Caracterización clínica y microbiológica de pacientes con trazas en Xpert MTB/RIF Ultra / Clinical and microbiological characterization of patients with Xpert MTB/RIF Ultra traces

INTRODUCCIÓN: El Xpert MTB/RIF Ultra (Ultra) ha mejorado dramáticamente el diagnóstico de la tuberculosis (TBC). Con él ha nacido la categoría de trazas, que es la menor carga bacilar detectable por este examen. OBJETIVO: Describir las características clínicas de los pacientes con presencia de trazas en el Ultra y evaluar la confirmación de la TBC como diagnóstico clínico. MATERIALES Y MÉTODOS: Estudio descriptivo de serie de casos. Se extrajo la información de fichas clínicas de pacientes con positividad a trazas. Se confrontaron datos clínicos, microbiológicos e histopatológicos. RESULTADOS: Se analizaron 21 pacientes. La edad promedio fue de 52 años. Todos los casos presentaron baciloscopias negativas. Cuatro cultivos en medio líquido MGIT fueron positivos, dos en pleura parietal, uno en líquido pleural y otro en expectoración. En pleura parietal, tres casos presentaron granulomas con necrosis caseosa y un granuloma esbozos de necrosis. En tejido pulmonar se observaron dos casos con granulomas con esbozos de necrosis y dos con granulomas no necrotizantes. Tres pacientes tenían el antecedente de TBC previa, se interpretó la positividad de trazas en ellos como falsos positivos. Finalmente se diagnosticaron 13 casos como TBC activa, donde cinco de ellos fueron TBC pleurales. La mayor concordancia clínica, microbiológica e histopatológica fue en muestras de líquido y tejido pleural. DISCUSIÓN: Se debe interpretar con cautela los hallazgos de esta prueba en muestras de vía aérea; el análisis multidisciplinario (clínica, imágenes, microbiología, histología) es crucial en las decisiones de nuestras conductas clínicas futuras. El hallazgo de trazas en pleura tiene, a nuestro parecer, un alto valor diagnóstico en el estudio de la tuberculosis en esta localización.

INTRODUCTION: Xpert MTB/RIF Ultra has dramatically changed the diagnosis of tuberculosis. A new category called traces appeared, which is the smallest amount of bacillar load detectable. OBJECTIVE: Describe the clinical characteristics of patients that present traces in Xpert MTB/RIF Ultra test, and to evaluate the confirmation of tuberculosis as clinical diagnosis. METHODS: We perform a descriptive case series study. Information was recovered from clinical records of patients with positive test for traces. Clinical, histopathological and microbiological results were confronted. RESULTS: Twenty one patients were analyzed. The mean age was 52 years-old. All cases had negative smear microscopy and four MGIT cultures were positive, two in pleural fluid and another in sputum. In parietal pleura, three cases presented granulomas with caseous necrosis, and one showed granuloma with very little necrosis. In pleural tissue we observed two cases of granulomas with traces of necrosis and two with non-necrotizing granulomas. Three patients had history of previous tuberculosis and positive traces, the test was interpreted as a false positive result. Finally, active tuberculosis was diagnosed in 13 cases, and five of them were pleural tuberculosis. The highest clinical, microbiological and histopathological agreement was in fluid and pleural tissue samples. DISCUSSION: The findings of Xpert MTB/RIF Ultra in airway samples must be interpreted carefully. Multi-disciplinary analysis is crucial in future clinical decisions. The finding of traces in pleura has, in our opinion, a high diagnostic value in the study of tuberculosis in this location.

Estrategia de pesquisa sistemática y seguimiento prolongado revela alto número de nuevas infecciones tuberculosas en contactos adultos en la Región Metropolitana, Chile / Systematic screening of adult household contacts of patients with active pulmonary tuberculosis reveals high rates of new infections during follow-up

Background: Contact investigation is cardinal in the control of tuberculosis (TB) since it helps to stop its transmission. In Chile, the National TB Program strategy does not include latent TB infection testing, regular chemoprophylaxis or follow-up in adults. Active TB was found in only 1.2% of contacts at country-level during 2018. Aim: To evaluate the performance of a systematic screening of adult household contacts with targeted chemoprophylaxis and prolonged active follow-up. Material and Methods: Prospective cohort of household contacts in Santiago. Two face-to-face visits (at 0 and 12 weeks) that included QuantiFERON TB-Gold plus tests (QFT), chest radiography (CXR) at 0 and 24 weeks and, periodic text messaging or phone call follow-up for up to 48 weeks were implemented. Contacts with positive QFT were referred for TB chemoprophylaxis. Results: A total of 200 contacts were enrolled, 69% were migrants. At baseline evaluation, 45% had a positive QFT result and 1.6% had co-prevalent active TB. At follow-up, 13% contacts further converted to QFT (+), and 5.1% more were diagnosed with active TB (mean follow-up time 32 weeks). Of these 10 further active TB cases, 6 (60%) had a negative QFT and all (100%) had normal CXR at baseline; while three cases occurred in QFT converters. Conclusions: In this cohort of household contacts, 6.7 % were diagnosed with active TB (more than 2/3 at follow-up) and 13% had a late QFT (+) conversion. Active and prolonged contacts' follow-up are essential to detect new infections and tackle the TB epidemic in Chile.

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.

