Evaluation of the GeneXpert MTB/RIF to diagnose tuberculosis in a public health laboratory

ABSTRACT OBJECTIVES To evaluate the performance of geneXpert MTB/Rif versus conventional methods (bacilloscopy and culture) in the diagnosis of tuberculosis in a Central Public Health Laboratory (LACEN, Tocantins), Northern Brazil. METHODS Retrospective study, with information from 1,973 suspected cases of tuberculosis from patients treated from January 2015 to December 2020. RESULTS From the culture (reference standard), the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the geneXpert MTB/Rif were 100%, 97%, 74%, 100%, and 97%, respectively, against 85%, 98%, 80%, 98%, and 97% of bacilloscopy. CONCLUSIONS The geneXpert MTB/Rif performed similarly to culture and better than bacilloscopy. Although positive cases with negative culture should be evaluated with caution, its routine use is important for the early detection of tuberculosis.

Mycobacterium tuberculosis latent infection in healthcare students: systematic review of prevalence / Infecção latente por Mycobacterium tuberculosis em estudantes da área da saúde: revisão sistemática de prevalência / Infección latente por Mycobacterium tuberculosis en estudiantes de la salud: revisión sistemática de la prevalencia

ABSTRACT Objective: The aim of this study was to synthesize the evidence on the prevalence of latent Mycobacterium tuberculosis infection (LTBI) among undergraduate health care students. Methods: A systematic review of prevalence with meta-analysis was conducted. Prospective and retrospective cohorts and cross-sectional studies involving probable exposure to M. tuberculosis during undergraduate education, along with the tuberculin skin test (TST) or interferon-γ release assay (IGRA) for investigation of latent tuberculosis were searched. Searches were conducted in MEDLINE, CINAHL, EMBASE, LILACS, Scopus, and Web of Science databases. Independent reviewers were responsible for the selection and inclusion of studies. Data were extracted, critically appraised, and synthesized using the JBI approach. PRISMA was used to report the study. Results: Twenty-two studies were analyzed. The overall prevalence in healthcare undergraduate students was 12.53%. Conclusion: The prevalence of LTBI in undergraduate health students was high for such a highly educated population. Screening with TST and/or IGRA and chemoprophylaxis, when necessary, should be provided to undergraduate health students when in contact with respiratory symptomatic patients.

RESUMO Objetivo: O objetivo deste estudo foi sintetizar as evidências sobre a prevalência de infecção de Mycobacterium tuberculosis (ILTB) entre estudantes de graduação da área da saúde. Método: Foi realizada uma revisão sistemática de prevalência com metanálise. Coortes prospectivas e retrospectivas e estudos transversais envolvendo provável exposição a M. tuberculosis durante a graduação, juntamente com o teste tuberculínico (TT) ou ensaio de liberação de interferon-γ (IGRA) para investigação de tuberculose latente foram pesquisados. As buscas foram realizadas nas bases de dados MEDLINE, CINAHL, EMBASE, LILACS, Scopus e Web of Science. Revisores independentes foram responsáveis pela seleção e inclusão dos estudos. Os dados foram extraídos, avaliados criticamente e sintetizados utilizando a abordagem JBI. PRISMA foi usado para relatar o estudo. Resultados: Vinte e dois estudos foram analisados. A prevalência geral em estudantes de graduação da área da saúde foi de 12,53%. Conclusão: A prevalência de ILTB em estudantes de graduação em saúde foi alta para uma população com alto nível de escolaridade. Triagem com TT e/ou IGRA e quimioprofilaxia, quando necessária, deve ser fornecida aos estudantes de graduação da área da saúde quando em contato com pacientes sintomáticos respiratórios.

RESUMEN Objetivo: El objetivo de este estudio fue sintetizar la evidencia sobre la prevalencia de infección latente por Mycobacterium tuberculosis (ILTB) entre estudiantes universitarios de la salud. Métodos: Se realizó una revisión sistemática de la prevalencia con metanálisis. Cohortes prospectivas y retrospectivas y estudios transversales que involucran exposición probable a M tuberculosis durante la educación universitaria, junto con la prueba cutánea de tuberculina (TST) o el ensayo de liberación de interferón-γ (IGRA) para la investigación de tuberculosis latente. Las búsquedas se realizaron en las bases de datos MEDLINE, CINAHL, EMBASE, LILACS, Scopus y Web of Science. Revisores independientes fueron responsables de la selección e inclusión de los estudios. Los datos se extrajeron, se evaluaron críticamente y se sintetizaron utilizando el enfoque JBI. Se utilizó PRISMA para informar el estudio. Resultados: Se analizaron veintidós estudios. La prevalencia global en estudiantes universitarios en salud fue del 12,53%. Conclusión: La prevalencia de LTBI en estudiantes universitarios de salud fue alta para una población con un nivel educativo tan alto. Se debe proporcionar tamizaje con TST y/o IGRA y quimioprofilaxis, cuando sea necesario, a los estudiantes universitarios en salud cuando estén en contacto con pacientes sintomáticos respiratorios.

