Analysis of catastrophic costs incurred by patients with multidrug-resistant tuberculosis in an outpatient clinic in the state of Rio de Janeiro

ABSTRACT Background: Multidrug-resistant tuberculosis (MDR-TB) is a serious global public health concern associated with social vulnerability. In Brazil, the Unified Health System (SUS, Portuguese) provides free diagnosis and treatment for MDR-TB; however, other expenses may still be incurred for patients and their families which, according to the World Health Organization (WHO), can be catastrophic when these costs surpass 20.0% of the annual household income. This study aimed to assess the extent of catastrophic costs related to the diagnostic and therapeutic aspects of MDR-TB among patients receiving care at an outpatient clinic in Rio de Janeiro. Methods: This prospective study used convenience sampling from July 2019 to June 2021. Data regarding direct and indirect costs were collected using a standardized questionnaire endorsed by the WHO. To analyze any impoverishment occurred from MDR-TB, a threshold established by the Brazilian Institute of Geography and Statistics for 2019 and 2020 of US$ 79,562 and US$ 94,5273, respectively, was applied. Descriptive statistics were used for data analysis, including mean; standard deviation; variation coefficient; median; and maximum, minimum, and interquartile ranges. Results: A total of 65 patients were interviewed. Among the participants, 73.8% experienced catastrophic costs, with indirect costs exerting the most significant impact (median: US$ 3,825.9), in contrast to direct costs (median: US$ 542.7). When comparing the periods before and after diagnosis, the prevalence of poverty increased from 12.0% to 28.0%. Conclusions: Despite the support from the SUS in Brazil, diagnostic and therapeutic cascades incur additional costs, exacerbating social vulnerability among patients with MDR-TB.

Nontuberculous mycobacteria in patients of a specialty hospital

ABSTRACT The incidence and clinical characteristics of NTM diseases in Brazil remain relatively unknown. The present study describes the diagnosis of NTM isolates, the clinical presentation and treatment outcomes. We analyzed NTM isolates in patients of a tertiary hospital in the Southeast region of Brazil, from January 2008 to July 2019. The ATS/IDSA criteria for diagnosis and treatment of these patients was applied. Mycobacterium kansasii were identified in 13/113 (11.5%) patients. In 59/113 (52.2%) patients who met the ATS criteria for disease, 29/59 (49.1%) received treatment, and 22/29 (75.8%) were cured. The major species identified was M. kansasii. The most frequent symptoms among the treated patients were dyspnea and cough, and the proportion of cured patients was high.

Clinical Impact of the Line Probe Assay and Xpert® MTB/RIF Assay in the Presumptive Diagnosis of Drug-Resistant Tuberculosis in Brazil: A Pragmatic Clinical Trial

ABSTRACT Background: Rapid molecular methods such as the line probe assay (LPA) and Xpert® MTB/RIF assay (Xpert) have been recommended by the World Health Organization for drug-resistant tuberculosis (DR-TB) diagnosis. We conducted an interventional trial in DR-TB reference centers in Brazil to evaluate the impact of the use of LPA and Xpert. Methods: Patients with DR-TB were eligible if their drug susceptibility testing results were available to the treating physician at the time of consultation. The standard reference MGITTM 960 was compared with Xpert (arm 1) and LPA (arm 2). Effectiveness was considered as the start of the appropriate TB regimen that matched drug susceptibility testing (DST) and the proportions of culture conversion and favorable treatment outcomes after 6 months. Results: A higher rate of empirical treatment was observed with MGIT alone than with the Xpert assay (97.0% vs. 45.0%) and LPA (98.2% vs. 67.5%). Patients started appropriate TB treatment more quickly than those in the MGIT group (median 15.0 vs. 40.5 days; p<0.01) in arm 1. Compared to the MGIT group, culture conversion after 6 months was higher for Xpert in arm 1 (90.9% vs. 79.3%, p=0.39) and LPA in arm 2 (80.0% vs. 83.0%, p=0.81). Conclusions: In the Xpert arm, there was a significant reduction in days to the start of appropriate anti-TB treatment and a trend towards greater culture conversion in the sixth month.

