Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

OBJECTIVES: This study investigated the reporting rates of adverse events following immunization (AEFIs) to the spontaneous reporting system (SRS) and its predictors among individuals with AEFIs after coronavirus disease 2019 (COVID-19) vaccination. METHODS: A cross-sectional, web-based survey was conducted from December 2, 2021 to December 20, 2021, recruiting participants >14 days after completion of a primary COVID-19 vaccination series. Reporting rates were calculated by dividing the number of participants who reported AEFIs to the SRS by the total number of participants who experienced AEFIs. We estimated adjusted odds ratios (aORs) using multivariate logistic regression to determine factors associated with spontaneous AEFIs reporting. RESULTS: Among 2,993 participants, 90.9% and 88.7% experienced AEFIs after the first and second vaccine doses, respectively (reporting rates, 11.6 and 12.7%). Furthermore, 3.3% and 4.2% suffered moderate to severe AEFIs, respectively (reporting rates, 50.5 and 50.0%). Spontaneous reporting was more prevalent in female (aOR, 1.54; 95% confidence interval [CI], 1.31 to 1.81); those with moderate to severe AEFIs (aOR, 5.47; 95% CI, 4.45 to 6.73), comorbidities (aOR, 1.31; 95% CI, 1.09 to 1.57), a history of severe allergic reactions (aOR, 2.02; 95% CI, 1.47 to 2.77); and those who had received mRNA-1273 (aOR, 1.25; 95% CI, 1.05 to 1.49) or ChAdOx1 (aOR, 1.62; 95% CI, 1.15 to 2.30) vaccines versus BNT162b2. Reporting was less likely in older individuals (aOR, 0.98; 95% CI, 0.98 to 0.99 per 1-year age increment). CONCLUSIONS Spontaneous reporting of AEFIs after COVID-19 vaccination was associated with younger age, female sex, moderate to severe AEFIs, comorbidities, history of allergic reactions, and vaccine type. AEFIs under-reporting should be considered when delivering information to the community and in public health decision-making.

OBJECTIVES: Vaccination is one of the most important strategies to contain the spread of coronavirus disease 2019 (COVID-19). Vaccination in children is dependent on their parents, making it important to understand parents’ awareness and attitudes toward vaccines in order to devise strategies to raise vaccination rates in children. METHODS: A web-based nationwide survey was conducted among Korean parents of 7-year-old to 18-year-old children in August 2021 to estimate parents’ intention to vaccinate their children against COVID-19 and identify key factors affecting parental acceptance and hesitancy through regression analysis. RESULTS: Approximately 56.4% (575/1,019) were willing to vaccinate their children against COVID-19. Contributing factors to COVID-19 vaccine hesitancy were being a mother (adjusted odds ratio [aOR], 0.36; 95% confidence interval [CI], 0.25 to 0.52), a lower education level (aOR, 0.83; 95% CI, 0.70 to 0.97), hesitancy to other childhood vaccines (aOR, 0.78; 95% CI, 0.64 to 0.96), and refusal to vaccinate themselves (aOR, 0.08; 95% CI, 0.02 to 0.20). Having older children (aOR, 1.20; 95% CI, 1.13 to 1.28), trusting the child’s doctor (aOR, 1.19; 95% CI, 1.07 to 1.32), positive perceptions of the COVID-19 vaccine’s effectiveness (aOR, 2.60; 95% CI, 1.90 to 3.57) and perceiving the COVID-19 vaccine as low-risk (aOR, 1.68; 95% CI, 1.27 to 2.24) were associated with COVID-19 vaccine acceptance. Concerns about adverse reactions were the most common cause of hesitancy. CONCLUSIONS Providing parents with accurate and reliable information on vaccine effectiveness and safety is important to increase COVID-19 vaccine uptake in children. Differential or targeted approaches to parents according to gender, age, and their children’s age are necessary for effective communication about vaccination in children.

Background: There is difference in the incidence of multi-system inflammatory syndrome in children (MIS-C) in patients with different variants of severe acute respiratory syndrome coronavirus 2, however, little is known about the epidemiology in Asian countries. We investigated and compared the epidemiology of the MIS-C during omicron-dominant period with that of previous periods in South Korea. Methods: We obtained clinical, epidemiological and laboratory data on MIS-C cases from national MIS-C surveillance in South Korea. We defined pre-delta period as January 2020–May 2021; delta period as June 2021–December 2021; and omicron period as January 2022–April 2022. We describe the clinical characteristics and outcomes of MIS-C patients by period. Results: A total of 91 cases were assessed to be MIS-C cases. Number of MIS-C cases have increased from six cases during pre-delta period to 66 cases during omicron period, while the incidence rate (the number of MIS-C cases per 100,000 cases of reported coronavirus disease 2019) has decreased from 38.5 cases per 100,000 (95% confidence interval [CI], 14.1–83.9) during pre-delta period to 1.6 cases per 100,000 (95% CI, 1.2–2.0) during omicron periods. During pre-delta period, 66.7% and 100% had hypotension and gastrointestinal involvement, respectively; while during omicron period, 12.1% and 6.1% had such clinical manifestations. Fifty percent of pre-delta MIS-C patients were taken intensive care unit (ICU) cares, while 10.6% of patients during omicron periods were in ICUs. Conclusion Omicron period were associated with less severe clinical manifestation compared to pre-delta and delta periods. Although incidence rate of MIS-C was lower for the omicron period than pre-delta and delta periods, number of patients reported with MIS-C may pose a substantial clinical burden.

