RESUMO
In settings with high tuberculosis (TB) endemicity, distinct genotypes of the Mycobacterium tuberculosis complex (MTBC) often differ in prevalence. However, the factors leading to these differences remain poorly understood. Here we studied the MTBC population in Dar es Salaam, Tanzania over a six-year period, using 1,082 unique patient-derived MTBC whole-genome sequences (WGS) and associated clinical data. We show that the TB epidemic in Dar es Salaam is dominated by multiple MTBC genotypes introduced to Tanzania from different parts of the world during the last 300 years. The most common MTBC genotypes deriving from these introductions exhibited differences in transmission rates and in the duration of the infectious period, but little differences in overall fitness, as measured by the effective reproductive number. Moreover, measures of disease severity and bacterial load indicated no differences in virulence between these genotypes during active TB. Instead, the combination of an early introduction and a high transmission rate accounted for the high prevalence of L3.1.1, the most dominant MTBC genotype in this setting. Yet, a longer co-existence with the host population did not always result in a higher transmission rate, suggesting that distinct life-history traits have evolved in the different MTBC genotypes. Taken together, our results point to bacterial factors as important determinants of the TB epidemic in Dar es Salaam.
Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Mycobacterium tuberculosis/genética , Tanzânia/epidemiologia , Tuberculose/epidemiologia , Genótipo , VirulênciaRESUMO
BACKGROUND: CD4 measurement is pivotal in the management of advanced HIV disease. VISITECT® CD4 Advanced Disease (AccuBio Limited, Alva, UK; VISITECT) is an instrument-free, point-of-care, semi-quantitative test allowing visual identification of a CD4 ≤200 cells/µl, or >200 cells/µl from finger-prick or venous blood. METHODS: As part of a diagnostic accuracy study of FUJIFILM SILVAMP TB LAM (clinicaltrials.gov: NCT04089423), people living with HIV of ≥18 years old were prospectively recruited in seven countries from outpatient departments if a tuberculosis symptom was present, and from inpatient departments. Participants provided venous blood for CD4 measurement using flow cytometry (reference standard) and finger-prick blood for VISITECT (index text), performed at point-of-care. Sensitivity, specificity, and positive and negative predictive values of VISITECT to determine a CD4 ≤200 cells/µl were evaluated. RESULTS: Among 1604 participants, the median flow cytometry CD4 was 367 (IQR 128-626) cells/µl and 521 (32.5%) had a CD4 ≤200 cells/µl. VISITECT sensitivity was 92.7% (483/521, 95% CI 90.1-94.7%) and specificity was 61.4% (665/1083, 95% CI 58.4-64.3%). For participants with a CD4 between 0-100, 101-200, 201-300, 301-500, and >500 cells/µl, VISITECT misclassified 4.5% (95% CI 2.5-7.2%), 12.5 (95% CI 8.0-18.2%), 74.1% (95% CI 67.0-80.5%), 48.0% (95% CI 42.5-53.6%), and 22.6% (95% CI 19.3-26.3%), respectively. CONCLUSIONS: VISITECT's sensitivity, but not specificity, met the World Health Organization's minimal sensitivity and specificity threshold of 80% for point-of-care CD4 tests. VISITECT's quality needs to be assessed and its accuracy optimized. VISITECT´s utility as CD4 triage test should be investigated.
RESUMO
Bacterial killing in patients with tuberculosis (TB) relapse was compared to that in patients achieving cure, measured by TB molecular bacterial load assay (TB-MBLA) or mycobacteria growth indicator tube (MGIT) time to positivity (TTP). TB-MBLA in 4 relapsed patients was significantly different compared to 132 cured patients after 2 weeks of treatment; MGIT TTP showed a significant difference from week 8.
Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Carga Bacteriana , Tuberculose/diagnóstico , Tuberculose/microbiologia , Recidiva , Escarro/microbiologiaRESUMO
BACKGROUND: Patients with suspected extrapulmonary tuberculosis are often treated empirically. We hypothesized that extended focused assessment with sonography for human immunodeficiency virus (HIV) and tuberculosis (eFASH), in combination with other tests, would increase the proportion of correctly managed patients with suspected extrapulmonary tuberculosis. METHODS: This trial in adults with suspected extrapulmonary tuberculosis was performed in a rural and an urban hospital in Tanzania. Participants were randomized 1:1 to intervention or routine care, stratified by site and HIV status. All participants underwent clinical evaluation, chest radiography, and testing with sputum Xpert MTB/RIF and urine Xpert MTB/RIF Ultra assays. The intervention was a management algorithm based on results of eFASH plus microbiology, adenosine deaminase (ADA), and chest radiography. The primary outcome was the proportion of correctly managed patients. The presence of positive microbiological or ADA results defined definite tuberculosis. An independent end-point review committee determined diagnoses of probable or no tuberculosis. We evaluated outcomes using logistic regression models, adjusted for randomization stratification factors. RESULTS: From September 2018 to October 2020, a total of 1036 patients were screened and 701 were randomized (350 to the intervention and 351 to the control group). Of participants in the intervention group, 251 (72%) had a positive eFASH outcome. In 258 (74%) of the intervention and 227 (65%) of the control participants antituberculosis was initiated treatment at baseline. More intervention participants had definite tuberculosis (n = 124 [35%]), compared with controls (n = 85 [24%]). There was no difference between groups for the primary outcome (intervention group, 266 of 286 [93%]; control group, 245 of 266 [92%]; odds ratio, 1.14 [95% confidence interval: .60-2.16]; P = .68). There were no procedure-associated adverse events. CONCLUSIONS: eFASH did not change the proportion of correctly managed patients but increased the proportion of those with definite tuberculosis. CLINICAL TRIALS REGISTRATION: Pan African Registry: PACTR201712002829221.