Impact of a computer system as a triage tool in the management of pulmonary tuberculosis in a HIV reference center in Brazil

ABSTRACT Background: The Neural Clinical Score for tuberculosis (NCS-TB) is a computer system developed to improve the triage of presumed pulmonary TB (pPTB). Methods: A study was performed with cohorts of pPTB patients cared for at a reference hospital in Northeast Brazil. Results: The NCS-TB sensitivity was 76.5% for TB diagnosis, which shortened the time from triage to smear microscopy results (3.3 to 2.5 days; p<0.001) and therapy initiation (6.7 to 4.1 days; p=0.045). Conclusions: Although the NCS-TB was not suitable as a screening tool, it was able to optimize laboratory diagnosis and shorten the time to treatment initiation.

Molecular characterization of nontuberculous Mycobacteria in a tuberculosis and HIV reference unit in the State of Amazonas, Brazil

ABSTRACT Background: In recent years, the prevalence of nontuberculous mycobacterial (NTM) infections has increased in different regions of the world. The American Thoracic Society (ATS) recommends standardized identification criteria, reinforcing the need for faster and less complicated clinical and laboratory techniques. Methods: In this retrospective study, NTM species isolated from pulmonary, extrapulmonary, and disseminated samples from patients treated at a TB/HIV reference unit in the State of Amazonas from 2011 to 2014 were identified through a combination of molecular techniques. Results: To identify the molecular technique, 50 cryopreserved NTM cultures were recovered and subcultivated in culture medium. The potentially pathogenic NTM species identified were M. avium, M. intracellulare, M. kansasii, M. chelonae, M. abscessus, M. fortuitum, and M. peregrinum. Results of GenoType® showed moderate agreement with those of genomic sequencing (kappa = 0.60), whereas the results obtained by the PRA-hsp65 technique disagreed with the results obtained by sequencing (kappa = 0.49). Conclusions: Our findings highlight that GenoType CM is a good method for the identification of NTM, as well as the need for the application of standardized criteria, such as those set forth by the ATS.

Avaliação do desempenho dos serviços de atenção primária à saúde no controle da tuberculose em metrópole do Sudeste do Brasil / Performance assessment of primary healthcare services in tuberculosis control in a city in Southeast Brazil / Evaluación del desempeño de los servicios de atención primaria en salud para el control de la tuberculosis en metrópolis del sudeste de Brasil

Resumo: A Organização Mundial da Saúde destaca a importância da organização e do desempenho dos serviços de saúde nas ações de controle da tuberculose. O objetivo deste estudo foi avaliar o desempenho dos serviços de atenção primaria à saúde em Belo Horizonte, Minas Gerais, Brasil, em relação às ações de controle da tuberculose nos eixos Estrutura e Processo, antes e após a utilização do instrumento validado denominado Estratificação por Grau de Risco Clínico e de Abandono do Tratamento da Tuberculose (ERTB). Estudo descritivo e prospectivo, no qual foram realizadas duas entrevistas (455 profissionais), tendo a segunda ocorrido após a ERTB. A classificação do desempenho seguiu os valores: ≤ 49,9%, críticos; entre 50% e 79,9%, insatisfatórios; e, ≥ 80%, satisfatórios. Na avaliação comparativa, foi utilizado o teste estatístico de McNemar, com p < 0,05. Após a estratificação de risco, a maior parte das variáveis de cada eixo melhorou significativamente. Nós concluímos que, por meio de um questionário padronizado, foi possível identificar o desempenho satisfatório dos serviços de atenção primária à saúde em Belo Horizonte em relação às ações de controle da tuberculose, na maioria das variáveis avaliadas nos eixos Estrutura e Processo.

Abstract: The World Health Organization highlights the importance of health services organization and performance in tuberculosis (TB) control activities. This study aimed to assess the performance of primary healthcare services in Belo Horizonte, Minas Gerais State, Brazil, in TB control activities in the dimensions Structure and Process, before and after the use of a validated instrument called Stratification by Degree of Clinical Risk and Tuberculosis Treatment Dropout (ERTB). This was a descriptive and prospective study with two interviews (455 professionals), the second of which after the ERTB. Performance classification was: ≤ 49.9%, critical; 50-79.9%, unsatisfactory, and ≥ 80%, satisfactory. The comparative assessment used the McNemar statistical test with p < 0.05. After risk stratification, most of the variables in each dimension improved significantly. The authors conclude that it was possible to identify satisfactory performance in most of the variables assessed in the Structure and Process dimensions in primary healthcare services in Belo Horizonte in relation to TB control activities, using a standardized questionnaire.