Hemoptisis secundaria a tuberculosis pulmonar complicada con pseudoaneurisma de Rasmussen. Reporte de un caso en pediatría. / Hemoptysis in Pulmonary Tuberculosis Complicated by Rasmussen's Pseudoaneurysm. A Pediatric Case Report.

Presentamos el caso de un niño de 12 años que consultó por hemoptisis, sin otros sín- tomas asociados. Se realizó radiografía de tórax (patológica), laboratorio con aumen- to moderado de reactantes de fase aguda, PPD (negativa), esputos x 3 con bacilosco- pias negativas y tomografía de tórax con contraste i.v. que mostró imágenes de árbol en brote en todos los lóbulos y una imagen de dilatación vascular de una rama de la ar- teria pulmonar en lóbulo superior izquierdo. Se plantearon diagnósticos diferenciales: malformación vascular primaria o lesión secundaria a infección. La angiografía digital permitió confirmar el pseudoaneurisma y embolizarlo. Luego de 17 días, 2/3 cultivos de esputo fueron positivos para Mycobacterium tuberculosis. El niño realizó tratamiento antituberculoso con drogas de primera línea con evolución clínica favorable. Este caso resalta la importancia de considerar el pseudoaneurisma de Rasmussen en- tre las posibles complicaciones de un paciente con tuberculosis y hemoptisis recurren- te o masiva.

We present the case of a 12-year-old boy admitted to the hospital due to hemoptysis without other symptoms. We performed a Thorax X-Ray (pathological), laboratory with elevated acute phase reactants, TST (negative), sputum x 3 with negative smear and computed tomography angiography showing a tree-in-bud pattern in all lobes, and di-latation of a brunch of the pulmonary artery in the upper left lobe. We considered pri-mary vascular anomaly or lesion due to infection as a differential diagnosis. The patient underwent digital angiography and therapeutic embolization of this pseudoaneurysm. After seventeen days, 2/3 of the sputum cultures were positive for Mycobacterium tu-berculosis. The patient received standard anti-TB therapy with favorable evolution. This case highlights the importance of considering complications such as Rasmussen's pseudoaneurysm in patients with pulmonary tuberculosis and recurrent or massive hemoptysis.

Aplicación de PCR a partir de cultivo en la identificación de subespecies del complejo Mycobacterium Tuberculosis / The use of culture-based PCR for the identification of subspecies of the mycobacterium tuberculosis complex

Los métodos diagnósticos clásicos de tuberculosis (TB) se basan en la utilización de baciloscopía y cultivo. La identificación del agente etiológico desde la positivización del cultivo requiere entre 10 y 15 días, mientras que el empleo de la reacción en cadena de la polimerasa (PCR) disminuye el tiempo a 24 h, lo que permite no solo identificar las subespecies del complejo Mycobacterium tuberculosis (CMTB) sino también diferenciarlas de otras especies ambientales clínicamente importantes (MOTT) facilitando el diagnóstico y tratamiento. El objetivo del presente trabajo fue determinar la utilidad de la PCR en la identificación temprana de las micobacterias pertenecientes al CMTB, a partir de cultivos positivos, de pacientes con sospecha de TB, atendidos en un hospital pediátrico de alta complejidad, durante un período de cuatro años. A cada muestra, se le realizó baciloscopía y cultivo en medio líquido. A los cultivos positivos, una inmunocromatografía lateral (TBIDR) y luego PCR. El 4,6% del total de muestras (510/11.162) pertenecientes a 198 pacientes presentó cultivos positivos. Cuatrocientos veintiseis (84%) correspondieron a muestras respiratorias. El rendimiento de la baciloscopía directa fue del 41% (194/470). Cuatrocientos treinta y ocho (86%) resultaron M. tuberculosis, 21 (4%) Mycobacterium bovis, 7 (1%), M. bovis-BCG y 44 (9%) MOTT. La utilización de medios de cultivos líquidos junto con el empleo de PCR favorecen una rápida orientación microbiológica y constituye una estrategia útil para optimizar el manejo clínico de estas infecciones, desde el punto de vista terapéutico y epidemiológico, especialmente en pediatría (AU)

Classical diagnostic methods for tuberculosis (TB) are based on the use of smear microscopy and culture. The identification of the etiological agent from positive culture requires 10 to 15 days, while the use of the polymerase chain reaction (PCR) reduces the time to 24 h, which allows not only to identify the subspecies of the Mycobacterium tuberculosis complex (MTC) but also to differentiate them from clinically important environmental mycobacteria other than tuberculosis (MOTT), facilitating diagnosis and treatment. The aim of this study was to determine the usefulness of PCR in the early identification of mycobacteria belonging to the MTC, from positive cultures of patients with suspected TB seen in a pediatric tertiary hospital over a 4-year period. For each sample, smear microscopy and culture in liquid medium was performed. Positive cultures were subjected to lateral immunochromatography (TBIDR) and then PCR. Of the total number of samples (510/11,162) belonging to 198 patients, 4.6% showed positive cultures; 426 (84%) were respiratory samples. The direct smear microscopy yield was 41% (194/470). Overall, 438 (86%) were found to be M. tuberculosis, 21 (4%) Mycobacterium bovis, 7 (1%), M. bovis-BCG, and 44 (9%) MOTT. The use of liquid culture media together with the use of PCR favors a rapid microbiological orientation and is a useful strategy to optimize the clinical management of these infections, from a therapeutic and epidemiological point of view, especially in children (AU)

