1.Group B Streptococcus Detection Rate and Clindamycin Resistance Among Reproductive-Age Women in Korea During 2003–2022
Areum SHIN ; Doo Ri KIM ; Ji-Hee SUNG ; Jinyoung YANG ; Suk-Joo CHOI ; Cheong-Rae ROH ; Tae Yeul KIM ; Hee Jae HUH ; Nam Yong LEE ; Soo-young OH ; Yae-Jean KIM
Journal of Korean Medical Science 2025;40(15):e29-
Background:
Group B Streptococcus (GBS) is one of the leading causes of neonatal earlyonset sepsis, resulting in high mortality and significant comorbidity. Intrapartum penicillin prophylaxis is recommended for pregnant women with GBS colonization to prevent vertical transmission. For pregnant women at high risk of anaphylaxis to penicillin, clindamycin is recommended only if the susceptibility of GBS isolates has been identified. We retrospectively examined the GBS detection rate and clindamycin resistance among Korean women of reproductive age over the last 20 years.
Methods:
Microbiologic studies using vaginal, vaginal–rectal or vaginal–perianal swabs from female patients 15–49 years of age during 2003–2022 were reviewed. Annual GBS detection rates and clindamycin resistance rates were calculated. The study period was divided into two periods (period 1, 2003–2015; period 2, 2016–2022) based on the introduction of universal culture-based GBS screening in our center in 2016. GBS detection rates and clindamycin resistance rates were compared between the periods using χ2 tests.
Results:
A total of 14,571 women were tested 16,879 times and GBS was isolated in 1,054 tests (6.2%), with 423 clindamycin-resistant isolates (40.1%). The GBS detection rate increased from 3.4% (301/8,869) in period 1 to 9.4% (2,753/8,010) in period 2 (P < 0.001). Even during period 1, the GBS detection rate was higher in 2009–2015 compared to 2003–2008 (P < 0.001). Clindamycin resistance rates have remained at similar levels since 2009, which were 39.5% (199/301) in period 1 and 40.2% (303/753) in period 2 (P = 0.833).
Conclusion
This study demonstrated that GBS detection rates in Korean women of reproductive age significantly increased almost three times during the twenty years of the study period, with a persistently high clindamycin resistance rate of up to 40%.
2.Real-World Utilization Patterns of Oral Corticosteroids During Pregnancy:A Nationwide Population-Based Study in Korea
Jeongin OH ; Yongtai CHO ; Jung Yeol HAN ; Ahhyung CHOI ; Ju-Young SHIN
Journal of Korean Medical Science 2025;40(2):e80-
Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.
3.Risk of Kawasaki Disease/Multisystem Inflammatory Syndrome Following COVID-19 Vaccination in Korean Children: A Self-Controlled Case Series Study
Suyeon KIM ; Hwa Yeon KO ; Jeongin OH ; Dongwon YOON ; Ju Hwan KIM ; Young June CHOE ; Ju-Young SHIN ; On behalf of the CoVaSC Investigators
Journal of Korean Medical Science 2025;40(3):e10-
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.
4.Rapid Recovery From SARS-CoV-2Infection Among Immunocompromised Children Despite Limited Neutralizing Antibody Response: A Virologic and Sero-Immunologic Analysis of a Single-Center Cohort
Doo Ri KIM ; Byoung Kwon PARK ; Jin Yang BAEK ; Areum SHIN ; Ji Won LEE ; Hee Young JU ; Hee Won CHO ; Keon Hee YOO ; Ki Woong SUNG ; Chae-Hong JEONG ; Tae Yeul KIM ; June-Young KOH ; Jae-Hoon KO ; Yae-Jean KIM
Journal of Korean Medical Science 2025;40(12):e52-
Background:
Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood.
Methods:
From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays.
Results:
Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed.
Conclusion
IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.
5.Maternal Exposures to COVID-19 Vaccine and Adverse Birth Outcomes:National Population Study in Korea
Kyuwon KIM ; Erdenetuya BOLORMAA ; Eunseon GWAK ; Ju-Young SHIN ; Nam-Kyong CHOI ; Young June CHOE ; Seung-Ah CHOE
Journal of Korean Medical Science 2025;40(17):e63-
Background:
This study aimed to estimate the association between mRNA coronavirus disease 2019 (COVID-19) vaccine exposure during pregnancy and the risks of preterm birth and congenital malformations leveraging a national population data.
Methods:
This retrospective cohort study utilized national data from the National Health Insurance System, linking maternal and infant records with COVID-19 vaccination registries.Newborns with congenital malformations were identified using diagnosis codes. The analysis included women aged 20–49 who gave live births between February 2022 and December 2022. Odds ratios (ORs) for preterm birth and any congenital malformation per COVID-19 vaccination during pregnancy compared to 1:4 matched unvaccinated controls, adjusted for maternal age, residential area, employment, income, disability, month of conception, prepregnancy obesity, smoking, and severe acute respiratory syndrome coronavirus 2 infection prior to pregnancy, were calculated. We compared the risk of two outcomes between BNT162b2 and mRNA-1273.
