Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Granular cell tumor is a rare disease, and it is even rarer in the male breast. Although it is typically a benign tumor, due to its features and image findings, it can be easily misdiagnosed and managed as a malignant tumor. Therefore, the extent of the surgery can inappropriately be expanded. To avoid misdiagnosis and overtreatment, surgeons must perform a careful evaluation. We describe a case of a granular cell tumor of the male breast treated with mastectomy.

Background: Catheter-associated urinary tract infections (CAUTIs) account for a large proportion of healthcare-associated infections and have a significant impact on morbidity, length of hospital stay, and mortality. Adherence to the recommended infection prevention practices can effectively reduce the incidence of CAUTIs. This study aimed to assess the characteristics of CAUTIs and the efficacy of prevention programs across hospitals of various sizes. Methods: Intervention programs, including training, surveillance, and monitoring, were implemented. Data on the microorganisms responsible for CAUTIs, urinary catheter utilization ratio, rate of CAUTIs per 1,000 device days, and factors associated with the use of indwelling catheters were collected from 2017 to 2019. The incidence of CAUTIs and associated data were compared between university hospitals and small- and medium-sized hospitals. Results: Thirty-two hospitals participated in the study, including 21 university hospitals and 11 small- and medium-sized hospitals. The microorganisms responsible for CAUTIs and their resistance rates did not differ between the two groups. In the first quarter of 2018, the incidence rate was 2.05 infections/1,000 device-days in university hospitals and 1.44 infections/1,000 device-days in small- and medium-sized hospitals. After implementing interventions, the rate gradually decreased in the first quarter of 2019, with 1.18 infections/1,000 device-days in university hospitals and 0.79 infections/1,000 device-days in small- and medium-sized hospitals. However, by the end of the study, the infection rate increased to 1.74 infections/1,000 device-days in university hospitals and 1.80 infections/1,000 device-days in small- and medium-sized hospitals. Conclusion We implemented interventions to prevent CAUTIs and evaluated their outcomes. The incidence of these infections decreased in the initial phases of the intervention when adequate support and personnel were present. The rate of these infections may be reduced by implementing active interventions such as consistent monitoring and adherence to guidelines for preventing infections.

Background: In the face of the unexpected coronavirus disease 2019 (COVID-19) pandemic, every country has struggled with insufficient human resources and medical supplies. This study aims to provide the statistical information necessary for discussing how to model stockpiles of medical resources. Methods: This study was conducted at the Hallym University Kangnam Sacred Heart Hospital, in South Korea. The study duration was 2 weeks, centered on March 16, 2022, when the number of daily confirmed patients with COVID-19 in Korea peaked. The number of human resources was obtained by counting the number of healthcare workers using CCTV. Drug prescriptions and medical device usage were obtained from electronic medical records. Results: In total, 117 inpatients and 26,485 outpatients were managed at this hospital during the 2-week study period. Daily visits were highest among nurses in all units, followed by doctors and radiology technicians. The mean daily consumption of personal protective equipment (PPE) per bed was 4.3 sets in the intensive care unit (ICU), 1.8 in the semi-ICU, and 1.4 in the ward. Despite the four-fold difference in the number of patients, there was no statistically significant difference between the two wards in the number of daily visits. Drug prescription rates were higher among inpatients than at-home patients. Conclusions The higher the COVID-19 severity, the higher the consumption of PPE per patient. Among healthcare workers, nurses had the highest number of inpatient treatment visits for COVID-19. To efficiently utilize, PPE, structures containing more isolation beds in a single negative pressure isolation system would be preferred.

Background: As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results: In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

Background: Nirmatrelvir/ritonavir was Korea's first oral antiviral agent to treat coronavirus disease 2019 (COVID-19). We analyzed the nirmatrelvir/ritonavir prescription rate and treatment outcomes in treatment-eligible patients with COVID-19 receiving home-based care. Materials and Methods: We retrospectively collected data of patients with COVID-19-eligible for nirmatrelvir/ritonavir treatment from January 14, 2022, to February 15, 2022. We analyzed the prescription rate of nirmatrelvir/ritonavir, the reasons for non-prescription, and patient outcomes. Results: A total of 414 patients were included, of whom 44.2% were male, and the mean age was 64.6 (standard deviation [SD] = 8.5). Approximately 73.2% (n = 303) of patients were not prescribed nirmatrelvir/ritonavir. More than fourth-fifths of the patients refused nirmatrelvir/ ritonavir treatment (n = 262, 86.5%). The mean symptom duration was significantly shorter in the prescription group (5.2 days [SD = 2.3] vs. 4.4 days [SD = 1.9], P = 0.001). A total of 6 (1.4%) patients were hospitalized, and none of the patients who received nirmatrelvir/ ritonavir required admission. Among the patients prescribed nirmatrelvir/ritonavir (n = 111), 17 (15.3%) patients experienced side effects, and 5 (4.5%) patients discontinued nirmatrelvir/ ritonavir due to side effects. Conclusion The nirmatrelvir/ritonavir prescription rate was low, with more than fourth-fifths of non-prescriptions being due to patient refusal. Symptom resolution was faster, and no life-threatening side effects were reported. Accurate information about drug safety must be provided to patients to make informed decisions regarding nirmatrelvir/ritonavir treatment.

Purpose: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community-acquired pneumonia (CAP) in children and is associated with extrapulmonary manifestations (EPM). The incidence and risk factors for EPM in children are unknown. Methods: This was a retrospective study involving 65,243 pediatric patients with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Medical records were reviewed to collect information regarding the clinical characteristics, radiological results, and laboratory findings. Logistic regression with multivariate analysis was performed to evaluate the risk factors associated with EPM in MP. Results: The incidence of EPM was 23.9%, including elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurological manifestations (0.4%), hematologic manifestations (0.2%), and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR], 3.623; 95% confidence interval [CI], 1.933-6.790) and atopic sensitization (aOR, 2.973; 95% CI, 1.615–5.475) and decreased with respiratory virus coinfection (aOR, 0.273; 95% CI, 0.084–0.887). Elevated liver enzymes were significantly associated with elevated lactate dehydrogenase (aOR, 3.055; 95% CI, 2.257–4.137), presence of pleural effusion (aOR, 2.635; 95% CI, 1.767–3.930), and proteinuria with respiratory virus coinfection (aOR, 2.245; 95% CI, 1.113–4.527). Conclusion Approximately 24% of pediatric patients with MP had various EPM. As the risk factors associated with each EPM were different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.