Neumonía lipoidea exógena crónica y sobreinfección por Mycobacterium tuberculosis / Chronic Exogenous Lipoid Pneumonia and Superinfection by Mycobacterium Tuberculosis

Introducción: la neumonía lipoidea exógena es una enfermedad pulmonar inflamatoria poco común, desencadenada por la inhalación o aspiración de material graso de origen animal, vegetal o mineral. El diagnóstico se establece a través de confirmación histo-patológica, por la presencia de macrófagos cargados de lípidos en muestras respirato-rias, asociado a las características clínicas específicas al momento de su presentación.Requiere de un alto nivel de sospecha y una adecuada anamnesis de los antecedentes exposicionales del paciente debido a que muchos casos son subdiagnosticados y trat-ados como neumonía adquirida en la comunidad, lo que retrasa su diagnóstico y mane-jo, sumado a la ausencia de guías disponibles para su tratamiento.Se han reportado pocos casos de sobreinfección por tuberculosis en pacientes con neu-monía lipoidea exógena crónica. Caso clínico: femenino 33 años, con antecedentes de exposición crónica a sustancias desinfectantes de características aceitosas sin protección de vía aérea, con cuadro de tos y dolor torácico. Conclusión: el diagnóstico temprano, asociado a tratamiento de soporte, general-mente conservador, favorece la mejoría clínica y radiológica, y de esta manera dis-minuye la morbimortalidad. (AU)

Introduction: exogenous lipoid pneumonia is a rare inflammatory lung disease, trigge-red by inhalation or aspiration of fatty material of animal, vegetable or mineral origin. The diagnosis is established through histological confirmation by the presence of lipid-laden macrophages in respiratory samples, associated with the specific clinical charac-teristics at the time of presentation. It requires a high level of suspicion and an adequate anamnesis of the patient's expo-sure history, since many cases are underdiagnosed and treated as community-acquired pneumonia, what delays its diagnosis and management, added to the absence of avai-lable guidelines for its treatment. Few cases of tuberculosis superinfection have been reported in patients with exoge-nous lipoid pneumonia.Clinical case: 33-year-old female, with a history of chronic exposure to oily disinfectant substances without airway protection, with symptoms of cough and chest pain.Conclusion: early diagnosis, associated with supportive treatment, generally conser-vative, favors clinical and radiological improvement, thus reducing morbidity and mor-tality. (AU)

Clinical value of the MeltPro MTB assays in detection of drug-resistant tuberculosis in paraffin-embedded tissues / 中华病理学杂志

Objective: To evaluate the clinical value of the MeltPro MTB assays in the diagnosis of drug-resistant tuberculosis. Methods: A cross-sectional study design was used to retrospectively collect all 4 551 patients with confirmed tuberculosis between January 2018 and December 2019 at Beijing Chest Hospital, Capital Medical University. Phenotypic drug sensitivity test and GeneXpert MTB/RIF (hereafter referred to as "Xpert") assay were used as gold standards to analyze the accuracy of the probe melting curve method. The clinical value of this technique was also evaluated as a complementary method to conventional assays of drug resistance to increase the detective rate of drug-resistant tuberculosis. Results: By taking the phenotypic drug susceptibility test as the gold standard, the sensitivity of the MeltPro MTB assays to detect resistance to rifampicin, isoniazid, ethambutol and fluoroquinolone was 14/15, 95.7%(22/23), 2/4 and 8/9,respectively; and the specificity was 92.0%(115/125), 93.2%(109/117), 90.4%(123/136) and 93.9%(123/131),respectively; the overall concordance rate was 92.1%(95%CI:89.6%-94.1%),and the Kappa value of the consistency test was 0.63(95%CI:0.55-0.72).By taking the Xpert test results as the reference, the sensitivity of this technology to the detection of rifampicin resistance was 93.6%(44/47), the specificity was100%(310/310), the concordance rate was 99.2%(95%CI:97.6%-99.7%), and the Kappa value of the consistency test was 0.96(95%CI:0.93-0.99). The MeltPro MTB assays had been used in 4 551 confirmed patients; the proportion of patients who obtained effective drug resistance results increased from 83.3% to 87.8%(P<0.01); and detection rate of rifampicin, isoniazid, ethambutol, fluoroquinolone resistance, multidrug and pre-extensive drug resistance cases were increased by 3.2%, 14.7%, 22.2%, 13.7%, 11.2% and 12.5%, respectively. Conclusion: The MeltPro MTB assays show satisfactory accuracy in the diagnosis of drug-resistant tuberculosis. This molecular pathological test is an effective complementary method in improving test positivity of drug-resistant tuberculosis.