Resumen: La Organización Mundial de la Salud destaca la importancia de la organización y del desempeño de los servicios de salud en acciones de control de la tuberculosis. El objetivo de este estudio fue evaluar el desempeño de los servicios de atención primaria en salud en Belo Horizonte, Minas Gerais, Brasil, en relación con las acciones de control de la tuberculosis respecto a los ejes Estructura y Proceso, antes y después de la utilización del instrumento validado, denominado Estratificación por Grado de Riesgo Clínico y de Abandono del Tratamiento de la Tuberculosis (ERTB). Se trata de un estudio descriptivo y prospectivo, donde se realizaron dos entrevistas (455 profesionales), siendo que la segunda se produjo tras la ERTB. La clasificación del desempeño siguió los valores: ≤ 49,9%, críticos; entre 50 y 79,9%, insatisfactorios; y, ≥ 80%, satisfactorios. En la evaluación comparativa, se utilizó el test estadístico de McNemar, con p < 0,05. Tras la estratificación de riesgo, la mayor parte de las variables de cada eje mejoró significativamente. Concluimos que fue posible identificar el desempeño satisfactorio en la mayoría de las variables evaluadas en los ejes Estructura y Proceso de los servicios de atención primaria en salud en Belo Horizonte, en relación con las acciones de control de la tuberculosis mediante un cuestionario estandarizado.

Cost-effectiveness of Xpert®MTB/RIF in the diagnosis of tuberculosis: pragmatic study

Abstract INTRODUCTION: The intensification of research and innovation with the creation of networks of rapid and effective molecular tests as strategies for the end of tuberculosis are essential to avoid late diagnosis and for the eradication of the disease. We aimed to evaluate the cost-effectiveness of Xpert®MTB/RIF (Xpert) in the diagnosis of drug-resistant tuberculosis in reference units, in scenarios with and without subsidies, and the respective cost adjustment for today. METHODS: The analyses were performed considering as criterion of effectiveness, negative culture or clinical improvement in the sixth month of follow-up. The comparison was performed using two diagnostic strategies for the drug susceptibility test (DST), BactecTMMGITTM960 System, versus Xpert. The cost effectiveness and incremental cost-effectiveness ratio (ICER) were calculated and dollar-corrected for American inflation (US$ 1.00 = R$ 5,29). RESULTS: Subsidized Xpert had the lowest cost of US$ 33.48 (R$67,52) and the highest incremental average efficiency (13.57), thus being a dominated analysis. After the inflation was calculated, the mean cost was DST-MGIT=US$ 74.85 (R$ 396,73) and Xpert = US$ 37.33 (R$197,86) with subsidies. CONCLUSIONS: The Xpert in the diagnosis of TB-DR in these reference units was cost-effective with subsidies. In the absence of a subsidy, Xpert in TB-DR is not characterized as cost effective. This factor reveals the vulnerability of countries dependent on international organizations' subsidy policies.

The impact of the stratification by degree of clinical severity and abandonment risk of tuberculosis treatment / O impacto da estratificação por grau de risco clínico e de abandono do tratamento da tuberculose

ABSTRACT Objective: Evaluate the impact of the instrument of the "Stratification by Degree of Clinical Severity and Abandonment Risk of Tuberculosis Treatment" (SRTB) on the tuberculosis outcome. Methods: This study was a pragmatic clinical trial involving patients with a confirmed diagnosis of tuberculosis treated at one of the 152 primary health care units in the city of Belo Horizonte, Brazil, between May of 2016 and April of 2017. Cluster areas for tuberculosis were identified, and the units and their respective patients were divided into intervention (use of SRTB) and nonintervention groups. Results: The total sample comprised 432 participants, 223 and 209 of whom being allocated to the nonintervention and intervention groups, respectively. The risk of treatment abandonment in the nonintervention group was significantly higher than was that in the intervention group (OR = 15.010; p < 0.001), regardless of the number of risk factors identified. Kaplan-Meier curves showed a hazard ratio of 0.0753 (p < 0.001). Conclusions: The SRTB instrument was effective in reducing abandonment of tuberculosis treatment, regardless of the number of risk factors for that. This instrument is rapid and easy to use, and can be adapted to different realities. Its application showed characteristics predisposing to a non-adherence to the treatment and established bases to mitigate its impact.