Characteristic profile of antibody responses to PPD, ESAT-6, and CFP-10 of Mycobacterium tuberculosis in pulmonary tuberculosis suspected cases in Surabaya, Indonesia

Abstract Accurate and rapid diagnostic tools are important aspects of managing tuberculosis (TB) cases appropriately. However, the sensitivity and specificity of diagnostic kits based on immune response such as the tuberculin skin test (TST) and interferon gamma release assay (IGRA) are still debated. Thus, the exploration and assessment of specific biomarker-targeted antibodies are needed for the development of an accurate and rapid diagnostic tool. The present study was conducted in patients with a respiratory problem suspected to be TB at Dr. Soetomo Hospital, Surabaya, Indonesia. Among 102 patients tested by GeneXpert and AFB, 59 serum samples were from cases retrospectively determined to have active TB. A total of 102 serum of healthy controls (HC) was also collected. The PPD antigen and the recombinant CFP-10 and ESAT-6 proteins were prepared. Antibody responses against these proteins were evaluated by ELISA. All samples were also screened for the possibility of Mycobacterium avium-intracellulare complex (MAC) infection using Capilla MaC kit. The results showed that TB patients had a significantly higher concentration of IgG antibody in response to PPD than the HC. In addition, the receiver operating characteristic (ROC) curve analysis showed that PPD was acceptable for diagnostic purposes with an AUC value of 0.835 (95% CI 0.770-0.900, p < 0.0001). However, ESAT-6 and CFP-10 had low AUCs, and 32 samples from both groups showed a low concentration of IgA antibody against all antigens. The MAC detection results also showed that the concentration of IgA in the HC group was the highest. The current results indicate that PPD is a better antigen for antibody-based detection of TB than ESAT-6 and CFP-10. Based on the MAC detection assay, 53 people in the HC group were probably infected with rapidly growing nontuberculous mycobacteria (NTM), although antibody response to PPD was low.

Modelo predictivo clínico-radiológico para diagnosticar tuberculosis pulmonar activa / Predictive clinical-radiological model for diagnosing active pulmonary tuberculosis

Resumen: Introducción: El objetivo de este estudio fue desarrollar un modelo predictivo sobre la presencia de tuberculosis pulmonar activa utilizando datos clínico-epidemiológicos y hallazgos de radiografía simple (Rx) y tomografía computadorizada (TC) de tórax. Material y métodos: Se realizó un estudio observacional, retrospectivo, descriptivo y analítico, que recopiló 22 variables clínico-epidemiológicas, 11 hallazgos radiológicos en Rx de tórax y 23 en la TC, que se realizaron en pacientes con sospecha clínica de tuberculosis pulmonar durante un período de 10 años. Se aplicó un modelo de regresión logística multivariado a los predictores potenciales de cultivo positivo, obteniendo un modelo predictivo. Resultados: Se recogieron 1.540 pacientes con sospecha clínica de tuberculosis a los que se les realizó Rx y TC torácico. El cultivo fue positivo en 101 casos. Se utilizó un proceso de eliminación hacia atrás para obtener el mejor conjunto de variables predictivas. Se obtuvieron 24 variables que fueron significativas (6 clínicas, 5 de Rx y 13 de TC) y se les asignó una puntuación. A la suma de estas puntuaciones se restó la edad en años multiplicada por 0,03. El modelo sugiere el diagnóstico de tuberculosis pulmonar activa en pacientes con una puntuación superior a 1,845. Obtuvo una sensibilidad de 85,1%, especificidad de 83,6%, valor predictivo positivo de 26,6%, y valor predictivo negativo de 98,7%. El área bajo la curva ROC fue de 0,9163. Conclusión: Este sistema de puntuación basado en criterios clínico-epidemiológicos y hallazgos radiológicos puede ayudar a diagnosticar tuberculosis pulmonar activa en casos de sospecha diagnóstica.

Abstract:Introduction: The objective of this study was to develop a predictive model on the presence of active pulmonary tuberculosis using clinical-epidemiological data and findings of chest radiography and thoracic computed tomography (CT). Material and methods: An observational, retrospective, descriptive and analytical study was conducted, which collected 22 clinical and epidemiological variables, 11 radiological findings on chest x-ray and 23 on CT that were performed in patients with clinical suspicion of pulmonary tuberculosis during a period of 10 years. A multivariate logistic regression model was applied to the potential predictors of positive culture, obtaining a predictive model. Results: We collected 1,540 patients with clinical suspicion of tuberculosis who underwent radiography and thoracic CT. The culture was positive in 101 cases. A backward elimination process was used to obtain the best set of predictive variables. We obtained 24 variables that were significant (6 clinical, 5 of chest plain films and 13 of CT) and were assigned a score. The sum of these scores was subtracted from the age in years and multiplied by 0.03. The model suggests the diagnosis of active pulmonary tuberculosis in patients with a score higher than 1.845. The model obtained a sensitivity of 85.1%, specificity of 83.6%, positive predictive value of 26.6, and negative predictive value of 98.7%. The area under the ROC curve was 0.9163. Conclusion: This scoring system based on clinical-epidemiological criteria and radiological findings can help rule out active pulmonary tuberculosis in cases of diagnostic suspicion.