Research progress in transcriptional and immunological biomarkers associated with tuberculosis infection / 中华预防医学杂志

Tuberculosis (TB) is an infectious disease that poses a serious threat to human health. About a quarter of the world's population were infected with Mycobacterium tuberculosis in 2020, and the majority of them were latently infected. Approximately 5%-10% of the population with latent tuberculosis infection may progress to active TB disease. Identifying latent TB infection from active TB by biomarkers and screening people with latent TB infection at high risk of progression for preventive treatment by biomarkers that can reliably predict the progression is one of the most effective strategies to control TB. This article reviews the progress of research on transcriptional and immunological biomarkers for identifying TB infection and predicting the progression from latent infection to active TB, with the aim of providing new ideas for tuberculosis control.

Characterization of the cellular immune response induced by Mycobacterium tuberculosis Rv2626c / 生物工程学报

Nearly a quarter of the world's population is infected with Mycobacterium tuberculosis and remains long-term asymptomatic infection. Rv2626c is a latent infection-related protein regulated by DosR of M. tuberculosis. In this study, the Rv2626c protein was prokaryotically expressed and purified, and its immunobiological characteristics were analyzed using RAW264.7 cells and mice as infection models. SDS-PAGE and Western blotting analysis showed that the Rv2626c-His fusion protein was mainly expressed in soluble form and specifically reacted with the rabbit anti-H37RV polyclonal serum. In addition, we found that the Rv2626c protein bound to the surface of RAW264.7 macrophages and up-regulated the production of NO. Moreover, the Rv2626c protein significantly induced the production of pro-inflammatory cytokines IFN-γ, TNF-α, IL-6 and MCP-1, and induced strong Th1-tendency immune response. These results may help to reveal the pathogenic mechanism of M. tuberculosis and facilitate the development of new tuberculosis vaccine.

Cryo-EM structures for the Mycobacterium tuberculosis iron-loaded siderophore transporter IrtAB

The adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter, IrtAB, plays a vital role in the replication and viability of Mycobacterium tuberculosis (Mtb), where its function is to import iron-loaded siderophores. Unusually, it adopts the canonical type IV exporter fold. Herein, we report the structure of unliganded Mtb IrtAB and its structure in complex with ATP, ADP, or ATP analogue (AMP-PNP) at resolutions ranging from 2.8 to 3.5 Å. The structure of IrtAB bound ATP-Mg2+ shows a "head-to-tail" dimer of nucleotide-binding domains (NBDs), a closed amphipathic cavity within the transmembrane domains (TMDs), and a metal ion liganded to three histidine residues of IrtA in the cavity. Cryo-electron microscopy (Cryo-EM) structures and ATP hydrolysis assays show that the NBD of IrtA has a higher affinity for nucleotides and increased ATPase activity compared with IrtB. Moreover, the metal ion located in the TM region of IrtA is critical for the stabilization of the conformation of IrtAB during the transport cycle. This study provides a structural basis to explain the ATP-driven conformational changes that occur in IrtAB.

A multi-stage and multi-epitope vaccine against Mycobacterium tuberculosis based on an immunoinformatics approach / 细胞与分子免疫学杂志

Objectives To develop a multi-stage and multi-epitope vaccine, which consists of epitopes from the early secretory and latency-associated antigens of Mycobacterium tuberculosis (MTB). Methods The B-cell, cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes of 12 proteins were predicted using an immunoinformatics. The epitopes with antigenicity, without cytotoxicity and sensitization, were further screened to construct the multi-epitope vaccine. Furthermore, the proposed vaccine underwent physicochemical properties analysis and secondary structure prediction as well as 3D structure modeling, refinement and validation. Then the refined model was docked with TLR4. Finally, an immune simulation of the vaccine was carried out. Results The proposed vaccine, which consists of 12 B-cell, 11 CTL and 12 HTL epitopes, had a flexible and stable globular conformation as well as a thermostable and hydrophilic structure. A stable interaction of the vaccine with TLR4 was confirmed by molecular docking. The efficiency of the candidate vaccine to trigger effective cellular and humoral immune responses was assessed by immune simulation. Conclusion A multi-stage multi-epitope MTB vaccine construction strategy based on immunoinformatics is proposed, which is expected to prevent both active and latent MTB infection.