RESUMO Objetivo: Avaliar o impacto do instrumento denominado "Estratificação por Grau de Risco Clínico e de Abandono do Tratamento da Tuberculose" (ERTB) nos desfechos da tuberculose. Métodos: Ensaio clínico pragmático envolvendo pacientes com diagnóstico confirmado de tuberculose atendidos em uma das 152 unidades de atenção primária à saúde na cidade de Belo Horizonte (MG) entre maio de 2016 e abril de 2017. Foram identificadas áreas de cluster para tuberculose, e as unidades e os respectivos pacientes foram divididos em grupos intervenção (uso do instrumento ERTB) e não intervenção. Resultados: A amostra total foi composta por 432 participantes, dos quais 223 e 209 foram alocados nos grupos não intervenção e intervenção, respectivamente. O risco de abandono do tratamento no grupo não intervenção foi significativamente maior do que no grupo intervenção (OR = 15,010; p < 0,001), independentemente do número de fatores de risco identificados. As curvas de Kaplan-Meier mostraram uma razão de risco de 0,0753 (p < 0,001). Conclusões: O instrumento ERTB foi eficaz em reduzir o abandono do tratamento da tuberculose, independentemente do número de fatores de risco identificados. Esse instrumento é rápido e fácil de utilizar e pode ser adaptado a diferentes realidades.

Cost analysis of smear microscopy and the Xpert assay for tuberculosis diagnosis: average turnaround time

Abstract INTRODUCTION: Rapid and accurate tuberculosis detection is critical for improving patient diagnosis and decreasing tuberculosis transmission. Molecular assays can significantly increase laboratory costs; therefore, the average time and economic impact should be evaluated before implementing a new technology. The aim of this study was to evaluate the cost and average turnaround time of smear microscopy and Xpert assay at a university hospital. METHODS: The turnaround time and cost of the laboratory diagnosis of tuberculosis were calculated based on the mean cost and activity based costing (ABC). RESULTS: The average turnaround time for smear microscopy was 16.6 hours while that for Xpert was 24.1 hours. The Xpert had a mean cost of USD 17.37 with an ABC of USD 10.86, while smear microscopy had a mean cost of USD 13.31 with an ABC of USD 6.01. The sensitivity of smear microscopy was 42.9% and its specificity was 99.1%, while the Xpert assay had a sensitivity of 100% and a specificity of 96.7%. CONCLUSIONS: The Xpert assay has high accuracy; however, the turnaround time and cost of smear microscopy were lower than those of Xpert.

Genotype®MTBDRplus and Xpert®MTB/RIF in the diagnosis of tuberculosis and resistant tuberculosis: cost analysis in a tertiary referral hospital

Abstract INTRODUCTION: The present study sought to assess the mean and activity based cost (ABC) of the laboratory diagnosis for tuberculosis through the application of conventional and molecular techniques-Xpert®MTB/RIF and Genotype®MTBDRplus-in a tertiary referral hospital in Brazil. METHODS: The mean cost and ABC formed the basis for the cost analysis of the TB laboratory diagnosis. RESULTS: The mean cost and ABC were US$ 4.00 and US$ 3.24, respectively, for a bacilloscopy; US$ 6.73 and US$ 5.27 for a Lowenstein-Jensen (LJ) culture; US$ 105.42 and US$ 76.56 for a drug sensitivity test (DST)-proportions method (PM) in LJ; US$ 148.45 and US$ 136.80 for a DST-BACTECTM MGITTM 960 system; US$ 11.53 and US$ 9.89 for an Xpert®MTB/RIF; and US$ 84.21 and US$ 48.38 for a Genotype®MTBDRplus. CONCLUSIONS: The mean cost and ABC proved to be good decision-making parameters in the diagnosis of TB and MDR-TB. The effective implementation of algorithms will depend on the conditions at each location.