Assuntos
Infecções por HIV , Tuberculose Extrapulmonar , Tuberculose , Adulto , Humanos , Tuberculose/diagnóstico por imagem , Tuberculose/tratamento farmacológico , Tanzânia , Escarro/microbiologiaRESUMO
Genome-wide association studies rely on the statistical inference of untyped variants, called imputation, to increase the coverage of genotyping arrays. However, the results are often suboptimal in populations underrepresented in existing reference panels and array designs, since the selected single nucleotide polymorphisms (SNPs) may fail to capture population-specific haplotype structures, hence the full extent of common genetic variation. Here, we propose to sequence the full genomes of a small subset of an underrepresented study cohort to inform the selection of population-specific add-on tag SNPs and to generate an internal population-specific imputation reference panel, such that the remaining array-genotyped cohort could be more accurately imputed. Using a Tanzania-based cohort as a proof-of-concept, we demonstrate the validity of our approach by showing improvements in imputation accuracy after the addition of our designed add-on tags to the base H3Africa array.
Assuntos
Genética Populacional , Estudo de Associação Genômica Ampla , Genótipo , Polimorfismo de Nucleotídeo Único/genética , Biologia Computacional/métodos , Genética Populacional/métodos , Genética Populacional/normas , Estudo de Associação Genômica Ampla/métodos , Estudo de Associação Genômica Ampla/normas , Humanos , Masculino , TanzâniaRESUMO
BACKGROUND: The health impact of the COVID-19 pandemic largely depends on the ability of the healthcare systems to develop effective and adaptable preparedness and mitigation strategies. A collaborative initiative (BRCCH-EDCTP COVID-19 Initiative) was set up between Lesotho and Zambia early on in the pandemic, to jointly conduct a project to investigate creating access to SARS-CoV-2 screening and testing through community-based COVID-19 case-finding. METHODS: Two different community case-finding strategies were deployed. In Lesotho, an approach was implemented whereby a community (village) health worker screened community members at their home or during community gatherings for COVID-19 signs and symptoms. All community members who screened positive were then offered SARS-CoV-2 testing. In Zambia, so-called community hubs, staffed by community health care workers, were set up at different locations in the community for people to walk in and get tested for SARS-CoV-2. Hubs changed location from week-to-week and targeted transmission hotspots. All persons visiting the hubs were offered testing for SARS-CoV-2 irrespective of self-reported signs and symptoms of COVID-19 though information was collected on occurrence of these. Testing in both approaches was done using SARS-CoV-2 rapid antigen tests. RESULTS: Setting up testing in the community setting was feasible in both countries. In Lesotho in the village health worker approach, over a period of 46 weeks, 7221 persons were screened, and 49 (11.4%) SARS-COV-2 cases identified among 428 COVID-19 screen positive participants. In the community hubs among 3150 people tested, 166 (5.3%) SARS-CoV-2 cases were identified in a period of 26 weeks. From the community hubs approach, where all seen were offered COVID-19 testing it was learned that people screening positive for COVID-19 signs and symptoms were more likely to test SARS-COV-2 positive, especially those reporting classic COVID-19 symptoms like loss of sense/smell for a short period of time (1-3 days). CONCLUSIONS: In conclusion, in this project we learned that implementing COVID-19 screening and testing by lay health workers in the community is possible. Characteristics of the population screened, tested, and identified to have SARS-CoV-2 are described to help guide development of future testing strategies.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Teste para COVID-19 , Estudos Transversais , Lesoto , Pandemias , Zâmbia , Agentes Comunitários de SaúdeRESUMO
BACKGROUND: Automated radiologic analysis using computer-aided detection software (CAD) could facilitate chest X-ray (CXR) use in tuberculosis diagnosis. There is little to no evidence on the accuracy of commercially available deep learning-based CAD in different populations, including patients with smear-negative tuberculosis and people living with human immunodeficiency virus (HIV, PLWH). METHODS: We collected CXRs and individual patient data (IPD) from studies evaluating CAD in patients self-referring for tuberculosis symptoms with culture or nucleic acid amplification testing as the reference. We reanalyzed CXRs with three CAD programs (CAD4TB version (v) 6, Lunit v3.1.0.0, and qXR v2). We estimated sensitivity and specificity within each study and pooled using IPD meta-analysis. We used multivariable meta-regression to identify characteristics modifying accuracy. RESULTS: We included CXRs and IPD of 3727/3967 participants from 4/7 eligible studies. 17% (621/3727) were PLWH. 17% (645/3727) had microbiologically confirmed tuberculosis. Despite using the same threshold score for classifying CXR in every study, sensitivity and specificity varied from study to study. The software had similar unadjusted accuracy (at 90% pooled sensitivity, pooled specificities were: CAD4TBv6, 56.9% [95% confidence interval {CI}: 51.7-61.9]; Lunit, 54.1% [95% CI: 44.6-63.3]; qXRv2, 60.5% [95% CI: 51.7-68.6]). Adjusted absolute differences in pooled sensitivity between PLWH and HIV-uninfected participants were: CAD4TBv6, -13.4% [-21.1, -6.9]; Lunit, +2.2% [-3.6, +6.3]; qXRv2: -13.4% [-21.5, -6.6]; between smear-negative and smear-positive tuberculosis was: were CAD4TBv6, -12.3% [-19.5, -6.1]; Lunit, -17.2% [-24.6, -10.5]; qXRv2, -16.6% [-24.4, -9.9]. Accuracy was similar to human readers. CONCLUSIONS: For CAD CXR analysis to be implemented as a high-sensitivity tuberculosis rule-out test, users will need threshold scores identified from their own patient populations and stratified by HIV and smear status.
