Background: Single room isolation with contact precautions is widely regarded as a fundamental strategy to prevent the transmission of multidrug-resistant organisms (MDROs). However, its implementation demands substantial resources, limiting its universal application to all MDROs. In this study, we assessed the effect of discontinuing single room isolation for vancomycin-resistant Enterococcus (VRE). Methods: This is a retrospective, observational study conducted at a single 750-bed tertiary center. We conducted an interrupted time series analysis to compare incidence rates and trends of new-onset VRE colonization and bacteremia during the one year before and after the strategy change on January 1, 2023. Results: Single-room occupancy decreased from 79.7% pre-intervention to 23.6% postintervention (P < 0.001). The incidence rate of new-onset VRE colonization was 0.452 and 0.535 per 1,000 patient-days in the pre- and post-intervention periods, respectively, with no statistically significant difference (P = 0.202). However, there was a slightly increasing trend (0.036 [95% confidence interval, −0.002, 0.074] increase per month, P = 0.066). The new-onset VRE bacteremia incidence rate was not differed in incidence (0.060 and 0.055, P= 0.571) or trend (P = 0.720). Conclusion Our study suggests that discontinuing single-room isolation for VRE patients may not affect the incidence of new-onset VRE bacteremia, but caution is needed due to the potential increase in colonization.

Background: Single room isolation with contact precautions is widely regarded as a fundamental strategy to prevent the transmission of multidrug-resistant organisms (MDROs). However, its implementation demands substantial resources, limiting its universal application to all MDROs. In this study, we assessed the effect of discontinuing single room isolation for vancomycin-resistant Enterococcus (VRE). Methods: This is a retrospective, observational study conducted at a single 750-bed tertiary center. We conducted an interrupted time series analysis to compare incidence rates and trends of new-onset VRE colonization and bacteremia during the one year before and after the strategy change on January 1, 2023. Results: Single-room occupancy decreased from 79.7% pre-intervention to 23.6% postintervention (P < 0.001). The incidence rate of new-onset VRE colonization was 0.452 and 0.535 per 1,000 patient-days in the pre- and post-intervention periods, respectively, with no statistically significant difference (P = 0.202). However, there was a slightly increasing trend (0.036 [95% confidence interval, −0.002, 0.074] increase per month, P = 0.066). The new-onset VRE bacteremia incidence rate was not differed in incidence (0.060 and 0.055, P= 0.571) or trend (P = 0.720). Conclusion Our study suggests that discontinuing single-room isolation for VRE patients may not affect the incidence of new-onset VRE bacteremia, but caution is needed due to the potential increase in colonization.

Background: Single room isolation with contact precautions is widely regarded as a fundamental strategy to prevent the transmission of multidrug-resistant organisms (MDROs). However, its implementation demands substantial resources, limiting its universal application to all MDROs. In this study, we assessed the effect of discontinuing single room isolation for vancomycin-resistant Enterococcus (VRE). Methods: This is a retrospective, observational study conducted at a single 750-bed tertiary center. We conducted an interrupted time series analysis to compare incidence rates and trends of new-onset VRE colonization and bacteremia during the one year before and after the strategy change on January 1, 2023. Results: Single-room occupancy decreased from 79.7% pre-intervention to 23.6% postintervention (P < 0.001). The incidence rate of new-onset VRE colonization was 0.452 and 0.535 per 1,000 patient-days in the pre- and post-intervention periods, respectively, with no statistically significant difference (P = 0.202). However, there was a slightly increasing trend (0.036 [95% confidence interval, −0.002, 0.074] increase per month, P = 0.066). The new-onset VRE bacteremia incidence rate was not differed in incidence (0.060 and 0.055, P= 0.571) or trend (P = 0.720). Conclusion Our study suggests that discontinuing single-room isolation for VRE patients may not affect the incidence of new-onset VRE bacteremia, but caution is needed due to the potential increase in colonization.

Background: Single room isolation with contact precautions is widely regarded as a fundamental strategy to prevent the transmission of multidrug-resistant organisms (MDROs). However, its implementation demands substantial resources, limiting its universal application to all MDROs. In this study, we assessed the effect of discontinuing single room isolation for vancomycin-resistant Enterococcus (VRE). Methods: This is a retrospective, observational study conducted at a single 750-bed tertiary center. We conducted an interrupted time series analysis to compare incidence rates and trends of new-onset VRE colonization and bacteremia during the one year before and after the strategy change on January 1, 2023. Results: Single-room occupancy decreased from 79.7% pre-intervention to 23.6% postintervention (P < 0.001). The incidence rate of new-onset VRE colonization was 0.452 and 0.535 per 1,000 patient-days in the pre- and post-intervention periods, respectively, with no statistically significant difference (P = 0.202). However, there was a slightly increasing trend (0.036 [95% confidence interval, −0.002, 0.074] increase per month, P = 0.066). The new-onset VRE bacteremia incidence rate was not differed in incidence (0.060 and 0.055, P= 0.571) or trend (P = 0.720). Conclusion Our study suggests that discontinuing single-room isolation for VRE patients may not affect the incidence of new-onset VRE bacteremia, but caution is needed due to the potential increase in colonization.

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients.The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold.Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cellmediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

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.

