Background: With a rapid decrease in tuberculosis (TB) incidence, the significance of latent tuberculosis infection (LTBI) has been underscored in South Korea. Although South Korea does not have a high proportion of immigrants compared to other countries, there is a growing argument that it should actively embrace immigrants as a solution to address issues of low birth rates and population aging. This study aimed to assess TB incidence among immigrants who participated a pilot LTBI screening program in South Korea. Methods: Records of immigrants participated in a pilot LTBI screening program in South Korea between 2018 and 2019 were linked with Korean National TB Surveillance System to determine TB development. Participants underwent interferon-gamma release assay (IGRA) and chest X-rays. Standardized incidence ratios (SIRs) stratified by age, country of origin’s TB burden was calculated with a reference group of general South Korean population. Results: Of a total of 9,517 participants, 14 TB cases were identified. Participants with positive IGRA results who did not initiate LTBI treatment showed TB incidence of 312.5 per 100,000 person-years, whereas those with negative results showed TB incidence of 34.4 per 100,000 person-years, resulting in an incidence rate ratio of 9.08 (95% confidence interval [CI], 2.50–32.99). SIR of TB among total participants including those with negative IGRA results was 2.60 (95% CI, 1.54–4.38; P < 0.001), whereas SIR among those with positive IGRA results was 5.86 (95% CI, 3.15–10.89; P < 0.001). In the calculation of SIR among participants with positive IGRA results, those aged under 35 from high TB-burden countries or intermediate TBburden countries showed a high SIR (18.08; 95% CI, 2.55–128.37; P = 0.004), and 11.30 (95% CI, 2.82–45.16; P < 0.001), respectively). Contrary to previous reports that suggest the majority of elderly population with a positive IGRA result were due to remote infection and had a lower TB risk compared to younger ages, SIR among those aged 65 or over from intermediate TB-burden countries was 6.15 (95% CI, 0.87–43.69; P = 0.069), which was comparable to that in younger participants aged between 35 and 49 (SIR, 4.87; 95% CI, 1.22–19.49; P = 0.025) or those aged between 50 and 64 (SIR, 4.62; 95% CI, 1.73–12.31; P = 0.002). Conclusion Young immigrants with positive IGRA results from countries with high or intermediate TB burden showed a relatively high TB risk compared to a general South Korea population. In addition, unexpected high TB risk was observed among elderly immigrants with positive IGRA results. In establishing future policies for LTBI in immigrants in South Korea, screenings should primarily focus on younger age group (who aged under 35).Additionally, further research is needed on the high TB risk observed in elderly immigrants.

Purpose: To find out the incidence and predictors for late high-grade genitourinary (GU) toxicity following salvage radiotherapy (SRT), we investigated the consecutive patients who were treated with SRT after radical prostatectomy. Materials and Methods: Patients who underwent SRT for biochemical recurrence after radical prostatectomy were reviewed. The incidence of GU toxicity was assessed and risk factors for grade ≥2 and ≥3 GU toxicity were evaluated. The STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guided the reporting of this study. Results: Among the total of 217 patients, 88 patients (40.5%) showed late grade ≥2 GU toxicity. The incidence of late grade ≥3 GU toxicity was 11.5%. The presence of grade ≥2 baseline GU dysfunction (hazard ratio [HR], 6.097; 95% confidence interval [CI], 3.280–11.333; p<0.001) and short interval (<1 year) from surgery to SRT (HR, 1.994; 95% CI, 1.182–3.365; p=0.01) were associated with late grade ≥2 GU toxicity. A short interval from surgery to SRT was an independent predictor of late grade ≥3 GU toxicity (HR, 2.975; 95% CI, 1.135–7.794; p=0.027). Conclusions The incidence of late high-grade GU toxicity was not uncommon after SRT. Thus, care should be taken when we consider SRT in patients with baseline urinary dysfunction and a short interval from surgery to SRT, to determine an optimal treatment strategy with balancing quality of life and oncologic outcome of patients.

