Evaluation of xpert Mycobacterium tuberculosis rifampicin for tuberculosis diagnosis in a reference laboratory.

Background: The Xpert Mycobacterium tuberculosis Rifampicin (MTB-RIF) is a technological innovation that presents precision and speed in the diagnosis of tuberculosis (TB). The study aimed to evaluate the performance of Xpert MTB/RIF in the TB diagnosis and compare its results with those of culture, species identification, Antimicrobial Susceptibility Testing (AST), and rpoB gene sequencing of discordant results in AST, used for the diagnosis of TB in a reference laboratory. Methods: Cross-sectional descriptive study of pulmonary and extrapulmonary samples requesting Xpert MTB/RIF and culture for TB diagnosis from 2015 to 2019 at Adolfo Lutz Institute-São Paulo/Brazil. The analysis was performed with Epi-Info 7.2.1, presenting the distribution of frequencies and, for comparative analyses, Pearson's Chi-square test and Fisher's exact test were used, considering P ≤ 0.05 as statistically significant. For variables agreement, the Kappa method was used. Results: A total of 1575 pulmonary and extrapulmonary samples were analyzed using Xpert MTB/RIF and culture, of which 293 were positive for the MTB Complex in both methodologies with a sensitivity of 94.55%; specificity of 95.97%; accuracy 95.69%; positive predictive value 85.53%; negative predictive value 98.59%, substantial agreement by Kappa 0.87, and detection sensitivity even at lower levels of bacillary load (P < 0.05). The Xpert MTB/RIF and AST showed concordant results (P < 0.05). Conclusion: The study brings forward that the Xpert MTB/RIF shows substantial agreement with the results of culture and AST, contributing to the diagnosis of TB and the rapid detection of resistance. The sequencing of resistant cultures in Xpert MTB/RIF and sensitivity in AST identified the H526N mutation, characterized by a low level of resistance to RIF.

Laboratory diagnosis of leprosy: Two staining methods from bacilloscopy and rapid ml flow test.

Background: The diagnosis of leprosy is based on the characteristic signs and symptoms of the disease, subsidized by laboratory tests. When positive, the bacilloscopy closes the diagnosis for leprosy. Phenolic glycolipid-I, or PGL-I, is a molecule in the bacillus cell wall that confers a greater immune response. The ML Flow test is an immunochromatographic test for the detection of anti-PGL-I IgM in human blood or serum. Methods: A prospective study with data collection and biological materials in patients with suspected leprosy from August 2020 to May 2021. For microscopy, intradermal smears were stained with Auramine O, and after reading under a fluorescence microscope, reviewed by Ziehl-Neelsen. The ML flow test was performed according to the Bührer-Sékula protocol. To assess the agreement between the methods, the Kappa index was estimated. Results: Of the 94 suspected leprosy patients, 31 (32.9%) were diagnosed with leprosy. There was moderate agreement between the results of the ML Flow and Auramine O tests (Kappa = 0.58) and substantial agreement between the ML Flow and Ziehl-Neelsen microscopy (Kappa = 0.72). In paucibacillary cases, serology was positive in 100% of patients. Conclusions: This study concluded that the Ziehl-Neelsen technique remains the best option for standard leprosy staining, and the ML flow test is more positive among the three techniques evaluated and can be an effective tool in the early diagnosis of leprosy cases.

A laboratory-based analysis of rapidly growing mycobacteria in Northwest Paulista, Sao Paulo, Brazil.

