The prevention and response to infectious diseases in long-term care facilities in Korea: a nationwide survey.

Objectives: Long-term care facilities (LTCFs) are communal environments for patients with chronic diseases or older adults, making them particularly susceptible to significant harm during infectious disease outbreaks. Nonetheless, LTCFs have historically been subject to less stringent infection prevention and control (IPC) mandates. This study aimed to assess the current state of LTCFs and to develop an IPC system tailored for these facilities following the coronavirus disease 2019 (COVID-19) pandemic. Methods: We conducted an online survey of 11,366 LTCFs in Korea from December 30, 2022 to January 20, 2023, to evaluate the components of IPC in LTCFs. The infectious diseases targeted for IPC included COVID-19, influenza, and scabies. Additionally, we compared institution-based and home-based long-term care insurance facilities. Results: Overall, 3,537 (31.1%) LTCFs responded to the survey, comprising 1,819 (51.4%) institution-based and 1,718 (48.6%) home-based facilities. A majority (87.4%, 2,376/2,720) of these facilities experienced COVID-19 outbreaks. However, only 42% of home-based facilities, in contrast to 90.6% of institution-based facilities, were equipped to manage concurrent COVID-19 cases. Similarly, while 92.1% of institution-based facilities were capable of managing influenza, only 50.5% of home-based facilities could do the same. The incidence of scabies was significantly higher in institution-based facilities than in home-based ones (26.1% vs. 4.3%). Additionally, 88.7% of institution-based facilities managed scabies cases effectively, compared to only 42.1% of home-based facilities. Conclusion: Approximately half of the LTCFs had a basic capacity to respond to infectious diseases. However, there were differences in response capabilities between institution-based facilities and home-based facilities.

Impact of Infection Prevention Programs on Catheter-Associated Urinary Tract Infections Analyzed in Multicenter Study.

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.

Effectiveness of COVID-19 XBB.1.5 monovalent mRNA vaccine in Korea: interim analysis.

As coronavirus disease-2019 (COVID-19) becomes an endemic disease, the virus continues to evolve and become immunologically distinct from previous strains. Immune imprinting has raised concerns about bivalent mRNA vaccines containing both ancestral virus and Omicron variant. To increase efficacy against the predominant strains as of the second half of 2023, the updated vaccine formulation contained only the mRNA of XBB.1.5 sublineage. We conducted a multicenter, test-negative, case-control study to estimate XBB.1.5 monovalent vaccine effectiveness (VE) and present the results of an interim analysis with data collected in November 2023. Patients who underwent COVID-19 testing at eight university hospitals were included and matched based on age (19-49, 50-64, and ≥65 years) and sex in a 1:1 ratio. VE was calculated using the adjusted odds ratio derived from multivariable logistic regression. Of the 992 patients included, 49 (5.3%) received the XBB.1.5 monovalent vaccine at least 7 days before COVID-19 testing. Patients with COVID-19 (cases) were less likely to have received the XBB.1.5 monovalent vaccine (case 3.5% vs. control 7.2%, p=0.019) and to have a history of COVID-19 within 6 months (2.2% vs. 4.6%, p=0.068). In contrast, patients with COVID-19 were more likely to be healthcare workers (8.2% vs. 3.0%, p=0.001) and to have chronic neurological diseases (16.7% vs. 11.9%, p=0.048). The adjusted VE of the XBB.1.5 monovalent mRNA vaccine was 56.8% (95% confidence interval: 18.7-77.9%). XBB.1.5 monovalent mRNA vaccine provided significant protection against COVID-19 in the first one to two months after vaccination.

Interim Estimates of 2023-2024 Seasonal Influenza Vaccine Effectiveness Among Adults in Korea.

In the 2023-2024 season, the influenza epidemic in South Korea peaked earlier than in recent years. In this study, we aimed to estimate the interim vaccine effectiveness (VE) of the influenza vaccination to prevent influenza during the early season. From November 1, 2023, to December 31, 2023, we enrolled 2,632 subjects with influenza-like illness from eight hospitals participating in hospital-based influenza morbidity and mortality surveillance. A retrospective test-negative case-control study was conducted to estimate the VE. The results showed an adjusted VE of 22.5% (95% confidence interval [CI], 6.6 to 35.8) for the total population. The adjusted VE was 22.3% (95% CI, 6.1 to 35.7) for influenza A and 9.4% (95% CI, -51.3 to 45.7) for influenza A/H1N1. Full results of the analysis will be reported.

Effectiveness of Bivalent mRNA Booster Vaccine Against COVID-19 in Korea.

