Prevalence and risk factors of latent tuberculosis among Korean healthcare workers using whole-blood interferon-γ release assay

The Association Between Diabetes Mellitus and the Risk of Latent Tuberculosis Infection: A Systematic Review and Meta-Analysis

Background

The estimated global latent tuberculosis infection (LTBI) burden indicates a large reservoir of population at risk of developing active tuberculosis (TB). Previous studies suggested diabetes mellitus (DM) might associate with LTBI, though still controversial. We aimed to systematically assess the association between DM and LTBI.

Methods

We searched PubMed, Embase, Cochrane Library and Web of Science. Observational studies reporting the number of LTBI and non-LTBI individuals with and without DM were included. Random-effects or fixed-effects models were used to estimate the pooled effect by risk ratios (RRs) and odds ratios (ORs) and its 95% confidence interval (CI), using the original number of participants involved.

Results

20 studies involving 4,055,082 participants were included. The pooled effect showed a significant association between DM and LTBI (for cohort studies, RR = 1.62, 95% CI: 1.02-2.56; for cross-sectional studies, OR = 1.55, 95% CI: 1.30-1.84). The pooled OR was high in studies with healthcare workers (5.27, 95% CI: 1.52-8.20), refugees (2.88, 95% CI: 1.93-4.29), sample size of 1,000-5,000 (1.99, 95% CI: 1.49-2.66), and male participants accounted for less than 40% (2.28, 95% CI: 1.28-4.06). Prediabetes also associated with LTBI (OR = 1.36, 95% CI: 1.01-1.84).

Conclusion

The risk of LTBI was found to be a 60% increase in DM patients, compared with non-DM patients. LTBI screening among DM patients could be of vital importance. More studies are needed to explore appropriate strategies for targeted LTBI screening among DM patients.

Prevalence of Latent Tuberculous Infection in Patients with Nontuberculous Mycobacterial Lung Disease and Colonization: A Prospective Study in An Intermediate Tuberculosis Burden Country

Background

Controlling latent tuberculosis infection (LTBI) is important in eliminating tuberculosis (TB); however, the prevalence of LTBI has rarely been studied in patients with nontuberculous mycobacterial (NTM) lung disease (LD) and colonization (LC).

Methods

We prospectively recruited subjects with NTM isolated from sputum mycobacterial cultures from December 2011 to June 2019. NTM-LD and NTM-LC were defined according to the American Thoracic Society guidelines. Patients with negative cultures were recruited as controls. Patients with a history of active TB or positive TB cultures were excluded. LTBI was confirmed using a QuantiFERON-TB Gold In-tube test. The prevalence and factors associated with LTBI were analyzed.

Results

A total of 406 participants were enrolled, including 171 in the NTM-LD group, 153 in the NTM-LC group, and 82 in the control group. The prevalence of LTBI was higher in the NTM-LD and NTM-LC groups than in the controls (21.6%, 20.9%, and 6.1%; P = .006). Multivariable analysis showed that old age (adjusted odds ratio [aOR], 1.021, per year increment; P = .042), NTM-LD (aOR, 4.030; P = .005), NTM-LC (aOR, 3.610; P = .011, compared with the controls), and pulmonary cavitary lesions (aOR, 3.393; P = .034) were independently associated with LTBI.

Conclusions

The prevalence of LTBI was higher in the patients with NTM-LD and NTM-LC than in the controls. Old age, pulmonary cavitation, and NTM isolated from sputum were associated with a higher risk of LTBI.

Extrapulmonary tuberculosis in patients with RET fusion-positive non-small cell lung cancer treated with pralsetinib: A Korean single-centre compassionate use experience

BACKGROUND

Pralsetinib, an RET inhibitor, has shown a dramatic response in patients with RET fusion- or mutation-positive tumours in previous studies. As a novel target agent, however, the safety of pralsetinib remains to be determined. Herein, we present two cases of extrapulmonary tuberculosis (TB) that developed during pralsetinib therapy.

METHODS

From April 2020, we administered pralsetinib to a total of 10 patients with RET fusion-positive non-small cell lung cancer under the compassionate use program. We retrospectively analysed the clinical efficacy of and adverse events related to pralsetinib therapy.

