Prevalence and Characteristics of Tuberculosis in the Korean Homeless Population Based on Nationwide Tuberculosis Screening.

Background: The government of Korea implemented a strategy of prevention and early diagnosis in high-risk groups to reduce the tuberculosis (TB) burden. This study aims to investigate the TB epidemiology and gap in understanding of TB prevalence among homeless individuals by analyzing active TB chest X-ray (CXR) screening results in Korea. Methods: The Korean National Tuberculosis Association conducted active TB screening with CXR for homeless groups from January 1 to December 31, 2021. Sputum acid fast bacilli smear and culture were performed for the subjects suggestive of TB on CXR. We performed a cross-sectional analysis of the data in comparison with the national health screening results from the general population. Results: Among 17,713 homeless persons, 40 (0.23%), 3,077 (17.37%), and 79 (0.45%) were categorized as suggested TB, inactive TB, and observation required, respectively. Prevalence of suggested TB in the homeless was significantly higher (3-5 fold) than in the national general health screening based on age category (p < 0.005). Twenty-nine cases were confirmed as TB, yielding a prevalence of 164 cases per 100,000 individuals; 19 of these 29 cases showed inactive TB on CXR. Body mass index (p = 0.0478) and CXR result (p < 0.001) significantly correlated with confirmed TB based on multivariable analysis. Conclusion: Nutrition status and CXR results, especially that of inactive TB, should be considered in active TB screening of the homeless population, where TB prevalence is higher than the general population.

Impact of air pollution on healthcare utilization in patients with bronchiectasis.

Introduction: Air pollutants are increasingly recognized to affect long-term outcomes in patients with bronchiectasis. We aimed to figure out the association between air pollutants and the risk of healthcare utilization in patients with bronchiectasis. Methods: Data for 1,029 subjects with bronchiectasis in Seoul were extracted. The air pollutants included particulate matter of 10 µm or less in diameter (PM10), particulate matter of 2.5 µm or less in diameter (PM2.5), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and nitrogen dioxide (NO2). The outcome was all-cause healthcare uses, defined as outpatient visit, emergency department visit, or hospitalization. The concentration-response curves between each air pollutant and relative risks for healthcare utilization were obtained. Results: There were significant correlations between air pollutant concentrations and the risk of healthcare utilization, particularly for PM10, NO2, SO2, and CO. This risk was observed even at concentrations below the recommended safe thresholds for the general population. The slopes for the association between PM10 and NO2 and the risk of healthcare use showed a logarithmic growth pattern, with the steepest increase up to 30 µg/m3 and 0.030 parts per million (ppm), respectively. The curves for SO2 and CO showed an inverted U-shaped pattern, with a peak at 0.0045 ppm and a slow upward curve, respectively. No specific trends were observed for PM2.5 and O3 and the risk of healthcare use. Discussion: Increased concentrations of PM10, NO2, SO2, and CO were associated with increased healthcare utilization in patients with bronchiectasis. For patients with bronchiectasis, there were no safety thresholds for those air pollutants, and even low levels of air pollutant exposure can negatively impact bronchiectasis outcomes.