BACKGROUND: Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023. METHODS: A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1-adjusted odds ratio from multivariable logistic regression. RESULTS: In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, -8, 49%). CONCLUSION: The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions.

Immunogenicity and safety of SARS-CoV-2 recombinant protein nanoparticle vaccine GBP510 adjuvanted with AS03: interim results of a randomised, active-controlled, observer-blinded, phase 3 trial.

Background: GBP510 vaccine contains self-assembling, recombinant nanoparticles displaying SARS-CoV-2 spike receptor-binding domains. We report interim phase 3 immunogenicity results for GBP510 adjuvanted with AS03 (GBP510/AS03) compared with ChAdOx1-S (Vaxzevria, AstraZeneca) in healthy adults aged ≥18 years, up to 6 months after the second dose. Methods: This was a randomised, active-controlled, observer-blinded, parallel group, phase 3 study, conducted at 38 sites across six countries (South Korea, Philippines, Thailand, Vietnam, Ukraine and New Zealand). Cohort 1 (no history of SARS-CoV-2 infection/COVID-19 vaccination) was randomised 2:1 to receive two doses of GBP510/AS03 or ChAdOx1-S (immunogenicity and safety), while Cohort 2 (regardless of baseline serostatus) was randomised 5:1 (safety). Primary objectives were to demonstrate superiority in geometric mean titre (GMT) and non-inferiority in seroconversion rate (SCR; ≥4-fold rise from baseline) of GBP510/AS03 vs. ChAdOx1-S for neutralising antibodies against the ancestral strain by live-virus neutralisation assay. Secondary objectives included assessment of safety and reactogenicity (long-term 6 months cut-off date: 09 August 2022). This study was registered on ClinicalTrials.gov (NCT05007951). Findings: Between 30 August 2021 and 11 January 2022, a total of 4913 participants were screened and 4036 participants (1956 in Cohort 1 and 2080 in Cohort 2) who met eligibility criteria were enrolled and randomised to receive 2 doses of GBP510/AS03 (n = 3039) or ChAdOx1-S (n = 997). Most participants were Southeast Asian (81.5%) and aged 18-64 years (94.7%). The primary objectives assessed in per-protocol set included 877 participants in GBP510/AS03 and 441 in ChAdOx1-S group: at 2 weeks after the second vaccination, the GMT ratio (GBP510/AS03/ChAdOx1-S) in per-protocol set was 2.93 (95% CI 2.63-3.27), demonstrating superiority (95% CI lower limit >1) of GBP510/AS03; the between-group SCR difference of 10.8% (95% CI 7.68-14.32) also satisfied the non-inferiority criterion (95% CI lower limit > -5%). Neutralizing antibody titres sustained higher for the GBP510/AS03 group compared to the ChAdOx1-S group through 6 months after the second vaccination. In Safety analysis (Cohort 1 & 2), the proportion of participants with adverse events (AEs) after any vaccination was higher with GBP510/AS03 vs. ChAdOx1-S for solicited local AEs (56.7% vs. 49.2%), but was similar for solicited systemic AEs (51.2% vs. 53.5%) and unsolicited AEs (13.3% vs. 14.6%) up to 28 days after the second vaccination. No safety concerns were identified during follow-up for 6 months after the second vaccination. Interpretation: Our interim findings suggested that GBP510/AS03 met the superiority criterion for neutralising antibodies and non-inferiority criterion for SCR compared with ChAdOx1-S, and showed a clinically acceptable safety profile. Funding: This work was supported, in whole or in part, by funding from CEPI and the Bill & Melinda Gates Foundation Investments INV-010680 and INV-006462. The Bill & Melinda Gates Foundation supported this project for the generation of IND-enabling data and CEPI supported this clinical study.

Clinical Characteristics and Risk Factors for Mortality in Critical COVID-19 Patients Aged 50 Years or Younger During Omicron Wave in Korea: Comparison With Patients Older Than 50 Years of Age.

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/m² 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.

Wastewater Knows Pathogen Spread: Analysis of Residential Wastewater for Infectious Microorganisms including SARS-CoV-2.