RESULTS

Of the nine patients with measurable lesions, seven achieved a partial response. Additionally, one patient without measurable lesions also showed a clinical response. As of January 8, 2021, nine patients were still receiving pralsetinib therapy, while only one had discontinued pralsetinib therapy. Most adverse events were mild and manageable. However, two patients experienced extrapulmonary TB shortly after starting pralsetinib. The disease was well controlled with anti-TB medication, and the cancer lesions were managed through ongoing pralsetinib therapy.

CONCLUSION

The development of TB during pralsetinib therapy is worth noting, although further large studies are required to demonstrate definitive relationship between causality and underlying mechanism.

Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for inflammatory bowel disease: a hospital-based cohort study from Korea

BACKGROUND

Anti-tumor necrosis factor (TNF) treatment for inflammatory bowel disease (IBD) increases the risk of tuberculosis (TB) infection. In the present study, we analyzed the clinical characteristics and risks of TB in Korean patients with IBD who received anti-TNF treatment.

METHODS

The study included patients with IBD who were treated using anti-TNF agents between January 2001 and June 2018 at the Asan Medical Center. Overall, 1434 patients with ulcerative colitis or Crohn's disease were enrolled. We calculated the incidence of active TB infection after anti-TNF treatment and compared the clinical characteristics of the TB group with those of the non-TB group.

RESULTS

Twenty-one patients (1.46%) developed active TB infection, and the incidence rate of active TB was 366.73 per 100,000 person-years. In total, 198 patients (14.9%) were positive for latent tuberculosis infection (LTBI), of whom only eight (4%) did not complete LTBI treatment. The age at which the anti-TNF therapy was started was significantly higher in the TB group than in the non-TB group (HR 1.041, 95% CI 1.014-1.069, p = 0.002), and as age increased, so did the incidence rate of active TB infection (linearity p < 0.001). There was no significant difference in the incidence rate of LTBI between the TB and non-TB groups (HR 0.896, 95% CI 0.262-3.066, p = 0.862).

CONCLUSIONS

In patients with IBD, the incidence rate of TB increased with age at anti-TNF therapy initiation. Active treatment of LTBI may lower the incidence of TB in patients with IBD who are to undergo anti-TNF therapy.

Frequency and Factors of Indeterminate QuantiFERON-TB Gold In-Tube and QuantiFERON-TB Gold PLUS Test Results in Rheumatic Diseases

We compared the results and differences of indeterminate rates between the QuantiFERON-TB Gold In-Tube (QFT-GIT) and QuantiFERON-TB Gold PLUS (QFT-PLUS) tests in patients with rheumatic diseases and analyzed the associated factors. Data of patients with rheumatic diseases who had undergone the QFT-GIT or QFT-PLUS test were used, and information regarding patient demographics, primary diagnosis, laboratory results, and medications was collected. Furthermore, indeterminate result rates of the patient cohort and healthy controls were also compared. A total of 177 (43.4%) and 231 (56.6%) patients had undergone QFT-GIT and QFT-PLUS tests, respectively. Among them, four (2.3%) and seven (3.0%) patients had indeterminate results, which did not differ between the QFT-GIT and QFT-PLUS groups. Indeterminate results were significantly higher among patients with rheumatic diseases than in healthy controls (2.7% vs. 0.2%, p < 0.001). Multivariate logistic regression revealed that the lymphocyte count (hazard ratio (HR) 0.998, 95% confidence interval (CI) 0.997, 1.000; p = 0.012) and albumin level (HR 0.366, 95% CI 0.150, 0.890; p = 0.027) were predictive of indeterminate results. A lymphocyte count of ≤810/mm³ and an albumin level of ≤3.7 mg/dL were capable of discriminating between indeterminate and determinate results. The QFT-GIT and QFT-PLUS tests have comparable diagnostic performances in patients with rheumatic diseases. Decreased lymphocyte and albumin levels contribute to indeterminate results.

Screening for Mycobacterium tuberculosis Infection Using Beijing/K Strain-Specific Peptides in a School Outbreak Cohort

Background

The Beijing strain of Mycobacterium tuberculosis (M. tb) has been most frequently isolated from TB patients in South Korea, and the hyper-virulent Beijing/K genotype is associated with TB outbreaks. To examine the diagnostic potential of Beijing/K-specific peptides, we performed IFN-γ release assays (IGRA) using a MTBK antigen tube containing Beijing/K MTBK_24800, ESAT-6, and CFP-10 peptides in a cohort studied during a school TB outbreak.