Background: Rapidly growing mycobacteria (RGM) are a group of nontuberculous mycobacteria (NTM) implicated in difficult-to-treat pulmonary and extrapulmonary diseases, possibly associated with invasive procedures and failures in sterilization of materials and equipment. Methods: We report our experience with the laboratory identification of RGM in a routine work and give an overview of the RGM isolated in our setting. Laboratorial data from all RGM mycobacterial isolates received at Adolfo Lutz Institute of São José do Rio Preto were analyzed from January 2000 to December 2015. Results: Five hundred and seventy-nine isolates were identified with NTM, of which 193 were RGM, which affected 113 patients. Among the 113 patients, the female gender was more frequent (55%) and the average age was 50 years. Pulmonary samples were the most frequent (79%), and 54.9% of the cases were isolated from sputum. Twelve different species were found and the most identified were group Mycobacterium abscessus and Mycobacterium fortuitum, making up 77.9% of all identified RGM. The most frequent comorbidities were smoking (n = 21), alcoholism (n = 12), and human immunodeficiency virus (n = 16). Drug susceptibility test was performed for nine patients and all showed susceptibility to amikacin and seven resistances to doxycycline. Conclusions: This study showed the experience of mycobacterial diagnosis in a routine laboratory, revealing that failure to meet the bacteriological criteria generates losses in the establishment of cases of RGM and consequently its correct treatment.

Estimativa da prevalência oculta da hanseníase em município do interior do Estado de São Paulo / Estimates of the hidden prevalence of leprosy in a municipality in the State of São Paulo

Introdução: O diagnóstico da hanseníase no Brasil ainda é tardio, a maioria dos casos são multibacilares e considerável percentual de pacientes apresenta deficiências físicas, indicando haver casos não diagnosticados na população, ocasionando uma prevalência oculta. Objetivo: analisar a situação da hanseníase em município do interior do Estado de São Paulo perante a situação mundial, e calcular a prevalência oculta. Métodos: Estudo descritivo e epidemiológico, utilizando a metodologia proposta pela Organização Mundial da Saúde para verificar a prevalência oculta. Os dados foram coletados do Sistema de Informação de agravos de notificação de pacientes residentes no município e que iniciaram tratamento entre 01/01/2006 a 31/12/2016. Resultados: O Estado de São Paulo e o município mostraram uma diminuição de casos novos de hanseníase nos anos estudados. Enquanto o Brasil apresenta-se em declínio gradativo, o Estado apresenta discreta queda e o município alternância dos números. No município, foram notificados 295 casos de hanseníase, sendo 74 casos de formas paucibacilares e 221 casos multibacilares, com taxa de prevalência decrescente e a taxa de detecção oscilante entre o período. Do total de casos, em 271 foram avaliadas as incapacidades físicas e 141 foram classificados como graus 1 ou 2. Conforme a metodologia proposta, os números representam um acréscimo de 23,90/10.000 habitantes na prevalência oculta, o que resultaria em uma prevalência real de 378,73 casos/10.000 habitantes no período estudado. Conclusão: Os dados do município permanecem oscilantes diante dos dados nacionais e do Estado de São Paulo, apresentam alto índice de pessoas diagnosticadas com hanseníase com alguma incapacidade física, assim como casos multibacilares, e uma prevalência oculta de 23,90 casos por 10.000 habitantes.

Introduction: The diagnosis of leprosy in Brazil is still late, most cases are multibacillary and a considerable percentage of patients have physical disabilities, indicating undiagnosed cases in the population, causing a hidden prevalence. Objective: To analyze the leprosy situation in a municipality in the interior of the state of São Paulo in view of the world situation, and to calculate the hidden prevalence. Methods: Descriptive and epidemiological study, using the methodology proposed by the World Health Organization to verify the hidden prevalence. Data were collected from the Information System of notification problems of patients residing in the municipality and who started treatment between 01/01/2006 to 12/31/2016. Results: The state of São Paulo and the municipality showed a decrease in new cases of leprosy in the years studied. While Brazil is in gradual decline, the state presents a slight decline and the municipality alternating numbers. In the municipality, 295 leprosy cases were reported, 74 cases of paucibacillary forms and 221 multibacillary cases, with decreasing prevalence rate and oscillating detection rate between the period. Of the 271 cases, physical disabilities were evaluated and 141 were classified as grades 1 or 2. According to the proposed methodology, the numbers represent an increase of 23.90 / 10,000 inhabitants in the hidden prevalence, which would result in a real prevalence. of 378.73 cases / 10,000 inhabitants in the period studied. Conclusion: The data from the municipality remain oscillating from the national data and from the State of São Paulo, have a high rate of people diagnosed with leprosy with some physical disability, as well as multibacillary cases, and a hidden prevalence of 23.90 cases per 10.000 inhabitants.