Assuntos
Aprendizado Profundo , Infecções por HIV , Tuberculose Pulmonar , Tuberculose , Infecções por HIV/complicações , Humanos , Sensibilidade e Especificidade , Software , Triagem , Tuberculose Pulmonar/diagnóstico por imagem , Tuberculose Pulmonar/microbiologia , Raios XRESUMO
BACKGROUND: The burden of chronic respiratory symptoms and respiratory functional limitations is underestimated in Africa. Few data are available on carbon monoxide (CO) poisoning in sub-Saharan Africa and existing data is derived from CO in ambient air, but not from biomarkers in the blood. METHODS: Data from the Tanzanian Lung Health study, a cross-sectional study on lung health among outpatients and visitors to an urban as well as a rural hospital in Tanzania, was analyzed to describe respiratory symptoms and functional limitations. Saturation of peripheral blood with carbon monoxide (SpCO) was measured transcutaneously and non-invasively in participants using a modified pulse oxymeter indicative of CO poisoning. Univariate and multivariate analysis was performed. RESULTS: Nine hundred and ninety-seven participants were included in the analysis, the median age of participants was 46 years (49% male). 38% of participants reported some degree of chronic shortness of breath and 26% felt limited in their daily activities or at work by this symptom. The median SpCO was 7% (IQR 4-13, range 2-31%) among all participants without active smoking status (N = 808). Participants cooking with gas or electricity had the lowest SpCO (median 5%), followed by participants cooking with charcoal (median 7%). Cooking with wood, particularly using a stove, resulted in highest SpCO (median 11.5%). Participants from households where cooking takes place in a separate room had the lowest SpCO as compared to cooking outside or cooking in a shared room inside (6% vs. 9% vs.10.5%, p < 0.01). Sex or the activity of cooking itself was not associated with a difference in SpCO. Multivariate analysis confirmed cooking in a separate room (as compared to cooking outside) and living in a rural vs. urban setting as protective factors against high SpCO. CONCLUSION: The findings demonstrate a high burden of chronic respiratory symptoms which also cause socioeconomic impact. High levels of SpCO indicate a relevant burden of carbon monoxide poisoning in the local population. The level of CO in the blood is more dependent on shared exposure to sources of CO with the type of housing and type of cooking fuel as most relevant factors, and less on person-individual risk factors or activities.
Assuntos
Intoxicação por Monóxido de Carbono , Monóxido de Carbono/análise , Intoxicação por Monóxido de Carbono/diagnóstico , Intoxicação por Monóxido de Carbono/epidemiologia , Intoxicação por Monóxido de Carbono/etiologia , Culinária/métodos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tanzânia/epidemiologiaRESUMO
BACKGROUND: The World Health Organization (WHO) recommends Xpert MTB/RIF in place of smear microscopy to diagnose tuberculosis (TB), and many countries have adopted it into their diagnostic algorithms. However, it is not clear whether the greater accuracy of the test translates into improved health outcomes. OBJECTIVES: To assess the impact of Xpert MTB/RIF on patient outcomes in people being investigated for tuberculosis. SEARCH METHODS: We searched the following databases, without language restriction, from 2007 to 24 July 2020: Cochrane Infectious Disease Group (CIDG) Specialized Register; CENTRAL; MEDLINE OVID; Embase OVID; CINAHL EBSCO; LILACS BIREME; Science Citation Index Expanded (Web of Science), Social Sciences citation index (Web of Science), and Conference Proceedings Citation Index - Social Science & Humanities (Web of Science). We also searched the WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and the Pan African Clinical Trials Registry for ongoing trials. SELECTION CRITERIA: We included individual- and cluster-randomized trials, and before-after studies, in participants being investigated for tuberculosis. We analysed the randomized and non-randomized studies separately. DATA COLLECTION AND ANALYSIS: For each study, two review authors independently extracted data, using a piloted data extraction tool. We assessed the risk of bias using Cochrane and Effective Practice and Organisation of Care (EPOC) tools. We used random effects meta-analysis to allow for heterogeneity between studies in setting and design. The certainty of the evidence in the randomized trials was assessed by GRADE. MAIN RESULTS: We included 12 studies: eight were randomized controlled trials (RCTs), and four were before-and-after studies. Most included RCTs had a low risk of bias in most domains of the Cochrane 'Risk of bias' tool. There was inconclusive evidence of an effect of Xpert MTB/RIF on all-cause mortality, both overall (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.75 to 1.05; 5 RCTs, 9932 participants, moderate-certainty evidence), and restricted to studies with six-month follow-up (RR 0.98, 95% CI 0.78 to 1.22; 3 RCTs, 8143 participants; moderate-certainty evidence). There was probably a reduction in mortality in participants known to be infected with HIV (odds ratio (OR) 0.80, 95% CI 0.67 to 0.96; 5 RCTs, 5855 participants; moderate-certainty evidence). It is uncertain whether Xpert MTB/RIF has no or a modest effect on the proportion of participants starting tuberculosis treatment who had a successful treatment outcome (OR) 1.10, 95% CI 0.96 to 1.26; 3RCTs, 4802 participants; moderate-certainty evidence). There was also inconclusive evidence of an effect on the proportion of participants who were treated for tuberculosis (RR 1.10, 95% CI 0.98 to 1.23; 5 RCTs, 8793 participants; moderate-certainty evidence). The proportion of participants treated for tuberculosis who had bacteriological confirmation was probably higher in the Xpert MTB/RIF group (RR 1.44, 95% CI 1.29 to 1.61; 6 RCTs, 2068 participants; moderate-certainty evidence). The proportion of participants with bacteriological confirmation who were lost to follow-up pre-treatment was probably reduced (RR 0.59, 95% CI 0.41 to 0.85; 3 RCTs, 1217 participants; moderate-certainty evidence). AUTHORS' CONCLUSIONS: We were unable to confidently rule in or rule out the effect on all-cause mortality of using Xpert MTB/RIF rather than smear microscopy. Xpert MTB/RIF probably reduces mortality among participants known to be infected with HIV. We are uncertain whether Xpert MTB/RIF has a modest effect or not on the proportion treated or, among those treated, on the proportion with a successful outcome. It probably does not have a substantial effect on these outcomes. Xpert MTB/RIF probably increases both the proportion of treated participants who had bacteriological confirmation, and the proportion with a laboratory-confirmed diagnosis who were treated. These findings may inform decisions about uptake alongside evidence on cost-effectiveness and implementation.
