact test, Cohen's kappa coefficient and logistic regression were used for data analysis. A p-value < 0.05 was considered statistically significant. RESULTS: The prevalence of UTIs was 41% (141/344) and elders (>=60 years) had five times higher odds of having UTI as compared to adolescents (p < 0.001). E. coli was the most predominant bacteria (47%; 66/141), which displayed moderate susceptibility against ciprofloxacin (59.1%) and nitrofurantoin (57.6%). A total of 72 (51%) of all isolated bacteria were multi-drug resistant. All isolated bacteria demonstrated high resistance (> 85%) against ampicillin and co-trimoxazole. In this study, 51.5% (34/66) were biofilm-forming E. coli and demonstrated relatively higher antibiotic resistance as compared to non-biofilm forming bacteria (p < 0.05). CONCLUSION: We report high antibiotic resistance against commonly used antibiotics. Slightly more than half of the isolated bacteria were biofilm forming E. coli. A need to strengthen stewardship programs is urgently advocated.
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Antibacterianos , Infecciones Urinarias , Adolescente , Humanos , Anciano , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Estudios Transversales , Escherichia coli , Pacientes Ambulatorios , Prevalencia , Tanzanía/epidemiología , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/epidemiología , Infecciones Urinarias/microbiología , Bacterias , BiopelículasRESUMEN
BACKGROUND: HIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR are driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remains unclear and African policy makers encounter difficulties setting priorities combating HIVDR. By viewing HIVDR as a complex adaptive system, through the eyes of multi-disciplinary HIVDR experts, we aimed to make a first attempt to linking different influencing factors and gaining a deeper understanding of the complexity of the system. METHODS: We designed a detailed systems map of factors influencing HIVDR based on semi-structured interviews with 15 international HIVDR experts from or with experience in sub-Saharan Africa, from different disciplinary backgrounds and affiliated with different types of institutions. The resulting detailed system map was conceptualized into three main HIVDR feedback loops and further strengthened with literature evidence. RESULTS: Factors influencing HIVDR in sub-Saharan Africa and their interactions were sorted in five categories: biology, individual, social context, healthcare system and 'overarching'. We identified three causal loops cross-cutting these layers, which relate to three interconnected subsystems of mechanisms influencing HIVDR. The 'adherence motivation' subsystem concerns the interplay of factors influencing people living with HIV to alternate between adherence and non-adherence. The 'healthcare burden' subsystem is a reinforcing loop leading to an increase in HIVDR at local population level. The 'ART overreliance' subsystem is a balancing feedback loop leading to complacency among program managers when there is overreliance on ART with a perceived low risk to drug resistance. The three subsystems are interconnected at different levels. CONCLUSIONS: Interconnectedness of the three subsystems underlines the need to act on the entire system of factors surrounding HIVDR in sub-Saharan Africa in order to target interventions and to prevent unwanted effects on other parts of the system. The three theories that emerged while studying HIVDR as a complex adaptive system form a starting point for further qualitative and quantitative investigation.
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Fármacos Anti-VIH , Infecciones por VIH , Personal Administrativo , África del Sur del Sahara , Fármacos Anti-VIH/uso terapéutico , Resistencia a Medicamentos , Farmacorresistencia Viral , Infecciones por VIH/epidemiología , HumanosRESUMEN
Sickle cell disease is a genetic disease with a predisposition to infections caused by encapsulated organisms, especially Streptococcus pneumoniae. Pneumococcal vaccines and prophylactic penicillin have reduced the rate of this infection and mortality in sickle cell disease. However, implementation of these interventions is limited in Africa. The objectives of the study were to assess health care providers' behaviors with the implementation of pneumococcal vaccination and penicillin prophylaxis and to identify barriers to their use. A 25-item online questionnaire was administered through SickleinAfrica: a network of researchers, and healthcare providers, in Ghana, Nigeria, and Tanzania, working to improve health outcomes of sickle cell disease in Africa. Data was collected and managed using the Research Electronic Data Capture (REDCap), tools and data analysis was done using STATA version 13 and R statistical software. Eighty-two medical practitioners responded to the questionnaire. Only 54.0 and 48.7% of respondents indicated the availability of published guidelines on sickle cell disease management and pneumococcal vaccine use, respectively, at their facilities. The majority (54.0%) perceived that the vaccines are effective but over 20.0% were uncertain of their usefulness. All respondents from Ghana and Tanzania affirmed the availability of guidelines for penicillin prophylaxis in contrast to 44.1% in Nigeria. Eighty-five percent of respondents affirmed the need for penicillin prophylaxis but 15.0% had a contrary opinion for reasons including the rarity of isolation of Streptococcus pneumoniae in African studies, and therefore, the uncertainty of its benefit. Lack of published guidelines on the management of sickle cell disease and doubts about the necessity of prophylactic measures are potential barriers to the implementation of effective interventions.