Genotipificación de aislamientos del complejo Mycobacterium tuberculosis mediante MIRU-VNTR, Cali, Colombia, 2013-2015 / MIRU-VNTR genotyping of Mycobacterium tuberculosis in a population of patients in Cali, Colombia, 2013-2015

Resumen Introducción. La tuberculosis continúa siendo uno de los problemas de salud más importantes a nivel mundial y, con la infección por el virus de la inmunodeficiencia humana (HIV), constituye la principal causa de muerte por infecciones. En el 2016, se notificaron 6,3 millones de casos nuevos de la enfermedad. Objetivo. Describir los patrones genéticos determinados mediante la genotipificación del número variable de repeticiones en tándem de unidades repetitivas interespaciadas de micobacterias (Mycobacterial Interspersed Repetitive Units - Variable Number of Tandem Repeats, MIRU-VNTR) en la población de estudio y compararlos con los hallados en otros estudios locales e internacionales. Materiales y métodos. Mediante MIRU-VNTR, entre el 2013 y el 2015 se hizo la genotipificación de 105 muestras de ADN extraídas del esputo o de aislamientos en cultivo de M. tuberculosis provenientes de pacientes residentes en Cali con diagnóstico de tuberculosis pulmonar. La amplificación de 24 loci MIRU-VNTR se hizo por medio de la reacción en cadena de la polimerasa (PCR). Los amplicones resultantes se visualizaron por electroforesis en geles de agarosa (2 %) teñidos con SYBR Safe™. La asignación de los alelos se hizo con un análisis gráfico con el programa GelAnalyzer 2010. Los resultados obtenidos se analizaron con el algoritmo UPGMA y se compararon con las bases de datos internacionales MIRU-VNTRplus y SITVITWEB. Resultados. Se genotipificaron por completo 62 de las muestras y se obtuvieron 58 perfiles diferentes de MIRU-VNTR. Al comparar con las bases de datos internacionales, su distribución por linajes fue la siguiente: 54,8 % para el LAM, 25,8 % para el Haarlem, 14,5 % para el S, 3,2 % para el Beijing y 1,6 % para el Cameroon. Los patrones MIRU-VNTR correspondieron a 20 tipos internacionales de MIRU (MIRU International Types, MIT) diferentes, y los más frecuentes fueron el MIT 190 y el MIT 110, con 22,6 y 6,5 %, respectivamente. Conclusión. Estos resultados confirmaron hallazgos previos sobre el predominio de los linajes LAM y Haarlem en la ciudad y la presencia de los MIT encontrados en otra ciudad de Colombia.

Abstract Introduction: Tuberculosis continues to be one of the main public health problems in the world. Together with the HIV infection, it is one of the main causes of death due to infections worldwide. In 2016, 6.3 million new cases of the disease were reported. Objective: To describe the genetic patterns determined by genotyping using variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR) in the study population and compare them with other studies carried out in Cali, Colombia, and the world. Materials and methods: We genotyped a total of 105 DNA samples extracted from sputum or culture isolates of the Mycobacterium tuberculosis complex, which were obtained from pulmonary tuberculosis diagnosed patients over the period 2013-2015, in Cali. We performed PCR amplification of 24 loci by MIRU-VNTR on the DNA extracted from the samples. The amplicons were visualized in agarose gel electrophoresis (2%) with SYBR Safe™ staining. Then, the alleles were designated by graphical analysis using the GelAnalyzer 2010 software. These results were analyzed using the UPGMA logarithm and compared with the registers from the MIRU-VNTR plus and SITVITWEB databases. Results: We genotyped 62 of the samples completely and we obtained 58 different MIRU-VNTR profiles. By comparing with the international databases, we determined the following distributions per lineage: LAM, 54.8%; Haarlem,25.8%; S, 14.5%; Beijing, 3.2%, and Cameroon, 1.6%. The MIRU-VNTR patterns corresponded to 17 different MITs; the most frequent were MIT 190 and MIT 110, with 22.6% and 6.5%, respectively. Conclusions: These results demonstrated previous observations about the predominance of the LAM and Haarlem lineages in the city, and the presence of the MITs found in another city of Colombia.

Accuracy of a rapid molecular test for tuberculosis in sputum samples, bronchoalveolar lavage fluid, and tracheal aspirate obtained from patients with suspected pulmonary tuberculosis at a tertiary referral hospital / Acurácia do teste rápido molecular para tuberculose em amostras de escarro, lavado broncoalveolar e aspirado traqueal obtidos de pacientes com suspeita de tuberculose pulmonar em um hospital de referência terciária

ABSTRACT Tuberculosis continues to be a major public health problem worldwide. The aim of the present study was to evaluate the accuracy of the Xpert MTB/RIF rapid molecular test for tuberculosis, using pulmonary samples obtained from patients treated at the Júlia Kubitschek Hospital, which is operated by the Hospital Foundation of the State of Minas Gerais, in the city of Belo Horizonte, Brazil. This was a retrospective study comparing the Xpert MTB/RIF test results with those of standard culture for Mycobacterium tuberculosis and phenotypic susceptibility tests. Although the Xpert MTB/RIF test showed high accuracy for the detection of M. tuberculosis and its resistance to rifampin, attention must be given to the clinical status of the patient, in relation to the test results, as well as to the limitations of molecular tests.

RESUMO A tuberculose permanece como um grave problema de saúde pública. O objetivo deste estudo foi avaliar a acurácia do teste rápido molecular Xpert MTB/RIF em amostras pulmonares no Hospital Júlia Kubitschek, Fundação Hospitalar do Estado de Minas Gerais, localizado em Belo Horizonte (MG). Trata-se de um estudo descritivo retrospectivo, considerando-se como método padrão a cultura para o bacilo da tuberculose e o teste de sensibilidade fenotípico. O teste Xpert MTB/RIF apresentou ótima acurácia para a detecção da tuberculose e resistência à rifampicina, mas é necessária a atenção a dados clínicos do paciente em relação ao resultado do exame e às limitações dos testes moleculares.

