Background: The epidemiology of pathogenic bacteria varies according to the socioeconomic status and antimicrobial resistance status. However, longitudinal epidemiological studies to evaluate the changes in species distribution and antimicrobial susceptibility of pathogenic bacteria nationwide are lacking. We retrospectively investigated the nationwide trends in species distribution and antimicrobial susceptibility of pathogenic bacteria over the last 20 years in Korea. Methods: From 1997 to 2016, annual cumulative antimicrobial susceptibility and species distribution data were collected from 12 university hospitals in five provinces and four metropolitan cities in South Korea. Results: The prevalence of Staphylococcus aureus was the highest (13.1%) until 2012 but decreased to 10.3% in 2016, consistent with the decrease in oxacillin resistance from 76.1% in 2008 to 62.5% in 2016. While the cefotaxime resistance of Escherichia coli increased from 9.0% in 1997 to 34.2% in 2016, E. coli became the most common species since 2013, accounting for 14.5% of all isolates in 2016. Pseudomonas aeruginosa and Acinetobacter baumannii rose to third and fifth places in 2008 and 2010, respectively, while imipenem resistance increased from 13.9% to 30.8% and 0.7% to 73.5% during the study period, respectively.Streptococcus agalactiae became the most common pathogenic streptococcal species in 2016, as the prevalence of Streptococcus pneumoniae decreased since 2010. During the same period, pneumococcal penicillin susceptibility decreased to 79.0%, and levofloxacin susceptibility of S. agalactiae decreased to 77.1% in 2016. Conclusion The epidemiology of pathogenic bacteria has changed significantly over the past 20 years according to trends in antimicrobial resistance in Korea. Efforts to confine antimicrobial resistance would change the epidemiology of pathogenic bacteria and, consequently, the diagnosis and treatment of infectious diseases.

Coronavirus disease 2019 (COVID-19) has become a major health burden worldwide, with over 450 million confirmed cases and 6 million deaths. Although the acute phase of COVID-19 management has been established, there is still a long way to go to evaluate the long-term clinical course or manage complications due to the relatively short outbreak of the virus. Pulmonary fibrosis is one of the most common respiratory complications associated with COVID-19. Scarring throughout the lungs after viral or bacterial pulmonary infection have been commonly observed, but the prevalence of post– COVID-19 pulmonary fibrosis is rapidly increasing. However, there is limited information available about post–COVID-19 pulmonary fibrosis, and there is also a lack of consensus on what condition should be defined as post–COVID-19 pulmonary fibrosis. During a relatively short follow-up period of approximately 1 year, lesions considered related to pulmonary fibrosis often showed gradual improvement; therefore, it is questionable at what time point fibrosis should be evaluated. In this review, we investigated the epidemiology, risk factors, pathogenesis, and management of post–COVID-19 pulmonary fibrosis.

Background: The main cause of death in pulmonary embolism (PE) is right-heart failure due to acute pressure overload. In this sense, extracorporeal membrane oxygenation (ECMO) might be useful in maintaining hemodynamic stability and improving organ perfusion. Some previous studies have reported ECMO as a bridge to reperfusion therapy of PE. However, little is known about the patients that benefit from ECMO. Methods: Patients who underwent ECMO due to pulmonary thromboembolism at a single university-affiliated hospital between January 2010 and December 2018 were retrospectively reviewed. Results: During the study period, nine patients received ECMO in high-risk PE. The median age of the patients was 60 years (range, 22–76 years), and six (66.7%) were male. All nine patients had cardiac arrests, of which three occurred outside the hospital. All the patients received mechanical support with veno-arterial ECMO, and the median ECMO duration was 1.1 days (range, 0.2–14.0 days). ECMO with anticoagulation alone was performed in six (66.7%), and ECMO with reperfusion therapy was done in three (33.3%). The 30-day mortality rate was 77.8%. The median time taken from the first cardiac arrest to initiation of ECMO was 31 minutes (range, 30–32 minutes) in survivors (n=2) and 65 minutes (range, 33–482 minutes) in non-survivors (n=7). Conclusion High-risk PE with cardiac arrest has a high mortality rate despite aggressive management with ECMO and reperfusion therapy. Early decision to start ECMO and its rapid initiation might help save those with cardiac arrest in high-risk PE.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial pneumonia, which presents with a progressive worsening dyspnea, and thus a poor outcome. The members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Korea Interstitial Lung Disease Study Group drafted this clinical practice guideline for IPF management. This guideline includes a wide range of topics, including the epidemiology, pathogenesis, risk factors, clinical features, diagnosis, treatment, prognosis, and acute exacerbation of IPF in Korea. Additionally, we suggested the PICO for the use of pirfenidone and nintendanib and for lung transplantation for the treatment of patients with IPF through a systemic literature review using experts' help in conducting a meta-analysis. We recommend this guideline to physicians, other health care professionals, and government personnel in Korea, to facilitate the treatment of patients with IPF.
Delivery of Health Care ; Diagnosis ; Disease Management ; Dyspnea ; Epidemiology ; Humans ; Idiopathic Pulmonary Fibrosis ; Korea ; Lung Diseases, Interstitial ; Lung Transplantation ; Prognosis ; Risk Factors ; Tuberculosis