Background: The International Agency for Research on Cancer (IARC) Monograph conducted a systematic review of the relationship between asbestos and ovarian cancer. However, there may have been information bias due to the undue weight given to few articles. To address this limitation, the present study performed a meta-analysis integrating studies published both before and after the 2012 IARC Monograph on Asbestos, with the aim of investigating the association between asbestos exposure and ovarian cancer. Methods: A comprehensive search of major journal databases was conducted to identify studies examining the relationship between asbestos exposure and ovarian cancer, including those featured in the 2012 IARC Monograph on Asbestos. A meta-analysis on asbestos exposure and cancer risk was performed. Results: The meta-analysis of studies published after the 2012 IARC Monograph on Asbestos found a summary Standardized Mortality Ratio (SMR) of 2.04 (95% CI: 1.03—4.05; p = 0.0123; 5 studies), with a significant degree of heterogeneity among the studies (I2 = 72.99%). The combined analysis of 15 studies before and after the 2012 IARC Monograph showed an overall summary SMR of 1.72 (95% CI: 1.43—2.06; p = 0.0349; 15 studies), with a moderate degree of heterogeneity (I2 = 42.99%). Conclusion This meta-analysis provides evidence of a significant association between asbestos exposure and ovarian cancer mortality. While the possibility of misdiagnosis in earlier studies cannot be completely ruled out, recent findings suggest a robust correlation between asbestos exposure and ovarian cancer. This highlights the importance of sustained efforts to minimize asbestos exposure and protect public health.

Background: This study aimed to determine whether serum uric acid (SUA) levels are associated with various indices of liver damage in the adult Korean population. Methods: We used the Seventh (VII) Korean National Health and Nutritional Examination Surveys. Our study population comprised 6,007 men and 8,488 women. Levels of SUA were divided into four groups (≤ 5.3, 5.3–6.0, 6.0–7.0, and > 7.0 mg/dL for men and ≤ 4.0, 4.0–4.8, 4.8–6.0, and > 6.0 mg/dL for women). Elevated liver enzyme levels were defined as > 35 (men) and > 31 (women) IU/L for aspartate aminotransferase (AST), > 45 (men) and > 34 (women) IU/L for alanine aminotransferase (ALT). Hepatic steatosis index and fibrosis (FIB)-4 index was used to determine nonalcoholic fatty liver disease (NAFLD) and liver FIB, respectively. Adjusted odds ratios (aORs) were calculated by logistic regression analysis for liver enzymes, NAFLD, and liver FIB, according to the SUA level. Results: Among women, the 4.8–6.0 and > 6.0 mg/dL SUA groups showed higher ORs of elevated AST (aOR, 1.78 and 2.03; 95% confidence interval [CI], 1.37–2.32 and 1.40–2.96, respectively; P < 0.001) and the 4.0–4.8, 4.8–6.0, and > 6.0 mg/dL SUA groups showed a higher ORs of ALT elevation (aOR, 1.35, 2.26, and 2.37; 95% CI, 1.02–1.79, 1.72–2.97, and 1.60–3.50, respectively; P < 0.001) compared to the lowest level SUA group. Among women with normal ALT, > 6.0 mg/dL SUA group showed higher OR of NAFLD status (aOR, 1.52; 95% CI, 1.06–2.19). Among men and women with NAFLD, hyperuricemia showed higher ORs of liver FIB (aOR, 2.25 and 1.89; 95% CI, 1.21–4.19 and 1.09–3.27, respectively) than the lowest level SUA group. Conclusion High SUA levels may be associated with elevated liver enzymes and NAFLD, mainly in women. Even in women with normal ALT levels, SUA levels may predict the NAFLD status. Hyperuricemia may predict advanced liver FIB in both men and women with NAFLD. Further studies investigating the causal effects of SUA on liver damage are required.

Background: We conducted a case-control study to identify high-risk occupations and exposure to occupational hazards for acute myeloid leukemia (AML). Methods: When patients with AML admitted to the Department of Hematology in the study hospital for the first time are referred to the Department of Occupational and Environmental Medicine, data on occupation are collected by investigators to evaluate work-relatedness. Community-based controls were recruited through an online survey agency, and four controls per case were matched. Occupational information was estimated using structured questionnaires covering 27 specific occupations and 32 exposure agents. Conditional logistic regression analysis was performed by pairing cases and controls. Results: In the analysis of the risk of AML according to occupational classification, a significant association was found in paint manufacturing or painting work (OR = 2.22, 95% CI: 1.03–4.81) and aircrew (OR = 6.00, 95% CI: 1.00–35.91) in males, and in pesticide industry (OR = 6.89, 95% CI: 1.69–28.07) and cokes and steel industry (OR = 2.00, 95% CI: 1.18–22.06) in ≥60 years old. Moreover, the risk of AML increased significantly as the cumulative exposure to thinners increased. In the analyses stratified by sex and age, the association between pesticide exposure and AML was significant in males (OR = 3.28, 95% CI: 1.10–9.77) and in ≥60 years old (OR = 6.22, 95% CI: 1.48–26.08). Conclusion This case-control study identified high-risk occupational groups in the Republic of Korea including paint manufacturers and painters, aircrew, and those who are occupationally exposed to pesticides or paint thinners.