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing / Desempenho de testes para o diagnóstico de tuberculose pulmonar em populações indígenas no Brasil: a contribuição do Teste Rápido Molecular

ABSTRACT Objective: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. Methods: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). Results: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. Conclusions: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

RESUMO Objetivo: Avaliar a acurácia do teste rápido molecular como ferramenta diagnóstica e estimar a incidência de casos pulmonares positivos entre a população indígena. Métodos: Estudo epidemiológico baseado em dados secundários. Foi calculada a incidência de casos de tuberculose pulmonar positiva entre 1° de janeiro de 2011 e 31 de dezembro de 2016, e o desempenho da baciloscopia e do teste rápido molecular no diagnóstico de tuberculose pulmonar, em comparação à cultura de escarro (teste padrão). Resultados: Foram incluídos 4.048 casos de indígenas considerados sintomáticos respiratórios, que forneceram amostras de escarro para análise. Destes, 3,7%, 6,7% e 3,7% apresentaram resultados positivos para baciloscopia, cultura e teste rápido molecular, respectivamente. A incidência média de tuberculose pulmonar foi de 269,3/100 mil habitantes. A sensibilidade do teste rápido molecular, em relação à cultura, foi 93,1% e a especificidade foi 98,2%. A baciloscopia apresentou sensibilidade 55,1% e especificidade 99,6%. Conclusões: O teste rápido molecular pode ser útil em áreas remotas, com recursos limitados e incidência de tuberculose elevada, como as aldeias indígenas nas áreas rurais do país. Ademais, o teste rápido molecular apresenta como principais vantagens o fácil manuseio, os resultados rápidos e a possibilidade de identificar a resistência à rifampicina. Em conjunto, esses atributos facilitam o início do tratamento precoce, contribuindo para reduzir a transmissão em comunidades reconhecidamente vulneráveis à infecção e à doença.

Comparison of GeneXpert MTB/RIF assay and LED-FM microscopy for the diagnosis of extra pulmonary tuberculosis in Khyber Pakhtunkhwa, Pakistan

ABSTRACT GeneXpert is one of the recent technological instruments used to diagnose tuberculosis in a short span of time. In this study, the performance of GeneXpert MTB/RIF assay for the diagnosis of extrapulmonary tuberculosis (EPTB) was compared with light-emitting diode Fluorescent Microscopy (LED-FM) in Khyber Pakhtunkhwa, Pakistan. A total of 737 EPTB samples were collected from tuberculosis (TB) suspected patients. Out of these samples, male to female ratio was 53% (n = 390) to 47% (n = 347) respectively. The sensitivity and specificity was 73% and 100% for GeneXpert, while 40% and 100% for LED-FM microscopy. This shows that the sensitivity of GeneXpert is 40-50%, higher than LED-FM microscopy. GeneXpert also detected low number of bacilli as compared to LED-FM microscopy.

Impact of smoking on sputum culture conversion and pulmonary tuberculosis treatment outcomes in Brazil: a retrospective cohort study / Impacto do tabagismo na conversão de cultura e no desfecho do tratamento da tuberculose pulmonar no Brasil: estudo de coorte retrospectivo

ABSTRACT Objective: To evaluate the impact of smoking on pulmonary tuberculosis (PTB) treatment outcomes and the two-month conversion rates for Mycobacterium tuberculosis sputum cultures among patients with culture-confirmed PTB in an area with a moderate incidence of tuberculosis in Brazil. Methods: This was a retrospective cohort study of PTB patients diagnosed and treated at the Thoracic Diseases Institute of the Federal University of Rio de Janeiro between 2004 and 2012. Results: Of the 298 patients diagnosed with PTB during the study period, 174 were included in the outcome analysis: 97 (55.7%) were never-smokers, 31 (17.8%) were former smokers, and 46 (26.5%) were current smokers. Smoking was associated with a delay in sputum culture conversion at the end of the second month of TB treatment (relative risk = 3.58 &091;95% CI: 1.3-9.86&093;; p = 0.01), as well as with poor treatment outcomes (relative risk = 6.29 &091;95% CI: 1.57-25.21&093;; p = 0.009). The association between smoking and a positive culture in the second month of treatment was statistically significant among the current smokers (p = 0.027). Conclusions: In our sample, the probability of a delay in sputum culture conversion was higher in current smokers than in never-smokers, as was the probability of a poor treatment outcome.