Detection of Drug Resistant Mycobacterium Tuberculosis Strains Using Kit SIRE Nitratase®: a Multicenter Study

Abstract (1) Background: The Commercial Kit SIRE Nitratase® PlastLabor, is a drug susceptibility test kit used to detect Mycobacterium tuberculosis resistance to first-line TB treatment drugs. The present study aimed at evaluating its performance in a multicenter study. (2) Methods: To determine its accuracy, the proportion methods in Lowenstein Jensen medium or the BACTECTMMGITTM960 system was used as a gold standard. (3) Results: The study revealed that the respective accuracies of the kit with 190 M. tuberculosis clinical isolates, using the proportion methods in Lowenstein Jensen medium or BACTECTMMGITTM960 system as a gold standard, were 93.9% and 94.6%, 96.9% and 94.6%, 98.0% and 97.8%, and 98.0% and 98.9%, for streptomycin, isoniazid, rifampicin, and ethambutol, respectively. (4) Conclusion: Thus, the kit can rapidly screen resistance to streptomycin, isoniazid, rifampicin, and ethambutol. Additionally, it does not require sophisticated equipment; hence, it can be easily used in the laboratories of low and middle income countries.

Factors associated with tuberculosis and multidrug-resistant tuberculosis in patients treated at a tertiary referral hospital in the state of Minas Gerais, Brazil / Fatores associados à tuberculose e à tuberculose multirresistente em pacientes atendidos em um hospital de referência terciária em Minas Gerais, Brasil

ABSTRACT Objective: To evaluate the risk factors for the development of tuberculosis and multidrug-resistant tuberculosis (MDR-TB) in patients treated at a tertiary referral hospital. Methods: This was a cross-sectional study based on data obtained from patients treated at the Júlia Kubitschek Hospital, located in the city of Belo Horizonte, Brazil, between October of 2012 and October of 2014. We evaluated sociodemographic, behavioral, clinical, and radiological variables. The outcome considered to identify associations between tuberculosis and the explanatory variables was the treatment prescribed. To evaluate the associations between MDR-TB and the same explanatory variables, the change in MDR-TB treatment was considered. Results: The factors associated with tuberculosis were alcoholism, comorbidities, pulmonary cavitations, and a radiological pattern suggestive of tuberculosis. Cavitation and previous treatment for tuberculosis were associated with MDR-TB. Conclusions: Despite the significant progress made in the fight against tuberculosis, there is a need for coordinated actions that include social protection measures and patient support.

RESUMO Objetivo: Avaliar os fatores de risco de pacientes atendidos em um hospital de referência terciária para o desenvolvimento de tuberculose e tuberculose multirresistente (TBMR). Métodos: Estudo transversal baseado em dados obtidos de pacientes atendidos no Hospital Júlia Kubitschek, na cidade de Belo Horizonte (MG), entre outubro de 2012 e outubro de 2014. As variáveis utilizadas foram agrupadas em características sociodemográficas, comportamentais, clínicas e radiológicas. O desfecho considerado para verificar associações entre tuberculose e variáveis explicativas foi o tratamento prescrito para tuberculose. Para avaliar a associação entre a tuberculose resistente e as mesmas variáveis explicativas considerou-se a mudança de tratamento para TBMR. Resultados: Alcoolismo, padrão radiológico sugestivo de tuberculose, presença de comorbidades e presença de cavitações pulmonares foram fatores associados à tuberculose. A TBMR foi associada a tratamento prévio para tuberculose e presença de cavitações. Conclusões: Apesar dos importantes progressos na luta contra a tuberculose, é necessário um conjunto de ações articuladas que incluam medidas de proteção social e suporte aos pacientes.