Background: In 2017, Korea implemented nationwide latent tuberculosis infection (LTBI) project targeting healthcare workers (HCWs). We aimed to assess its performance using the cascade of care model. Methods: We included 45,503 employees of medical institutions with positive interferongamma release assay result who participated between March 2017 and December 2018. We described percentages of LTBI participants completing each step in the cascade of care.Poisson regression model was conducted to assess individual characteristics and factors associated with not-visiting clinics for further care, not-initiating LTBI treatment, and notcompleting treatment. Results: Proportions of visiting clinics and initiating and completing treatment in HCWs were 54.9%, 38.5%, and 32.0%, respectively. Despite of less likelihood of visiting clinics and initiating LTBI treatment, older age ≥ 65 years were more likely to complete treatment (adjusted relative risk [aRR], 0.80; 95% confidence interval [CI], 0.64–0.99), compared to young age < 35 years. Compared to nurses, doctors were less likely to visit clinic; however, were more likely to initiate treatment (aRR, 0.88; 95% CI, 0.81–0.96). Those who visited public health centers were associated with not-initiating treatment (aRR, 1.34; 95% CI, 1.29–1.40). When treated at private hospitals, 9-month isoniazid monotherapy was less likely to complete treatment, compared to 3-month isoniazid and rifampicin combination therapy (aRR, 1.33; 95% CI, 1.16–1.53). Conclusion Among employees of medical institutions with LTBI, only one third completed treatment. Age, occupation, treatment center, and initial regimen were significantly related to LTBI treatment performance indicators. Rifampicin-based short treatment regimens were effective under standard of care.

Background/Aims: Workers who are exposed to dust in the workplace tend to show a higher incidence of gastric cancer. Nevertheless, scientific evidence to support an association between dust exposure and the risk of gastric cancer is inadequate. This study aimed to investigate whether or not occupational dust exposure influences the risk of gastric cancer. Methods: We collected the electronic data from the Pneumoconiosis Health Examination (PHE) program, provided by the Ministry of Employment and Labor and the Korea Workers’ Compensation and Welfare Service from 2002 to 2017. The PHE database was linked to the National Health Insurances databases. The age-standardized incidence ratio (SIR) and 95% confidence intervals (CIs) of the risk of gastric cancers were evaluated in workers with occupational dust exposure, and the results were compared to those in the general population. Results: From 2004 to 2015, 1,543 cases of gastric cancer were observed in the male participants, as compared with 1,174 of expected cases, which yielded an SIR of 1.314 (95% CI, 1.249 to 1.380). Under dust exposure, the risk of gastric cancer was increased 23.9% in the male participants (95% CI, 19.9 to 27.5), and the degree of impairment of lung function was inversely related to the risk of gastric cancer. Conclusions Workers with occupational dust exposure were at higher risk of developing gastric cancer than the general population. Thus, future efforts for the prevention of gastric cancer are necessary for dust exposed workers.

In 2017, the Korean government launched an unprecedentedly large-scaled latent tuberculosis infection (LTBI) screening project which covered more than a million individuals in congregate settings. A total of 1,047,689 participants of source population (n = 2,336,157) underwent LTBI testing from 2017 to 2018. The overall LTBI test uptake rate during this project was 44.8%. Workers in daycare centers (83.5%) and kindergartens (78.9%) showed high participation rate. A total of 1,012,206 individuals with valid results of interferongamma release assay (IGRA) were selected to constitute the IGRA cohort. Most of the enrolled participants in the IGRA cohort were in their working age. Approximately, threequarters of total enrolled population were female. Investigating the LTBI prevalence, stages of LTBI care cascade, natural history of LTBI, efficacy of LTBI treatment and cost-effectiveness of LTBI screening are feasible within this IGRA cohort.

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. Conclusions 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.

In 2017, the Korean government launched an unprecedentedly large-scaled latent tuberculosis infection (LTBI) screening project which covered more than a million individuals in congregate settings. A total of 1,047,689 participants of source population (n = 2,336,157) underwent LTBI testing from 2017 to 2018. The overall LTBI test uptake rate during this project was 44.8%. Workers in daycare centers (83.5%) and kindergartens (78.9%) showed high participation rate. A total of 1,012,206 individuals with valid results of interferongamma release assay (IGRA) were selected to constitute the IGRA cohort. Most of the enrolled participants in the IGRA cohort were in their working age. Approximately, threequarters of total enrolled population were female. Investigating the LTBI prevalence, stages of LTBI care cascade, natural history of LTBI, efficacy of LTBI treatment and cost-effectiveness of LTBI screening are feasible within this IGRA cohort.