BACKGROUND: We aimed to identify the genes of 35 pathogens, including viruses, bacteria, and protozoa that cause waterborne infectious diseases, and to assess the feasibility of a wastewater-based surveillance system. MATERIALS AND METHODS: Wastewater was aseptically sampled once a month from 2 sites. A total of 1 L of wastewater from each site underwent 0.2 µm filtration to generate the sample A. Subsequently, 200 ul of the filtered water was ultra-filtered and concentrated to generate the sample B, which was mixed with sample A in a 1:1 ratio. We performed a Filmarray® Gastrointestinal (GI) panel (BioFire Diagnnostics', Salt Lake City, UT, USA) test to simultaneously detect 13 enterobacteria, 5 enterovirus, and 4 protozoa. RNA was extracted to assess 18 types of viruses. RESULTS: Severe acute respiratory syndrome coronavirus 2 adenovirus, bocavirus, and rhinovirus was detected at both site. Norovirus GI/GII was continuously detected at both sites. Moreover, adenovirus, group A rotaviruses, and hepatitis A virus were frequently detected; however, hepatitis E virus was absent at either site. Campylobacter, enteroaggregative Escherichia coli, enterotoxigenic E. coli, Shiga toxin-producing E. coli, and Clostridioides difficile toxin A/B were detected at both sites. Giardia lamblia was also detected in both sites. CONCLUSION: We analyze multiple infectious disease pathogens under sample surveillance with incidence. Further in-depth studies on wastewater-based surveillance will be feasible and important.

A Randomized Clinical Trial of Regdanvimab in High-Risk Patients With Mild-to-Moderate Coronavirus Disease 2019.

Background: We evaluated clinical effectiveness of regdanvimab (CT-P59), a severe acute respiratory syndrome coronavirus 2 neutralizing monoclonal antibody, in reducing disease progression and clinical recovery time in patients with mild-to-moderate coronavirus disease 2019 (COVID-19), primarily Alpha variant. Methods: This was phase 3 of a phase 2/3 parallel-group, double-blind, randomized clinical trial. Outpatients with mild-to-moderate COVID-19 were randomized to single-dose regdanvimab 40 mg/kg (n = 656) or placebo (n = 659), alongside standard of care. The primary endpoint was COVID-19 disease progression up to day 28 among "high-risk" patients. Key secondary endpoints were disease progression (all randomized patients) and time to recovery (high-risk and all randomized patients). Results: Of 1315 randomized patients, 880 were high risk; the majority were infected with Alpha variant. The proportion with disease progression was lower (14/446, 3.1% [95% confidence interval {CI}, 1.9%-5.2%] vs 48/434, 11.1% [95% CI, 8.4%-14.4%]; P < .001) and time to recovery was shorter (median, 9.27 days [95% CI, 8.27-11.05 days] vs not reached [95% CI, 12.35-not calculable]; P < .001) with regdanvimab than placebo. Consistent improvements were seen in all randomized and non-high-risk patients who received regdanvimab. Viral load reductions were more rapid with regdanvimab. Infusion-related reactions occurred in 11 patients (4/652 [0.6%] regdanvimab, 7/650 [1.1%] placebo). Treatment-emergent serious adverse events were reported in 5 of (4/652 [0.6%] regdanvimab and 1/650 [0.2%] placebo). Conclusions: Regdanvimab was an effective treatment for patients with mild-to-moderate COVID-19, significantly reducing disease progression and clinical recovery time without notable safety concerns prior to the emergence of the Omicron variant. Clinical Trials Registration: NCT04602000; 2020-003369-20 (EudraCT).

Clinical Characteristics and Pregnancy-Related Outcomes of Pregnant Women Hospitalized with COVID-19 During the Delta Wave: A Single-Center Observational Study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) during pregnancy is associated with increased disease severity and an increased risk of perinatal complications. However, few studies of pregnant women with COVID-19 have been conducted in Korea. The purpose of this study was to describe the clinical course and pregnancy outcomes of pregnant women admitted to our hospital with COVID-19 according to the severity. MATERIALS AND METHODS: This retrospective cohort study included women aged 18 years of age or older who were hospitalized in the Gachon University Gil Medical Center with COVID-19 during pregnancy between July 1, 2021 and January 31, 2022. COVID-19 severity was classified according to the "Criteria for severity classification by symptoms of COVID-19" presented by the Korea Disease Control and Prevention Agency. Severe cases were defined as those who required oxygen treatment administered via a high-flow nasal cannula or invasive mechanical ventilation or should be applied extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy. RESULTS: A total of 103 pregnant women were hospitalized with COVID-19 during the study period. Their mean age was 33 (± 4.14) years, and 4 (3.9%) had been vaccinated against COVID-19. At the time of diagnosis of COVID-19, 3 (2.9%), 33 (32.0%), and 67 (65.1%) patients were in the first, second, and third trimester, respectively. The most common symptoms were cough (99 patients, 96.1%) and fever (85 patients, 82.5%). There was 1 (1.0%) asymptomatic patient. Forty patients (38.8%) required supplemental oxygen and 19 patients (18.4%) had severe disease. Of the 19 severe cases, 7 were in the 2nd trimester and 12 were in the 3rd trimester. Forty-one (39.8%) patients delivered, including two twin deliveries. Of the 41 cases of delivery, 14 were premature, 4 out of 21 (19.0%) in mild, 4 out of 12 (25.0%) in moderate, and 6 out of 8 (75.0%) in severe. Severe disease was associated with an increased rate of preterm birth (P = 0.012). Four of the 43 neonates (9.1%) received oxygen treatment. CONCLUSION: Pregnant women with COVID-19 had a high rate of severe disease and a high preterm delivery rate, especially among those with severe disease.