Comparative study of RFLP-IS6110 and MIRU-VNTR from Mycobacterium tuberculosis isolated in the state of Minas Gerais, Brazil

Abstract DNA genotyping of Mycobacterium tuberculosis has been widely applied in the understanding of disease transmission in many countries. The purpose of this study was to genotype the strains of M. tuberculosis isolated in patients with new tuberculosis (TB) cases in Minas Gerais, as well as to compare the similarity, discriminatory power, and agreement of the clusters between the IS6110 Restriction Fragment Length Polymorfism (RFLP) and 12 loci Variable Number Tandem Repeat - Mycobacterial Interspersed Repetitive Units (MIRU-VNTR) techniques. It was observed that 32% (66/204) of the isolated strains in the RFLP-IS6110 and 50.9% (104/204) of the isolated strains in the MIRU-VNTR presented a similarity of equal to or above 85%. The RFLP-IS6110 and MIRU-VNTR proved to contain a high discriminatory power. The similarity index resulting from the RFLP showed no recent transmission. Good agreement was observed between the techniques when clusters were detected; however, the best epidemiological relationship was found when using the RFLP-IS6110.

Correlation between the BACTEC MGIT 960 culture system with Genotype MTBDRplus and TB-SPRINT in multidrug resistant Mycobacterium tuberculosis clinical isolates from Brazil

BACKGROUND The accurate detection of multidrug-resistant tuberculosis (MDR-TB) is critical for the application of appropriate patient treatment and prevention of transmission of drug-resistant Mycobacterium tuberculosis isolates. The goal of this study was to evaluate the correlation between phenotypic and molecular techniques for drug-resistant tuberculosis diagnostics. Molecular techniques used were the line probe assay genotype MTBDRplus and the recently described tuberculosis-spoligo-rifampin-isoniazid typing (TB-SPRINT) bead-based assay. Conventional drug susceptibility testing (DST) was done on a BACTECTM MGIT 960 TB. METHOD We studied 80 M. tuberculosis complex (MTC) clinical isolates from Minas Gerais state, of which conventional DST had classified 60 isolates as MDR and 20 as drug susceptible. FINDINGS Among the 60 MDR-TB isolates with MGIT as a reference, sensitivity, specificity, accuracy, and kappa for rifampicin (RIF) resistance using TB-SPRINT and MTBDRplus, were 96.7% versus 93.3%, 100.0% versus 100.0%, 97.5% versus 95.0% and 0.94 versus 0.88, respectively. Similarly, the sensitivity, specificity, accuracy, and kappa for isoniazid (INH) resistance were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. Finally, the sensitivity, specificity, accuracy, and kappa for MDR-TB were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. MAIN CONCLUSIONS Both methods exhibited a good correlation with the conventional DST. We suggest estimating the cost-effectiveness of MTBDRplus and TB-SPRINT in Brazil.

Evaluation of the commercial kit SIRE nitratase for detecting resistant mycobacterium tuberculosis in Brazil

Abstract INTRODUCTION: This study aimed to evaluate a new commercial kit, Kit SIRE Nitratase-PlastLabor, for testing the drug susceptibility of clinical Mycobacterium tuberculosis isolates. METHODS: The accuracy of the Kit SIRE Nitratase was evaluated by examining the susceptibility (streptomycin, isoniazid, rifampicin, and ethambutol) of 40 M. tuberculosis isolates, using the proportion method with Lowenstein-Jensen medium or the BACTEC MGIT 960 system. RESULTS: The detection accuracy for streptomycin, isoniazid, rifampicin, and ethambutol was 95%, 97.5%, 100%, and 80%, respectively. CONCLUSIONS: The exceptional accuracy demonstrated by Kit SIRE Nitratase for isoniazid and rifampicin makes the kit an attractive option for screening M. tuberculosis strain resistance.

Prevalence of latent Mycobacterium tuberculosis infection in prisoners / Prevalência da infecção latente por Mycobacterium tuberculosis em pessoas privadas de liberdade

