Exposure to Mycobacterium tuberculosis during Flexible Bronchoscopy in Patients with Unexpected Pulmonary Tuberculosis

Bronchoscopic Strategies to Improve Diagnostic Yield in Pulmonary Tuberculosis Patients

In cases where pulmonary tuberculosis (PTB) is not microbiologically diagnosed via sputum specimens, bronchoscopy has been the conventional method to enhance diagnostic rates. Although the additional benefit of bronchoscopy in diagnosing PTB is well-known, its overall effectiveness remains suboptimal. This review introduces several strategies for improving PTB diagnosis via bronchoscopy. First, it discusses how bronchoalveolar lavage or an increased number of bronchial washings can increase specimen abundance. Second, it explores how thin or ultrathin bronchoscopes can achieve specimen acquisition closer to tuberculosis (TB) lesions. Third, it highlights the importance of conducting more sensitive TB-polymerase chain reaction tests on bronchoscopic specimens, including the Xpert MTB/RIF assay and the Xpert MTB/RIF Ultra assay. Finally, it surveys the implementation of endobronchial ultrasound with a guide sheath for tuberculomas, collection of post-bronchoscopy sputum, and reduced use of lidocaine for local anesthesia. A strategic combination of these approaches may enhance the diagnostic rates in PTB patients undergoing bronchoscopy.

Estimating the burden of nosocomial exposure to tuberculosis in South Korea, a nationwide population based cross-sectional study

BACKGROUND/AIMS

The aim of the study was to investigate the current nationwide burden of nosocomial exposure to tuberculosis (TB) using national health insurance claims data.

METHODS

All patients who had claims for drug susceptibility testing for TB from 2012 to 2016, which indicated culture-proven TB, were included. The first day of the infectious period was defined as 3 months before a doctor's suspicion of TB in patients with respiratory symptoms and 1 month before in patients without symptoms. The last day of the infectious period was defined as one day before the prescription of anti-TB medications. Patients hospitalized during infectious periods were investigated and their hospitalization days were calculated. Records of medical procedures which increased the risk of nosocomial transmission by generating aerosols were also investigated.

RESULTS

A total of 7,186 cases with 94,636 person-days of hospitalization with unrecognized active TB were found. Patients above 60 years of age accounted for 63.99% of the total number and 69.70% of the total duration of hospitalization. TB patients in the older age group showed a trend toward higher risks for hospitalization with unrecognized active TB. Patients in their 80s showed the highest risk (12.65%). Bronchoscopy (28.86%), nebulizer therapy (28.48%), and endotracheal intubation (13.02%) were common procedures performed in these patients during hospitalization.

CONCLUSION

The burden of nosocomial exposure to TB in South Korea is still substantial. Hospitalization with unrecognized active TB, especially among the elderly TB patients could be a serious public health issue in South Korea.

Reducing the risk of tuberculosis transmission for HCWs in high incidence settings

Globally, tuberculosis (TB) is a leading cause of death from a single infectious agent. Healthcare workers (HCWs) are at increased risk of hospital-acquired TB infection due to persistent exposure to Mycobacterium tuberculosis (Mtb) in healthcare settings. The World Health Organization (WHO) has developed an international system of infection prevention and control (IPC) interventions to interrupt the cycle of nosocomial TB transmission. The guidelines on TB IPC have proposed a comprehensive hierarchy of three core practices, comprising: administrative controls, environmental controls, and personal respiratory protection. However, the implementation of most recommendations goes beyond minimal physical and organisational requirements and thus cannot be appropriately introduced in resource-constrained settings and areas of high TB incidence. In many low- and middle-income countries (LMICs) the lack of knowledge, expertise and practice on TB IPC is a major barrier to the implementation of essential interventions. HCWs often underestimate the risk of airborne Mtb dissemination during tidal breathing. The lack of required expertise and funding to design, install and maintain the environmental control systems can lead to inadequate dilution of infectious particles in the air, and in turn, increase the risk of TB dissemination. Insufficient supply of particulate respirators and lack of direction on the re-use of respiratory protection is associated with unsafe working practices and increased risk of TB transmission between patients and HCWs. Delayed diagnosis and initiation of treatment are commonly influenced by the effectiveness of healthcare systems to identify TB patients, and the availability of rapid molecular diagnostic tools. Failure to recognise resistance to first-line drugs contributes to the emergence of drug-resistant Mtb strains, including multidrug-resistant and extensively drug-resistant Mtb. Future guideline development must consider the social, economic, cultural and climatic conditions to ensure that recommended control measures can be implemented in not only high-income countries, but more importantly low-income, high TB burden settings. Urgent action and more ambitious investments are needed at both regional and national levels to get back on track to reach the global TB targets, especially in the context of the COVID-19 pandemic.

Unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe endobronchial ultrasound

BACKGROUND

Bronchoscopy using radial probe endobronchial ultrasound (EBUS) is performed when a peripheral lung lesion (PLL) is suspected to be malignant. However, pulmonary tuberculosis is diagnosed in some patients, and healthcare workers could therefore be exposed to tuberculosis if sufficient precautions are not taken. In this study, we examined the proportion of and factors associated with unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe EBUS.

METHODS

This retrospective study included 970 patients who received bronchoscopy using radial probe EBUS between December 2015 and November 2018. Clinical, histological, radiological, and microbiological data were reviewed.

RESULTS

Pulmonary tuberculosis was diagnosed in 31 patients (3.2%) during bronchoscopy using radial probe EBUS. Patients with a lower age were significantly more likely to be diagnosed with tuberculosis than elderly patients (odds ratio [OR], 0.951; 95% confidence interval [CI], 0.924-0.978; P = 0.001). Among the various CT findings, a low HUs difference between pre- and post-enhanced CT (OR, 0.976; 95% CI, 0.955-0.996; P = 0.022), the presence of concentric cavitation (OR, 5.211; 95% CI, 1.447-18.759; P = 0.012), and the presence of satellite centrilobular nodules (OR, 22.925; 95% CI, 10.556-49.785; P < 0.001) were independently associated with diagnosis of tuberculosis.

CONCLUSIONS

The proportion of unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe EBUS was 3.2%. A higher risk was independently associated with a younger age and CT findings of a small difference in HUs between pre- and post-enhancement images, concentric cavitation, and the presence of a satellite centrilobular nodule.

Pulmonary infections mimicking malignancy on bronchoscopy: A retrospective single-center study in Japan

BACKGROUND

Pulmonary infections can imitate pulmonary neoplasms. Pulmonary tuberculosis (TB) is a typical example of an infection that mimics cancer and results in unexpected exposure of healthcare workers to TB. A large number of patients with suspected lung malignancy are referred to cancer centers, although the epidemiology of the final diagnosis is unclear in Japan. This study aimed to determine the frequency and nature of pulmonary infections that imitate malignancy among patients with presumed lung cancer that is subsequently diagnosed as a pulmonary infection based on bronchoscopy findings. We also aimed to identify the prevalence of formerly undiagnosed pulmonary tuberculosis that could pose an occupational risk to healthcare workers.

METHODS

This single-center retrospective cross-sectional study included patients with suspected pulmonary malignancy who underwent bronchoscopy at a tertiary care cancer center in Japan between April 2017 and March 2020. Electronic medical records of the bronchoscopy database were reviewed to identify the final diagnoses recorded by physicians.

RESULTS

Among the 460 patients enrolled in the present study, 362 (78.7%) and 8 (1.7%) had primary or metastatic pulmonary lesions and benign lesions, respectively. Sixty-six patients (14.3%) had nonspecific findings or other pulmonary diseases. Infection was confirmed in 24 patients (5.2%). Mycobacterial infections (n = 16) were the most frequent infectious disease; four patients had TB and 12 had nontuberculous mycobacterial infections.

CONCLUSIONS

Despite the rare occurrence of TB in patients with suspected lung malignancy, healthcare workers should remain vigilant regarding the possibility of TB to prevent occupational exposure during invasive procedures such as routine bronchoscopy.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.