Objective: Adenomyosis impacts pregnancy outcomes, although there is a lack of consensus regarding the actual effects. It is likely, however, that the severity of adenomyosis or ultrasound findings or timing of diagnosis can have different effects on adverse pregnancy outcomes (APOs). Methods: In this study, we aimed to investigate the impact of the timing of adenomyosis diagnosis on pregnancy outcomes. Singleton pregnant women who delivered between 2017 and 2022 were analyzed based on the timing of adenomyosis diagnosis, using a national database. The final cohort was classified into three groups: 1) group 1, without adenomyosis; 2) group 2, those diagnosed with adenomyosis before pregnancy; and 3) group 3, those diagnosed with adenomyosis during pregnancy. Results: A total of 1,226,475 cases were ultimately included in this study. Women with a diagnosis of adenomyosis had a significantly higher risk of APOs including hypertensive disorder during pregnancy (HDP), gestational diabetes mellitus (GDM), postpartum hemorrhage, placental abruption, preterm birth, and delivery of a small-for-gestational-age infant even after adjusting for covariates. In particular, concerning HDP, the risk was highest in group 3 (group 2: adjusted odds ratio [aOR], 1.15 vs. group 3: aOR, 1.36). However, the highest GDM risk was in group 2 (GDM; group 2: aOR, 1.24 vs. group 3: aOR, 1.04). Conclusion The increased risk of APO differed depending on the timing of adenomyosis diagnosis. Therefore, efforts for more careful monitoring and prevention of APOs may be necessary when such women become pregnant.

Background: The coronavirus disease 2019 (COVID-19) pandemic has caused the death of thousands of patients worldwide. Although age is known to be a risk factor for morbidity and mortality in COVID-19 patients, critical illness or death is occurring even in the younger age group as the epidemic spreads. In early 2022, omicron became the dominant variant of the COVID-19 virus in South Korea, and the epidemic proceeded on a large scale. Accordingly, this study aimed to determine whether young adults (aged ≤ 50 years) with critical COVID-19 infection during the omicron period had different characteristics from older patients and to determine the risk factors for mortality in this specific age group. Methods: We evaluated 213 critical adult patients (high flow nasal cannula or higher respiratory support) hospitalized for polymerase chain reaction-confirmed COVID-19 in nine hospitals in South Korea between February 1, 2022 and April 30, 2022. Demographic characteristics, including body mass index (BMI) and vaccination status; underlying diseases; clinical features and laboratory findings; clinical course; treatment received; and outcomes were collected from electronic medical records (EMRs) and analyzed according to age and mortality. Results: Overall, 71 critically ill patients aged ≤ 50 years were enrolled, and 142 critically ill patients aged over 50 years were selected through 1:2 matching based on the date of diagnosis. The most frequent underlying diseases among those aged ≤ 50 years were diabetes and hypertension, and all 14 patients who died had either a BMI ≥ 25 kg/m 2 or an underlying disease. The total case fatality rate among severe patients (S-CFR) was 31.0%, and the S-CFR differed according to age and was higher than that during the delta period. The S-CFR was 19.7% for those aged ≤ 50 years, 36.6% for those aged > 50 years, and 38.1% for those aged ≥ 65 years. In multivariate analysis, age (odds ratio [OR], 1.084; 95% confidence interval [CI], 1.043–1.127), initial low-density lipoprotein > 600 IU/L (OR, 4.782; 95% CI, 1.584–14.434), initial C-reactive protein > 8 mg/dL (OR, 2.940; 95% CI, 1.042–8.293), highest aspartate aminotransferase > 200 IU/L (OR, 12.931; 95% CI, 1.691–98.908), and mechanical ventilation implementation (OR, 3.671; 95% CI, 1.294–10.420) were significant independent predictors of mortality in critical COVID-19 patients during the omicron wave. A similar pattern was shown when analyzing the data by age group, but most had no statistical significance owing to the small number of deaths in the young critical group. Although the vaccination completion rate of all the patients (31.0%) was higher than that in the delta wave period (13.6%), it was still lower than that of the general population. Further, only 15 (21.1%) critically ill patients aged ≤ 50 years were fully vaccinated. Overall, the severity of hospitalized critical patients was significantly higher than that in the delta period, indicating that it was difficult to find common risk factors in the two periods only with a simple comparison. Conclusion Overall, the S-CFR of critically ill COVID-19 patients in the omicron period was higher than that in the delta period, especially in those aged ≤ 50 years. All of the patients who died had an underlying disease or obesity. In the same population, the vaccination rate was very low compared to that in the delta wave, indicating that non-vaccination significantly affected the progression to critical illness. Notably, there was a lack of prescription for Paxlovid for these patients although they satisfied the prescription criteria. Early diagnosis and active initial treatment was necessary, along with the proven methods of vaccination and personal hygiene. Further studies are needed to determine how each variant affects critically ill patients.

Background: To investigate the relationship between polycystic ovary syndrome (PCOS) in Korean women and childhood growth and obesity of their offspring. Methods: This longitudinal case-control study using the Korean National Health Insurance claims database and the National Health Screening Program for Infants and Children database included women who delivered singletons between January 2007 and December 2008. Offspring’s body mass index (BMI) measurements taken between 42 and 80 months of age were compared according to a maternal history of PCOS. Results: Among a total of 131,805 participants, 1,213 women had a history of PCOS and 130,592 women did not. Female offspring aged 66–80 months born to women with PCOS had significantly higher BMI than those born to women without PCOS; there was no significant difference in that of male offspring regardless of maternal PCOS. In the generalized estimating equation and multivariable logistic regression analyses, the female offspring born to women with PCOS had a significantly higher risk of obesity during the age of 42–54 and 66–80 months (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.09–2.21 and OR, 1.5; 95% CI, 1.05–2.15, respectively), than those born to women without PCOS, after adjusting for several confounding factors. Conclusion Maternal PCOS is independently associated with an increased incidence of childhood obesity in female offspring among Korean women. Women with PCOS should consider the risk of early childhood obesity in their daughters, even if they maintain a healthy weight themselves.