Background/Aims: As the novel coronavirus (coronavirus disease 2019 [COVID-19]) outbreak progresses rapidly, staying home is recommended for suspected patients; however, the safety of this recommendation is uncertain. In Korea, non-hospital facilities called “living and treatment centers (LTCs)” have been established since 5 March 2020. The LTCs provided a unique opportunity to evaluate the safety of selection criteria for low-risk groups. Methods: Between 5 March and 9 April 2020, patients with COVID-19 who met the following criteria were admitted to the LTC; alert, age below 65 years old, no underlying disease or well-controlled underlying disease, body temperature below 38.0°C, whether taking antipyretics or not, and no dyspnea. Patients were closely observed by doctors or nurses’ interviews twice a day and transferred to hospitals when symptoms worsened. Results: A total of 113 patients were admitted to the LTC; 52.2% were female, with a median age of 25 years (interquartile range, 21.5 to 39.5). Of 113 patients, 54 (47.8%) were asymptomatic at diagnosis, and 15 (13.3%) had no symptoms until they were released from isolation. During the follow-up period, two (1.8%) patients were transferred to a hospital but did not progress to severe status during hospitalization. Conclusions The risk of progression was negligible in COVID-19 patients who met the admission criteria for LTC at the time of diagnosis. LTCs could be a safe alternative considering shortage of hospital beds.

Peptic ulcer bleeding is a common complication of peptic ulcer disease and the most common cause of upper gastrointestinal bleeding. Despite advances in drug usage and endoscopic modalities, no significant improvement is observed in the mortality rate of bleeding ulcers. The purpose of this review is to discuss various endoscopic hemostatic methods to treat peptic ulcer bleeding. Endoscopic hemostatic techniques can be classified into injection, mechanical, electrocoagulation, hemostatic powder, and endoscopic Doppler-guided hemostatic therapies (the last mentioned being a newly developed technique). Endoscopic hemostasis can be performed as mono or combination therapy using the aforementioned methods. Endoscopic hemostasis is the most important treatment for patients with peptic ulcer bleeding. Endoscopists should consider the treatment approach for peptic ulcer bleeding based on patient characteristics, the size and shape of the lesion, the endoscopist's expertise, and the resources and circumstances at each hospital. Follow-up studies are needed to evaluate the efficacy of newly developed hemostatic powder therapy and endoscopic Doppler-guided hemostasis.
Duodenum ; Electrocoagulation ; Follow-Up Studies ; Hemorrhage ; Hemostasis ; Hemostasis, Endoscopic ; Hemostatic Techniques ; Humans ; Mortality ; Peptic Ulcer Hemorrhage ; Peptic Ulcer ; Stomach ; Ulcer

A new CT-based diagnostic method of protrusio acetabuli (PA) was introduced. However, prevalence of PA by this method and correlation between PA and other manifestations of Marfan syndrome (MFS) is unknown in Korean MFS patients. This study aimed to investigate the prevalence of PA diagnosed by a CT-based method in Korean patients with MFS, the association of PA with other manifestations of MFS, and the contribution of PA to MFS diagnosis. We retrospectively reviewed the records of 146 MFS patients with the presence of a causative FBN1 mutation and 146 age- and sex-matched controls from a single tertiary care center. All MFS patients underwent a complete assessment of criteria based on the revised Ghent nosology. PA was assessed quantitatively using a CT-based circle-wall distance (CWD) method. PA was diagnosed in 77.4% of patients in the MFS group and in 11.0% of the control group. CWD was significantly different between the two groups (1.50 mm vs. -0.64 mm, P<0.001). The presence of PA did not correlate with the presence of ectopia lentis, aortic root diameter, or history of aortic dissection. The presence of PA did not have a significant impact on the final diagnosis of MFS. Even though the presence of PA does not related to the cardinal clinical features of MFS or influence MFS diagnosis, its presence may be helpful for the suspicion of MFS when aortic dissection or aneurysm is found on CT angiography of the aorta because of the high frequency of PA in MFS patients.
Acetabulum/*abnormalities/radiography ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Aortic Aneurysm/*epidemiology/radiography ; Comorbidity ; Female ; Humans ; Male ; Marfan Syndrome/*epidemiology/*radiography ; Middle Aged ; Prevalence ; Reproducibility of Results ; Republic of Korea/epidemiology ; Risk Factors ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods/*statistics & numerical data ; Young Adult