RESUMO Objetivo: Avaliar o impacto do tabagismo no desfecho do tratamento da tuberculose pulmonar (TBP) e na taxa de conversão da cultura de Mycobacterium tuberculosis no escarro ao final do segundo mês de tratamento em pacientes com TBP confirmada por cultura em um local com incidência de tuberculose moderada no Brasil. Métodos: Estudo de coorte retrospectivo envolvendo pacientes com TBP diagnosticados e tratados no Instituto de Doenças do Tórax da Universidade Federal do Rio de Janeiro entre 2004 e 2012. Resultados: De 298 pacientes com diagnóstico confirmado de TBP no período do estudo, 174 foram incluídos na análise dos desfechos: 97 nunca fumaram (55,7%), 31 eram ex-tabagistas (17,8%), e 46 eram tabagistas atuais (26,5%). O tabagismo foi associado ao atraso na conversão da cultura do final do segundo mês do tratamento (risco relativo = 3,58 &091;IC95%: 1,30-9,86&093;; p = 0,01), assim como ao desfecho de tratamento não favorável (risco relativo = 6,29 &091;IC95%: 1,57-25,21&093;; p = 0,009). A associação entre tabagismo e cultura positiva ao final do segundo mês de tratamento foi estatisticamente significante entre os tabagistas atuais (p = 0.027). Conclusões: Nesta amostra, os pacientes tabagistas atuais apresentaram uma maior probabilidade de atraso na conversão da cultura após dois meses de tratamento e de desfecho de tratamento não favorável do que aqueles que nunca fumaram.

Cuando la baciloscopía positiva no es tuberculosis. A propósito de un caso y breve review de la literatura / When smear positive is not tuberculosis. About a case and brief review of the literature

El método gold standar para el diagnóstico de la tuberculosis (TB) es el cultivo en medio sólido de Lowenstein-Jensen. Dado el alto costo y los requerimientos de infraestructura y personal entrenado que exige este método, tanto el programa nacional, como las recomendaciones de la Organización Mundial de la Salud (OMS), establecen que una baciloscopía positiva (BAAR +) confirma el diagnóstico de TB. Si bien el cultivo amplía la sensibilidad diagnóstica, tipifica los bacilos, y permite realizar pruebas de sensibilidad, no es un requisito operativo para la definición de confirmación bacteriológica de TB. En Argentina, el 1% de las BAAR (+) corresponden a otras etiologías3. Presentamos un caso comprendido en ese 1%, en el cual mostramos los problemas a los que se enfrenta un paciente (fundamentalmente demora diagnóstica y exposición innecesaria a drogas potencialmente tóxicas) cuando tiene un diagnóstico de TB de acuerdo con los stándares nacionales e internacionales y sin embargo no es TB.

The method gold standard for the diagnosis of tuberculosis (TB) is the culture in Lowenstein-Jensen’s solid way. In view of the high cost and the requirements of infrastructure and trained personnel that demands this method, both the national program, and the recommendations of the World Health Organization (WHO), they establish that a smear-positive confirms TB’s diagnosis. In addition, the culture increases the diagnostic sensitivity, typifies the bacillus and allows the sensitivity tests to be performed, but it is not an operative requirement for the definition of TB’s bacteriological confirmation. In Argentina, 1% of the BAAR (+) are due to other etiologies3. We present a case included in that 1%, in which we show the problems that a patient faces (basically diagnostic delay and unnecessary exposure to potentially toxic drugs) when it has TB’s diagnosis of agreement to the national and international standards and nevertheless it is not TB.

Combination of commercially available molecular assays and culture based methods in diagnosis of tuberculosis and drug resistant tuberculosis

ABSTRACT Early diagnosis of tuberculosis is of major clinical importance. Among 4733 clinical specimens collected from 3363 patients and subjected to Ziehl-Neelsen microscopy, 4109 were inoculated onto Löwenstein-Jensen slants and 3139 in Bactec/9000MB. Polymerase Chain Reaction (PCR) was performed in 3139 specimens, whereas, a genotypic assay was directly applied in 93 Mycobacterium tuberculosis complex PCR-positive for isoniazid and rifampicin resistance detection specimens (GenoType MTBDRplus). Recovered M. tuberculosis isolates (64) as well as, 21 more sent from Regional Hospitals were tested for antimycobacterial resistance with a phenotypic (manual MGIT-SIRE) and a genotypic assay (GenoType MTBDRplus). PCR in the clinical specimens showed excellent specificity (97.4%) and accuracy (96.8%), good sensitivity (70.4%), but low positive predictive value (40.3%). MGIT-SIRE performed to M. tuberculosis did not confer a reliable result in 16 isolates. Of the remaining 69 isolates, 15 were resistant to streptomycin, seven to isoniazid, seven to ethambutol and five to rifampicin. GenoType MTBDRplus correctly detected isoniazid (seven) and rifampicin-resistant M. tuberculosis strains (five), showing an excellent performance overall (100%). Susceptibility results by the molecular assay applied directly to clinical specimens were identical to those obtained from recovered isolates of the corresponding patients. Combining molecular and conventional methods greatly contribute to early diagnosis and accurate susceptibility testing of tuberculosis.

Performance of LED fluorescence microscopy for the detection of acid-fast bacilli from respiratory samples in peripheral laboratories in Argentina / Rendimiento de la microscopía de fluorescencia LED para la detección de bacilos ácido-alcohol resistentes en muestras respiratorias en laboratorios periféricos de Argentina

