In order to evaluate the predictive value of acid fast bacilii (AFB) smear for the diagnosis of Mycobacterium tuberculosis in respiratory specimens in a setting with a high prevalence of AIDS and an unknown prevalence of nontuberculous mycobacteria (NTM), we retrospectively examined specimens cultured for mycobacteria between 1 September 1993 and 30 September 1994 and medical records of patients with positive culture in a General Hospital, AIDS reference in Rio de Janeiro, Brazil. Seventy three per cent (1517/2077) of samples were respiratory specimens and mycobacteria were recovered from 20.6% (313/1517) of these. M. tuberculosis was identified in 94.2% (295/313) and NTM in 5.8% (18/313). The yield of positive AFB smear and of positive culture was 6.1% (93/1517) and 20.6% (313/1517), respectively. The positive predictive value (PPV) of AFB for M. tuberculosis was 98.4% in expectorated sputum and 96.4% in bronchoalveolar lavage. Forty four percent (130/295) of specimens with positive culture for M. tuberculosis and 66.7% (12/18) for NTM were from patients HIV positive. The conclusion was that in our study population, the PPV of AFB for M. tuberculosis in respiratory specimens was high and the prevalence of NTM was low despite the high prevalence of HIV positive.

Download full-text PDF

Source
http://dx.doi.org/10.1590/s0074-02761999000600014DOI Listing

Publication Analysis

Top Keywords

respiratory specimens
16
tuberculosis respiratory
12
high prevalence
12
positive culture
12
predictive acid
8
acid fast
8
mycobacterium tuberculosis
8
rio janeiro
8
janeiro brazil
8
afb smear
8

Similar Publications

Evaluation of an enhanced ResNet-18 classification model for rapid On-site diagnosis in respiratory cytology.

BMC Cancer

January 2025

Department of Pathology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China.

Objective: Rapid on-site evaluation (ROSE) of respiratory cytology specimens is a critical technique for accurate and timely diagnosis of lung cancer. However, in China, limited familiarity with the Diff-Quik staining method and a shortage of trained cytopathologists hamper utilization of ROSE. Therefore, developing an improved deep learning model to assist clinicians in promptly and accurately evaluating Diff-Quik stained cytology samples during ROSE has important clinical value.

View Article and Find Full Text PDF

Background: Although recommended isolation periods for Coronavirus disease 2019 (COVID-19) have been shortened as the pandemic has subsided, prolonged Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) shedding remains common in immunocompromised patients. This study estimated the probability of viral clearance in these patients based on elapsed days and specific risk factors.

Methods: We prospectively enrolled immunocompromised patients with a confirmed COVID-19 diagnosis from January 2022 to May 2023 during the Omicron variant era.

View Article and Find Full Text PDF

Background: Institutions of higher education (IHE) have been a focus of SARS-CoV-2 transmission studies but there is limited information on how viral diversity and transmission at IHE changed as the pandemic progressed.

Methods: Here we analyze 3606 viral genomes from unique COVID-19 episodes collected at a public university in Seattle, Washington from September 2020 to September 2022.

Results: Across the study period, we found evidence of frequent viral transmission among university affiliates with 60% (n = 2153) of viral genomes from campus specimens genetically identical to at least one other campus specimen.

View Article and Find Full Text PDF

Diagnosis and insight into the unique lung microbiota of pediatric pulmonary tuberculosis patients by bronchoalveolar lavage using metagenomic next-generation sequencing.

Front Cell Infect Microbiol

January 2025

The Affiliated Changsha Central Hospital, Department of Center for Tuberculosis Diagnosis and Treatment, Hengyang Medical School, University of South China, Changsha, China.

Background: Although previous studies have reported the dysregulation of respiratory tract microbiota in infectious diseases, insufficient data exist regarding respiratory microbiota imbalances in the lower respiratory tracts of children with pulmonary tuberculosis (PTB). In this study, we assessed the value of mNGS in the pathogen diagnosis and microbiome analysis of PTB patients using bronchoalveolar lavage fluid (BALF) samples.

Methods: A total of 64 participants, comprising 43 pediatric PTB and 21 pediatric pneumonia patients were recruited in the present study.

View Article and Find Full Text PDF

Background: Tuberculosis (TB) remains a major cause of infectious disease mortality globally, with significant underdiagnosis perpetuating transmission. Tongue swab analysis has emerged as a promising non-invasive method for pulmonary TB diagnosis. This study evaluates the diagnostic accuracy of the TB-EASY quantitative PCR (qPCR) assay using tongue swab specimens.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!