Safety and immunogenicity of a SARS-CoV-2 recombinant protein nanoparticle vaccine (GBP510) adjuvanted with AS03: A randomised, placebo-controlled, observer-blinded phase 1/2 trial.

Background: Vaccination has helped to mitigate the COVID-19 pandemic. Ten traditional and novel vaccines have been listed by the World Health Organization for emergency use. Additional alternative approaches may better address ongoing vaccination globally, where there remains an inequity in vaccine distribution. GBP510 is a recombinant protein vaccine, which consists of self-assembling, two-component nanoparticles, displaying the receptor-binding domain (RBD) in a highly immunogenic array. Methods: This randomised, placebo-controlled, observer-blinded phase 1/2 study was conducted to evaluate the safety and immunogenicity of GBP510 (2-doses at a 28-day interval) adjuvanted with or without AS03 in adults aged 19-85 years at 14 hospital sites in Korea. This study was consisted of two stages (stage I, healthy adults aged 19-55 years; stage II, 240 healthy adults aged 19-85 years). Healthy participants who did not previously receive any vaccine within 4 weeks (2 weeks for flu vaccine) prior to the study, no history of COVID-19 vaccination/medication, and were naïve to SARS-CoV-2 infection at screening were eligible for the study enrollment. Participants were block-randomized in a 2:2:1 ratio to receive 2 doses of 10 µg GBP510 adjuvanted with AS03 (group 1), 10 µg unadjuvanted GBP510 (group 2) or placebo intramuscularly in stage I, while they were block-randomized in a 2:2:1:1 ratio to receive 10 µg GBP510 adjuvanted with AS03 (group 1), 25 µg GBP510 adjuvanted with AS03 (group 3), 25 µg unadjuvanted GBP510 (group 4) or placebo in stage II. The primary safety outcomes were solicited and unsolicited adverse events, while primary immunogenicity outcomes included anti-SARS-CoV-2 RBD IgG antibodies; neutralizing antibody responses; and T-cell immune responses. Safety assessment included all participants who received at least 1 dose of study intervention (safety set). Immunogenicity assessment included all participants who completed the vaccination schedule and had valid immunogenicity assessment results without any major protocol deviations (per-protocol set). This study was registered with ClinicalTrials.gov (NCT04750343). Findings: Of 328 participants who were enrolled between February 1 and May 28, 2021, 327 participants received at least 1 dose of vaccine. Each received either 10 µg GBP510 adjuvanted with AS03 (Group 1, n = 101), 10 µg unadjuvanted GBP510 (Group 2, n = 10), 25 µg GBP510 adjuvanted with AS03 (Group 3, n = 104), 25 µg unadjuvanted GBP510 (Group 4, n = 51), or placebo (n = 61). Higher reactogenicity was observed in the GBP510 adjuvanted with AS03 groups compared to the non-adjuvanted and placebo groups. The most frequently reported solicited local adverse event (AE) was injection site pain after any vaccination: (88·1% in group 1; 50·0% in group 2; 92·3% in group 3; 66·7% in group 4). Fatigue and myalgia were two most frequently reported systemic AEs and more frequently reported in GBP510 adjuvanted with AS03 recipients (79·2% and 78·2% in group 1; 75·0% and 79·8% in group 3, respectively) than in the unadjuvanted vaccine recipients (40·0% and of 40·0% in group 2; 60·8% and 47·1% in group 4) after any vaccination. Reactogenicity was higher post-dose 2 compared to post-dose 1, particularly for systemic AEs. The geometric mean concentrations of anti-SARS-CoV-2-RBD IgG antibody reached 2163·6/2599·2 BAU/mL in GBP510 adjuvanted with AS03 recipients (10 µg/25 µg) by 14 days after the second dose. Two-dose vaccination of 10 µg or 25 µg GBP510 adjuvanted with AS03 induced high titres of neutralizing antibody via pseudovirus (1369·0/1431·5 IU/mL) and wild-type virus (949·8/861·0 IU/mL) assay. Interpretation: GBP510 adjuvanted with AS03 was well tolerated and highly immunogenic. These results support further development of the vaccine candidate, which is currently being evaluated in Phase 3. Funding: This work was supported, in whole or in part, by funding from CEPI and the Bill & Melinda Gates Foundation Investment ID OPP1148601. The Bill & Melinda Gates Foundation supported this project for the generation of IND-enabling data and CEPI supported this clinical study.

