Prevalence of nontuberculous mycobacteria in a tertiary hospital in Beijing, China, January 2013 to December 2018
BMC MICROBIOLOGY
Authors: Huang, Jing-jing; Li, Ying-xing; Zhao, Ying; Yang, Wen-hang; Xiao, Meng; Kudinha, Timothy; Xu, Ying-chun
Abstract
Background To investigate the species distribution of non-tuberculous mycobacteria (NTM) among tuberculosis (TB) specimens collected from January 2013 to December 2018 at Peking Union Medical Hospital (Beijing), China. NTM species identification was carried out by DNA microarray chip. Results Mycobacterial species were detected in 1514 specimens from 1508 patients, among which NTM accounted for 37.3% (565/1514), increasing from a proportion of 15.6% in 2013 to 46.1% in 2018 (P < 0.001). Among the 565 NTM positive specimens, the majority (55.2%) were from female patients. Furthermore, patients aged 45-65 years accounted for 49.6% of the total patients tested. Among 223 NTM positive specimens characterized further, the majority (86.2%) were from respiratory tract, whilst 3.6 and 3.1% were from lymph nodes and pus, respectively.Mycobacterium intracellulare(31.8%) andMycobacterium chelonae/Mycobacterium abscessus(21.5%) were the most frequently detected species, followed byM. avium(13.5%),M. gordonae(11.7%),M. kansasii(7.6%), and others. Conclusion The proportion of NTM among mycobacterial species detected in a tertiary hospital in Beijing, China, increased rapidly from year 2013 to 2018. Middle-aged patients are more likely to be infected with NTM, especially females.Mycobacterium intracellulareandMycobacterium chelonae/Mycobacterium abscessuswere the most frequently detected NTM pathogens. Accurate and timely identification of NTM is important for diagnosis and treatment.
Early diagnosis of miliary tuberculosis in a hemodialysis patient by combining two interferon-gamma-release assays: a case report
BMC NEPHROLOGY
Authors: Bonkain, Florence; De Clerck, Dieter; Dirix, Violette; Singh, Mahavir; Locht, Camille; Mascart, Francoise; Corbiere, Veronique
Abstract
Background Patients with end-stage renal disease undergoing chronic hemodialysis (HD) are at high risk to develop tuberculosis (TB) associated with a high mortality rate. TB diagnosis is often delayed due to non-specific symptoms, frequent extra-pulmonary manifestations, and rare microbiological confirmation. This case report illustrates the clear added value of combined interferon-gamma -release assays (IGRA) in response to different mycobacterial antigens for an early diagnosis of TB in HD patients. Case presentation We report the case of an Egyptian patient under chronic HD treatment, who presented with recurrent episodes of fever and myalgia of unknown origin, associated with an important inflammatory syndrome. These episodes resolved partially or completely within less than 1 month without any treatment but recurred 10 times within 3 years. Chest Computed Tomography and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18FDG PET-CT) demonstrated several active mediastinal lymphadenopathies. TB was the first suspected diagnosis but cultures and polymerase chain reaction (PCR) remained negative on a mediastinal lymph node aspiration. In contrast, the results from two different IGRA performed on blood were highly suggestive of TB disease. Several granulomas, some of them with central non-caseating necrosis, were demonstrated on a pulmonary nodule obtained by thoracoscopic resection, but PCR and culture remained negative for M. tuberculosis. Three years after the initial symptoms, a new PET-CT revealed a retro-clavicular lymphadenopathy in addition to the mediastinal lymphadenopathies, and the M. tuberculosis culture performed on the resected lymphadenopathy was positive. Antibiotic treatment for TB was started and resulted in a clear improvement of the patient's clinical condition, allowing him to successfully receive a renal graft. Conclusions In view of the high frequency of TB in patients undergoing chronic HD and of the limitations of the classical diagnosis procedures, nephrologists have to diagnose TB mostly on clinical suspicion. We demonstrate here that the use of a combined IGRA to two different mycobacterial antigens may significantly raise the index of suspicion and help clinicians to decide starting anti-TB treatment in HD patients.