Methods

A total of 758 contacts were investigated for M. tb infection, and 43 contacts with latent TB infection (LTBI) and 25 active TB patients were enrolled based on serial screening with QuantiFERON-TB Gold In-Tube tests followed by clinical examinations. Blood collected in MTBK antigen tubes was utilized for IGRA and multiplex cytokine bead arrays. Immune responses were retested in 24 patients after TB treatment, and disease progression was investigated in subjects with LTBI.

Results

Total proportions of active disease and LTBI during the outbreak were 3.7% (28/758) and 9.2% (70/758), respectively. All clinical isolates had a Beijing/K M. tb genotype. IFN-γ responses to the MTBK antigen identified M. tb infection and distinguished between active disease and LTBI. After anti-TB treatment, IFN-γ responses to the MTBK antigen were significantly reduced, and strong TNF-α responses at diagnosis were dramatically decreased.

Conclusions

MTBK antigen-specific IFN-γ has diagnostic potential for differentiating M. tb infection from healthy controls, and between active TB and LTBI as well. In addition, TNF-α is a promising marker for monitoring therapeutic responses. These data provide informative readouts for TB diagnostics and vaccine studies in regions where the Beijing/K strain is endemic.

Etiological Distribution and Morphological Patterns of Granulomatous Pleurisy in a Tuberculosis-prevalent Country

The cause of epithelioid granulomatous inflammation varies widely depending on the affected organ, geographic region, and whether the granulomas morphologically contain necrosis. Compared with other organs, the etiological distribution and morphological patterns of pleural epithelioid granulomas have rarely been investigated. We evaluated the final etiologies and morphological patterns of pleural epithelioid granulomatous inflammation in a tuberculosis (TB)-prevalent country. Of 83 patients with pleural granulomas, 50 (60.2%) had confirmed TB pleurisy (TB-P) and 29 (34.9%) had probable TB-P. Four patients (4.8%) with non-TB-P were diagnosed. With the exception of microbiological results, there was no significant difference in clinical characteristics and granuloma patterns between the confirmed TB-P and non-TB-P groups, or between patients with confirmed and probable TB-Ps. These findings suggest that most pleural granulomatous inflammation (95.2%) was attributable to TB-P in TB-endemic areas and that the granuloma patterns contributed little to the prediction of final diagnosis compared with other organs.

Factors Associated with Latent Tuberculosis Infection among the Hospital Employees in a Tertiary Hospital of Northeastern Thailand

Latent tuberculosis infection (LTBI) can develop into tuberculosis (TB). The WHO requires the discovery and management of LTBI among high-risk groups. Health care workers (HCWs) constitute a high-risk group. Factors associated with LTBI among HCWs in Thailand need further study. The current study aimed to explore the factors related to LTBI among Thai HCWs. A hospital-based, matched case-control study was conducted. All cases and controls were HCWs at a tertiary hospital in northeastern Thailand. Between 2017 and 2019, a total of 85 cases of interferon-γ release assays (IGRAs)-proven LTBI, and 170 control subjects were selected from a hospital (two controls per case). The two recruited controls were individually matched with LTBI cases by sex and age (±5 years). Secondary data were obtained from the occupational health and safety office. Case HCWs had a higher proportion of significant factors than control HCWs (i.e., working closely with pulmonary TB-94.1% vs. 88.8%, and working in the area of aerosol-generating procedures (AGPs) 81.2% vs. 69.4%). The bivariate conditional logistic regression showed that the occurrence of LTBI in HCWs was statistically significant (p-value < 0.05), particularly with respect to: workplaces of AGPs (crude OR = 1.90, 95% CI: 1.01-3.58, p = 0.041); among HCWs performing AGPs (crude OR = 2.04, 95% CI: 1.20, 3.48, p = 0.007); and, absent Bacille Calmette-Guérin (BCG) scar (crude OR = 2.59, 95% CI: 1.50-4.47, p = 0.001). Based on the multivariable conditional logistics analysis, HCWs who performed AGPs while contacting TB cases had a statistically significant association with LTBI (adjusted OR = 1.82, 95% CI: 1.04-3.20, p = 0.035). HCWs who reported the absence of a BCG scar had a statistically significant association with LTBI (adjusted OR = 2.49, 95% CI: 1.65-5.36, p = 0.001), whereas other factors including close contact with TB (adjusted OR = 2.44, 95% CI: 0.74, 8.09, p = 0.123) were not significantly associated with LTBI. In conclusion, HCWs who performed AGPs and were absent a BCG scar had a significant association with LTBI, while other factors played a less critical role.

