Usefulness of Mycobacterium tuberculosis-polymerase chain reaction with bronchial washing samples in predicting discontinuation of airborne infection isolation in patients hospitalized with suspected pulmonary tuberculosis

PLOS ONE RESEARCH ARTICLE Usefulness of Mycobacterium tuberculosispolymerase chain reaction with bronchial washing samples in predicting discontinuation of airborne infection isolation in patients hospitalized with suspected pulmonary tuberculosis a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 Tae-Ok Kim1,2, Young-Ok Na1, Hwa Kyung Park1, Jae-Kyeong Lee1, Hyung-Joo Oh ID1, Bo Gun Kho1, Ha-Young Park1, Yong-Soo Kwon1,2, Yu-Il Kim1,2, Sung-Chul Lim1,2, HongJoon Shin ID1,2* 1 Department of Internal Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea, 2 Chonnam National University Medical School, Gwangju, Republic of Korea * OPEN ACCESS Citation: Kim T-O, Na Y-O, Park HK, Lee J-K, Oh HJ, Kho BG, et al. (2022) Usefulness of Mycobacterium tuberculosis-polymerase chain reaction with bronchial washing samples in predicting discontinuation of airborne infection isolation in patients hospitalized with suspected pulmonary tuberculosis. PLoS ONE 17(12): e0279256. https://doi.org/10.1371/journal. pone.0279256 Editor: Mao-Shui Wang, Shandong Public Health Clinical Center: Shandong Provincial Chest Hospital, CHINA Abstract Objective In-hospital tuberculosis (TB) transmission remains a concern. Airborne infection isolation (AII) can be discontinued in hospitalized patients with suspected active pulmonary TB when the results of three consecutive sputum acid-fast bacilli (AFB) smears are negative. However, fiberoptic bronchoscopy can be performed in patients who may have difficulty in producing sputum samples. This study aimed to investigate the usefulness of Mycobacterium tuberculosis-polymerase chain reaction (MTB-PCR) with bronchial washing specimens in predicting AII discontinuation in hospitalized patients with suspected active pulmonary TB. Received: November 11, 2021 Accepted: December 2, 2022 Methods Published: December 30, 2022 We reviewed the medical charts of patients admitted to a tertiary hospital who were isolated and underwent fiberoptic bronchoscopy for suspicious pulmonary TB from January 2016 to December 2019. Patients with positive MTB-PCR results in the initial sputum examination were excluded. Criteria for discontinuing AII were defined as negative results for three consecutive AFB smears from respiratory specimens, or cases diagnosed other than TB. The study patients were divided into two groups: TB group and non-TB group. Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0279256 Copyright: © 2022 Kim et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Results In total, 166 patients were enrolled in the study. Of them, 35 patients were diagnosed with TB. There was no significant difference between the number of males in the TB (81; 61.8%) and non-TB (21; 60.0%) group. Though 139 patients had negative results on MTB-PCR using washing specimens, eight showed positive AFB culture. Of the 139 patients with PLOS ONE | https://doi.org/10.1371/journal.pone.0279256 December 30, 2022 1 / 11 PLOS ONE Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The authors report the following sources of funding: Grant BCRI20021 from Chonnam National University Hospital Biomedical Research Institute awarded to TOK and Grant 2022R1F1A1069623 from National Research Foundation of Korea funded by the Korean Government awarded to TOK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. TB-PCR using bronchial washing to predict AII discontinuation negative MTB-PCR results, 138 had negative results for three consecutive AFB smears or were established to not have pulmonary TB. Therefore, the predictive accuracy of MTBPCR with bronchial washing samples for discontinuing AII was 99.2%. Conclusion Although a negative result from MTB-PCR with bronchial washing samples cannot exclude pulmonary TB, it can predict AII discontinuation in hospitalized patients with suspected active pulmonary TB. Introduction According to the 2020 World Health Organization tuberculosis (TB) report, 10.0 million patients were diagnosed with TB and 1.4 million people died from TB in 2019 [1]. As TB is transmitted through the air, airborne infection isolation (AII) is required for inpatients with suspected pulmonary TB. To diagnose pulmonary TB, acid-fast bacilli (AFB) smear examination, AFB culture, and Mycobacterium tuberculosis-polymerase chain reaction (MTB-PCR) using respiratory samples—such as expectorated or induced sputum, endotracheal aspirates, and fiberoptic bronchoscopy specimens—are required [2]. As it takes several weeks to confirm the results of AFB culture, the initial AFB smear and MTB-PCR results are important in diagnosing TB or determining the need for AII discontinuation. However, the criteria for discontinuing AII in patients who were not diagnosed with TB based on the initial AFB smear and MTB-PCR results have not been clearly established. The Centers for Disease Control and Prevention (CDC) guidelines recommend that AII should be discontinued if the results of three consecutive AFB smear tests performed within an interval of 8 to 24 hours are negative [3]. However, delayed AII discontinuation was reported in 81% of patients with suspected TB [4]. Though a single sputum Xpert test significantly reduced the AII duration in a recent study, good-quality sputum specimens were needed for this test [5]. There was no study establishing the criteria for AII discontinuation in patients who have difficulty in producing good-quality sputum samples or who cannot undergo a sputum examination. This study aimed to determine whether the results of an MTB-PCR from fiberoptic bronchoscopy specimens can predict AII discontinuation in hospitalized patients who are suspected of pulmonary TB. Patients and methods Study population This study retrospectively investigated hospitalized patients in AII who underwent fiberoptic bronchoscopy for suspected pulmonary TB in a single tertiary hospital of South Korea from January 2017 to December 2019. All enrolled patients underwent fiberoptic bronchoscopy because they were unable to expectorate sputum or because TB could not be ruled out based on the results of initial sputum AFB smear and MTB-PCR. We screened patients undergoing fiberoptic bronchoscopy under AII during the study period. Patients who were already undergoing treatment for TB and those aged < (...truncated)