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Anemia de Células Falciformes , Penicilinas , Infecciones Neumocócicas , Vacunas Neumococicas/uso terapéutico , Anemia de Células Falciformes/complicaciones , Personal de Salud , Humanos , Nigeria , Penicilinas/uso terapéutico , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/etiología , Infecciones Neumocócicas/prevención & control , Streptococcus pneumoniaeRESUMEN
Background and Purpose- Widespread reductions in white matter integrity are associated with cognitive dysfunction in sickle cell anemia. Silent cerebral infarction (SCI), vasculopathy (VSC), and low hemoglobin concentration (Hb) are implicated; we aimed to determine independent contributions to microstructural white matter injury and whether white matter integrity differs across arterial territories. Methods- Sixty two children with sickle cell anemia aged 6 to 19 years were prospectively studied at Muhimbili National Hospital, Tanzania. SCI± and VSC± were identified on magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) scans by 2 neuroradiologists. Tract-based spatial statistics tested for voxel-wise differences in diffusion tensor imaging metrics (ie, fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity) between SCI± and VSC± groups, with correlations between diffusion tensor imaging metrics and Hb. In tract-based spatial statistics analyses, potentially mediating factors (ie, age, sex, as well as Hb, SCI, and/or vasculopathy) were covariates. Differences in mean diffusion tensor imaging metrics across regions of interest in arterial territories were explored. Results- Compared with SCI- patients (n=45), SCI+ patients (n=17) exhibited increased radial diffusivity in multiple regions; negative relationships were observed between mean diffusivity, axial diffusivity, and Hb (P<0.005). Compared with VSC- patients (n=49), mild (n=6) or moderate (n=7) VSC+ patients exhibited reduced fractional anisotropy in widespread regions (P<0.05) including the anterior longitudinal fasciculi, corpus callosum, internal capsule, corona radiata, and corticospinal tracts. Overall, the posterior cerebral arterial territory had higher mean mean diffusivity and mean radial diffusivity than the anterior and middle cerebral arterial territories, although no patient had vasculopathy in this area. There was an interaction between territory and vasculopathy. Conclusions- SCI, vasculopathy, and Hb are independent risk factors, and thus treatment targets, for diffuse white matter injury in patients with sickle cell anemia. Exacerbation of hemodynamic stress may play a role.
