Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Clostridioides difficile infection (CDI) is one of the most common hospitalacquired infections, with its incidence and disease burden increasing markedly worldwide over the past decade. Methods: To assess the attributable costs of CDI in Korea, the expenses related to hospital management of CDI cases were computed. This analysis used data from the National Health Insurance Service–National Sample Cohort spanning a decade (2010–2019). The annual national burden of CDI was determined by combining the attributable cost per CDI case with the number of patients with CDI obtained from the Health Insurance Review and Assessment Service data. Results: The attributable costs of CDI were determined based on variations in the length of hospital stay and medical costs between patients with CDI and control patients. The mean length of hospital stay was significantly longer for patients with CDI than that for control patients: 43.06 vs. 14.76 days (a difference of 28.30 days, P < 0.001). The adjusted medical costs (2019 = 100) for cases of CDI and controls were 11,162 USD and 3,318 USD, respectively, with a significant difference of 7,843 USD (P < 0.001). The cost of CDI per case exhibited a noticeable annual increase from 2010 to 2019, despite an annual decreasing trend in length of hospital stay. The estimated national cost attributed to CDI was $28.9 million in 2010; however, it increased gradually each year, reaching $205.6 million in 2019 (a 600% increase over 10 years). Conclusion CDI is associated with substantial healthcare costs in Korea. The economic burden of CDI has gradually increased in South Korea.

Background: Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly. Methods: To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020. Results: In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patientdays was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25–12.05) and 4.18 per 1,000 admissions (range: 1.92–8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68–13.90) and 6.73 per 1,000 admissions (range: 3.18–15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively. Conclusion The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

Prevention and diagnosis of postcontrast acute kidney injury (AKI) after contrast-enhanced computed tomography is burdensome in outpatient department. We investigated whether an electronic alert system could improve prevention and diagnosis of postcontrast AKI. Methods: In March 2018, we launched an electronic alert system that automatically identifies patients with a baseline estimated glomerular filtration rate of <45 mL/min/1.73 m2, provides a prescription of fluid regimen, and recommends a follow-up for serum creatinine measurement. Participants prescribed contrast-enhanced computed tomography at outpatient department before and after the launch of the system were categorized as historical and alert group, respectively. Propensity for the surveillance of postcontrast AKI was compared using logistic regression. Risks of AKI, admission, mortality, and renal replacement therapy were analyzed. Results: The historical and alert groups included 289 and 309 participants, respectively. The alert group was more likely to be men and take diuretics. The most frequent volume of prophylactic fluid in historical and alert group was 1,000 and 750 mL, respectively. Follow-up for AKI was more common in the alert group (adjusted odds ratio, 6.00; p < 0.001). Among them, incidence of postcontrast AKI was not statistically different. The two groups did not differ in risks of admission, mortality, or renal replacement therapy. Conclusion: The electronic alert system could assist in the detection of high-risk patients, prevention with reduced fluid volume, and proper diagnosis of postcontrast AKI, while limiting the prescribing clinicians’ burden. Whether the system can improve long-term outcomes remains unclear.

Purpose: Biliary tract cancers (BTCs) are rare and show a dismal prognosis with limited treatment options. To improve our understanding of these heterogeneous tumors and develop effective therapeutic agents, suitable preclinical models reflecting diverse tumor characteristics are needed. We established and characterized new patient-derived cancer cell cultures and patient-derived xenograft (PDX) models using malignant ascites from five patients with BTC. Materials and Methods: Five patient-derived cancer cell cultures and three PDX models derived from malignant ascites of five patients with BTC, AMCBTC-01, -02, -03, -04, and -05, were established. To characterize the models histogenetically and confirm whether characteristics of the primary tumor were maintained, targeted sequencing and histopathological comparison between primary tissue and xenograft tumors were performed. Results: From malignant ascites of five BTC patients, five patient-derived cancer cell cultures (100% success rate), and three PDXs (60% success rate) were established. The morphological characteristics of three primary xenograft tumors were compared with those of matched primary tumors, and they displayed a similar morphology. The mutated genes in samples (models, primary tumor tissue, or both) from more than one patient were TP53 (n=2), KRAS (n=2), and STK11 (n=2). Overall, the pattern of commonly mutated genes in BTC cell cultures was different from that in commercially available BTC cell lines. Conclusion We successfully established the patient-derived cancer cell cultures and xenograft models derived from malignant ascites in BTC patients. These models accompanied by different genetic characteristics from commercially available models will help better understand BTC biology.

The emergence of hypervirulent Clostridioides difficile strains has decreased the efficacy of metronidazole in the treatment of C. difficile infection (CDI). Therefore, revised guidelines no longer recommend the use of metronidazole as a first-line regimen for CDI and restrict its use for non-severe CDI, only when vancomycin and fidaxomicin are unavailable. In Korea, an epidemic caused by a hypervirulent C. difficile strain or the emergence of metronidazole resistant C. difficile strains have not been reported. This review article aims to compare the treatment outcomes and adverse effects of vancomycin and metronidazole and discuss the validity of the guidelines of various agencies, which restrict the use of metronidazole, for Korean patients. There are no substantial adverse effects of metronidazole, and its clinical outcomes against non-severe CDI are similar to those of vancomycin. Based on these findings, we recommend that the use of metronidazole for the treatment of non-severe CDI is still an appropriate option in Korea.

Background: This study aimed to describe the maternal, obstetrical, and neonatal outcomes in pregnant women with coronavirus disease 2019 (COVID-19) and identify the predictors associated with the severity of COVID-19. Methods: This multicenter observational study included consecutive pregnant women admitted because of COVID-19 confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR) test at 15 hospitals in the Republic of Korea between January 2020 and December 2021. Results: A total of 257 women with COVID-19 and 62 newborns were included in this study. Most of the patients developed this disease during the third trimester. Nine patients (7.4%) developed pregnancy-related complications. All pregnant women received inpatient treatment, of whom 9 (3.5%) required intensive care, but none of them died. The gestational age at COVID-19 diagnosis (odds ratio [OR], 1.096, 95% confidence interval [CI], 1.04–1.15) and parity (OR, 1.703, 95% CI, 1.13–2.57) were identified as significant risk factors of severe diseases. Among women who delivered, 78.5% underwent cesarean section. Preterm birth (38.5%), premature rupture of membranes (7.7%), and miscarriage (4.6%) occurred, but there was no stillbirth or neonatal death. The RT-PCR test of newborns’ amniotic fluid and umbilical cord blood samples was negative for severe acute respiratory syndrome coronavirus 2. Conclusion At the time of COVID-19 diagnosis, gestational age and parity of pregnant women were the risk factors of disease severity. Vertical transmission of COVID-19 was not observed, and maternal severity did not significantly affect the neonatal prognosis.