ANTECEDENTES: La Organización Mundial de la Salud (OMS) recomienda la Xpert MTB/RIF en lugar de la baciloscopia para diagnosticar la tuberculosis (TB) y muchos países la han adoptado en sus algoritmos de diagnóstico. Sin embargo, no está claro si la mayor exactitud de la prueba se traduce en mejores desenlaces de salud. OBJETIVOS: Evaluar el impacto de la Xpert MTB/RIF en los desenlaces de las personas sometidas a pruebas para la tuberculosis. MÉTODOS DE BÚSQUEDA: Se realizaron búsquedas en las siguientes bases de datos, sin restricción de idioma, desde 2007 hasta el 24 de julio de 2020: Registro especializado del Grupo Cochrane de Enfermedades infecciosas (Cochrane Infectious Disease Group [CIDG]); CENTRAL; MEDLINE OVID; Embase OVID; CINAHL EBSCO; LILACS BIREME; Science Citation Index Expanded (Web of Science), Social Sciences citation index (Web of Science), y Conference Proceedings Citation Index Social Science & Humanities (Web of Science). También se buscaron ensayos en curso en la Plataforma de registros internacionales de ensayos clínicos de la OMS, en ClinicalTrials.gov y en el Pan African Clinical Trials Registry. CRITERIOS DE SELECCIÓN: Se incluyeron ensayos aleatorizados individuales y por conglomerados, y estudios tipo antes y después (beforeafter studie), con participantes sometidos a pruebas para la tuberculosis. Los estudios aleatorizados y no aleatorizados se analizaron por separado. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Dos autores de la revisión, de forma independiente, extrajeron los datos de cada estudio mediante una herramienta de extracción de datos analizada. El riesgo de sesgo se evaluó mediante las herramientas de Cochrane y del Grupo Cochrane para una Práctica y organización sanitarias efectivas (Effective Practice and Organisation of Care [EPOC]). Se utilizó el metanálisis de efectos aleatorios para considerar la heterogeneidad entre los estudios en cuanto al contexto y el diseño. La certeza de la evidencia en los ensayos aleatorizados se evaluó mediante el método GRADE. RESULTADOS PRINCIPALES: Se incluyeron 12 estudios: ocho eran ensayos controlados aleatorizados (ECA) y cuatro eran estudios tipo antes y después. La mayoría de los ECA incluidos tenían un bajo riesgo de sesgo en la mayoría de los dominios de la herramienta Cochrane "Risk of bias". Hubo evidencia no concluyente de un efecto de la Xpert MTB/RIF sobre la mortalidad por todas las causas, tanto en general (razón de riesgos [RR] 0,89; intervalo de confianza [IC] del 95%: 0,75 a 1,05; cinco ECA, 9932 participantes, evidencia de certeza moderada), como limitada a los estudios con seguimiento de seis meses (RR 0,98; IC del 95%: 0,78 a 1,22; tres ECA, 8143 participantes; evidencia de certeza moderada). Probablemente hubo una reducción de la mortalidad en los participantes que se sabía que estaban infectados por el VIH (odds ratio [OR] 0,80; IC del 95%: 0,67 a 0,96; cinco ECA, 5855 participantes; evidencia de certeza moderada). No está claro si la Xpert MTB/RIF no tiene efectos o tiene un efecto modesto sobre la proporción de participantes que inician el tratamiento de la tuberculosis y que tienen un desenlace exitoso del tratamiento (OR 1,10; IC del 95%: 0,96 a 1,26; tres ECA, 4802 participantes; evidencia de certeza moderada). También hubo evidencia no concluyente de un efecto sobre el porcentaje de participantes que recibieron tratamiento para la tuberculosis (RR 1,10; IC del 95%: 0,98 a 1,23; cinco ECA, 8793 participantes; evidencia de certeza moderada). Es probable que la proporción de participantes tratados por tuberculosis que tuvieron confirmación bacteriológica fuera mayor en el grupo de Xpert MTB/RIF (RR 1,44; IC del 95%: 1,29 a 1,61; seis ECA, 2068 participantes; evidencia de certeza moderada). Es probable que se redujera la proporción de participantes con confirmación bacteriológica que se perdió durante el seguimiento previo al tratamiento (RR 0,59; IC del 95%: 0,41 a 0,85; tres ECA, 1217 participantes; evidencia de certeza moderada). CONCLUSIONES DE LOS AUTORES: No fue posible descartar con seguridad el efecto sobre la mortalidad por todas las causas del uso de Xpert MTB/RIF en lugar de la baciloscopia. La Xpert MTB/RIF probablemente reduce la mortalidad en los participantes que se sabe que están infectados por el VIH. No hay certeza con respecto a si la Xpert MTB/RIF tiene un efecto modesto o no en la proporción tratada o, entre los tratados, en la proporción con un desenlace exitoso. Probablemente no tenga un efecto importante sobre estos desenlaces. La Xpert MTB/RIF probablemente aumenta la proporción de participantes tratados que tenían confirmación bacteriológica, así como la de aquellos con un diagnóstico confirmado por el laboratorio que fueron tratados. Estos hallazgos podrían servir de base para las decisiones sobre la adopción de la prueba, junto con la evidencia sobre la costeefectividad y la aplicación.