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Anemia de Células Falciformes/diagnóstico por imagen , Anemia de Células Falciformes/epidemiología , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora/tendencias , Angiografía por Resonancia Magnética/tendencias , Sustancia Blanca/diagnóstico por imagen , Adolescente , Niño , Femenino , Humanos , Masculino , Estudios Prospectivos , Tanzanía/epidemiología , Adulto JovenRESUMEN
Patients with sickle cell disease (SCD) with high fetal haemoglobin (HbF) tend to have a lower incidence of complications and longer survival due to inhibition of deoxyhaemoglobin S (HbS) polymerisation by HbF. HbF-containing cells, namely F cells, are strongly influenced by genetic factors. We measured the percentage of F cells (Fcells%) in 222 patients with SCD to evaluate the association of (i) Fcells% with genetic HbF-modifier variants and (ii) Fcells% with haematological parameters. There was a different distribution of Fcells% in females compared to males. The association of the B-cell lymphoma/leukaemia 11A (BCL11A) locus with Fcells% (ß = 8·238; P < 0·001) and with HbF% (ß = 2·490; P < 0·001) was significant. All red cell parameters except for Hb and mean corpuscular Hb concentration levels in males and females were significantly different. The Fcells% was positively associated with mean cell Hb, mean cell volume and reticulocytes. To explain the significant gender difference in Fcells%, we tested for associations with single nucleotide polymorphisms on the X chromosomal region Xp22.2, where a genetic determinant of HbF had been previously hypothesised. We found in males a significant association with a SNP in FERM and PDZ domain-containing protein 4 (FRMPD4) and adjacent to male-specific lethal complex subunit 3 (MSL3). Thus, we have identified an X-linked locus that could account for a significant fraction of the Fcells% variation in patients with SCD.
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Anemia de Células Falciformes , Cromosomas Humanos X/genética , Eritrocitos Anormales/metabolismo , Genes Ligados a X , Polimorfismo Genético , Proteínas Represoras/genética , Reticulocitos/metabolismo , Adolescente , Adulto , Anemia de Células Falciformes/sangre , Anemia de Células Falciformes/genética , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND/OBJECTIVE: Sickle cell disease (SCD) is a monogenic disease with multiple phenotypic expressions. Previous studies describing SCD clinical phenotypes in Nigeria were localized, with limited data, hence the need to understand how SCD varies across Nigeria. METHOD: The Sickle Pan African Research Consortium (SPARCO) with a hub in Tanzania and collaborative sites in Tanzania, Ghana and Nigeria, is establishing a single patient-consented electronic database with a target of 13,000 SCD patients. In collaboration with the Sickle Cell Support Society of Nigeria, 20 hospitals, with paediatric and adult SCD clinics, are participating in patient recruitment. Demographic and clinical information, collected with uniform case report forms, were entered into Excel spreadsheets and uploaded into Research Electronic Data Capture software by trained data clerks and frequency tables generated. RESULT: Data were available on 3622 patients enrolled in the database, comprising 1889 (52.9%) females and 1434 (39.6%) children ≤15 years. The frequencies of Hb SS, Hb SC and Hb Sß thalassemia in this data set were 97.5%, 2.5% and 0% respectively. Sixty percent, 23.8%, 5.9%, 4.8% and 2.5% have had bone pain crisis, dactylitis, acute chest syndrome, priapism and stroke respectively. The most frequent chronic complications were: leg ulcers (6.5%), avascular necrosis of bone (6.0%), renal (6.3%) and pulmonary hypertension (1.1%). Only 13.2% had been hospitalized while 67.5% had received blood transfusion. CONCLUSION: These data on the spectrum of clinical phenotypes of SCD are useful for planning, improving the management of SCD across Nigeria and provide a foundation for genomic research on SCD.