Clinical Characteristics and Risk Factors for Mortality in Critical Coronavirus Disease 2019 Patients 50 Years of Age or Younger During the Delta Wave: Comparison With Patients > 50 Years in Korea.

BACKGROUND: Numerous patients around the globe are dying from coronavirus disease 2019 (COVID-19). While age is a known risk factor, risk analysis in the young generation is lacking. The present study aimed to evaluate the clinical features and mortality risk factors in younger patients (≤ 50 years) with a critical case of COVID-19 in comparison with those among older patients (> 50 years) in Korea. METHODS: We analyzed the data of adult patients only in critical condition (requiring high flow nasal cannula oxygen therapy or higher respiratory support) hospitalized with PCR-confirmed COVID-19 at 11 hospitals in Korea from July 1, 2021 to November 30, 2021 when the delta variant was a dominant strain. Patients' electronic medical records were reviewed to identify clinical characteristics. RESULTS: During the study period, 448 patients were enrolled. One hundred and forty-two were aged 50 years or younger (the younger group), while 306 were above 50 years of age (the older group). The most common pre-existing conditions in the younger group were diabetes mellitus and hypertension, and 69.7% of the patients had a body mass index (BMI) > 25 kg/m². Of 142 younger patients, 31 of 142 patients (21.8%, 19 women) did not have these pre-existing conditions. The overall case fatality rate among severity cases was 21.0%, and it differed according to age: 5.6% (n = 8/142) in the younger group, 28.1% in the older group, and 38% in the ≥ 65 years group. Age (odds ratio [OR], 7.902; 95% confidence interval [CI], 2.754-18.181), mechanical ventilation therapy (OR, 17.233; 95% CI, 8.439-35.192), highest creatinine > 1.5 mg/dL (OR, 17.631; 95% CI, 8.321-37.357), and combined blood stream infection (OR, 7.092; 95% CI, 1.061-18.181) were identified as independent predictors of mortality in total patients. Similar patterns were observed in age-specific analyses, but most results were statistically insignificant in multivariate analysis due to the low number of deaths in the younger group. The full vaccination rate was very low among study population (13.6%), and only three patients were fully vaccinated, with none of the patients who died having been fully vaccinated in the younger group. Seven of eight patients who died had a pre-existing condition or were obese (BMI > 25 kg/m²), and the one remaining patient died from a secondary infection. CONCLUSION: About 22% of the patients in the young critical group did not have an underlying disease or obesity, but the rate of obesity (BMI > 25 kg/m²) was high, with a fatality rate of 5.6%. The full vaccination rate was extremely low compared to the general population of the same age group, showing that non-vaccination has a grave impact on the progression of COVID-19 to a critical condition. The findings of this study highlight the need for measures to prevent critical progression of COVID-19, such as vaccinations and targeting young adults especially having risk factors.

Effects of Non-Pharmacological Interventions on Respiratory Viruses Other Than SARS-CoV-2: Analysis of Laboratory Surveillance and Literature Review From 2018 to 2021.