Results:
Among 106,692 women who gave birth during the study period, 8,966 (8.4%) received a COVID-19 vaccination during pregnancy. Of the newborns, 7,039 (6.6%) were preterm births and 7,658 (7.2%) had congenital malformations. COVID-19 vaccination during pregnancy was associated with a comparable risk of preterm birth (OR, 1.03; 95% confidence interval [CI], 0.77–1.36) and a similar risk of congenital malformations (0.90; 95% CI, 0.72–1.12) compared to non-vaccinees. The ORs of preterm birth (1.02; 95% CI, 0.77–1.36) and congenital malformation (0.91; 95% CI, 0.73–1.14) for mRNA-1273 were comparable to those for BNT162b2.
Conclusion
COVID-19 vaccines during pregnancy poses no increased risk of preterm birth and congenital malformations compared to those not exposed to the vaccine, with similar risk levels observed between the two mRNA vaccines. This finding provides additional evidence supporting the safety of COVID-19 vaccines.
6.Association Between Childhood Trauma and Anhedonia-Related Symptoms: The Mediation Role of Trait Anhedonia and Circulating Proteins
Sang Jin RHEE ; Dongyoon SHIN ; Daun SHIN ; Yoojin SONG ; Eun-Jeong JOO ; Hee Yeon JUNG ; Sungwon ROH ; Sang-Hyuk LEE ; Hyeyoung KIM ; Minji BANG ; Kyu Young LEE ; Jihyeon LEE ; Yeongshin KIM ; Youngsoo KIM ; Yong Min AHN
Journal of Korean Medical Science 2025;40(18):e66-
Background:
Though accumulating evidence suggests an association between childhood trauma and anhedonia, further analysis is needed to consider specific traumatic dimensions, both traits and state anhedonia, and the role of circulating proteins. Therefore, this study investigated the association between different types of childhood traumas and their influence on anhedonia-related symptoms, and to evaluate the influence of anhedonia traits and plasma proteins as mediators.
Methods:
This study included 170 patients with schizophrenia, bipolar disorder, major depressive disorder, and healthy controls aged 19–65 years. Multiple reaction monitoring was performed to quantify plasma proteins, and 464 proteins were analyzed. The association between childhood trauma dimensions, anhedonic traits, and related symptoms was analyzed with linear regression. A series of mediation analyses was performed to determine whether anhedonic traits and plasma proteins mediated the association between childhood trauma and anhedonia-related symptoms.
Results:
Childhood emotional neglect was significantly associated with anhedonic traits and anhedonia-related symptoms. Mediation analysis revealed that the indirect effect of anhedonic traits for childhood emotional neglect on anhedonia-related symptoms (effect = 0.037; bias-corrected CI, 0.009 to 0.070) was statistically significant. The indirect effect of plasma TNR5 for anhedonic traits on anhedonia-related symptoms was statistically significant (effect = −0.011; bias-corrected CI, −0.026 to −0.002). Serial mediation analysis revealed that the indirect effect of childhood emotional neglect on anhedonia-related symptoms via anhedonic traits and TNR5 was statistically significant (effect = 0.007; biascorrected CI, 0.001 to 0.017).
Conclusion
Anhedonic traits and plasma TNR5 protein levels serially mediated the association between childhood emotional neglect and anhedonia-related symptoms.The study highlights the importance of considering both psychopathological traits and biological correlates when investigating the association between childhood trauma and psychopathological symptoms.
7.Estimating the Prevalence of Autosomal Recessive Neuromuscular Diseases in the Korean Population
Soo-Hyun KIM ; Yunjung CHOI ; Young-Chul CHOI ; Seung Woo KIM ; Ha Young SHIN ; Hyung Jun PARK
Journal of Korean Medical Science 2025;40(19):e68-
Background:
Genetic neuromuscular diseases (NMDs) are a heterogeneous group of conditions that primarily affect the peripheral nerves, muscles, and neuromuscular junctions. This study was performed to identify pathogenic or likely pathogenic variants (PLPVs), calculate carrier frequencies, and predict the genetic prevalence of autosomal recessive-NMDs (AR-NMDs) in a Korean population.
Methods:
In total, 267 genes were associated with AR-NMDs. We analyzed genetic variants from 984 Korean whole genomes and identified PLPVs to assess the carrier frequency and genetic prevalence of the variants.
Results:
We identified 165 PLPVs, including 75 literature verified and 90 manually verified variants. Most PLPVs in AR-NMD genes were frameshifts (61, 37.0%), followed by nonsense (36, 21.8%), missense (35, 21.2%), and splice variants (28, 17.0%). The carrier frequency of the AR-NMDs was 27.1%. DYSF exhibited the highest carrier frequency (1.63%), followed by GAA (1.55%), HEXB (1.53%), PREPL (0.76%), NEB (0.66%), ADSS1 (0.65%), ALPK3 (0.65%), and CHRNG (0.65%). The predicted genetic prevalence of AR-NMDs in the Korean population was 38.0 cases per 100,000 individuals. DYSF (6.7 cases per 100,000 individuals) showed the highest genetic prevalence. The variant with the highest allele frequency was c.1250C>T in HEXB at 0.00764, followed by c.[752T>C; c.761C>T] in GAA at 0.00505, and c.2055+2T>G in DYSF at 0.00437.