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Anemia de Células Falciformes/complicaciones , Síndrome Torácico Agudo/etiología , Adolescente , Adulto , Anemia/etiología , Anemia de Células Falciformes/epidemiología , Niño , Femenino , Humanos , Úlcera de la Pierna/etiología , Masculino , Nigeria/epidemiología , Dolor/etiología , Accidente Cerebrovascular/etiología , Adulto JovenRESUMEN
BACKGROUND: Sickle cell disease (SCD) is a blood disorder caused by a point mutation on the beta globin gene resulting in the synthesis of abnormal hemoglobin. Fetal hemoglobin (HbF) reduces disease severity, but the levels vary from one individual to another. Most research has focused on common genetic variants which differ across populations and hence do not fully account for HbF variation. METHODS: We investigated rare and common genetic variants that influence HbF levels in 14 SCD patients to elucidate variants and pathways in SCD patients with extreme HbF levels (≥7.7% for high HbF) and (≤2.5% for low HbF) in Tanzania. We performed targeted next generation sequencing (Illumina_Miseq) covering exonic and other significant fetal hemoglobin-associated loci, including BCL11A, MYB, HOXA9, HBB, HBG1, HBG2, CHD4, KLF1, MBD3, ZBTB7A and PGLYRP1. RESULTS: Results revealed a range of genetic variants, including bi-allelic and multi-allelic SNPs, frameshift insertions and deletions, some of which have functional importance. Notably, there were significantly more deletions in individuals with high HbF levels (11% vs 0.9%). We identified frameshift deletions in individuals with high HbF levels and frameshift insertions in individuals with low HbF. CHD4 and MBD3 genes, interacting in the same sub-network, were identified to have a significant number of pathogenic or non-synonymous mutations in individuals with low HbF levels, suggesting an important role of epigenetic pathways in the regulation of HbF synthesis. CONCLUSIONS: This study provides new insights in selecting essential variants and identifying potential biological pathways associated with extreme HbF levels in SCD interrogating multiple genomic variants associated with HbF in SCD.
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Anemia de Células Falciformes/genética , Hemoglobina Fetal/genética , Variación Genética , Adolescente , Niño , Preescolar , Redes Reguladoras de Genes , Humanos , Mutación con Pérdida de Función/genética , Tanzanía , Adulto JovenRESUMEN
BACKGROUND: Monitoring patient's clinical attendance is a crucial means of improving retention in care and treatment programmes. Sickle cell patients' outcomes are improved by participation in comprehensive care programmes, but these benefits cannot be achieved when patients are lost from clinical care. In this study, patients are defined as loss to follow-up when they did not attend clinic for more than 9 months. Precise information on the retention rate and characteristics of those who are not following their clinic appointments is needed to enable the implementation of interventions that will be effective in increasing the retention to care. METHOD: This was a retrospective study involving sickle cell patients registered in the Muhimbili Sickle Cohort in Tanzania. Descriptive and survival analysis techniques both non-parametric methods (Kaplan-Meier estimator and Log-rank test) and semi-parametric method (Cox's proportional hazard model), were used. A p-value of 0.05 was considered significant to make an inference from the analysis. RESULTS: A total of 5476 patients were registered in the cohort from 2004 to 2016. Of these, 3350 (58.13%) were actively participating in clinics, while 2126 (41.87%) were inactive, of which 1927 (35.19%) were loss to follow-up. We used data from 2004 to 2014 because between 2015 and 2016, patients were referred to other government hospitals. From the survival analysis results, pediatric (HR: 14.29,95% CI: 11.0071-18.5768, p < 0.001) and children between 5 and 17 years [HR:2.61,95% CI:2.2324-3.0705, p < 0.001] patients were more likely to be loss to follow-up than the adult (18 and above years) patients. It was found that patients with above averages for hematocrit (HR: 2.38, 95% CI: 1.0076-1.0404, p = 0.0039) or mean cell volume (HR: 4.28, (95% CI: 1.0260-1.0598, p < 0.001) were more likely to be loss to follow-up than their counterparts. CONCLUSION: Loss to follow-up is evident in the cohort of patients in long term comprehensive care. It is, therefore, necessary to design interventions that improve patients' retention. Suggested solutions include refresher training for health care workers and those responsible for patient follow-up on techniques for retaining patients and comprehensive transition programs to prepare patients who are moving from pediatric to adult clinics.