Assuntos
Antibióticos Antituberculose/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Rifampina/farmacologia , Tuberculose Pulmonar/diagnóstico , Viés , Intervalos de Confiança , Estudos Controlados Antes e Depois , Farmacorresistência Bacteriana , Infecções por HIV/mortalidade , Humanos , Mycobacterium tuberculosis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto , Kit de Reagentes para Diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/mortalidadeRESUMO
Human immunodeficiency virus (HIV) infection is the major risk factor predisposing for Mycobacterium tuberculosis progression from latent tuberculosis infection (LTBI) to tuberculosis disease (TB). Since long-term-treated aviremic HIV-infected individuals remained at higher risk of developing TB than HIV-uninfected individuals, we hypothesized that progression from LTBI to pulmonary TB (PTB) might be due not only to CD4 T-cell depletion but also to M. tuberculosis-specific CD4 T-cell functional impairment. To test this hypothesis, M. tuberculosis-specific T-cell frequencies and cytokine profiles were investigated in untreated Tanzanian individuals suffering from LTBI (n = 20) or PTB (n = 67) and compared to those of untreated M. tuberculosis/HIV-coinfected individuals suffering from LTBI (n = 15) or PTB (n = 10). We showed that HIV infection significantly reduced the proportion of Th2 (interleukin 4 [IL-4]/IL-5/IL-13) producing M. tuberculosis-specific CD4 T cells and IL-2-producing M. tuberculosis-specific CD4 and CD8 T cells in individuals with LTBI or PTB (P < 0.05). Interestingly, the loss of IL-2 production was associated with a significant increase of PD-1 expression on M. tuberculosis-specific CD4 and CD8 T cells (P < 0.05), while the loss of Th2 cytokine production was associated with a significant reduction of Gata-3 expression in memory CD4 T cells (P < 0.05). Finally, we showed that the serum levels of IL-1α, IL-6, C-reactive protein (CRP), IL-23, and IP-10 were significantly reduced in M. tuberculosis/HIV-coinfected individuals with PTB compared to those in HIV-negative individuals with PTB (P < 0.05), suggesting that HIV infection significantly suppresses M. tuberculosis-induced systemic proinflammatory cytokine responses. Taken together, this study suggests that in addition to depleting M. tuberculosis-specific CD4 T cells, HIV infection significantly impairs functionally favorable M. tuberculosis-specific CD4 T-cell responses in Tanzanian individuals with LTBI or PTB.IMPORTANCEMycobacterium tuberculosis and human immunodeficiency virus (HIV) infections are coendemic in several regions of the world, and M. tuberculosis/HIV-coinfected individuals are more susceptible to progression to tuberculosis disease. We therefore hypothesized that HIV infection would potentially impair M. tuberculosis-specific protective immunity in individuals suffering from latent tuberculosis infection (LTBI) or active pulmonary tuberculosis (PTB). In this study, we demonstrated that M. tuberculosis/HIV-coinfected individuals have fewer circulating M. tuberculosis-specific CD4 T cells and that those that remained were functionally impaired in both LTBI and PTB settings. In addition, we showed that HIV infection significantly interferes with M. tuberculosis-induced systemic proinflammatory cytokine/chemokine responses. Taken together, these data suggest that HIV infection impairs functionally favorable M. tuberculosis-specific immunity.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Citocinas/sangue , Infecções por HIV/imunologia , Mycobacterium tuberculosis/imunologia , Células Th2/imunologia , Tuberculose Pulmonar/imunologia , Adulto , Proteína C-Reativa/metabolismo , Contagem de Linfócito CD4 , Coinfecção/sangue , Citocinas/metabolismo , Feminino , Fator de Transcrição GATA3/sangue , HIV-1/imunologia , Humanos , Tuberculose Latente/patologia , Masculino , Receptor de Morte Celular Programada 1/sangue , Tuberculose Pulmonar/patologiaRESUMO
BACKGROUND: Patients with clinically suspected tuberculosis are often treated empirically, as diagnosis - especially of extrapulmonary tuberculosis - remains challenging. This leads to an overtreatment of tuberculosis and to underdiagnosis of possible differential diagnoses. METHODS: This open-label, parallel-group, superiority randomized controlled trial is done in a rural and an urban center in Tanzania. HIV-positive and -negative adults (≥18 years) with clinically suspected extrapulmonary tuberculosis are randomized in a 1:1 ratio to an intervention- or control group, stratified by center and HIV status. The intervention consists of a management algorithm including extended focused assessment of sonography for HIV and tuberculosis (eFASH) in combination with chest X-ray and microbiological tests. Treatment with anti-tuberculosis drugs is started, if eFASH is positive, chest X-ray suggests tuberculosis, or a microbiological result is positive for tuberculosis. Patients in the control group are managed according national guidelines. Treatment is started if microbiology is positive or empirically according to the treating physician. The primary outcome is the proportion of correctly managed patients at 6 months (i.e patients who were treated with anti-tuberculosis treatment and had definite or probable tuberculosis, and patients who were not treated with anti-tuberculosis treatment and did not have tuberculosis). Secondary outcomes are the proportion of symptom-free patients at two and 6 months, and time to death. The sample size is 650 patients. DISCUSSION: This study will determine, whether ultrasound in combination with other tests can increase the proportion of correctly managed patients with clinically suspected extrapulmonary tuberculosis, thus reducing overtreatment with anti-tuberculosis drugs. TRIAL REGISTRATION: PACTR, Registration number: PACTR201712002829221, registered December 1st 2017.
Assuntos
Tuberculose/diagnóstico por imagem , Ultrassonografia/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , TanzâniaRESUMO
Approximately 3.6 million cases of active tuberculosis (TB) go potentially undiagnosed annually, partly due to limited access to confirmatory diagnostic tests, such as molecular assays or mycobacterial culture, in community and primary healthcare settings. This article provides guidance for TB triage test evaluations. A TB triage test is designed for use in people with TB symptoms and/or significant risk factors for TB. Triage tests are simple and low-cost tests aiming to improve ease of access and implementation (compared with confirmatory tests) and decrease the proportion of patients requiring more expensive confirmatory testing. Evaluation of triage tests should occur in settings of intended use, such as community and primary healthcare centers. Important considerations for triage test evaluation include study design, population, sample type, test throughput, use of thresholds, reference standard (ideally culture), and specimen flow. The impact of a triage test will depend heavily on issues beyond accuracy, primarily centered on implementation.
Assuntos
Bioensaio/normas , Testes Diagnósticos de Rotina/normas , Mycobacterium tuberculosis/isolamento & purificação , Guias de Prática Clínica como Assunto , Triagem/métodos , Tuberculose Pulmonar/diagnóstico , Adulto , Bioensaio/economia , Biomarcadores/sangue , Biomarcadores/urina , Hemocultura/normas , Criança , Estudos de Coortes , Estudos Transversais , Testes Diagnósticos de Rotina/economia , Humanos , Mycobacterium tuberculosis/patogenicidade , Mycobacterium tuberculosis/fisiologia , Padrões de Referência , Projetos de Pesquisa , Fatores de Risco , Sensibilidade e Especificidade , Escarro/microbiologia , Triagem/economia , Triagem/normas , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/fisiopatologia , Organização Mundial da SaúdeRESUMO
BACKGROUND: Delay in healthcare seeking and loss to diagnostic follow-up (LDFU) contribute to substantial increase in tuberculosis (TB) morbidity and mortality. We examined factors, including perceived causes and prior help seeking, contributing to delay and LDFU during referral to a TB clinic among patients with presumptive TB initially seeking help at the pharmacies in Dar es Salaam Tanzania. METHODS: In a TB clinic, a semi-structured interview based on the explanatory model interview catalogue (EMIC) framework for cultural epidemiology was administered to presumptive TB patients enrolled at pharmacies during an intervention study. We assessed delay in seeking care at any medical care provider for a period of ≥3 weeks after the onset of symptoms, LDFU during referral (not reaching the TB clinic), and LDFU for three required TB clinic visits among the presumptive and confirmed TB patients. Logistic regression models were used to assess factors associated with delay and LDFU. RESULTS: Among 136 interviewed patients, 86 (63.2%) were LDFU from pharmacies and TB clinic while 50 (36.8%) were non-LDFU. Out of 136 patients 88 (64.7%) delayed seeking care, of whom 59 (67%) were females. Among the 86 (63.2%) patients in LDFU group, 62 (72.1%) delayed seeking care, while among the 50 (36.8%) non-LDFU, 26 (52.0%) had also delayed seeking care. Prior consultation with a traditional healer (aOR 2.84, 95% CI 1.08-7.40), perceived causes as ingestion (water and food) (aOR 0.38 CI 0.16-0.89), and substance use (smoking and alcohol) (aOR 1.45 CI 0.98-2.14) were all associated with patient delay. Female gender was associated with LDFU (aOR 3.80, 95% CI 1.62-8.87) but not with delay. Other conditions as prior illness and heredity were also associated with LDFU but not delay (aOR 1.48 CI 1.01-2.17). CONCLUSION: Delay and LDFU after referral from the pharmacies were substantial. Notable effects of diagnosis and female gender indicate a need for more attention to women's health to promote timely and sustained TB treatment. Public awareness to counter misconceptions about the causes of TB is needed.