Drug-induced immune hemolytic anemia is a rare disease that occurs in 1 in 1 million individuals of the general population. Rifampin-induced immune hemolytic anemia is caused by drug-dependent antibodies and this can be treated without complication by drug cessation. Herein, we present a case of rifampin-induced immune hemolytic anemia in a patient with primary Sjogren's syndrome (pSS) which occurred during treatment of pulmonary tuberculosis. At admission, the patient's laboratory tests revealed hemolytic anemia and positive direct antiglobulin test result. Since the incidence of autoimmune hemolytic anemia (AIHA) in pSS is reported to be 3 percent, which is higher than that of the general population, differential diagnosis between AIHA and rifampin-induced immune hemolytic anemia was required for planning future anti-tuberculous treatment. We identified rifampin-dependent antibody by drug-induced immune complex test and diagnosed rifampin-induced immune hemolytic anemia. Based on this experience, if rifampin administration is considered in patients with systemic autoimmune disease such as pSS, which has a high incidence of AIHA, we suggest evaluating the presence and the cause of hemolytic anemia at baseline by testing serum lactate dehydrogenase, haptoglobin, and direct and indirect antiglobulin tests before drug administration to promptly identify the cause of hemolysis if hemolytic anemia develops.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial pneumonia, which presents with a progressive worsening dyspnea, and thus a poor outcome. The members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Korea Interstitial Lung Disease Study Group drafted this clinical practice guideline for IPF management. This guideline includes a wide range of topics, including the epidemiology, pathogenesis, risk factors, clinical features, diagnosis, treatment, prognosis, and acute exacerbation of IPF in Korea. Additionally, we suggested the PICO for the use of pirfenidone and nintendanib and for lung transplantation for the treatment of patients with IPF through a systemic literature review using experts' help in conducting a meta-analysis. We recommend this guideline to physicians, other health care professionals, and government personnel in Korea, to facilitate the treatment of patients with IPF.

BACKGROUND: Most patients with influenza recover spontaneously or following treatment with an anti-viral agent, but some patients experience pneumonia requiring hospitalization. We conducted a retrospective review to determine the incidence and risk factors of pneumonia in hospitalized patients with influenza A or B. METHODS: A total of 213 patients aged 18 years or older and hospitalized with influenza between January 2012 and January 2015 were included in this study. A reverse-transcriptase polymerase chain reaction assay was used to detect the influenza A or B virus in the patients' sputum samples. We collected demographic and laboratory data, combined coexisting diseases, and radiologic findings. RESULTS: The incidence of pneumonia was higher in patients in the influenza A group compared to those in the influenza B group (68.6% vs. 56.9%), but this difference was not statistically significant. The presence of underlying respiratory disease was significantly associated with pneumonia in the influenza A group (adjusted odds ratio [OR], 3.975; 95% confidence interval [CI], 1.312–12.043; p=0.015). In the influenza B group, the white blood cell count (adjusted OR, 1.413; 95% CI, 1.053–1.896; p=0.021), platelet count (adjusted OR, 0.988; 95% CI, 0.978–0.999; p=0.027), and existence of an underlying medical disease (adjusted OR, 15.858; 95% CI, 1.757–143.088; p=0.014) were all significantly associated with pneumonia in multivariate analyses. CONCLUSION: The incidence of pneumonia was 65.7% in hospitalized patients with influenza A or B. The risk factors of pneumonia differed in hospitalized patients with influenza A or B.
Comorbidity ; Herpesvirus 1, Cercopithecine ; Hospitalization ; Humans ; Incidence* ; Influenza, Human* ; Leukocyte Count ; Multivariate Analysis ; Odds Ratio ; Platelet Count ; Pneumonia* ; Polymerase Chain Reaction ; Retrospective Studies ; Risk Factors* ; Seasons* ; Sputum

