During nationwide Fantimicrobial surveillance (Korea Global Antimicrobial Resistance Surveillance System [Kor-GLASS]), the recent emergence of non-oxacillinase (OXA)-23 production by carbapenem-resistant Acinetobacter baumannii (CRAB) isolates was noted. In this study, we evaluated resistance mechanisms other than OXA-23 production to elucidate the shift in considerable CRAB clones. The presence of OXA carbapenemase genes, such as blaOXA-23 , blaOXA-24 , blaOXA-58 , and blaOXA-51-ISAba1, was determined by PCR. Other carbapenemase genes, such as blaIMP , blaVIM , blaNDM , blaKPC , blaGES , and blaOXA-48 , were determined using sequencing. Strains lacking carbapenemase genes were subjected to whole genome sequencing, and resistance genes were analyzed using ResFinder. Four CRAB strains were collected through a Kor-GLASS study in 2022, in which OXA-23 production was not identified. The carbapenemase genotypes of the four CRAB strains lacking blaOXA-23 were blaOXA-51 -ISAba1, blaOXA-66/ACD25 , blaOXA-182, and blaNDM-1 . To the best of our knowledge, this is the first study to identify CRAB producing New Delhi metallo-β-lactamase (NDM)-1 in Korea. In conclusion, domestic CRAB resistance mechanisms may undergo subtle changes. Continuous observations are required to monitor the emergence of new clones.

Background: A healthcare system’s collapse due to a pandemic, such as the coronavirus disease 2019 (COVID-19), can expose healthcare workers (HCWs) to various mental health problems. This study aimed to investigate the impact of the COVID-19 pandemic on the depression and anxiety of HCWs. Methods: A nationwide questionnaire-based survey was conducted on HCWs who worked in healthcare facilities and public health centers in Korea in December 2020. Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure depression and anxiety. To investigate factors associated with depression and anxiety, stepwise multiple logistic regression analysis was performed. Results: A total of 1,425 participating HCWs were included. The mean depression score (PHQ-9) of HCWs before and after COVID-19 increased from 2.37 to 5.39, and the mean anxiety score (GAD-7) increased from 1.41 to 3.41. The proportion of HCWs with moderate to severe depression (PHQ-9 ≥ 10) increased from 3.8% before COVID-19 to 19.5% after COVID-19, whereas that of HCWs with moderate to severe anxiety (GAD-7 ≥ 10) increased from 2.0% to 10.1%. In our study, insomnia, chronic fatigue symptoms and physical symptoms after COVID-19, anxiety score (GAD-7) after COVID-19, living alone, and exhaustion were positively correlated with depression. Furthermore, post-traumatic stress symptoms, stress score (Global Assessment of Recent Stress), depression score (PHQ-9) after COVID-19, and exhaustion were positively correlated with anxiety. Conclusion In Korea, during the COVID-19 pandemic, HCWs commonly suffered from mental health problems, including depression and anxiety. Regularly checking the physical and mental health problems of HCWs during the COVID-19 pandemic is crucial, and social support and strategy are needed to reduce the heavy workload and psychological distress of HCWs.

This systematic review evaluated psychiatric adverse events (AEs) following vaccination against coronavirus disease 2019 (COVID-19). We included studies that reported or investigated psychiatric AEs in individuals who had received an approved COVID-19 vaccine in the Republic of Korea. Systematic electronic searches of Ovid-Medline, Embase, CENTRAL, and KoreaMed databases were conducted on March 22, 2023. Risk of bias was assessed using the Risk of Bias Assessment Tool for Non-randomized Studies 2.0. The study protocol was registered in the International Prospective Register of Systematic Reviews (CRD42023449422). Of the 301 articles initially selected, 7 were included in the final analysis. All studies reported on sleep disturbances, and 2 highlighted anxiety-related AEs. Sleep disorders like insomnia and narcolepsy were the most prevalent AEs, while depression was not reported. Our review suggests that these AEs may have been influenced by biological mechanisms as well as the broader psychosocial context of the COVID-19 pandemic. Although this study had limitations, such as a primary focus on the BNT162b2 vaccine and an observational study design, it offered a systematic, multi-vaccine analysis that fills a critical gap in the existing literature. This review underscores the need for continued surveillance of psychiatric AEs and guides future research to investigate underlying mechanisms, identify risk factors, and inform clinical management.

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.

Imipenemase (IMP)-6–producing Pseudomonas aeruginosa sequence type (ST) 235 is a dominant clone of carbapenemase-producing P. aeruginosa (CPPAE) in Korea. As part of the Antimicrobial Resistance Surveillance System in Korea, we found an increase in the carbapenem resistance rate of P. aeruginosa isolates from blood cultures and a shift in the molecular epidemiology of CPPAE. A total of 212 non-duplicated P. aeruginosa blood isolates were obtained from nine general hospitals and two nursing homes. Twenty-four isolates were identified as CPPAE. We observed the emergence of the NDM-1 P. aeruginosa ST 773 clone (N=10), mostly from Gyeongsang Province. The IMP-6 ST 235 clone (N=11) was detected in all provinces. CPPAE isolates showed very high resistance rates to amikacin, and all NDM-1 P. aeruginosa strains carried rmtB. This is the first nationwide surveillance of the recently emerged NDM-1–producing P. aeruginosa ST773 clone in Korea. Continuous surveillance is necessary to prevent the infection and transmission of carbapenem- and amikacin-resistant P. aeruginosa in Korea.