Assuntos
Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Tuberculose/terapia , Adolescente , Adulto , Idoso , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Conscientização , Diagnóstico Tardio/estatística & dados numéricos , Atenção à Saúde/estatística & dados numéricos , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Farmácias/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Distribuição por Sexo , Tanzânia/epidemiologia , Fatores de Tempo , Tempo para o Tratamento/estatística & dados numéricos , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/psicologia , Adulto JovemRESUMO
BACKGROUND: Chronic obstructive pulmonary disease is a global problem and available data from sub-Saharan Africa is very limited. METHODS: A cross-sectional facility-based pilot study among patients and visitors to an urban and a rural primary healthcare facility was conducted in coastal Tanzania. The primary outcome was the prevalence of chronic airflow obstruction. RESULTS: The final analysis included 598 participants with valid post-bronchodilator spirometry. Applying ATS/ERS spirometric criteria, chronic airflow obstruction was found in n = 24 (4%, CI95 2.7-5.9) participants and in n = 30 (5%, CI95 3.5-7.1) applying GOLD spirometric criteria. To analyse risk factors for chronic airflow obstruction including those not meeting ATS/ERS or GOLD criteria, FEF25-75 and FEV1% predicted was analysed in participants without evidence of pulmonary restriction among those exposed or not exposed to risk factors (n = 552). FEV1% predicted, but in particular FEF25-75 decreased with increasing symptom severity of shortness of breath as well as limitations in daily activities of participants. Cooking in general and cooking with biomass fuels vs. gas or electricity was associated with significantly lower FEF25-75, but not with lower FEV1% predicted. Participants having refrained from taking a job because of shortness of breath exhibited lower FEF25-75 (p < 0.01). A history of prior active TB was the most relevant risk factor associated with a decrease in FEF25-75 as well as FEV1% predicted. CONCLUSION: This study demonstrated a relevant prevalence of chronic airflow obstruction in primary healthcare attendants and healthy visitors of a Tanzanian hospital. Using the baseline data provided, larger and population-based studies are needed to validate these findings. TB may have more impact on development of chronic airway obstruction than smoking in Africa. Due to the influence of age on the GOLD definition of chronic airflow obstruction, studies should report results using both ATS/ERS and GOLD definitions and include age-stratified analysis. Analysis of FEV1 and in particular FEF25-75 may yield additional information on risk factors and earlier stages of chronic airflow obstruction.
Assuntos
Culinária , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Tuberculose Pulmonar/fisiopatologia , Atividades Cotidianas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Dispneia/etiologia , Dispneia/fisiopatologia , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Fluxo Máximo Médio Expiratório , Pessoa de Meia-Idade , Prevalência , Doença Pulmonar Obstrutiva Crônica/complicações , Fatores de Risco , Tanzânia/epidemiologia , Tuberculose Pulmonar/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Culture contamination with environmental bacteria is a major challenge in tuberculosis (TB) laboratories in hot and humid climate zones. We studied the effect of cetylpyridinium chloride (CPC) preservation on culture results and performance of Xpert MTB/RIF. METHODS: Consecutive sputum samples from microscopy smear-positive TB patients were collected. Two-hundred samples were equally split in two aliquots, one aliquot was treated with CPC and stored at ambient temperature for 7 days. The second aliquot was immediately processed. Samples were decontaminated for 20, 15 or 10 min, and subsequently cultured on Löwenstein-Jensen medium. Furthermore, 50 samples were stored for 7, 14 and 21 days, and 100 CPC-pretreated samples tested by Xpert MTB/RIF. RESULTS: CPC pretreated samples showed a higher culture yield compared to non-treated sputum samples across all decontamination times: 94% vs. 73% at 10 min (p = 0.01), 94% vs. 64% at 15 min (p = 0.004), and 90% vs. 52% at 20 min (p < 0.001). The quantitative culture grading was consistently higher in CPC treated compared to non-CPC treated samples. The proportion of contaminated cultures was lower in CPC pretreated samples across all decontamination times (range 2-6%) compared to non-CPC treated samples (15-16%). For storage times of CPC treated samples of 7, 14, and 21 days, 84, 86, and 84% of the respective cultures were positive. Of 91 CPC treated samples with a positive culture, 90 were also Xpert MTB/RIF positive. CONCLUSIONS: CPC increases culture yield, decreases the proportion of contamination, and does not alter the performance of Xpert MTB/RIF.