ABSTRACT Introduction: Light-emitting diode fluorescence microscopy (LED-FM) has been endorsed by the World Health Organization (WHO) for tuberculosis diagnosis, but its accuracy in HIV-infected patients remains controversial, and only some few studies have explored procedural factors that may affect its performance. Objective: To evaluate the performance of LED-FM for tuberculosis diagnosis in patients with and without HIV infection using a newer, less expensive LED lamp. Materials and methods: We compared the performance of LED-FM and Ziehl-Neelsen (ZN) microscopy on respiratory specimen smears from tuberculosis (TB) suspects and patients on treatment examined by different technicians blinded for HIV-status and for the result of the comparative test. We analyzed the effect of concentrating specimens prior to microscopy using different examination schemes and user-appraisal of the LED device. Results: Of the 6,968 diagnostic specimens collected, 869 (12.5%) had positive Mycobacterium tuberculosis cultures. LED-FM was 11.4% more sensitive than ZN (p<0.01). Among HIV-positive TB patients, sensitivity differences between LED-FM and ZN (20.6%) doubled the figure obtained in HIV-negative patients or in those with unknown HIV status (9.3%). After stratifying by direct and concentrated slides, the superiority of LED-FM remained. High specificity values were obtained both with LED-FM (99.9%) and ZN (99.9%).The second reading of a sample of slides showed a significantly higher positive detection yield using 200x magnification (49.4 %) than 400x magnification (33.8%) (p<0.05). The LED-device had a very good acceptance among the technicians. Conclusion: LED-FM better performance compared with ZN in HIV-infected patients and user-appraisal support the rapid roll-out of LED-FM. Screening at 200x magnification was essential to achieve LED-FM increased sensitivity.

RESUMEN Introducción. La microscopía de fluorescencia con lámpara LED (MF-LED) ha sido recomendada por la Organización Mundial de la Salud (OMS) para el diagnóstico de la tuberculosis, pero su precisión en pacientes con HIV continúa siendo controversial y en pocos estudios se han explorado los factores metodológicos que pueden afectar su utilidad. Objetivo. Evaluar el rendimiento de la MF-LED en el diagnóstico de la tuberculosis en pacientes con HIV y sin él mediante un novedoso dispositivo LED. Materiales y métodos. Se comparó el rendimiento de la MF-LED y la microscopía en frotis de muestras respiratorias con tinción de Ziehl-Neelsen (M-ZN) examinados por técnicos cegados en cuanto al estado de HIV y el resultado de la prueba comparativa. Se analizó el efecto de concentrar muestras antes de la microscopía, usar diferentes esquemas de observación y la valoración con el dispositivo LED. Resultados. De las 6.968 muestras recolectadas, 869 (12,5 %) resultaron con cultivo positivo para Mycobacterium tuberculosis. La MF-LED fue 11,4 % más sensible que la M-ZN (p<0,01). Entre los pacientes con tuberculosis positivos para HIV, la diferencia de sensibilidad entre la MF-LED y la M-ZN (20,6 %) duplicó la cifra obtenida en pacientes negativos para HIV o con estatus desconocido (9,3 %). Al estratificar los frotis en directos y concentrados, se mantuvo la superioridad de la MF-LED. Las especificidades de la MF-LED (99,9 %) y la M-ZN (99,9 %) resultaron elevadas. La lectura de una muestra de frotis mostró una positividad significativamente mayor con un aumento de 200X (49,4 %) que con uno de 400X (33,8 %) (p<0,05). El dispositivo LED tuvo una buena aceptación entre los técnicos. Conclusión. Debido al mejor desempeño de la MF-LED comparada con la M-ZN en pacientes con HIV y su fácil utilización, se recomienda su adopción. La utilización del aumento de 200X fue esencial para el incremento de la sensibilidad de la MF-LED.

Tuberculosis associated factors caused by Mycobacterium tuberculosis of the RDRio genotype

BACKGROUND Tuberculosis (TB) continues to be a disease that affects many countries around the world, including Brazil. Recently, a subtype of Latin American-Mediterranean family strain was identified and characterised by RDRio. The strain has been associated with different characteristics of the disease. OBJECTIVES In the present study we investigated the association of epidemiological, clinical, radiological and bacteriological variables with pulmonary tuberculosis caused by RDRioMycobacterium tuberculosis strain in large regions of São Paulo. METHODS We conducted a cross-sectional study in 530 patients with pulmonary tuberculosis, diagnosed using sputum culture, from two regions of the São Paulo state in Brazil. The samples were brought to São Paulo reference laboratories for epidemiological, clinical, radiological and bacteriological analyses, and the data were obtained from a TB notification system. RDRio genotyping and Spoligotyping of the samples were performed. For the analysis of the categorical variables we used the chi-square test or the Fisher’s exact test, and for the continuous variables, the Mann-Whitney test. In addition, a logistic regression was used for multivariate analysis. Differences with p < 0.05 were considered significant. FINDINGS The RDRio deletion was identified in 152 (28.7%) samples. In the univariate analysis, both the age groups above 25 years and alcohol consumption were associated with the RDRio deletion. The multivariate analysis confirmed the association of the RDRio deletion with the age groups: 25-35 years old [OR: 2.28 (1.02-5.07; p = 0.04)] and 36-60 years old (OR: 2.36 (1.11-5.05); p = 0.03], and also with alcohol consumption [OR: 1.63 (1.05-2.54); p = 0,03]. MAIN CONCLUSIONS In this study, we identified new factors associated with the M. tuberculosis of the RDRio deletion strains infection.