Gastroesophageal Reflux Disease Increases Susceptibility to Nontuberculous Mycobacterial Pulmonary Disease.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common comorbidity of nontuberculous mycobacteria (NTM) pulmonary disease (PD). Although GERD is associated with more symptoms and severe disease in patients with NTM PD, whether GERD is associated with an increased risk of NTM PD developing is unknown. RESEARCH QUESTION: Does GERD influence the development of NTM PD? Are there any factors associated with an increased risk of NTM PD among patients with GERD? What is the impact of NTM PD on the health-care use of patients with GERD? STUDY DESIGN AND METHODS: Data from the Korean National Health Insurance Service National Sample Cohort between 2002 and 2015 were used. The incidence and risk of NTM PD were compared between patients with GERD (GERD cohort; n = 17,424) and patients matched for age, sex, type of insurance, and Charlson Comorbidity Index (matched cohort; n = 69,696). Using the GERD cohort, the factors associated with incident NTM PD also were evaluated. RESULTS: During a median follow-up duration of 5.1 years, the age- and sex-adjusted incidence of NTM PD was significantly higher in the GERD cohort (34.8 per 100,000 person-years [PY]) than in the matched cohort (10.5 per 100,000 PY; P < .001), with a subdistribution hazard ratio (HR) of 3.36 (95% CI, 2.10-5.37). Regarding risk factors associated with NTM PD, age of 60 years or older (adjusted HR, 3.57; 95% CI, 1.58-8.07) and bronchiectasis (adjusted HR, 18.69; 95% CI, 6.68-52.28) were associated with an increased risk of incident NTM PD in the GERD cohort. Compared with patients with GERD who did not demonstrate NTM PD, those with NTM PD showed higher all-cause (13,321 PY vs 5,932 PY; P = .049) and respiratory disease-related (5,403 vs 801; P = .011) ED visits or hospitalizations. INTERPRETATION: GERD is associated with an increased incidence of NTM PD. Older age and bronchiectasis are risk factors for NTM PD in patients with GERD. NTM PD in patients with GERD is associated with increased health-care use.

Additive effects of coexisting respiratory comorbidities on overall or respiratory mortality in patients with asthma: a national cohort study.

Asthmatic patients are generally considered to have an increased risk of mortality compared with subjects without asthma. However, this issue has been less evaluated using nationally representative data. Moreover, it is unclear whether respiratory comorbidities other than chronic obstructive pulmonary disease (COPD) are associated with increased mortality in asthmatic patients compared with subjects without. Using a nationally representative sample database, we performed a retrospective cohort study of patients with asthma and age-sex-matched control cohort. We estimated the hazard ratio (HR) and stratified the asthma cohort based on respiratory comorbidities. During a median 8.9-year follow-up, the overall mortality rate was higher in the asthma cohort than in the control cohort (p < 0.001). The hazard ratio (HR) for overall mortality in the asthma cohort compared with the control cohort was 1.13. The effects of asthma on overall mortality were more evident in males, patients under medical aid, and subjects with COPD. Respiratory comorbidities were significantly associated with increased risk of overall mortality in asthmatic patients compared with controls (adjusted HRs; 1.48 for COPD, 1.40 for bronchiectasis, 4.08 for lung cancer, and 1.59 for pneumonia). While asthma and lung cancer showed an additive effect only on overall mortality, asthma and other respiratory comorbidities (COPD, pneumonia, and bronchiectasis) had additive effects only on respiratory mortality. Patients with asthma had a higher overall mortality rate compared with subjects without asthma. Respiratory comorbidities showed an additive effect on overall or respiratory mortality in patients with asthma.

TNF inhibitors increase the risk of nontuberculous mycobacteria in patients with seropositive rheumatoid arthritis in a mycobacterium tuberculosis endemic area.

The aim of this study is to examine the impact of tumor necrosis factor inhibitors (TNFI) on nontuberculous mycobacterium (NTM) infection in rheumatoid arthritis (RA) patients in a mycobacterium tuberculosis (MTB) endemic area. We selected 1089 TNFI-treated RA patients and 4356 untreated RA patients using propensity-matching analysis according to age, gender, and Charlson comorbidity index using the Korean National Health Insurance Service database from July 2009 to December 2010. Both groups were followed-up until the end of 2016 to measure the incidence of mycobacterial diseases. The incidence rate of NTM in TNFI-treated RA group was similar to those of MTB (328.1 and 340.9 per 100,000 person-years, respectively). The adjusted hazard ratio (aHR) of NTM for TNFI-treated RA compared to untreated RA was 1.751(95% CI 1.105-2.774). The risk of TNFI-associated NTM in RA was 2.108-fold higher among women than men. The age-stratified effects of TNFI on NTM development were significantly high in RA patients aged 50-65 years (aHR 2.018). RA patients without comorbidities had a higher incidence of NTM following TNFI treatment (aHR 1.742). This real-world, observational study highlights the need to increase awareness of NTM in TNFI-treated RA patients in an MTB endemic area.