The past, present and future of tuberculosis treatment / 浙江大学学报·医学版

Tuberculosis (TB) is an ancient infectious disease. Before the availability of effective drug therapy, it had high morbidity and mortality. In the past 100 years, the discovery of revolutionary anti-TB drugs such as streptomycin, isoniazid, pyrazinamide, ethambutol and rifampicin, along with drug combination treatment, has greatly improved TB control globally. As anti-TB drugs were widely used, multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis emerged due to acquired genetic mutations, and this now presents a major problem for effective treatment. Genes associated with drug resistance have been identified, including katG mutations in isoniazid resistance, rpoB mutations in rifampin resistance, pncA mutations in pyrazinamide resistance, and gyrA mutations in quinolone resistance. The major mechanisms of drug resistance include loss of enzyme activity in prodrug activation, drug target alteration, overexpression of drug target, and overexpression of the efflux pump. During the disease process, Mycobacterium tuberculosis may reside in different microenvironments where it is expose to acidic pH, low oxygen, reactive oxygen species and anti-TB drugs, which can facilitate the development of non-replicating persisters and promote bacterial survival. The mechanisms of persister formation may include toxin-antitoxin (TA) modules, DNA protection and repair, protein degradation such as trans-translation, efflux, and altered metabolism. In recent years, the use of new anti-TB drugs, repurposed drugs, and their drug combinations has greatly improved treatment outcomes in patients with both drug-susceptible TB and MDR/XDR-TB. The importance of developing more effective drugs targeting persisters of Mycobacterium tuberculosis is emphasized. In addition, host-directed therapeutics using both conventional drugs and herbal medicines for more effective TB treatment should also be explored. In this article, we review historical aspects of the research on anti-TB drugs and discuss the current understanding and treatments of drug resistant and persistent tuberculosis to inform future therapeutic development.

Research progress on genetic control of host susceptibility to tuberculosis / 浙江大学学报·医学版

The "Lübeck disaster", twins studies, adoptees studies, and other epidemiological observational studies have shown that host genetic factors play a significant role in determining the host susceptibility to Mycobacterium tuberculosis infection and pathogenesis of tuberculosis. From linkage analyses to genome-wide association studies, it has been discovered that human leucocyte antigen (HLA) genes as well as non-HLA genes (such as SLC11A1, VDR, ASAP1 as well as genes encoding cytokines and pattern recognition receptors) are associated with tuberculosis susceptibility. To provide ideas for subsequent studies about risk prediction of MTB infection and the diagnosis and treatment of tuberculosis, we review the research progress on tuberculosis susceptibility related genes in recent years, focusing on the correlation of HLA genes and non-HLA genes with the pathogenesis of tuberculosis. We also report the results of an enrichment analysis of the genes mentioned in the article. Most of these genes appear to be involved in the regulation of immune system and inflammation， and are also closely related to autoimmune diseases.

Influencing factors of the adverse outcome of pulmonary tuberculosis among adolescents in Hangzhou City between 2005 and 2020: a school-based retrospective cohort study / 中华预防医学杂志

Objective: To explore the influencing factors of the adverse outcome of pulmonary tuberculosis (PTB) among adolescents in Hangzhou City between 2005 and 2020. Methods: A retrospective cohort study was used to collect the information of adolescent PTB patients with the onset of PTB occurring from January 1, 2005 to December 31 in 12 designated tuberculosis hospitals in Hangzhou, mainly including demographic, epidemiological, clinical manifestations, bacteriological characteristics and other data, through the China Management Information System for Infectious Disease Surveillance and Reporting and the follow-up survey. All patients were followed up and the end time was December 31, 2021. Multivariate Cox regression model was used to analyze the factors affecting the adverse outcome of these patients. Results: The mean age of 4 921 adolescent PTB patients was (18.9±3.6) years old, and the number of male and female patients were 3 074 and 1 847 respectively. The adverse outcome accounted for 14.7% (725) of all patients. Multivariate Cox regression model showed that eight risk factors, including management model from patients themselves or family members (HR=5.87, 95%CI: 4.55-7.64), molecular biology examination positive for PTB (HR=4.62, 95%CI: 2.98-7.19), the number of sputum smears-positive≥1 (HR=3.72, 95%CI: 2.87-4.83), non-standardized therapy regimens of PTB (HR=3.69, 95%CI: 2.95-4.64), history of retreated PTB (HR=2.22, 95%CI: 1.46-3.36), migrant adolescents (HR=1.89, 95%CI: 1.54-2.34), the number of chest X-ray scan (HR=1.83, 95%CI: 1.65-2.04), and severe PTB (HR=1.38, 95%CI: 1.02-2.05), were associated with the adverse outcome of adolescent PTB patients. Age (HR=0.94, 95%CI: 0.92-0.96), as the only protective factor, was associated with the adverse outcome of these patients. Conclusion: The management mode, molecular biological examination, chemotherapy program, history of tuberculosis, sputum smear examination, severity of tuberculosis, household residence, chest X-ray examination and age are associated with the adverse outcomes of adolescent PTB patients in Hangzhou.