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Anemia de Células Falciformes , Adulto , Anemia de Células Falciformes/epidemiología , Anemia de Células Falciformes/terapia , Niño , Estudios de Cohortes , Estudios de Seguimiento , Humanos , Estudios Retrospectivos , Tanzanía/epidemiologíaRESUMEN
BACKGROUND: Malaria is among the leading cause of infection in individuals with sickle cell disease (SCD) living in sub-Saharan Africa, including Tanzania. However, after 2005 the standard treatment guidelines (STGs) on malaria chemoprevention for SCD patients were non-existent, and at present no medicine is recommended for SCD patients. Since several anti-malarials have been approved for the treatment of malaria in Tanzania, it is important to establish if there is a continued use of chemoprevention against malaria among SCD children. METHODS: A cross-sectional, hospital-based study was conducted between January and June 2019 at tertiary hospitals in Dar es Salaam. Data were collected using a semi-questionnaire and analysed using SPSS software version 25. The descriptive statistics were summarized using proportions, while factors associated with the use of chemoprophylaxis were analysed using multivariate logistic regression. Statistical significance of p < 0.05 was accepted. RESULTS: A total of 270 SCD children were involved. The median age of SCD children was 6 years (interquartile range (IQR): 3-11 years). Of 270 SCD children, 77% (number (n) = 218) of children with SCD had not been diagnosed with malaria in the previous year, whereas 12.6% (n = 34) of children were admitted because of malaria in the previous year. Regarding the use of chemoprophylaxis in SCD children, 32.6% (n = 88) of parents were aware that, chemoprophylaxis against malaria is recommended in SCD children. Of the 270 participants, 17% (n = 46) were using malaria chemoprophylaxis. A majority used artemisinin combination therapy (ACT), 56.8% (n = 26). Of 223 parents who did not give chemoprophylaxis, the majority (n = 142, 63.7%) indicated unavailability at clinics as the reason. Children whose parents were primary level educated were 9.9 times more likely to not use chemoprophylaxis (adjusted odds ratio (AOR); 9.9, 95% CI 1.8-56.5, P = 0.01) compared to those whose parents had tertiary education. CONCLUSION: Despite the lack of STGs, a small proportion of children with SCD were using malaria chemoprophylaxis where the majority used ACT, i.e., dihydroartemisinin-piperaquine.
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Antimaláricos/uso terapéutico , Quimioprevención/estadística & datos numéricos , Malaria/prevención & control , Centros de Atención Terciaria/estadística & datos numéricos , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Masculino , TanzaníaRESUMEN
BACKGROUND: Optimal adherence to antiretroviral therapy is critical to prevent HIV drug resistance (HIVDR) epidemic. The objective of the study was to investigate the best performing adherence assessment method for predicting virological failure in resource-limited settings (RLS). METHOD: This study was a single-centre prospective cohort, enrolling 220 HIV-infected adult patients attending an HIV/AIDS Care and Treatment Centre in Dar es Salaam, Tanzania, in 2010. Pharmacy refill, self-report (via visual analog scale [VAS] and the Swiss HIV Cohort study-adherence questionnaire), pill count, and appointment keeping adherence measurements were taken. Univariate logistic regression (LR) was done to explore a cut-off that gives a better trade-off between sensitivity and specificity, and a higher area under the curve (AUC) based on receiver operating characteristic curve in predicting virological failure. Additionally, the adherence models were evaluated by fitting multivariate LR with stepwise functions, decision trees, and random forests models, assessing 10-fold multiple cross validation (MCV). Patient factors associated with virological failure were determined using LR. RESULTS: Viral load measurements at baseline and one year after recruitment were available for 162 patients, of whom 55 (34%) had detectable viral load and 17 (10.5%) had immunological failure at one year after recruitment. The optimal cut-off points significantly predictive of virological failure were 95%, 80%, 95% and 90% for VAS, appointment keeping, pharmacy refill, and pill count adherence respectively. The AUC for these methods ranged from 0.52 to 0.61, with pharmacy refill giving the best performance at AUC 0.61. Multivariate logistic regression with boost stepwise MCV had higher AUC (0.64) compared to all univariate adherence models, except pharmacy refill adherence univariate model, which was comparable to the multivariate model (AUC = 0.64). Decision trees and random forests models were inferior to boost stepwise model. Pharmacy refill adherence (<95%) emerged as the best method for predicting virological failure. Other significant predictors in multivariate LR were having a baseline CD4 T lymphocytes count < 200 cells/µl, being unable to recall the diagnosis date, and a higher weight. CONCLUSION: Pharmacy refill has the potential to predict virological failure and to identify patients to be considered for viral load monitoring and HIVDR testing in RLS.