Epidemiological characteristics of pulmonary tuberculosis among health-care workers in Henan, China from 2010 to 2017

Background

Health-care workers (HCWs) are an epidemiological group with increased exposure to tuberculosis (TB), especially at health-care facilities (HCFs) with poor TB infection control in high-TB-burden settings. China is a high-TB-burden country, and the comprehensive measures for stopping TB transmission at some HCFs were not implemented well owing to limited resources and other factors. The purpose of this study was to review risk of occupational exposure to TB among HCWs and its change trend, and identify epidemiological characteristics of pulmonary tuberculosis (PTB) among HCWs in Henan, central part of China.

Methods

A retrospective cohort study was conducted from 2010 to 2017. All HCWs and teachers in Henan were enrolled to the study as exposed group and non-exposed control group, respectively. Relative risk (RR), attributable risk (AR) and AR percent (AR%) were used to measure the association between the occupational exposure and PTB, and estimated with Poisson regression.

Results

The study results showed a total of 1663 cases of PTB were reported among the HCWs in Henan, accounting for 3.2‰ of all PTB cases reported in the whole population, and annual incidence rate of PTB among HCWs declined by 34% from 2010 to 2017. Over the eight years, the incidence rate of PTB among HCWs was 43.7 cases per 100,000 person-years (PYs), significantly higher than that among teachers (18.8 cases/100,000 PYs), and RR, AR and AR% were estimated to 2.3, 24.9 cases per 100,000 PYs and 57%, respectively. Among HCWs, males were more likely to suffer from PTB than females (adjusted RR: 1.3; 95%CI: 1.2–1.4), and HCWs aged under 25 years had the highest relative risk over all age groups with adjusted RR equaling to 8.3 (95%CI: 6.9-9.9) calculated with those aged 45–54 years as the reference.

Conclusions

Although overall incidence rate of PTB among HCWs showed decreasing temporal trends over the period of 2010–2017, attributable risk of occupational exposure to TB among HCWs did not decrease in Henan, and TB infection at HCFs for males, young or senior HCWs, especially for young HCWs is of much concern.

The use of a borderline zone for the interpretation of interferon-gamma release assay results for serial screening of healthcare workers

OBJECTIVE

An interferon-gamma release assay (IGRA) is used to screen for latent tuberculosis infection (LTBI). Among IGRAs, the QuantiFERON-TB Gold In-Tube (QFT-GIT) results are highly variable, so the borderline zone has been proposed to reduce unnecessary LTBI treatment. The aim of this study was to examine the proportion of the borderline zone of QFT-GIT in healthcare workers' (HCWs) serial IGRA and to retrospectively identify the utility of predicting tuberculosis (TB) in a moderate TB incidence setting.

METHODS

The participants were HCWs who had undergone serial LTBI screening between June 2013 and June 2018. IGRA-positive HCWs underwent examinations that included low-dose computed tomography (LDCT) and TB culture, if necessary. Applying the borderline zone (0.2-<0.7 IU/mL), the results were classified as definite negative, borderline negative, borderline positive and definite positive.

RESULTS

Through the follow-up of 477 HCWs, 441 (92.5%) invariant, 30 (6.3%) conversion, 2 (0.4%) reversion and 5 (1.0%) indeterminate results were observed with the manufacturer's cutoff. Applying the borderline zone, 419 (87.8%) invariant, 22 (4.6%) conversion, 1 (0.2%) reversion and 36 (7.5%) decision pending, including 5 (1.0%) indeterminate results, were observed. At the time of screening, five TB cases were identified. Chest X-ray (CXR) identified one TB case, and LDCT identified four additional TB cases. After one year, two TB cases were diagnosed, and their screening QFT-GIT results were definite positive and borderline negative. In the Cochran-Armitage trend test, the greater the maximum difference in the QFT-GIT grade with the borderline zone was, the higher the probability of developing TB (P-value <0.001).

CONCLUSION

The application of the borderline zone lowered the conversion rate but increased the decision pending rate. Introducing the borderline zone requires a careful approach, and a thorough examination needs to be performed to rule out TB in converters. HCWs with borderline QFT-GIT results also need close observation.