Assuntos
Técnicas Bacteriológicas/métodos , Cetilpiridínio/química , Mycobacterium tuberculosis/genética , Manejo de Espécimes/métodos , Escarro/microbiologia , Países em Desenvolvimento , Humanos , Microscopia/métodos , Mycobacterium tuberculosis/patogenicidade , Técnicas de Amplificação de Ácido Nucleico/métodos , Escarro/química , Tanzânia , Tuberculose Pulmonar/microbiologiaRESUMO
BACKGROUND: Diabetes mellitus (DM) increases tuberculosis risk while tuberculosis, as an infectious disease, leads to hyperglycemia. We compared hyperglycemia screening strategies in controls and patients with tuberculosis in Dar es Salaam, Tanzania. METHODS: Consecutive adults with tuberculosis and sex- and age-matched volunteers were included in a case-control study between July 2012 and June 2014. All underwent DM screening tests (fasting capillary glucose [FCG] level, 2-hour CG [2-hCG] level, and glycated hemoglobin A1c [HbA1c] level) at enrollment, and cases were tested again after receipt of tuberculosis treatment. Association of tuberculosis and its outcome with hyperglycemia was assessed using logistic regression analysis adjusted for sex, age, body mass index, human immunodeficiency virus infection status, and socioeconomic status. Patients with tuberculosis and newly diagnosed DM were not treated for hyperglycemia. RESULTS: At enrollment, DM prevalence was significantly higher among patients with tuberculosis (n = 539; FCG level > 7 mmol/L, 4.5% of patients, 2-hCG level > 11 mmol/L, 6.8%; and HbA1c level > 6.5%, 9.3%), compared with controls (n = 496; 1.2%, 3.1%, and 2.2%, respectively). The association between hyperglycemia and tuberculosis disappeared after tuberculosis treatment (adjusted odds ratio [aOR] for the FCG level: 9.6 [95% confidence interval {CI}, 3.7-24.7] at enrollment vs 2.4 [95% CI, .7-8.7] at follow-up; aOR for the 2-hCG level: 6.6 [95% CI, 4.0-11.1] vs 1.6 [95% CI, .8-2.9]; and aOR for the HbA1c level, 4.2 [95% CI, 2.9-6.0] vs 1.4 [95% CI, .9-2.0]). Hyperglycemia, based on the FCG level, at enrollment was associated with tuberculosis treatment failure or death (aOR, 3.3; 95% CI, 1.2-9.3). CONCLUSIONS: Transient hyperglycemia is frequent during tuberculosis, and DM needs confirmation after tuberculosis treatment. Performance of DM screening at tuberculosis diagnosis gives the opportunity to detect patients at risk of adverse outcome.
Assuntos
Diabetes Mellitus/diagnóstico , Hiperglicemia/sangue , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/complicações , Adulto , Algoritmos , Antituberculosos/administração & dosagem , Antituberculosos/uso terapêutico , Glicemia/metabolismo , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus/sangue , Diabetes Mellitus/epidemiologia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hiperglicemia/etiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prevalência , Tanzânia/epidemiologia , Fatores de Tempo , Tuberculose Pulmonar/epidemiologia , Adulto JovemRESUMO
BACKGROUND: New antituberculosis regimens are urgently needed to shorten tuberculosis treatment. Following on from favourable assessment in a 2 week study, we investigated a novel regimen for efficacy and safety in drug-susceptible and multidrug-resistant (MDR) tuberculosis during the first 8 weeks of treatment. METHODS: We did this phase 2b study of bactericidal activity--defined as the decrease in colony forming units (CFUs) of Mycobacterium tuberculosis in the sputum of patients with microscopy smear-positive pulmonary tuberculosis-at eight sites in South Africa and Tanzania. We enrolled treatment-naive patients with drug-susceptible, pulmonary tuberculosis, who were randomly assigned by computer-generated sequences to receive either 8 weeks of moxifloxacin, 100 mg pretomanid (formerly known as PA-824), and pyrazinamide (MPa100Z regimen); moxifloxacin, 200 mg pretomanid, and pyrazinamide (MPa200Z regimen); or the current standard care for drug-susceptible pulmonary tuberculosis, isoniazid, rifampicin, PZA, and ethambutol (HRZE regimen). A group of patients with MDR tuberculosis received MPa200Z (DRMPa200Z group). The primary outcome was bactericidal activity measured by the mean daily rate of reduction in M tuberculosis CFUs per mL overnight sputum collected once a week, with joint Bayesian non-linear mixed-effects regression modelling. We also assessed safety and tolerability by monitoring adverse events. This study is registered with ClinicalTrials.gov, number NCT01498419. FINDINGS: Between March 24, 2012, and July 26, 2013 we enrolled 207 patients and randomly assigned them to treatment groups; we assigned 60 patients to the MPa100Z regimen, 62 to the MPa200Z regimen, and 59 to the HRZE regimen. We non-randomly assigned 26 patients with drug-resistant tuberculosis to the DRMPa200Z regimen. In patients with drug-susceptible tuberculosis, the bactericidal activity of MPa200Z (n=54) on days 0-56 (0·155, 95% Bayesian credibility interval 0·133-0·178) was significantly greater than for HRZE (n=54, 0·112, 0·093-0·131). DRMPa200Z (n=9) had bactericidal activity of 0·117 (0·070-0·174). The bactericidal activity on days 7-14 was strongly associated with bactericidal activity on days 7-56. Frequencies of adverse events were similar to standard treatment in all groups. The most common adverse event was hyperuricaemia in 59 (29%) patients (17 [28%] patients in MPa100Z group, 17 [27%] patients in MPa200Z group, 17 [29%] patients. in HRZE group, and 8 [31%] patients in DRMPa200Z group). Other common adverse events were nausea in (14 [23%] patients in MPa100Z group, 8 [13%] patients in MPa200Z group, 7 [12%] patients in HRZE group, and 8 [31%] patients in DRMPa200Z group) and vomiting (7 [12%] patients in MPa100Z group, 7 [11%] patients in MPa200Z group, 7 [12%] patients in HRZE group, and 4 [15%] patients in DRMPa200Z group). No on-treatment electrocardiogram occurrences of corrected QT interval more than 500 ms (an indicator of potential of ventricular tachyarrhythmia) were reported. No phenotypic resistance developed to any of the drugs in the regimen. INTERPRETATION: The combination of moxifloxacin, pretomanid, and pyrazinamide, was safe, well tolerated, and showed superior bactericidal activity in drug-susceptible tuberculosis during 8 weeks of treatment. Results were consistent between drug-susceptible and MDR tuberculosis. This new regimen is ready to enter phase 3 trials in patients with drug-susceptible tuberculosis and MDR-tuberculosis, with the goal of shortening and simplifying treatment. FUNDING: Global Alliance for TB Drug Development.