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Fármacos Anti-VIH/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , VIH-1/aislamiento & purificación , Recursos en Salud/provisión & distribución , Cumplimiento de la Medicación , Servicios Farmacéuticos/estadística & datos numéricos , Adolescente , Adulto , Femenino , Humanos , Masculino , Área sin Atención Médica , Persona de Mediana Edad , Evaluación de Procesos y Resultados en Atención de Salud/métodos , Estudios Prospectivos , Autoinforme , Tanzanía , Carga Viral , Adulto JovenRESUMEN
Introduction Individuals with sickle cell disease (SCD) are particularly vulnerable to urinary tract infections (UTIs) due to immunological deficits and renal abnormalities associated with the disorder. These infections can exacerbate underlying health issues and lead to severe complications if not managed promptly and effectively. Due to the heightened risk and potential consequences of UTIs in this population, this study aimed to determine their prevalence and explore the resistance patterns of causative pathogens among children attending the SCD Clinic at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. Focusing on this demographic group, we sought to provide targeted insights to inform better clinical protocols and intervention strategies in regions heavily affected by SCD. Materials and methods This prospective cross-sectional study was conducted at the MNH, Dar es Salaam, Tanzania, with an enrollment over two months from 19th March to 21st May 2015. We diagnosed UTIs in children with SCD using dipstick and culture methods. Antibiotic susceptibility was assessed using the Kirby-Bauer disc diffusion method, evaluating resistance patterns to antibiotics such as ampicillin, cloxacillin, erythromycin, chloramphenicol, ceftriaxone, and trimethoprim-sulfamethoxazole. The diagnostic accuracy of the dipstick and culture methods was validated to ensure reliability in detecting UTIs. Statistical analysis was conducted using Statistical Product and Service Solutions (SPSS) software (Released 2019; IBM Corp., Armonk, New York, United States). Results Among the 250 children, 56 (22.4%) were UTI-positive according to the culture method and 62 (24.8%) were UTI-positive according to the dipstick test. Girls were more likely to be UTI-positive than boys (29.1% and 13.6%, respectively; p-value = 0.011). Escherichia coli was the most common uropathogen, followed by Klebsiella, Staphylococcus, Proteus, and Pseudomonas (44.2%, 26.9%, 21.2%, 3.8%, and 1.9%, respectively). All isolates were resistant to ampiclox. Resistance rates to ampicillin, erythromycin, cotrimoxazole, chloramphenicol, and ceftriaxone were 94.2%, 76.9%, 59.6%, 46.2%, and 21.2%, respectively. Conclusion This study indicated that dipsticks diagnosed more UTIs. The prevalence was higher in girls than in boys. Escherichia coli was the most commonly isolated antibiotic-resistant organism. High resistance levels were observed against the combination of ampicillin and cloxacillin. However, the isolates were less resistant to ceftriaxone. These results call for increased surveillance of resistant uropathogens in the pediatric population with SCD.
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Background: Antimicrobial resistance (AMR) is a growing public health concern globally, and misuse of antibiotics is a major contributor. Objective: This study investigated antibiotic utilization patterns before and during the COVID-19 pandemic in Tanzania using data from the Tanzania Medicines and Medical Devices Authority (TMDA). Methods: This retrospective longitudinal study analysed secondary data. The study compared antibiotics consumption in defined daily doses per 1000 inhabitants per day (DID) in two distinct eras: 2018-2019 as the pre-COVID-19 era and 2020-2021 as the intra-COVID-19 era. A sample t-test was conducted using Statistical Package for the Social Sciences. Results: The study analysed 10â614 records and found an overall increase in antibiotics consumption from 2018 to 2021. We found that the consumption was 61.24 DID in the intra-COVID-19 era and 50.32 DID in the pre-COVID-19 era. Levofloxacin had the highest percentage increase in use, with a 700% increase in DID during the intra-COVID-19 era. Azithromycin had a 163.79% increase, while cefotaxime had a 600% increase. By contrast, some antibiotics exhibited a decrease in usage during the intra-COVID-19 era, such as nalidixic acid, which had a 100% decrease, and cefpodoxime, which had a 66.67% decrease. Conclusions: Increased antibiotic consumption during the COVID-19 pandemic highlights the importance of implementing effective antimicrobial stewardship strategies to prevent AMR, especially during pandemics.