Background: Recently, CrpP enzymes have been described as a novel cause of ciprofloxacin resistance. The crpP gene encodes a novel protein that specifically confers resistance to ciprofloxacin through an adenosine triphosphate-dependent mechanism that phosphorylates the antimicrobial. In this study, the current prevalence of the crpP gene in carbapenemaseproducing Pseudomonas aeruginosa blood isolates was evaluated. Methods: During the study of the Antimicrobial Resistance Surveillance System in Korea, 22 blood isolates of carbapenemase-producing P. aeruginosa were collected from nine general hospitals and two nursing homes in the year 2020. Resistance genes and phylogenic trees were analyzed with the whole genome sequencing data. Results: A total of 11 P. aeruginosa blood isolates coharbored the crpP and carbapenemase genes (nine IMP-6 producers and two GES-5-producers). Nine NDM-1-producers coharbored aac(6')-Ib-cr and qnrVC1 . One GES-9-producer also carried aac(6')-Ib-cr, and one NDM-1-producer also carried qnrVC1. The phylogenic tree showed no epidemiologic link among the 22 carbapenemase-producing P. aeruginosa isolates. Conclusion This is the first report on the current prevalence of the crpP gene in carbapenemaseproducing P. aeruginosa blood isolates in Korea.

Background: Nilotinib is a tyrosine kinase inhibitor approved by the Ministry of Food and Drug Safety for frontline and 2nd line treatment of Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). This study aimed to confirm the safety and efficacy of nilotinib in routine clinical practice within South Korea. Methods: An open-label, multicenter, single-arm, 12-week observational post-marketing surveillance (PMS) study was conducted on 669 Korean adult patients with Ph + CML from December 24, 2010, to December 23, 2016. The patients received nilotinib treatment in routine clinical practice settings. Safety was evaluated by all types of adverse events (AEs) during the study period, and efficacy was evaluated by the complete hematological response (CHR) and cytogenetic response. Results: During the study period, AEs occurred in 61.3% (410 patients, 973 events), adverse drug reactions (ADRs) in 40.5% (271/669 patients, 559 events), serious AEs in 4.5% (30 patients, 37 events), and serious ADRs in 0.7% (5 patients, 8 events). Furthermore, unexpected AEs occurred at a rate of 6.9% (46 patients, 55 events) and unexpected ADRs at 1.2% (8 patients, 8 events). As for the efficacy results, CHR was achieved in 89.5% (442/494 patients), and minor cytogenetic response or major cytogenetic response was achieved in 85.8% (139/162 patients). Conclusion This PMS study shows consistent results in terms of safety and efficacy compared with previous studies. Nilotinib was well tolerated and efficacious in adult Korean patients with Ph + CML in routine clinical practice settings.

OBJECTIVES: Our study examined the dose-response relationship between smoking amounts (pack-years) and the risk of developing pancreatic cancer in Korean men. METHODS: Of 125,743 participants who underwent medical health checkups in 2009, 121,408 were included in the final analysis and observed for the development of pancreatic cancer. We evaluated the associations between smoking amounts and incident pancreatic cancer in 4 groups classified by pack-year amounts. Cox proportional hazards models were used to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of incident pancreatic cancer by comparing groups 2 (<20 pack-year smokers), 3 (20-≤40 pack-year smokers), and 4 (>40 pack-year smokers) with group 1 (never smokers). RESULTS: During 527,974.5 person-years of follow-up, 245 incident cases of pancreatic cancer developed between 2009 and 2013. The multivariate-adjusted HRs (95% CIs) for incident pancreatic cancer in groups 2, 3, and 4 were 1.05 (0.76 to 1.45), 1.28 (0.91 to 1.80), and 1.57 (1.00 to 2.46), respectively (p for trend=0.025). The HR (95% CI) of former smokers showed a dose-response relationship in the unadjusted model, but did not show a statistically significant association in the multivariate-adjusted model. The HR (95% CI) of current smokers showed a dose-response relationship in both the unadjusted (p for trend=0.020) and multivariate-adjusted models (p for trend=0.050). CONCLUSIONS The risk of developing pancreatic cancer was higher in current smokers status than in former smokers among Korean men, indicating that smoking cessation may have a protective effect.

Background/Aims: We evaluated the feasibility and long-term efficacy of the combination of cytarabine, idarubicin, and all-trans retinoic acid (ATRA) for treating patients with newly diagnosed acute promyelocytic leukemia (APL). Methods: We included 87 patients with newly diagnosed acute myeloid leukemia and a t(15;17) or promyelocytic leukemia/retinoic acid receptor alpha (PML-RARα) mutation. Patients received 12 mg/m2/day idarubicin intravenously for 3 days and 100 mg/m2/day cytarabine for 7 days, plus 45 mg/m2/day ATRA. Clinical outcomes included complete remission (CR), relapse-free survival (RFS), overall survival (OS), and the secondary malignancy incidence during a 20-year follow-up. Results: The CR, 10-year RFS, and 10-year OS rates were 89.7%, 94.1%, and 73.8%, respectively, for all patients. The 10-year OS rate was 100% for patients that achieved CR. Subjects were classified according to the white blood cell (WBC) count in peripheral blood at diagnosis (low-risk, WBC < 10,000/mm3; high-risk, WBC ≥ 10,000/mm3). The low-risk group had significantly higher RFS and OS rates than the high-risk group, but the outcomes were not superior to the current standard treatment (arsenic trioxide plus ATRA). Toxicities were similar to those observed with anthracycline plus ATRA, and higher than those observed with arsenic trioxide plus ATRA. The secondary malignancy incidence after APL treatment was 2.7%, among the 75 patients that achieved CR, and 5.0% among the 40 patients that survived more than 5 years after the APL diagnosis. Conclusions Adding cytarabine to anthracycline plus ATRA was not inferior to anthracycline plus ATRA alone, but it was not comparable to arsenic trioxide plus ATRA. The probability of secondary malignancy was low.