Tuberculosis and fungal co-infection present in a previously healthy patient / Coinfección de tuberculosis y candidiasis pulmonar en paciente previamente sana

Background: The coexistance among fungal pathogens and tuberculosis pulmonary is a clinical condition that generally occurs in immunosuppressive patients, however, immunocompetent patients may have this condition less frequently. Objective: We report the case of an immunocompetent patient diagnosed with coinfection Mycobacterium tuberculosis and Candida albicans. Case Description: A female patient, who is a 22-years old, with fever and a new onset of hemoptysis. Clinical findings and diagnosis: PDiminished vesicular breath sounds in the apical region and basal crackling rales in the left lung base were found in the physical examination. Microbiological tests include: chest radiography and CAT scan pictograms in high resolution, Ziehl-Neelsen stain, growth medium for fungus and mycobacteria through Sabouraudís agar method with D-glucose. Medical examinations showed Candida albicans fungus and Mycobacterium tuberculosis present in the patient. Treatment and Outcome: Patient was treated with anti-tuberculosis and anti-fungal medications, which produced good responses. Clinical relevance: Pulmonary tuberculosis and fungal co-infection are not common in immunocompetent patients. However, we can suspect that there is a presence of these diseases by detecting new onset of hemoptysis in patients.

Antecedentes: La coexistencia entre los hongos patógenos y la tuberculosis pulmonar es una condición clínica que se produce generalmente en pacientes inmunosuprimidos, sin embargo, los pacientes inmunocompetentes puede tener esta condición con menor frecuencia. Objetivo: Presentamos el caso de un paciente inmunocompetente con diagnóstico de una coinfección de tuberculosis Mycobacterium tuberculosis y Candida albicans. Caso clínico: Paciente femenina de 22 años con cuadro abrupto de tos, fiebre y hemoptisis sin antecedentes de enfermedad. Hallazgos clínicos y métodos diagnósticos: Al examen respiratorio se halló disminución del murmullo vesicular en la región apical y estertores crepitantes basales en el pulmón izquierdo. Se realizó estudios microbiológicos de muestras tomadas por expectoración y por fibrobroncoscopia en el que se incluyó la tinción de Ziehl-Neelsen, cultivo para micobacteria y hongos en medio Agar Dextrosa Sabouraud y filamentización en suero obteniéndose positividad para Mycobacterium tuberculosis y Candida albicans. Tratamiento y resultado: Se le realizó manejo con antifímicos de primera categoría y antimicóticos con buena respuesta clínica. Relevancia clínica: La coinfección fúngica y tuberculosis pulmonar no es frecuente en pacientes inmunocompetentes, debe sospecharse en episodios abruptos de hemoptisis.

Bronchoscopic diagnostic procedures and microbiological examinations in proving endobronchial tuberculosis / Procedimentos diagnósticos broncoscópicos e exames microbiológicos para a confirmação de tuberculose endobrônquica

ABSTRACT Objective: To determine the proportional distribution of endobronchial tuberculosis (EBTB) subtypes and to evaluate the types of bronchoscopic diagnostic procedures that can prove granulomatous inflammation. Methods: This was a retrospective study of 18 HIV-negative patients with biopsy-proven EBTB treated between 2010 and 2014. Results: The most common EBTB subtypes, as classified by the bronchoscopic features, were tumorous and granular (in 22.2% for both). Sputum smear microscopy was performed in 11 patients and was positive for AFB in 4 (36.3%). Sputum culture was also performed in 11 patients and was positive for Mycobacterium tuberculosis in 10 (90.9%). Smear microscopy of BAL fluid (BALF) was performed in 16 patients and was positive for AFB in 10 (62.5%). Culture of BALF was also performed in 16 patients and was positive for M. tuberculosis in 15 (93.7%). Culture of BALF was positive for M. tuberculosis in 93.7% of the 16 patients tested. Among the 18 patients with EBTB, granulomatous inflammation was proven by the following bronchoscopic diagnostic procedures: bronchial mucosal biopsy, in 8 (44.4%); bronchial brushing, in 7 (38.8%); fine-needle aspiration biopsy, in 2 (11.1%); and BAL, in 2 (11.1%). Bronchial anthracofibrosis was observed in 5 (27.7%) of the 18 cases evaluated. Conclusions: In our sample of EBTB patients, the most common subtypes were the tumorous and granular subtypes. We recommend that sputum samples and BALF samples be evaluated by smear microscopy for AFB and by culture for M. tuberculosis, which could increase the rates of early diagnosis of EBTB. We also recommend that bronchial brushing be employed together with other bronchoscopic diagnostic procedures in patients suspected of having EBTB.

RESUMO: Objetivo: Determinar a distribuição proporcional dos subtipos de tuberculose endobrônquica (TBEB) e avaliar os tipos de procedimentos diagnósticos broncoscópicos que podem revelar inflamação granulomatosa. Métodos: Este foi um estudo retrospectivo com 18 pacientes HIV negativos com TBEB comprovada por biópsia tratados entre 2010 e 2014. Resultados: Os subtipos mais comuns de TBEB, classificados pelas características na broncoscopia, foram tumoral e granular (em 22,2% para ambas) A baciloscopia de escarro foi realizada em 11 pacientes e foi positiva para BAAR em 4 (36,3%). A cultura de escarro também foi realizada em 11 pacientes e foi positiva para Mycobacterium tuberculosis em 10 (90,9%). A baciloscopia do LBA foi realizada em 16 pacientes e foi positiva para BAAR em 10 (62,5%). A cultura do LBA foi também realizada em 16 pacientes e foi positiva para o M. tuberculosis em 15 (93,7%). A cultura do LBA foi positiva para M. tuberculosis em 93,7% dos 16 pacientes testados. Nos 18 pacientes com TBEB, a presença de inflamação granulomatosa foi comprovada pelos seguintes procedimentos diagnósticos broncoscópicos: biópsia da mucosa brônquica, em 8 (44,4%); escovação brônquica, em 7 (38,8%); punção aspirativa por agulha fina, em 2 (11,1%); e LBA, em 2 (11,1%). Antracose/fibrose brônquica foi observada em 5 (27,7%) dos 18 casos avaliados. Conclusões: Em nossa amostra de pacientes com TBEB, os subtipos mais comuns foram o tumoral e o granular. Recomendamos que amostras de escarro e do LBA sejam avaliadas por baciloscopia para BAAR e cultura de M. tuberculosis, o que poderia aumentar as taxas de diagnóstico precoce de TBEB. Também recomendamos que a escovação brônquica seja empregada em conjunto com outros procedimentos diagnósticos broncoscópicos em pacientes com suspeita de TBEB.