Comparison of different diagnostic modalities for isolation of Mycobacterium Tuberculosis among suspected tuberculous lymphadenitis patients / Comparação de diferentes modalidades de diagnóstico para isolamento de Mycobacterium tuberculosis entre pacientes com suspeita de linfadenite tuberculosa

Abstract Tuberculosis is a communicable disease with high morbidity and mortality rates in developing countries. The study's primary objective is to compare conventional methods such as acid-fast bacillus (AFB) culture and microscopy with rapid diagnostic methods. The secondary objective is to compare histopathological and microbiological findings in suspected patients with tubercular lymphadenitis. A total of 111 samples (August 2018 to September 2019) of lymph nodes were processed for AFB microscopy, AFB cultures, drug-susceptibility testing (DST), histopathology, and Xpert Mycobacterium Tuberculosis (MTB)/resistance to Rifampin (RIF) assays. Out of 111 lymph node samples, 6 (5.4%) were positive for AFB smear microscopy, 84 (75.6%) were positive for AFB culture, 80 (70.7%) were positive on Gene Xpert, and 102 (91.8%) were indicative of tuberculosis for histopathology studies. Mycobacteria growth indicator tube (MGIT) culture positivity was 84 (75.6%) higher than solid Lowenstein-Jensen (LJ) culture 74 (66.6%). Positive cultures underwent phenotypic DST. Two cases were Multidrug-resistant (MDR) on DST, while three cases were Rifampicin resistant on Gene Xpert. The sensitivity of Genexpert was (62%) against the conventional AFB culture method. The poor performance of conventional lymphadenitis diagnostic methods requires early and accurate diagnostic methodology. Xpert MTB/RIF test can help in the treatment of multidrug-resistant TB cases. Nonetheless, rapid and conventional methods should be used for complete isolation of Mycobacterium tuberculosis.

Resumo A tuberculose é uma doença transmissível com altas taxas de morbimortalidade nos países em desenvolvimento. O objetivo principal do estudo é comparar métodos convencionais, como cultura de bacilo álcool-ácido resistente (BAAR) e microscopia, com métodos de diagnóstico rápido. O objetivo secundário é comparar os achados histopatológicos e microbiológicos em pacientes com suspeita de linfadenite tubercular. Um total de 111 amostras (agosto de 2018 a setembro de 2019) de gânglios linfáticos foi processado ​​para microscopia de AFB, culturas de AFB, teste de susceptibilidade a drogas (DST), histopatologia e Xpert Mycobacterium tuberculosis (MTB)/ensaios de resistência à rifampicina (RIF). Das 111 amostras de linfonodos, 6 (5,4%) foram positivas para baciloscopia de AFB, 84 (75,6%) foram positivas para cultura de AFB, 80 (70,7%) foram positivas para o GeneXpert e 102 (91,8%) foram indicativas de tuberculose para estudos histopatológicos. A positividade da cultura do tubo indicador de crescimento de micobactérias (MGIT) foi 84 (75,6%), maior que a cultura sólida de Lowenstein-Jensen (LJ), 74 (66,6%). As culturas positivas foram submetidas a DST fenotípico. Dois casos eram multirresistentes (MDR) ao DST, enquanto três casos eram resistentes à rifampicina no GeneXpert. A sensibilidade do GeneXpert foi 62% contra o método convencional de cultura AFB. O fraco desempenho dos métodos convencionais de diagnóstico de linfadenite requer metodologia de diagnóstico precoce e precisa. O teste Xpert MTB/RIF pode ajudar no tratamento de casos de tuberculose multirresistente. No entanto, métodos rápidos e convencionais devem ser usados ​​para o isolamento completo do Mycobacterium tuberculosis.

Tuberculose chez les enfants de 0-14 ans: résistance primaire de Mycobacterium tuberculosis aux antituberculeux et variants génétiques à Kinshasa / Tuberculosis in children aged 0-14: primary resistance of Mycobacterium tuberculosis to antituberculosis drugs and genetic variants in Kinshasa

Dans les régions endémiques y compris la République Démocratique du Congo, les enfants sont susceptibles d'être exposés à la tuberculose (TB) par un contact dans l'entourage. L'absence de diagnostic peut avoir des conséquences dévastatrices. L'objectif de la présente étude était de déterminer la fréquence de TB, la résistance primaire des souches de Mycobacterium tuberculosis aux antituberculeux ainsi que des variants génétiques. Méthodes. Cette étude transversale et descriptive a été réalisée, entre juin 2011 et décembre 2017, à Kinshasa chez les enfants présumés TB. Les enfants ayant les signes évocateurs de TB figurant dans la tranche d'âge de 0-14 ans étaient inclus. Les échantillons ont été examinés par le Ziehl et mis en culture sur le milieu de Löwenstein-Jensens. Les souches étaient testées aux antituberculeux par la technique des proportions et typées par Spoligotyping. La comparaison des proportions a été faite à l'aide du test de chi-carré de Pearson. Résultats. Quarante-huit souches de Mycobacterium tuberculosis (15,4 %) ont été isolées. Dix souches (20,8%) étaient résistantes à au moins un antituberculeux plus fréquemment à l'INH. Le génotype LAM (66,7 %) et Haarlem (33,3%) était observé. Conclusion. La recherche active de TB infantile confirme qu'elle est relativement fréquente et est résistante à au moins un antituberculeux (surtout à l'INH).