Assuntos
Antituberculosos/uso terapêutico , Fluoroquinolonas/uso terapêutico , Nitroimidazóis/uso terapêutico , Pirazinamida/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Adulto , Contagem de Colônia Microbiana , Quimioterapia Combinada , Etambutol/uso terapêutico , Feminino , Humanos , Isoniazida/uso terapêutico , Masculino , Moxifloxacina , Rifampina/uso terapêutico , África do Sul , Escarro/microbiologia , Tanzânia , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Extrapulmonary tuberculosis (EPTB) is associated with high rates of morbidity and mortality. Diagnosis of EPTB is challenging in resource-limited settings due to difficulties in obtaining samples, as well as the paucibacillarity of the specimens. Skeletal tuberculosis accounts for 10-35 % of EPTB cases, with vertebral osteomyelitis (Pott's disease) representing 50 % of the cases. We present two cases of suspected Pott's disease, diagnosed through GeneXpert MTB/RIF assay in urine at a rural Tanzanian hospital. CASE PRESENTATION: Case I A 49-year old male, HIV-1 positive, on co-formulated tenofovir disoproxil fumarate/lamivudine/efavirenz since 2009 and CD4 counts of 205 cells/µL (13 %). He presented with lower back pain and progressive lower limb weakness for two weeks prior to admission. The physical examination revealed bilateral flaccid paraplegia with reduced reflexes, but otherwise unremarkable findings. A lateral lumbar X-ray showed noticeable reduction of intervertebral space between L4 and L5, and a small calcification in the anterior longitudinal ligament between L4 and L5, being compatible with focal spondylosis deformans but inconclusive with regard to tuberculous spondylitis. An abdominal ultrasound showed normal kidneys, bladder and prostate gland. The urinalysis and complete blood counts (CBC) were normal. M. Tuberculosis was detected through GeneXpert MTB/RIF in centrifuged urine, with no resistance to rifampicin. Case II A 76-year old female, HIV-1 negative, presented with lower back pain and progressive weakness and numbness of the lower limbs for two months prior to admission. The physical examination revealed paraplegia, but otherwise unremarkable findings. The lumbosacral X-ray findings were compatible with spondylosis deformans of the lumbar spine and possible tuberculous spondylitis in L3-L4. The abdominal and renal ultrasound showed normal kidneys and bladder. The urinalysis and CBC were normal. M. Tuberculosis was detected through GeneXpert MTB/RIF in centrifuged urine, with no resistance to rifampicin. CONCLUSION: We report two cases of suspected tuberculous spondylitis diagnosed through Xpert MTB/RIF in urine samples from a rural Tanzanian hospital. Urine testing using Xpert MTB/RIF reflects disseminated disease and renal involvement, and may offer a feasible additional diagnostic approach for Pott's disease in rural Africa.
RESUMO
BACKGROUND: Fine needle aspiration biopsy has become a standard approach for diagnosis of peripheral tuberculous lymphadenitis. The aim of this study was to compare the performance of Xpert MTB/RIF and Ustar EasyNAT TB IAD nucleic acid amplification assays, against acid-fast bacilli microscopy, cytology and mycobacterial culture for the diagnosis of TB lymphadenitis in children from a TB-endemic setting in Tanzania. METHODS: Children of 8 weeks to 16 years of age, suspected of having TB lymphadenitis, were recruited at a district hospital in Tanzania. Fine needle aspirates of lymph nodes were analysed using acid-fast bacilli microscopy, liquid TB culture, cytology, Xpert MTB/RIF and EasyNAT. Latent class analysis and comparison against a composite reference standard comprising "culture and/or cytology" was done, to assess the performance of Xpert MTB/RIF and EasyNAT for the diagnosis of TB lymphadenitis. RESULTS: Seventy-nine children were recruited; 4 were excluded from analysis. Against a composite reference standard of culture and/or cytology, Xpert MTB/RIF and EasyNAT had a sensitivity and specificity of 58 % and 93 %; and 19 % and 100 % respectively. Relative to latent class definitions, cytology had a sensitivity of 100 % and specificity of 94.7 %. CONCLUSIONS: Combining clinical assessment, cytology and Xpert MTB/RIF may allow for a rapid and accurate diagnosis of childhood TB lymphadenitis. Larger diagnostic evaluation studies are recommended to validate these findings and on Xpert MTB/RIF to assess its use as a solitary initial test for TB lymphadenitis in children.
Assuntos
Linfonodos/microbiologia , Mycobacterium tuberculosis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Tuberculose dos Linfonodos/diagnóstico , Adolescente , Biópsia por Agulha Fina , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Linfonodos/patologia , Masculino , Microscopia , Estudos Prospectivos , Sensibilidade e Especificidade , Tanzânia , Tuberculose dos Linfonodos/microbiologiaRESUMO
BACKGROUND: Vitamin D level is inversely associated with tuberculosis (TB) and diabetes (DM). Vitamin D could be a mediator in the association between TB and DM. We examined the associations between vitamin D, TB and DM. METHODS: Consecutive adults with TB and sex- and age-matched volunteers were included in a case-control study in Dar es Salaam, Tanzania. Glycemia and total vitamin D (25(OH)D) were measured at enrolment and after TB treatment in cases. The association between low 25(OH)D (<75 nmol/l) and TB was evaluated by logistic regression adjusted for age, sex, body mass index, socioeconomic status, sunshine hours, HIV and an interaction between low 25(OH)D and hyperglycemia. RESULTS: The prevalence of low 25(OH)D was similar in TB patients and controls (25.8 % versus 31.0 %; p = 0.22). In the subgroup of patients with persistent hyperglycemia (i.e. likely true diabetic patients), the proportion of patients with low 25(OH)D tended to be greater in TB patients (50 % versus 29.7 %; p = 0.20). The effect modification by persistent hyperglycemia persisted in the multivariate analysis (pinteraction = 0.01). CONCLUSIONS: Low 25(OH)D may increase TB risk in patients with underlying DM. Trials should examine if this association is causal and whether adjunct vitamin D therapy is beneficial in this population.