Isoniazid and rifampin drug susceptibility testing: application of 2,3,5-triphenyl tetrazolium chloride assay and microscopic-observation drug-susceptibility assay directly on Ziehl-Neelsen smear positive sputum specimens

Abstract The current study was aimed to evaluate the performance of direct 2,3,5-triphenyl tetrazolium chloride assay and direct microscopic observation drug susceptibility assay with indirect Löwenstein-Jensen proportion method directly on Ziehl-Neelsen smear positive sputum specimens. Methods Direct acid fast bacilli smear positive sputum specimens (n = 264) were subjected to isoniazid and rifampicin drug susceptibility testing by direct 2,3,5-triphenyl tetrazolium chloride assay, direct microscopic observation drug susceptibility assay, and the performances were compared with indirect Löwenstein-Jensen proportion method. Results The direct 2,3,5-triphenyl tetrazolium chloride assay demonstrated an overall sensitivity, specificity, positive predictive value, and negative predictive value of 99.2%, 82.4%, 99.2%, and 88.5%, respectively, for the detection of isoniazid and rifampicin resistant Mycobacterium tuberculosis isolates when compared to indirect Löwenstein-Jensen proportion method. Likewise, the overall sensitivity, specificity, positive predictive value and negative predictive value of direct microscopic observation drug susceptibility assay were 98.8%, 82.4%, 99.2%, and 78.2%, respectively. Conclusion The direct 2,3,5-triphenyl tetrazolium chloride assay was found to be an economical alternative method for the rapid and accurate detection of isoniazid and rifampicin resistance from direct acid fast bacilli smear positive sputum specimens.

Historia natural de la tuberculosis, fisiopatogenia de la infección y la enfermedad en el niño / Natural history of tuberculosis, infection and disease pathogenesis in children

The multiple manifestations of tuberculosis (TB) are a result of the relationships between Mycobacterium tuberculosis, the host and the environmental, social and cultural conditions. In TB pathogenesis, three factors must be considered: the virulence of the bacillus, the potential of cellular destruction and caseous necrosis, and the immune response and hypersensitivity to the infection.

La expresión múltiple de la tuberculosis se debe a la relación entre el Mycobacterium tuberculosis, el huésped y las condiciones medioambientales, sociales y culturales. En la patogenia de la tuberculosis se deben tener en cuenta tres factores: la virulencia del bacilo, la capacidad de producir destrucción celular y necrosis caseosa y la respuesta inmunitaria e hipersensibilidad a la infección.

Dormancy models for Mycobacterium tuberculosis: A minireview

Dormancy models for Mycobacterium tuberculosis play important roles in understanding various aspects of tuberculosis pathogenesis and in the testing of novel therapeutic regimens. By simulating the latent tuberculosis infection, in which the bacteria exist in a non-replicative state, the models demonstrate reduced susceptibility to antimycobacterial agents. This minireview outlines the models available for simulating latent tuberculosis both in vitro and in several animal species. Additionally, this minireview discusses the advantages and disadvantages of these models for investigating the bacterial subpopulations and susceptibilities to sterilization by various antituberculosis drugs.

Primary drug resistance in a region with high burden of tuberculosis: A critical problem / Farmacorresistencia en casos nuevos en una región con alta carga de tuberculosis: Un problema crítico

Objective. To determine rates of drug resistance in new cases of pulmonary tuberculosis in a region with a high burden of the disease. Materials and methods. New case suspects were referred for drug susceptibility testing. Results. 28.9% of new cases were resistant to at least one first line drug; 3.9% had a multidrug-resistant strain, 15.6% a monoresistant strain and 9.4% a polyresistant strain. Conclusion. Our rate of drug resistant tuberculosis in new cases is very high; this has important clinical implications, since even monoresistance can have a negative impact on the outcome of new cases treated empirically with a six month regimen.

Objetivo. Determinar las tasas de resistencia a fármacos en casos nuevos de tuberculosis pulmonar en una región con alta prevalencia de farmacorresistencia. Material y métodos. Casos nuevos de tuberculosis pulmonar referidos para cultivo y pruebas de sensibilidad a los fármacos antituberculosis de primera línea. Resultados. 28.9% de los casos nuevos presentaban una cepa resistente al menos a un fármaco de primera línea; 3.9% eran multifarmacorresistentes, 15.6% eran monorresistentes y 9.4% polirresistentes. Conclusión. La presente tasa de tuberculosis resistente en casos nuevos es muy elevada; esto tiene importantes implicaciones clínicas ya que aún la monorresistencia puede tener un impacto negativo sobre los resultados del tratamiento de pacientes que reciben un esquema empírico de seis meses.