Anti-SARS-CoV-2 Spike Protein RBD Antibody Levels After Receiving a Second Dose of ChAdOx1 nCov-19 (AZD1222) Vaccine in Healthcare Workers: Lack of Association With Age, Sex, Obesity, and Adverse Reactions.

Response to vaccines generally varies according to individual factors of the vaccinated subjects such as demographics and immune status. While there are various reports of factors associated with immunogenicity of mRNA COVID-19 vaccines, little is known about those of adenovirus vector vaccines. We conducted a prospective observational study to assess the relationships of antibody level with age, sex, body mass index (BMI), and adverse reactions (ARs) to an adenovirus vector vaccine, ChAdOx1 nCoV-19. Healthcare workers who planned to receive both the first and second injections of the ChAdOx1 nCoV-19 vaccine at Hanyang University Hospital, Seoul, Korea, were enrolled in the study. Seven days after each injection, participants were asked to complete an online adverse reaction survey. In addition, anti-SARS-CoV-2 spike (S) protein receptor binding domain (RBD) antibody concentration was measured 4 weeks after the second injection. All participants (n = 447, 100%) showed serologic positivity (≥ 0.8 U/mL) 4 weeks after the second injection of ChAdOx1 nCoV-19 vaccine. Furthermore, the anti-SARS-CoV-2 S protein RBD concentration was similar among groups when stratified by age, sex, BMI, or presence and severity of AR; multivariable linear regression found no associations between antibody response to the ChAdOx1 nCoV-19 vaccine and age, BMI, sex, and vaccine-induced ARs. In conclusion, age, sex, obesity, and ARs were not associated with antibody responses after two doses of ChAdOx1 nCoV-19 vaccination.

Diagnosis of Pneumonia by Cough Sounds Analyzed with Statistical Features and AI.

Pneumonia is a serious disease often accompanied by complications, sometimes leading to death. Unfortunately, diagnosis of pneumonia is frequently delayed until physical and radiologic examinations are performed. Diagnosing pneumonia with cough sounds would be advantageous as a non-invasive test that could be performed outside a hospital. We aimed to develop an artificial intelligence (AI)-based pneumonia diagnostic algorithm. We collected cough sounds from thirty adult patients with pneumonia or the other causative diseases of cough. To quantify the cough sounds, loudness and energy ratio were used to represent the level and its spectral variations. These two features were used for constructing the diagnostic algorithm. To estimate the performance of developed algorithm, we assessed the diagnostic accuracy by comparing with the diagnosis by pulmonologists based on cough sound alone. The algorithm showed 90.0% sensitivity, 78.6% specificity and 84.9% overall accuracy for the 70 cases of cough sound in pneumonia group and 56 cases in non-pneumonia group. For same cases, pulmonologists correctly diagnosed the cough sounds with 56.4% accuracy. These findings showed that the proposed AI algorithm has value as an effective assistant technology to diagnose adult pneumonia patients with significant reliability.

The Usefulness of FEF25-75 in Predicting Airway Hyperresponsiveness to Mannitol.