BACKGROUND: Since the global coronavirus disease 2019 (COVID-19) pandemic, non-pharmacological interventions (NPIs) such as extensive and comprehensive hand hygiene, mask-wearing, and social distancing have been implemented globally. This study aimed to investigate changes in respiratory viruses other than severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that occurred following the implementation of these NPIs. METHODS: From January 2018 to December 2021, influenza-like illness patient specimens and specimens from the Korea Influenza and Respiratory Viruses Surveillance System were analyzed at the Incheon Metropolitan City Institute of Public Health and Environment. Oropharyngeal or nasopharyngeal swab samples from respiratory infection patients were transferred in a virus transport medium at 4°C. After RNA or DNA extraction, respiratory virus-specific genes for human influenza virus (IFV), adenovirus (ADV), parainfluenza virus (PIV), respiratory syncytial virus (RSV), human rhinovirus (hRV), human coronavirus, human bocavirus, and human metapneumovirus were detected by individual real-time reverse transcription polymerase chain reaction. RESULTS: A total 3,334 samples were collected. After NPI was implemented, the detection of respiratory viruses other than SARS-CoV-2 decreased overall. The yearly detection rate of respiratory viruses was decreased from 69.5% (399/574) in 2018 and 73.3% (505/689) in 2019 to 19.8% (206/1,043) in 2020 and 34.9% (365/1,028) in 2021. The epidemic was more prominent in respiratory viruses such as IFV and RSV, which were considered dominant viruses, especially those with viral envelopes. Among viruses that were not considered dominant, hRV showed no clear change before and after NPI, while PIV showed a rapid increase compared to the existing dominant viruses between October-December 2021, after the increase in the number of gatherings started at the end of September and the "Relaxing COVID19 and mitigation policy," which was implemented on November 1. CONCLUSION: NPI seems to have influenced the isolation and transmission of respiratory viruses in South Korea. In the future, additional studies focusing on the isolation and transmission patterns of respiratory viruses following NPI are needed.

Efficacy and Safety of Regdanvimab (CT-P59): A Phase 2/3 Randomized, Double-Blind, Placebo-Controlled Trial in Outpatients With Mild-to-Moderate Coronavirus Disease 2019.

Background: Regdanvimab (CT-P59) is a monoclonal antibody with neutralizing activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report on part 1 of a 2-part randomized, placebo-controlled, double-blind study for patients with mild-to-moderate coronavirus disease 2019 (COVID-19). Methods: Outpatients with mild-to-moderate COVID-19 received a single dose of regdanvimab 40 mg/kg (n = 100), regdanvimab 80 mg/kg (n = 103), or placebo (n = 104). The primary end points were time to negative conversion of SARS-CoV-2 from nasopharyngeal swab based on quantitative reverse transcription polymerase chain reaction (RT-qPCR) up to day 28 and time to clinical recovery up to day 14. Secondary end points included the proportion of patients requiring hospitalization, oxygen therapy, or mortality due to COVID-19. Results: Median (95% CI) time to negative conversion of RT-qPCR was 12.8 (9.0-12.9) days with regdanvimab 40 mg/kg, 11.9 (8.9-12.9) days with regdanvimab 80 mg/kg, and 12.9 (12.7-13.9) days with placebo. Median (95% CI) time to clinical recovery was 5.3 (4.0-6.8) days with regdanvimab 40 mg/kg, 6.2 (5.5-7.9) days with regdanvimab 80 mg/kg, and 8.8 (6.8-11.6) days with placebo. The proportion (95% CI) of patients requiring hospitalization or oxygen therapy was lower with regdanvimab 40 mg/kg (4.0% [1.6%-9.8%]) and regdanvimab 80 mg/kg (4.9% [2.1%-10.9%]) vs placebo (8.7% [4.6%-15.6%]). No serious treatment-emergent adverse events or deaths occurred. Conclusions: Regdanvimab showed a trend toward a minor decrease in time to negative conversion of RT-qPCR results compared with placebo and reduced the need for hospitalization and oxygen therapy in patients with mild-to-moderate COVID-19. Clinical trial registration : NCT04602000 and EudraCT 2020-003369-20.

Challenges to Early Discharge of Patients with Upper Urinary Tract Infections by ESBL Producers: TMP/SMX as a Step-Down Therapy for Shorter Hospitalization and Lower Costs.

BACKGROUND: Urinary tract infections (UTIs) caused by extended spectrum beta-lactamase (ESBL) producing pathogens have increased and are treated with carbapenem in general. Carbapenem use is associated with prolonged hospitalization or daily outpatient visit. The aim of this study was to investigate patients with UTIs by ESBL-producing pathogens for early discharge using an old oral antibiotic, trimethoprim-sulfamethoxazole (TMP-SMX), which is susceptible to ESBL-producing pathogens. METHODS: Data on UTIs caused by ESBL-producing pathogens from a single tertiary hospital were collected retrospectively. Patients who had been treated with intravenous carbapenems or oral TMP/SMX were included. Patients' clinical and microbiological outcomes were compared between oral TMP/SMX and ertapenem treatment groups. RESULTS: A total of 103 patients were included, 21 of whom had been treated with TMP/SMX, whereas 82 with ertapenem. Clinical outcomes between the two groups were not significantly different (TMP/SMX: 90.5%; ertapenem: 84.1%, p = 0.73). The microbiological cure rate was higher in the TMP/SMX group than in the ertapenem group (90.5% vs 58.5%, respectively, p = 0.01). The mean duration of hospitalization was significantly shorter in the TMP/SMX group than in the ertapenem group (8.00 ± 10.50 days vs 14.00 ± 37.00 days, p = 0.07). The mean duration of antibiotic treatment was longer in the ertapenem group than in the TMP/SMX group (16.45 ± 4.77 vs 12.76 ± 5.37 days, p = 0.006). CONCLUSION: For susceptible pathogens, TMP/SMX may enable early discharge as an effective oral antibiotic treatment option for UTIs caused by ESBL-positive pathogens. Additionally, use of oral antibiotics can shorten hospital stays and reduce medical costs.