A retrospective review of tuberculosis exposure among health care workers in a tertiary hospital

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he baseline prevalence of Latent Tuberculosis Infection (LTBI) among Healthcare workers screened for Tuberculosis exposure was 14.6%.

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Age above 40 years, non-Chinese ethnicity, and foreign nationality were associated with baseline LTBI.

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Only 2.5% of all healthcare workers screened for tuberculosis exposure experienced QFT-GIT conversion resulting in an incidence rate of 1.14 cases per 100 exposure episodes per year.

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Healthcare workers with more episodes of TB exposure are also more likely to develop post exposure LTBI.

Background

We evaluated tuberculosis (TB) acquisition rate and risk factors among health care workers (HCWs) exposed to index TB patients.

Methods

We performed a retrospective cohort study on exposed HCWs from August 2016 to January 2018 at a tertiary hospital in Singapore. Demographic factors and TB exposure episodes per HCW were obtained. A modified Poisson regression model was used to identify factors associated with TB infection.

Results

A total of 32 TB exposure events occurred during the study period. A total of 881 HCWs with 1,536 exposure episodes were screened with QuantiFERON-TB Gold In-tube assay (QFT-GIT) at baseline and 8 weeks. A total of 129 (14.6%) HCWs had positive QFT-TB at baseline, whereas 22 (2.5%) HCWs had QFT-GIT conversion, with a latent TB infection (LTBI) rate of 1.14 cases per 100 exposure episodes per year. Foreign nationality, non-Chinese ethnicity, and age above 40 years were independently associated with baseline LTBI, whereas having >2 TB exposure episodes and working in internal medicine, medical subspecialties, and psychiatry wards were associated with QFT-GIT conversion.

Discussion

The QFT-GIT conversion rate among screened HCWs is low. Foreign HCWs with LTBI likely came from countries with higher TB transmission. Targeted prevention of repeated TB exposures can reduce QFT-GIT conversion.

Conclusions

The study results will guide TB contact tracing protocols in health care institutions.

Multidrug-resistant Disseminated Tuberculosis Related to Infliximab in a Patient with Ulcerative Colitis and Negative Evaluation for Latent Tuberculosis

Anti-tumor necrosis factor (anti-TNF) is an effective biological agent for the treatment of moderate-to-severe active ulcerative colitis (UC) refractory to conventional therapy. On the other hand, anti-TNF therapy is strongly associated with a potential risk of tuberculosis (TB). Active TB is a critical complication that makes it difficult to treat patients who require anti-TNF for the treatment of UC refractory to conventional therapy. Based on the clinical guidelines, patients with inflammatory bowel disease (IBD) are strongly recommended to screen for latent TB before anti-TNF administration. Considering the possibility of active or reactivated TB related to anti-TNF therapy, all patients with IBD should be monitored closely for TB during anti-TNF therapy, irrespective of the screening results for latent TB. In particular, the risk of anti-TNF-related multidrug-resistant TB (MDR-TB) in patients with IBD has not been elucidated. This paper reports the first case of disseminated MDR-TB that developed in a UC patient receiving infliximab despite the negative evaluation for latent TB screening.

Factors associated with non-initiation of latent tuberculosis treatment among healthcare workers with a positive interferon-gamma releasing assay