BACKGROUND AND OBJECTIVE: Despite the usefulness of airway hyperresponsiveness (AHR) testing in diagnosing and monitoring asthma, it is challenging to perform in a real-world setting. Forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), a pulmonary measurement that can be obtained easily during routine spirometry, represents the status of medium-sized and small airways. However, the performance of FEF25-75 in predicting AHR has not been well elucidated. Therefore, we investigated whether FEF25-75 can predict AHR to mannitol. METHODS: We performed a retrospective cohort study of 428 patients who visited a single clinic due to cough, wheezing, or dyspnea. All patients underwent spirometry with a mannitol provocation test. We compared the area under the curve (AUC) of the percentage of the predicted values of FEF25-75 (FEF25-75 %pred) with that of forced expiratory volume in 1 second (FEV1%pred), FEV1/forced vital capacity (FVC), and FEF25-75/ FVC for predicting AHR. RESULTS: The rate of AHR to mannitol was 20.3%. In the overall study population, the AUC of FEF25-75 %pred for predicting AHR (0.772; 95% confidence interval [CI], 0.729-0.811) was significantly higher than that of FEV1%pred (0.666; 95% CI, 0.619-0.710; p < 0.001), FEV1/FVC (0.741; 95% CI, 0.697-0.782; p = 0.047), and FEF25-75/FVC (0.741, 95% CI = 0.696-0.782, p = 0.046). The sensitivity, specificity, positive predictive value, and negative predictive value of FEF25-75 %pred <81% for predicting AHR in the overall study population were 77.0% (95% CI = 66.8-85.4%), 63.9% (95% CI = 58.6-69.0), 35.3%, and 91.6%, respectively. When we restricted the study group to subjects with normal lung function, the results were similar. CONCLUSION: Our results indicate that FEF25-75 %pred can be used as a surrogate for predicting AHR in patients with respiratory symptoms.

Short-Acting Beta2-Agonist Use in Asthma in Korea: A 10-Year Population-Based Study.

Short-acting ß2-agonist (SABA) use is known to be lower in Korean patients with asthma than in those from other countries, while the rate of asthma exacerbations in Korea is higher than in other countries. Thus, an epidemiologic study on SABA use and the relationship between SABA overuse and treatment outcomes in asthma is needed in Korea. We performed a cross-sectional study using the National Health Insurance Service-National Sample Cohort 2002-2012 database. We evaluated the trend of annual SABA use and overuse (prescription of 3 or more SABA canisters/year) and the impact of SABA overuse on mortality. During the study period, the proportion of asthmatic patients who used SABA was approximately 8%-11%, with no significant change in trend. The mean annual SABA use in asthmatic patients was 0.15-0.22 canisters/patient/year and 1.93-2.05 canisters/patient/year in those who used SABA in 12 months. SABA overuse was observed in about 2%-4% of asthmatic patients during the study period. SABA overuse generally tended to increase as the age of patients increased, with triple peaks in the late 20s (3.3%), late 40s (3.1%), and late 70s (3.6%). SABA overuse was associated with mortality (adjusted odds ratio, 1.72; 95% confidence interval, 1.61-1.84). The rate of SABA use was very low in Korean asthmatic patients between 2002-2012. SABA overuse was found in 2%-4% of patients in Korea. SABA overuse was associated with an increased risk of mortality.

Risk Factors for Grade 3 to Grade 4 Adverse Reactions to the ChAdOx1 nCoV-19 Vaccine (AZD1222) Against SARS-CoV-2.

Objective: Limited data are available regarding the rates and risk factors of severe to serious adverse reactions (ARs) to the ChAdOx1 nCoV-19 vaccine. Methods: Eligible participants were healthcare workers who received their first dose of the ChAdOx1 nCoV-19 vaccine in either of two university hospitals in Seoul, Korea. We evaluated the type and severity of ARs 7 days after the first dose of the ChAdOx1 nCoV-19 vaccine using a questionnaire survey delivered via a smartphone application link. Results: Among the 1,603 participants who completed the survey, 684 (42.7%) participants experienced any kind of grade 3 to grade 4 AR. Being young (adjusted odds ratio [OR] for age 21-30 years = 2.49, 95% confidence interval [CI] = 1.75-3.56; adjusted OR for 31-40 years = 1.78, 95% CI = 1.22-2.62; adjusted OR for 41-50 years = 1.47, 95% CI = 1.03-2.11), being female (adjusted OR = 2.16. 95% CI = 1.62-2.89), and being underweight (adjusted OR = 1.61, 95% CI = 1.02-2.55) were identified as risk factors for grade 3 to grade 4 ARs. Among comorbidities, only diabetes mellitus (adjusted OR = 2.36, 95% CI = 1.03-5.53) was identified as a risk factor. When stratified by the type of AR, being young and being female were risk factors for both local and systemic grade 3 to grade 4 ARs. Conclusions: Being young, female, or underweight and having diabetes mellitus were associated with an increased risk of developing grade 3 to grade 4 ARs after receiving the first dose of the ChAdOx1 nCoV-19 vaccine.