Tuberculosis preventive practices among treatment supporters in Lagos, Nigeria

Context: Tuberculosis (TB) treatment support is one of the recommended strategies to enhance treatment adherence and outcomes. Treatment supporters are at risk of contracting TB and adequate knowledge of TB and good preventive practices are required for their protection. Aims: This study aimed at assessing the knowledge and preventive practices of TB treatment supporters at Directly Observed Treatment Short-course (DOTS) centers in Lagos Mainland Local Government Area of Lagos state, Nigeria. Settings and design: This cross-sectional study was conducted among 196 TB treatment supporters selected from five DOTS centers in Lagos. Methods: Data were obtained using an adapted pretested questionnaire. Statistical analysis used: Bivariate and multivariate analyses were performed to determine the factors associated with self-protection practices. A P < 0.05 was considered statistically significant. Results: The mean age of the participants was 37.3 ± 12.1 years. More than half of the respondents were females (59.2%) and immediate family members (61.3%). Overall, 22.5% had good knowledge of TB, while 53.0% had positive attitudes toward TB. Only 26.0% adequately protected themselves from infection. The caregiver's level of education (P = 0.001) and their relationship to the patient (P = 0.001) were significantly associated with good preventive practices in bivariate analysis. Not being related to the patient was a predictor of adequate TB prevention practices (adjusted odds ratio = 2.852; P = 0.006; 95% confidence interval = 1.360-5.984). Conclusions: This study revealed low levels of TB knowledge and fair preventive practices, especially among caregivers who are relatives. There is, therefore, a need to improve population literacy about TB and its prevention and a more focused orientation of relatives who volunteer as treatment supporters, through health education, with periodic monitoring during clinic visits, of how they prevent TB.

Vigilancia de la resistencia del Mycobacterium tuberculosis a los fármacos en Paraguay, 2014 a 2017 / Surveillance of drug resistance of Mycobacterium tuberculosis in Paraguay, 2014 to 2017

El objetivo del estudio fue identificar la resistencia del Mycobacterium tuberculosis a los fármacos en Paraguay, 2014 a 2017. Se realizó un estudio observacional retrospectivo. Se utilizaron los datos del Programa Nacional de Tuberculosis del Paraguay comprendidos entre los años 2014 a 2017. Se incluyeron todos los pacientes con diagnóstico de Tuberculosis que se realizaron un test de resistencia. Se extrajeron los datos en Excel y fueron analizados con Stata 17.0. Se incluyeron 3429 pacientes con tuberculosis que contaban con resultado de al menos una prueba de sensibilidad. La resistencia se encontró en 2.1% de los pacientes. La resistencia a la Rifampicina estuvo presente en el 0.3% de los casos mientras que a la Izionazida en el 0.6% de los casos. La prevalencia de resistencia fue más alta en hombres 3.4 (IC 95% 2.2 - 4.8) p=0.003, que residían en el chaco 6.0 (IC 95% 3.4 - 9.7) p=0.000, previamente tratados 2.7 (IC 95% 1.1 - 5.1) p=0.010. En el modelo se pudo observar que un paciente previamente tratado tiene mayores posibilidades de tener resistencia OR 2.62 (IC 95% 1.1 - 6.24). La prevalencia de resistencia del Mycobacterium tuberculosis a fármacos estuvo relacionada con haber sido previamente tratado

The objective of the study was to identify the resistance of Mycobacterium tuberculosis to drugs in Paraguay, 2014 to 2017. A retrospective observational study was carried out. The data from the National Tuberculosis Program of Paraguay between the years 2014 to 2017 were used. All patients with a diagnosis of Tuberculosis who underwent a resistance test were included. Data were extracted in Excel and analyzed with Stata 17.0. 3429 tuberculosis patients who had a result of at least one sensitivity test were included. Resistance was found in 2.1% of patients. Resistance to Rifampicin was present in 0.3% of cases while to Izionazide in 0.6% of cases. The prevalence of resistance was higher in men 3.4 (95% CI 2.2 - 4.8) p = 0.003, who resided in the Chaco 6.0 (95% CI 3.4 - 9.7) p = 0.000, previously treated 2.7 (95% CI 1.1 - 5.1) p = 0.010. In the model, it was observed that a previously treated patient has a greater chance of having resistance OR 2.62 (95% CI 1.1 - 6.24). The prevalence of resistance of Mycobacterium tuberculosis to drugs was related to having been previously treated

Pericarditis purulenta por mycobacterium tuberculosis y streptococcus pneumoniae: revisión del tema, a propósito de un caso / Purulent pericarditis due to mycobacterium tuberculosis and streptococcus pneumoniae: case report and review