Ciclesonide Inhaler Treatment for Mild-to-Moderate COVID-19: A Randomized, Open-Label, Phase 2 Trial.

Although some intravenous drugs have been used to treat coronavirus disease 2019 (COVID-19), no effective antiviral agents are currently available in the outpatient setting. We aimed to evaluate the efficacy and adverse events of 14-day ciclesonide treatment vs. standard care for patients with mild-to-moderate COVID-19. A randomized, open-label, multicenter clinical trial of ciclesonide inhalers was conducted in patients with mild-to-moderate COVID-19. Patients were enrolled within 3 days of diagnosis or within 7 days from symptom onset and randomly assigned to receive either ciclesonide (320 µg inhalation twice per day for 14 days) or standard care. The primary endpoint was the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) eradication rate on day 14 from study enrollment. Clinical status was assessed once daily, and serial nasopharyngeal viral load was evaluated by quantitative reverse transcription polymerase chain reaction. There were 35 and 26 patients in the ciclesonide and standard care groups, respectively. The SARS-CoV-2 eradication rate at day 14 was significantly higher in the ciclesonide group (p = 0.021). In multivariate analysis, SARS-CoV-2 negative conversion within 14 days was 12 times more likely in the ciclesonide group (95% confidence interval, 1.187-125.240). Additionally, the clinical failure rate (high-flow nasal oxygen therapy or mechanical ventilation) was significantly lower in the ciclesonide group (p = 0.034). In conclusion, ciclesonide inhalation shortened SARS-CoV-2 viral shedding duration, and it may inhibit the progression to acute respiratory failure in patients with mild-to-moderate COVID-19. Clinical Trial Registration NCT04330586.

Clinical and Virologic Effectiveness of Remdesivir Treatment for Severe Coronavirus Disease 2019 (COVID-19) in Korea: a Nationwide Multicenter Retrospective Cohort Study.

BACKGROUND: Remdesivir is widely used for the treatment of coronavirus disease 2019 (COVID-19), but controversies regarding its efficacy still remain. METHODS: A retrospective cohort study was conducted to evaluate the effect of remdesivir on clinical and virologic outcomes of severe COVID-19 patients from June to July 2020. Primary clinical endpoints included clinical recovery, additional mechanical ventilator (MV) support, and duration of oxygen or MV support. Viral load reduction by hospital day (HD) 15 was evaluated by calculating changes in cycle threshold (Ct) values. RESULTS: A total of 86 severe COVID-19 patients were evaluated including 48 remdesivir-treated patients. Baseline characteristics were not significantly different between the two groups. Remdesivir was administered an average of 7.42 days from symptom onset. The proportions of clinical recovery of the remdesivir and supportive care group at HD 14 (56.3% and 39.5%) and HD 28 (87.5% and 78.9%) were not statistically different. The proportion of patients requiring MV support by HD 28 was significantly lower in the remdesivir group than in the supportive care group (22.9% vs. 44.7%, P = 0.032), and MV duration was significantly shorter in the remdesivir group (average, 1.97 vs. 5.37 days; P = 0.017). Analysis of upper respiratory tract specimens demonstrated that increases of Ct value from HD 1-5 to 11-15 were significantly greater in the remdesivir group than the supportive care group (average, 10.19 vs. 5.36; P = 0.007), and the slope of the Ct value increase was also significantly steeper in the remdesivir group (average, 5.10 vs. 2.68; P = 0.007). CONCLUSION: The remdesivir group showed clinical and virologic benefit in terms of MV requirement and viral load reduction, supporting remdesivir treatment for severe COVID-19.

Clinical and computed tomography factors associated with sepsis in women with clinically uncomplicated pyelonephritis.