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Introduction Emergency contraceptives (ECs) are a critical method for preventing unwanted pregnancies following unprotected sexual intercourse. However, Tanzania is experiencing an alarming surge in the misuse of ECs among reproductive-aged females, particularly younger girls and women. Reports of their use as regular contraceptives are a rising concern. Deviations from their intended use in emergencies may not only increase the risk of contraceptive failure but also increase the risk of adverse health events. This study aims to delineate and evaluate the utilization patterns of ECs over six consecutive years using importation data obtained from the Tanzania Medicines and Medical Devices Authority (TMDA). Materials and methods We analyzed the EC data collected by TMDA over six consecutive years using a retrospective longitudinal design. Microsoft Power BI (Microsoft® Corp., Redmond, WA) was used to clean, organize, and aggregate the data. IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States) was used to analyze annual trend utilization using linear regression. Results We analyzed 114 importation consignments for ECs, identifying 95.6% (109 records) as oral ECs and 4.4% (five records) as intrauterine devices (IUDs) between 2018 and 2023. This data revealed a significant increase in the volume of EC imports, with its contribution increasing from 1.9% in 2018 to 60.1% in 2023. This highlights the marked increase in EC consumption in Tanzania. In 2023, the defined daily dose per 1000 inhabitants per year (DID) peaked at 3.917826, indicating an unprecedented increase of 4,983.06% compared to the lowest DID observed in 2019 at 0.0873552. The year 2023 alone accounted for 41.63% of the total DID (9.43) over the entire study period. In 2019 and 2020, there was a decrease in EC consumption, followed by a rapid increase from 2021 to 2023. The reduction in EC consumption from 2019 to 2020 was 36.9% compared to that between 2021 and 2022. Conclusions The significant rise in EC importation and utilization in Tanzania between 2018 and 2023, marked by fluctuating consumption trends and a notable surge, highlights the urgent need for targeted educational and policy intervention. This will guide the rational and informed use of ECs, ensuring access aligns with best practices for reproductive health.
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Introduction Erectile dysfunction (ED) profoundly affects millions of people globally, including interfering with mental health and quality of life. Phosphodiesterase type-5 inhibitors (PDE5Is) such as sildenafil are pivotal in ED treatment. This study aimed to examine the utilization patterns of PDE5Is in Tanzania. Materials and methods In this retrospective longitudinal study, data on sildenafil and other similar PDE5Is imported between 2019 and 2023 were sourced from the Tanzania Medicines and Medical Devices Authority (TMDA). Pre-processing and visualization were performed using Microsoft Power BI Desktop, and further analysis was performed using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States). Utilization trends were ascertained through curve fitting, Holt's linear trend model, and autoregressive integrated moving average (ARIMA) models. The defined daily doses (DDDS) per 1000 inhabitants (DID) were calculated using the World Health Organization (WHO) Anatomical Therapeutic Chemical (ATC) Classification System and the DDD methodology endorsed by the WHO Collaborating Centre for Drug Statistics Methodology. Results Between 2019 and 2023, there was a pronounced increase in the importation of approximately 587 consignments of PDE5Is. Employing the Holt model (R-square = 0.843), a substantial increase from 0.220910 DID in 2019 to 0.534272 DID by 2025 was observed and anticipated. The period witnessed sildenafil dominating 75.5% of the total use, with Erecto being the most consumed brand (37.6% of total DID). Notably, 2022 had the highest surge (27.2% of the total), albeit a slight decline was observed in 2023 (20.5%). This trend was supported by a linear regression model (R-square = 0.889). Conclusion We found increasing annual trends of PDE5Is of utilization. This requires critical oversight and effective policies to ensure appropriate use and risk minimization.