Additive Effect of Obesity and Dyslipidemia on Wheezing in Korean Adults: A Nationwide Representative Survey Study.

Besides obesity, there are limited studies regarding the relationship between the individual components of metabolic syndrome and wheezing. It is largely unknown whether the co-existence of other metabolic syndrome components has additive effects on wheezing in the adult population. The association between the individual components of metabolic syndrome and current wheezing was evaluated in adults using data from the Korea National Health and Nutrition Examination Survey from 2008 to 2012. Subjects with metabolic syndrome more frequently had wheezing during the past 12 months (current wheezing) (adjusted odds ratio [aOR] = 1.56; 95% confidence interval [CI] = 1.37-1.77) and wheezing during exercise in the past 12 months (aOR = 1.59; 95% CI = 1.37-1.84). Of the individual metabolic syndrome components, central obesity (aOR = 1.48; 95% CI = 1.31-1.66) and low high-density lipoprotein (HDL) cholesterol (aOR = 1.18; 95% CI = 1.05-1.34) were significantly associated with current wheezing. There were no significant associations between the other components of metabolic syndrome (high triglyceride level, blood pressure, and fasting plasma glucose level) and the presence of current wheezing. In addition, the association was much higher when both central obesity and low HDL cholesterol were present together compared to when either of the conditions was present alone (aOR = 1.67; 95% CI = 1.44-1.94). There is a significant association between metabolic syndrome and current wheezing in Korean adults. Of the components of metabolic syndrome, low HDL cholesterol and central obesity are independently and additively associated with the increased rate of current wheezing.

A case report of allergic bronchopulmonary mycosis caused by Alternaria alternata in colonization of Aspergillus.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disease caused by a complex hypersensitivity reaction to colonization of the airways with various fungi. ABPA caused by Alternaria alternata, other than Aspergillus spp., is named Allergic bronchopulmonary mycosis (ABPM). OBJECTIVE: To describe the first case of ABPM caused by Alternaria alternata in East Asia. METHODS: Case report. RESULTS: A 58-year-old female visited our hospital due to an abnormal chest x-ray, following chest computed tomography (CT) revealed consolidation in the left lower lobe. On laboratory finding, eosinophil count and total IgE level were high. The skin prick test and specific IgE for Alternaria alternata were positive. After diagnosis of ABPM, the patient was treated with prednisolone without antifungal agents, and her chest image was much improved. CONCLUSIONS: Aspergillus is most common etiology of allergic pulmonary disease, however, Alternaria should be considered even though positive culture of Aspergillus spp.

Increased mortality in patients with non cystic fibrosis bronchiectasis with respiratory comorbidities.

There are limited data regarding whether mortality is higher in patients with non cystic fibrosis bronchiectasis (bronchiectasis) than in those without bronchiectasis. Using 2005-2015 data from the Korean National Health Insurance Service, we evaluated hazard ratio (HR) for all-cause mortality in the bronchiectasis cohort relative to the matched cohort. The effect of comorbidities over the study period on the relative mortality was also assessed. All-cause mortality was significantly higher in the bronchiectasis cohort than in the matched cohort (2505/100,000 vs 2142/100,000 person-years, respectively; P < 0.001). Mortality risk was 1.15-fold greater in the bronchiectasis cohort than in the matched cohort (95% confidence interval [CI] 1.09-1.22); mortality was greatest among elderly patients (HR = 1.17, 95% CI 1.10-1.25) and men (HR = 1.19, 95% CI 1.10-1.29). Comorbidities over the study period significantly increased the risk of death in the bronchiectasis cohort relative to the matched cohort: asthma (adjusted HR = 1.20, 95% CI 1.11-1.30), chronic obstructive pulmonary disease (adjusted HR = 1.24, 95% CI 1.15-1.34), pneumonia (adjusted HR = 1.50, 95% CI 1.39-1.63), lung cancer (adjusted HR = 1.85, 95% CI 1.61-2.12), and cardiovascular disease (adjusted HR = 1.34, 95% CI 1.23-1.45). In contrast, there were no significant differences in the risk of death in patients without bronchiectasis-related comorbidities and the matched cohort, except in the case of non-tuberculous mycobacterial infection. In conclusion, all-cause mortality was higher in patients with bronchiectasis cohort than those without bronchiectasis, especially in elderly patients and men. Comorbidities over the study period played a major role in increasing mortality in patients with bronchiectasis relative to those without bronchiectasis.