Despite widespread use of the interferon-gamma release assay for the diagnosis of latent tuberculosis infection (LTBI), the initiation rate of and factors associated with LTBI treatment among healthcare workers (HCWs) have not been studied in depth. The aim of this study was to evaluate the initiation rate of LTBI treatment and also to identify any factors associated with non-initiation of LTBI treatment among HCWs. A retrospective cohort study of 293 HCWs with LTBI was performed at a teaching hospital in Korea. LTBI was diagnosed using QuantiFERON-TB Gold In-Tube tests (Cellestis Ltd., Carnegie, VIC, Australia). Of the 293 HCWs with LTBI, 189 HCWs (64.5%) visited an outpatient clinic for a medical consultation regarding LTBI treatment. Of these, 128 (67.7%) consented to LTBI treatment for a 43.7% LTBI treatment initiation rate. Upon multivariable analysis, having a liver disease or currently taking hepatotoxic drugs (adjusted odds ratio [OR] = 12.03, 95% confidence interval [CI] = 3.12–46.35), being a physician (adjusted OR = 14.01, 95% CI = 2.82–69.74) and other patient-related HCWs (adjusted OR = 3.58, 95% CI = 1.46–8.78), and years of employment ≥20 years (adjusted OR = 4.77, 95% CI = 1.74–13.12) were independent factors associated with the non-initiation of LTBI treatment. Upon bivariate multivariable analysis, while having a liver disease or currently taking hepatotoxic drugs (adjusted OR = 12.85, 95% CI = 3.06–55.92), being a physician (adjusted OR = 28.43, 95% CI = 4.78–169.28) and other patient-related HCWs (adjusted OR = 4.80, 95% CI = 1.56–14.74), and years of employment ≥20 years (adjusted OR = 4.55, 95% CI = 1.37–15.15) were factors associated with no outpatient clinic visit for a consultation of LTBI treatment, having a liver disease or currently taking hepatotoxic drugs (adjusted OR = 11.76, 95% CI = 2.68–51.73) and years of employment ≥20 years (adjusted OR = 5.29, 95% CI = 1.38–20.19) were factors associated with refusal of LTBI treatment after a consultation. The overall initiation rate of LTBI treatment was suboptimal in HCWs with LTBI diagnosed using an interferon-gamma releasing assay. Having a liver disease or currently taking hepatotoxic drugs, being a physician and other patient-related HCWs, and years of employment ≥20 years were associated with non-initiation of LTBI treatment.

Screening and Treatment of Latent Tuberculosis Infection among Healthcare Workers at a Referral Hospital in Korea

Background

Healthcare workers (HCWs) have a high risk of tuberculosis (TB) infection. Since August 2017, Korea has mandated the testing of latent TB infection (LTBI) and recommended treatment from HCWs at medical institutions. However, the acceptance/completion rate and adverse events of LTBI treatment have not been analyzed.

Materials and Methods

From February to August 2017, we conducted a retrospective study at a referral university hospital in Korea, to screen the interferon-gamma release assay (IGRA) tests conducted for all HCWs for detecting and treating LTBI. HCWs diagnosed with LTBI were offered a 9-month isoniazid (9H), 3-month isoniazid/rifampin (3HR), or 4-month rifampin regimen. We investigated the acceptance/completion rate, adverse events, and causes of discontinuation or change in LTBI medication. A major adverse event was one wherein a patient had any adverse event ≥grade 3 causing LTBI treatment interruption.

Results

Of the 1,538 HCWs, 1,379 underwent IGRA testing for LTBI. Among them, 13.6% (187/1,379) tested positive and 73.3% (137/187) received treatment. The overall completion rate was 97.8% (134/137). HCWs were significantly more likely to complete first-line therapy with 3HR than with 9H (91.4% vs. 76.7%, P = 0.02). The most common major adverse event was hepatotoxicity (n = 7), followed by thrombocytopenia (n = 1) and anaphylactic shock (n = 1). Hepatotoxicity and hepatotoxicity (≥ grade 2) were more frequent in 9H than in 3HR (39.5% vs. 17.2%, P = 0.006 and 18.6% vs. 3.7%, P = 0.005, respectively). The median time to hepatotoxicity was 96 days (interquartile range, 20 – 103 days).

Conclusion

Completion of first-line therapy for LTBI is more likely with 3HR than with 9H. This might be related to the development of hepatotoxicity after around 3 months of treatment. Anaphylactic shock and platelet count should be carefully monitored in those receiving rifampin-containing regimens.

Prevalence and risk factors of tuberculosis in developing countries through health care workers

In the last two decades, tuberculosis (TB) have threatened the public across the globe and continuing new TB cases and their transmission pooled with the global emergence of drug-resistant strains present an enduring occupational risk for health care workers (HCWs). Since last decade, government and funding agencies has given a significant amount of funds to tackle the problem of TB infection among medical staff or HCW in hospitals of developing countries, but the effects of these efforts have not yet been reported. Working environments are the major risk factors for TB infections among the HCW in hospital settings. Twenty-two high burden countries endorsed to the preponderance of worldwide tuberculosis cases in 2015. Urgent preventive strategies and mediations are needed to ensure the safety and sustained availability of these exquisite healthcare resources. This timeline review will provide the theoretical basis of high TB burden among the HCW which can be used for further improvement in strategies for the prevention of TB infections in hospital settings and provide a reliable basis for improving the personal health of HCW or medical staff.