La pericarditis purulenta es una patología poco frecuente pero que conlleva alta mortalidad. En la era pre antibióticos, se observaba en pacientes con neumonía complicada y las cocáceas gram positivas eran los gérmenes frecuentemente involucrados. Por otro lado, la pericarditis tuberculosa representa el 1% del total de casos de tuberculosis, aunque es frecuente zonas endémicas, principalmente asociada a la infección por el virus de la inmunodeficiencia humana (VIH). Presentamos el caso de un paciente de 19 años, en situación calle, infectado con VIH, con diagnóstico de pericarditis purulenta, donde se demostró la co-infección de Mycobacterium tuberculosis y Streptecoccus pneumoniae en el pericardio. La pericarditis purulenta polimicrobiana es poco frecuente y la co-infección por los gérmenes mencionados es anecdótica. A pesar del tratamiento antimicrobiano, el aseo quirúrgico, los esteroides y la fibrinolisis intrapericárdica, esta patología tiene un pronóstico ominoso, en parte, debido a la condición basal de los enfermos que la padecen.

Purulent pericarditis is a rare disease with a high mortality rate. In the pre-antibiotic era it was observed as a complication in patients with pneumonia. Gram-positive coccaceae were the most commonly implicated bacteria. Tuberculous pericarditis represents 1% of all tuberculosis (TBC) cases, although it is common in endemic areas, associated with human immunodeficiency virus (HIV) infection. We present the case of a 19-year-old homeless, admitted with HIV and malnutrition, diagnosed with purulent pericarditis. Mycobacterium tuberculosis and Streptococcus pneumoniae were found as a cause of purulent pericarditis. Polymicrobial purulent pericarditis is a rare condition and co-infection with the bacteria previously mentioned is merely anecdotal. Despite antimicrobial treatment, surgical management, steroids, and intrapericardial fibrinolysis, this pathology has an ominous prognosis, due in part to the pre-existing condition of these patients.

Rapid identification of Mycobacterium tuberculosis in cultures by molecular and immunological methods / Identificação rápida de Mycobacterium tuberculosis em culturas por método molecular e método imunológico

Objective: The study aimed to evaluate molecular and immunological methods and to propose a workflow using them for tuberculosis (TB) diagnosis routine. Methods: A cross-sectional retrospective study was performed, including 121 liquid cultures from a TB laboratory located in the extreme south of Brazil. All cultures were positive for Mycobacterium tuberculosis complex (MTBC) by in-house Polymerase Chain Reaction (PCR) using DNA extracted by the CTAB method (PCR-CTAB) for IS6110 detection. These cultures were subjected to faster tests than this one, the immunological MPT64 assay and the PCR using DNA extracted by thermal lysis method (PCR-TL), and these were evaluated for MTBC identification using PCR-CTAB as a reference method. Results: The sensitivity of MPT64 assay and PCR-TL to identify MTBC in positive cultures by PCR-CTAB were 73.6% (89/121) and 98.3% (119/121), respectively. We proposed a workflow based on the use of MPT64 assay in liquid cultures suggestive of MTBC, and in case of a negative result, we suggest the performance of PCR-TL. The PCR-CTAB is suggested only if faster tests are negative. Conclusions: Methods capable of confirming MTBC in cultures should continue to be standardized, tested, and optimized to meet the ideal requirements of simplicity, quickness, and effectiveness. The molecular and immunological methods evaluated have differences in the execution and detection of MTBC in cultures, but they are rapid tools for laboratory TB diagnosi

Objetivos: O estudo objetivou avaliar métodos molecular e imunológico e propor um fluxo de trabalho utilizando-os para a rotina de diagnóstico da tuberculose (TB). Métodos: Foi realizado um estudo transversal retrospectivo, incluindo 121 culturas líquidas de um laboratório de TB localizado no extremo sul do Brasil. Todas as culturas foram positivas para o complexo Mycobacterium tuberculosis (CMTB) por Reação em Cadeia da Polimerase (PCR) in-house para detecção do IS6110, usando DNA extraído pelo método CTAB (PCR-CTAB). Essas culturas foram submetidas a testes mais rápidos que este, o ensaio imunológico MPT64 e a PCR com DNA extraído pelo método de lise térmica (PCR-LT), e estas foram avaliadas para identificação de CMTB usando PCR-CTAB como método de referência. Resultados: A sensibilidade do ensaio MPT64 e da PCR-LT para identificar o CMTB em culturas positivas pela PCRCTAB foi de 73,6% (89/121) e 98,3% (119/121), respectivamente. Propusemos um fluxo de trabalho baseado no uso do ensaio MPT64 em culturas líquidas sugestivas de CMTB e, em caso de resultado negativo, sugerimos a realização de PCR-LT. Sugere-se a PCR-CTAB apenas se os testes mais rápidos forem negativos. Conclusões: Os métodos capazes de confirmar o CMTB em culturas devem continuar sendo padronizados, testados e otimizados para atender aos requisitos ideais de simplicidade, rapidez e eficácia. Os métodos molecular e imunológico avaliados apresentam diferenças na execução e detecção do CMTB em culturas, mas são ferramentas rápidas para o diagnóstico laboratorial da TB.