Clinical characteristics and treatment outcome of Candida tracheobronchitis.

ABSTRACT: Although Candida species can cause invasive fungal diseases, such as disseminated infection and pneumonia, they rarely cause tracheobronchitis, which is often fatal.To identify the clinical characteristics of Candida tracheobronchitis, we retrospectively evaluated 8 patients who had pathologically proven Candida tracheobronchitis.Their median age was 64 (range: 51-70) years and 5 were females. Three patients had solid cancers and 5 had hematological malignancies. We classified tracheobronchitis into localized and diffuse types. Of the 8 patients, 5 had localized and 3 had diffuse tracheobronchitis. While all patients with diffuse tracheobronchitis had predisposing risk factors for invasive fungal disease, such as prolonged corticosteroid use, recent use of nucleoside analogues, or recent neutropenia (<500/m3), only 2 of the 5 with localized tracheobronchitis had predisposing risk factors. Four of the 5 patients with localized tracheobronchitis had loco-regional bronchial mucosal damage (e.g., radiation or photodynamic therapy). Although all 8 patients ultimately died, some improved with or without antifungal treatment. Two of the 5 patients (1 with localized and the other with diffuse tracheobronchitis) who received antifungal agents improved after treatment, and 1 patient with localized tracheobronchitis who did not receive antifungal treatment improved spontaneously. Two of the 3 patients with diffuse tracheobronchitis did not respond to antifungal treatment.Candida tracheobronchitis can present as both localized and diffuse types. While the former was influenced more by loco-regional mucosal damage, the latter was influenced more by the patient's immune status. The treatment outcomes were especially poor in patients with diffuse tracheobronchitis.

Risk of Coronavirus Disease 2019 Occurrence, Severe Presentation, and Mortality in Patients with Lung Cancer.

PURPOSE: This study aimed to analyze whether patients with lung cancer have a higher susceptibility of coronavirus disease 2019 (COVID-19), severe presentation, and higher mortality than those without lung cancer. MATERIALS AND METHODS: A nationwide cohort of confirmed COVID-19 (n=8,070) between January 1, 2020, and May 30, 2020, and a 1:15 age-, sex-, and residence-matched cohort (n=121,050) were constructed. A nested case-control study was performed to compare the proportion of patients with lung cancer between the COVID-19 cohort and the matched cohort. RESULTS: The proportion of patients with lung cancer was significantly higher in the COVID-19 cohort (0.5% [37/8,070]) than in the matched cohort (0.3% [325/121,050]) (p=0.002). The adjusted odds ratio [OR] of having lung cancer was significantly higher in the COVID-19 cohort than in the matched cohort (adjusted OR, 1.51; 95% confidence interval [CI], 1.05 to 2.10). Among patients in the COVID-19 cohort, compared to patients without lung cancer, those with lung cancer were more likely to have severe COVID-19 (54.1% vs. 13.2%, p < 0.001), including mortality (18.9% vs. 2.8%, p < 0.001). The adjusted OR for the occurrence of severe COVID-19 in patients with lung cancer relative to those without lung cancer was 2.24 (95% CI, 1.08 to 4.74). CONCLUSION: The risk of COVID-19 occurrence and severe presentation, including mortality, may be higher in patients with lung cancer than in those without lung cancer.