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The COVID-19 pandemic has significantly disrupted healthcare systems at all levels globally, notably affecting routine healthcare services, such as childhood vaccination. This study examined the impact of these disruptions on routine childhood vaccination programmes in Tanzania. We conducted a longitudinal study over four years in five Tanzanian regions: Mwanza, Dar es Salaam, Mtwara, Arusha, and Dodoma. This study analyzed the trends in the use of six essential vaccines: Bacille Calmette-Guérin (BCG), bivalent Oral Polio Vaccine (bOPV), Diphtheria Tetanus Pertussis, Hepatitis-B and Hib (DTP-HepB-Hib), measles-rubella (MR), Pneumococcal Conjugate Vaccine (PCV), and Rota vaccines. We evaluated annual and monthly vaccination trends using time-series and regression analyses. Predictive modeling was performed using an autoregressive integrated moving average (ARIMA) model. A total of 32,602,734 vaccination events were recorded across the regions from 2019 to 2022. Despite declining vaccination rates in 2020, there was a notable rebound in 2021, indicating the resilience of Tanzania's immunization program. The analysis also highlighted regional differences in vaccination rates when standardized per 1000 people. Seasonal fluctuations were observed in monthly vaccination rates, with BCG showing the most stable trend. Predictive modeling of BCG indicated stable and increasing vaccination coverage by 2023. These findings underscore the robustness of Tanzania's childhood immunization infrastructure in overcoming the challenges posed by the COVID-19 pandemic, as indicated by the strong recovery of vaccination rates post-2020. We provide valuable insights into the dynamics of vaccination during a global health crisis and highlight the importance of sustained immunization efforts to maintain public health.
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COVID-19 , Programas de Inmunización , Vacunación , Humanos , Tanzanía/epidemiología , COVID-19/prevención & control , COVID-19/epidemiología , Vacunación/estadística & datos numéricos , Vacunación/tendencias , Estudios Longitudinales , Lactante , Preescolar , Programas de Inmunización/estadística & datos numéricos , Programas de Inmunización/tendencias , Niño , Vacuna BCG/administración & dosificación , Vacuna BCG/inmunología , SARS-CoV-2/inmunología , Pandemias/prevención & controlRESUMEN
BACKGROUND: Pharmacogenomics of hydroxyurea is an important aspect in the management of sickle cell disease (SCD), especially in the era of genomic medicine. Genetic variations in loci associated with HbF induction and drug metabolism are prime targets for hydroxyurea (HU) pharmacogenomics, as these can significantly impact the therapeutic efficacy and safety of HU in SCD patients. METHODS: This study involved designing of a custom panel targeting BCL11A, ARG2, HBB, HBG1, WAC, HBG2, HAO2, MYB, SAR1A, KLF10, CYP2C9, CYP2E1 and NOS1 as potential HU pharmacogenomics targets. These genes were selected based on their known roles in HbF induction and HU metabolism. The panel was designed using the Illumina Design Studio (Illumina, San Diego, CA, USA) and achieved a total coverage of 96% of all genomic targets over a span of 51.6 kilobases (kb). This custom panel was then sequenced using the Illumina MiSeq platform to ensure high coverage and accuracy. RESULTS: We are reporting a successfully designed Illumina (MiSeq) HU pharmacogenomics custom panel encompassing 51.6 kilobases. The designed panel achieved greater than 1000x amplicon coverage which is sufficient for genomic analysis. CONCLUSIONS: This study provides a valuable tool for research in HU pharmacogenomics, especially in Africa where SCD is highly prevalent, and personalized medicine approaches are crucial for improving patient outcomes. The custom-designed Illumina (MiSeq) panel, with its extensive coverage and high sequencing depth, provides a robust platform for studying genetic variations associated with HU response. This panel can contribute to the development of tailored therapeutic strategies, ultimately enhancing the management of SCD through more effective and safer use of hydroxyurea.