Oral anticoagulant therapy is frequently and increasingly prescribed for patients at risk of arterial or venous thromboembolism (VTE). Although elective surgical or invasive procedures have necessitated temporary interruption of anticoagulants, managing these patients has been performed empirically and been poorly investigated. This study was designed to evaluate the adequacy of perioperative anticoagulation using enoxaparin. This was a retrospective, single-center study that evaluated the efficacy and safety of therapeutic-dose enoxaparin for bridging therapy in patients on long-term warfarin at Soonchunhyang University Hospital in Korea between August 2009 and July 2011. Warfarin was discontinued 5 days before surgery, and enoxaparin was administered twice daily by subcutaneous injection at a dose of 1 mg per kg from 3 days before the procedure to the last dose 24 hours before the procedure. Anticoagulation was restarted if proper hemostasis had been confirmed. There were 49 patients, of whom 25 (51%) were men, and the mean age was 63 years. Thirty-four (69%) received warfarin therapy for VTE, and 9 (18%) for atrial fibrillation. Twenty-nine patients (59%) underwent major surgery and 20 (41%) minor surgery. The mean postoperative duration of enoxaparin was 4 days. No patients had thromboembolic complications through 30 days after the procedure. The overall 30-day mortality rate was 0%. In conclusion, our findings demonstrate that bridging therapy with therapeutic-dose enoxaparin is feasible and associated with a low incidence of major bleeding and no thromboembolic complications. However, the optimal approach to managing patients perioperatively is uncertain and requires further evaluation.
Anticoagulants ; Atrial Fibrillation ; Enoxaparin* ; Hemorrhage ; Hemostasis ; Heparin, Low-Molecular-Weight ; Humans ; Incidence ; Injections, Subcutaneous ; Korea ; Male ; Minor Surgical Procedures ; Mortality ; Retrospective Studies ; Thromboembolism ; Venous Thromboembolism ; Warfarin

PURPOSE: Asthma is a heterogeneous disease characterized by various types of airway inflammation and obstruction. Therefore, it is classified into several subphenotypes, such as early-onset atopic, obese non-eosinophilic, benign, and eosinophilic asthma, using cluster analysis. A number of asthmatics frequently experience exacerbation over a long-term follow-up period, but the exacerbation-prone subphenotype has rarely been evaluated by cluster analysis. This prompted us to identify clusters reflecting asthma exacerbation. METHODS: A uniform cluster analysis method was applied to 259 adult asthmatics who were regularly followed-up for over 1 year using 12 variables, selected on the basis of their contribution to asthma phenotypes. After clustering, clinical profiles and exacerbation rates during follow-up were compared among the clusters. RESULTS: Four subphenotypes were identified: cluster 1 was comprised of patients with early-onset atopic asthma with preserved lung function, cluster 2 late-onset non-atopic asthma with impaired lung function, cluster 3 early-onset atopic asthma with severely impaired lung function, and cluster 4 late-onset non-atopic asthma with well-preserved lung function. The patients in clusters 2 and 3 were identified as exacerbation-prone asthmatics, showing a higher risk of asthma exacerbation. CONCLUSIONS: Two different phenotypes of exacerbation-prone asthma were identified among Korean asthmatics using cluster analysis; both were characterized by impaired lung function, but the age at asthma onset and atopic status were different between the two.
Adult* ; Asthma ; Clothing ; Cluster Analysis* ; Eosinophils ; Follow-Up Studies ; Humans ; Inflammation ; Lung ; Methods ; Phenotype

BACKGROUND/AIMS: Diesel exhaust particles (DEPs) lead to elevation of reactive oxygen species, which can activate the nucleotide-binding oligomerization domain-like receptor (NLR) family members containing the pyrin domain 3 (NLRP3)-inf lammasome. In this study, we elucidated whether NLRP3 -inf lammasome is activated by DEPs and whether antioxidants (N-acetylcysteine [NAC]) could inhibit such activation. METHODS: RAW 264.7 cells and ex vivo lung tissues explants obtained from elastase-induced emphysema animal models were stimulated with cigarette smoking extract (CSE), DEPs, and lipopolysaccharide, and levels of interleukin-1β (IL-1β), caspase-1 and nucleotide-binding oligomerization domain-like receptor (NLR) family members containing the pyrin domain (NLRP3)-inflammasome were assessed by Western blotting and immunohistochemistry. RESULTS: NAC and caspase-1 inhibitor suppressed CSE- and DEP-induced secretion of IL-1β in RAW 264.7 cells. The expression levels of the NLRP3-inflammasome and caspase-1 were upregulated in RAW 264.7 cells by stimulation with CSE and DEPs and were inhibited by NAC. CSE and DEPs increased the secretion of IL-1β in lung tissues from both the normal and elastase-induced emphysema groups. The secretion of IL-1β by CSE and DEPs was increased in the elastin-induced emphysema group more than that in the normal group (CSE: 309 ± 19 pg/mL vs. 151 ± 13 pg/mL, respectively, p < 0.05; DEP: 350 ± 24 pg/mL vs. 281 ± 15 pg/mL, respectively, p < 0.05). NAC inhibited CSE- and DEP-induced IL-1β secretion in both the normal and elastase-induced emphysema groups. NLRP3-inflammasome expression as determined by immunohistochemistry was increased by CSE and DEPs in both the normal and elastin-induced emphysema groups, and was suppressed by NAC. CONCLUSIONS: The NLRP3-inf lammasome is activated by DEPs in ex vivo tissue explants from elastase-induced emphysema animal model, and this activation is inhibited by NAC.
Antioxidants ; Blotting, Western ; Emphysema* ; Humans ; Immunohistochemistry ; Lung* ; Models, Animal ; Pancreatic Elastase ; Pulmonary Disease, Chronic Obstructive ; RAW 264.7 Cells* ; Reactive Oxygen Species ; Smoking ; Vehicle Emissions*