ABSTRACT Objective: To determine the prevalence of and the factors associated with latent Mycobacterium tuberculosis infection (LTBI) in prisoners in the state of Minas Gerais, Brazil. Methods: This was a cross-sectional cohort study conducted in two prisons in Minas Gerais. Tuberculin skin tests were performed in the individuals who agreed to participate in the study. Results: A total of 1,120 individuals were selected for inclusion in this study. The prevalence of LTBI was 25.2%. In the multivariate analysis, LTBI was associated with self-reported contact with active tuberculosis patients within prisons (adjusted OR = 1.51; 95% CI: 1.05-2.18) and use of inhaled drugs (adjusted OR = 1.48; 95% CI: 1.03-2.13). Respiratory symptoms were identified in 131 (11.7%) of the participants. Serological testing for HIV was performed in 940 (83.9%) of the participants, and the result was positive in 5 (0.5%). Two cases of active tuberculosis were identified during the study period. Conclusions: Within the prisons under study, the prevalence of LTBI was high. In addition, LTBI was associated with self-reported contact with active tuberculosis patients and with the use of inhaled drugs. Our findings demonstrate that it is necessary to improve the conditions in prisons, as well as to introduce strategies, such as chest X-ray screening, in order to detect tuberculosis cases and, consequently, reduce M. tuberculosis infection within the prison system.

RESUMO Objetivo: Determinar a prevalência e os fatores associados à infecção latente por Mycobacterium tuberculosis (ILTB) em pessoas privadas de liberdade no Estado de Minas Gerais. Métodos: Estudo de coorte transversal realizado em duas penitenciárias em Minas Gerais. Foi realizada a prova tuberculínica nos indivíduos que aceitaram participar do estudo. Resultados: Foram selecionados 1.120 indivíduos para a pesquisa. A prevalência da ILTB foi de 25,2%. Na análise multivariada, a ILTB esteve associada com relato de contato com caso de tuberculose ativa dentro da penitenciária (OR ajustada = 1,51; IC95%: 1,05-2,18) e uso de drogas inaláveis (OR ajustada = 1,48; IC95%: 1,03-2,13). Foram identificados 131 pacientes sintomáticos respiratórios (11,7%). O teste anti-HIV foi realizado em 940 (83,9%) dos participantes, sendo positivo em 5 indivíduos (0,5%). Dois casos de tuberculose ativa foram identificados no período do estudo. Conclusões: A prevalência de ILTB dentro das penitenciárias estudadas foi alta. Além disso, a ILTB estava associada ao relato de contato com casos de tuberculose e ao uso de drogas inaláveis. Nossos achados demonstram que é necessária a melhoria das condições de encarceramento e a utilização de outras estratégias, como a triagem por radiografia de tórax, para a descoberta de casos de tuberculose e redução da infecção pelo M. tuberculosis no sistema penitenciário.

PCR interna con ADN extraído directamente de portaobjetos positivos para confirmar o excluir el diagnóstico de tuberculosis: enfoque en la bioseguridad / In-house PCR with DNA extracted directly from positive slides to confirm or exclude the diagnosis of tuberculosis: focus on biosafety

The possibility to obtain DNA from smears is a valuable alternative to remedy the lack of samples when they are totally used for bacilloscopy; this technique solves the biosafety problem related to a possible accident with the transportation of flasks containing potentially transmissible clinical samples. Hence, the purpose of this study was to utilize the insertion sequence IS6110 for amplification of DNA from a smear-positive sample for tuberculosis (TB) diagnosis. Among the 52 positive bacilloscopies, sensitivity, specificity, positive predictive value and negative predictive value were 52.3%, 100%, 100% and 89.7%, respectively whereas accuracy was 90.7%. The IS6110-based PCR for TB diagnosis developed in DNA extracted from a positive smear is a fast, simple, specific, and safe method

La posibilidad de obtener ADN a partir de frotis es una valiosa alternativa para remediar la falta de muestras cuando estas son totalmente utilizadas para la baciloscopia; esta opción soluciona, además, el problema de bioseguridad asociado a la posibilidad de accidente al transportar frascos que contienen muestras clínicas potencialmente infectivas. Por lo tanto, el propósito de este estudio fue utilizar para el diagnóstico de la tuberculosis la secuencia de inserción IS6110 para amplificación del ADN a partir de frotis que resultaron positivos por baciloscopia. Del análisis de 52 baciloscopias positivas surge que la sensibilidad, la especificidad, el valor predictivo positivo y el valor predictivo negativo de esta técnica fueron, respectivamente, del 52,3%, del 100%, del 100% y del 89,7%; y la precisión fue del 90,7%. La PCR IS6110 para el diagnóstico de tuberculosis, desarrollada con ADN extraído de frotis positivos, es un método rápido, simple, específico y seguro