OBJECTIVE: Sepsis is major determinants of prognosis in acute pyelonephritis (APN). This study aimed to assess factors associated with the development of sepsis among patients with clinically uncomplicated APN. SUBJECTS AND METHODS: We examined 463 patients presenting to our hospital without complications. We assessed clinical factors including demographic and laboratory features. Renal and extrarenal features on computed tomography (CT) were also analyzed. Risk factors of sepsis are assessed. RESULTS: The study included 361 patients without (78.0%) and 102 patients with sepsis (22.0%). Crude and attributable mortality rates were 3.9% and 2.0% versus 1.4% and 0.6%, respectively, among patients with and without sepsis. Clinical risk factors for sepsis were age >65 years (odds ratio [OR] 1.79, P = 0.02), absence of flank pain (OR 1.59, P = 0.04), absence of costovertebral tenderness (OR 1.89, P = 0.03), diabetes mellitus (OR 2.25, P = 0.02), bacteremia (OR 2.8, P = 0.01), C-reactive protein level >100 mg/L (OR 1.42, P = 0.02), and lack of previous APN history (OR 1.76, P = 0.04). APN grade IV (OR 3.16, P = 0.01), high grade hydronephrosis (OR 1.50, P = 0.03), diffuse peritoneal thickening (OR 4.12, P = 0.01), and acute interstitial pulmonary edema (OR 3.73, P = 0.01) were the CT features predictive of septic shock. CONCLUSIONS: Although uncomplicated APN was largely non-fatal, several clinical and CT features could lead to sepsis. Our findings may be useful for predicting sepsis risk and deciding whether intravenous antibiotic treatment and intensive management should be initiated for uncomplicated APN.

Protection and Response of a Tertiary Hospital in South Korea to the COVID-19 Outbreak.

OBJECTIVE: Here, we present an overview of how a tertiary hospital responded to maintain necessary activities and protect patients and staff from the coronavirus disease (COVID-19) outbreak. METHODS: Gil Medical Center, a tertiary hospital in Incheon, has operated a special response team since January 21, 2020. All visitors were assessed for body temperature and respiratory symptoms, and screened for recent overseas travel. Suspected COVID-19 patients were taken to a screening clinic. All febrile patients with or without respiratory symptoms were taken to a respiratory safety clinic. An isolation ward, which consisted of 10 negative-pressure rooms, was used to treat confirmed cases. More than 120 beds were prepared for the outbreak, and patients with pneumonia were preemptively isolated. RESULTS: By May 5, 480 960 visitors were assessed at the control station, 3350 patients visited the triage center, and 1794 were treated in the respiratory safety clinic. Seventeen confirmed cases were admitted to the negative isolation ward, and 350 patients with pneumonia were preemptively isolated. A total of 2977 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction tests were performed. CONCLUSIONS: While tertiary hospitals play an important role in treating both COVID-19 patients and non-COVID-19 patients, hospital staff have to protect themselves from unexpected in-hospital transmission. A multifaceted response must be undertaken to protect tertiary hospitals and their staff during the COVID-19 epidemic.

Predictors of Mortality in Patients with Carbapenem-Resistant Gram-Negative Bacilli or Vancomycin-Resistant Enterococci Bacteremia.

PURPOSE: The incidences of carbapenem-resistant gram-negative bacilli (CRGNB) and vancomycin-resistant Enterococci (VRE) have increased rapidly in South Korea since 2000. The mortality rate for CRGNB or VRE bacteremia cases is higher than that for non-resistant bacteremia cases. The factors associated with higher mortality are unclear. We investigated the factors associated with mortality from CRGNB or VRE bacteremia and compared the relative risk of these factors. PATIENTS AND METHODS: We retrospectively collected data from adult patients with CRGNB or VRE bacteremia. Patients were grouped according to whether they survived or died. The data from both groups were compared. RESULTS: During the study period, 171 cases of CRGNB or VRE bacteremia were identified, of which 100 were CRGNB bacteremia cases and 71 were VRE bacteremia cases. Multivariate analysis revealed significant associations with Pitt bacteremia score (PBS) (odds ratio [OR] 1.329, 95% confidence interval [CI] 1.049-1.684). In the multivariate analysis, negative conversion of follow-up blood culture (FUBC) was related with one-week mortality from CRGNB or VRE bacteremia (OR 17.623, 95% CI 5.726-54.244). In the multivariate analysis of risk factors for 28-day mortality for CRGNB or VRE bacteremia, the significant risk factors were bacteremia of respiratory origin (OR 4.491, 95% CI 1.622-12.435) and positive FUBC (OR 4.082, 95% CI 1.626-10.204). CONCLUSION: Despite the high mortality rate in patients with CRGNB or VRE bacteremia, the related mortality could be predicted by independent risk factors of PBS, positive FUBC, and bacteremia of respiratory origin.