Conclusion
Our study suggests that 27.1% of the Korean population are healthy carriers of at least one AR-NMD causing PLPV, revealing the genetic prevalence of NMDs in the Korean population.
8.Assessing and Charting the Future Path : Addressing the Decline of Brain Tumor Specialists in Korea - Insights from the Korean Brain Tumor Society (KBTS) Future Strategy Committee of 2023
Joonho BYUN ; Kyeong-O GO ; Kyung-Min KIM ; Dong-Won SHIN ; Jihwan YOO ; Yeo Song KIM ; Sae Min KWON ; Young Zoon KIM ; Seon-Hwan KIM
Journal of Korean Neurosurgical Society 2025;68(1):97-104
Objective:
: Although Republic of Korea is an advanced country in medical technology with a successful treatment rate for serious diseases, such as cancer, and has improved technology for highly difficult surgery, many excellent medical doctors and physicians are struggling due to the recent unreasonable medical environment. Specialization in brain tumor surgery also faces challenges in Republic of Korea, including low financial incentives, legal threats, and limited career prospects. In response, the Korean Brain Tumor Society (KBTS) formed the Future Strategy Committee to assess these obstacles and propose solutions.
Methods:
: A survey was conducted among the KBTS members to understand their perceptions and concerns across different career stages.
Results:
: The findings revealed a decline in interest among chief residents in brain tumor surgery, owing to limited job opportunities and income prospects. Neurosurgical fellows expressed neutral satisfaction but highlighted challenges, such as low patient numbers and income. Faculty members with varying levels of experience echoed similar concerns, emphasizing the need for improved financial incentives and job stability. Despite these challenges, the respondents expressed dedication to the field and suggested strategies for improvement.
Conclusion
: The KBTS outlines a vision that focuses on practical excellence, comprehensive research, professional education, responsibilities, and member satisfaction. Addressing these challenges requires collaborative efforts among healthcare institutions, professional societies, and policymakers to support brain tumor specialists and enhance patient care.
9.Epidemiology and Functional Outcome of Acute Stroke Patients in Korea Using Nationwide data
Seungmin SHIN ; Young Woo KIM ; Seung Hun SHEEN ; Sukh Que PARK ; Sung-Chul JIN ; Jin Pyeong JEON ; Ji Young LEE ; Boung Chul LEE ; Young Wha LIM ; Gui Ok KIM ; Youg Uk KWON ; Yu Ra LEE ; So Young HAN ; Jae Sang OH
Journal of Korean Neurosurgical Society 2025;68(2):159-176
Objective:
: Korea’s healthcare system and policy promotes early, actively stroke treatment to improve prognosis. This study represents stroke epidemiology and outcomes in Korea.
Methods:
: This study investigated data from the Acute Stroke Assessment Registry. The registry collects data from over 220 hospitals nationwide, focusing on quality stroke service management. Data analysis included patient demographics, stroke severity assessment, and discharge prognosis measurement using standardized scales.
Results:
: Eighty-six thousand five hundred sixty-eight acute stroke patients were collected with demographic and clinical characteristics during 18 months from 2016, 2018, and between 2020 to 2021, focusing on acute subarachnoid hemorrhage (SAH), acute intracerebral hemorrhage (ICH), and acute ischemic stroke. Of these 86568 patients, 8.3% was SAH, 16.3% ICH, and 74.9% ischemic stroke. Trends showed decreasing SAH and increasing ICH cases over the years. 68.3% stroke patients had the clear onset time. 49.6% stroke patients arrived within 4.5 hours of symptom onset, with more patients treated at general hospitals. Good functional outcomes at discharge was obtained with 58.3% of acute stroke patients, 55.9% of SAH patients, 34.6% of ICH patients, and 63.8% of ischemic stroke patients.
Conclusion
: The results showed that ischemic stroke was the most common subtype, followed by ICH and SAH. Prognosis differed among subtypes, with favorable outcomes more common in ischemic stroke and SAH compared to ICH.
10.Hepatocellular carcinoma in Korea: an analysis of the 2016-2018 Korean Nationwide Cancer Registry
Jihyun AN ; Young CHANG ; Gwang Hyeon CHOI ; Won SOHN ; Jeong Eun SONG ; Hyunjae SHIN ; Jae Hyun YOON ; Jun Sik YOON ; Hye Young JANG ; Eun Ju CHO ; Ji Won HAN ; Suk Kyun HONG ; Ju-Yeon CHO ; Kyu-Won JUNG ; Eun Hye PARK ; Eunyang KIM ; Bo Hyun KIM
Journal of Liver Cancer 2025;25(1):109-122
Background:
s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018.
Methods:
Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018.
Results:
The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%).
Conclusions
Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.

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