OBJECTIVES:Persistent symptoms after SARS-CoV-2 infection (PASC, long COVID) remain a major public-health concern. We developed a data-driven definition and static and dynamic PASC scoring systems in a multicenter, prospective-retrospective observational cohort across 12 South Korean institutions. METHODS:Adults enrolled December 2022-March 2025 were followed up to 24 months; 8761 were recruited (7208 infected; 1553 controls) and 4668 met analysis criteria (4388 infected; 280 controls). Using participant-reported symptoms, surveys, and laboratory data, we identified nine symptoms robustly associated with PASC, with anosmia/ageusia and fatigue most influential. RESULTS:A static score integrating indicators observed within 24 months yielded an optimal threshold of 13, classifying 19% of infected participants and 4% of controls as PASC positive. A dynamic score tracking six-month intervals showed symptom burdens peaking at 0-5 months post-infection and declining thereafter; at the same threshold, 33% of infected participants were classified as PASC positive, reflecting temporal fluctuation. CONCLUSION:These data establish a quantitative definition of PASC and introduce a dynamic scoring framework to identify and monitor PASC, supporting future clinical research and practice.

Purpose: This study systematically evaluated the effectiveness of a training program designed to enhance infectious disease response capabilities among primary care physicians. Using a mixed-methods design, the evaluation applied Kirkpatrick's 4-level model and the Context, Input, Process, and Product (CIPP) framework to assess program outcomes and identify areas for improvement. Methods: The study focused on a national infectious disease training program for primary care physicians conducted in 2022 (N=1,718). Quantitative pre- and post-training data were analyzed from 100 randomly selected participants, along with qualitative data obtained through in-depth interviews with 10 participants. Validated assessment tools, developed by psychometricians and content experts, were used to measure satisfaction (Kirkpatrick level 1), learning achievement (level 2), practical application (level 3), and organizational contribution (level 4). Results: Overall training satisfaction was high (3.96 +/- 0.72). Learning achievement (level 2) demonstrated statistically significant improvement from pre-training to post-training assessments (F=12.922, P<0.001). Scores for practical application (level 3; 3.19 +/- 0.86) and organizational contribution (level 4; 3.47 +/- 0.70) indicated both strong motivation to apply newly acquired knowledge and institutional readiness to implement response strategies. Conclusion: This study confirmed that the training program effectively enhanced both individual competencies and organizational response capacity across all 4 Kirkpatrick levels. The integrated application of the Kirkpatrick and CIPP models provided a robust framework for evaluating learning transfer and guiding program improvement. These findings highlight the importance of continued investment in diverse training initiatives, systematic evaluation processes, and the dissemination of successful practices to the broader healthcare community.

Background: In this study, we aimed to compare the effectiveness and adverse reactions of nirmatrelvir/ritonavir and molnupiravir in high-risk outpatients with coronavirus disease 2019 (COVID-19).Methods: This multicenter prospective observational study evaluated the rate of hospitalization, death, and adverse events within 28 days of oral antiviral agent prescription (molnupiravir, n = 240; nirmatrelvir/ritonavir, n = 240) to 480 nonhospitalized adult patients with COVID-19 from August 2, 2022 to March 31, 2023.Results: Patients receiving molnupiravir had a higher prevalence of comorbidities (85.8% vs. 70.4%; P < 0.001) and a higher Charlson comorbidity index (2.8 +/- 1.4 vs. 2.5 +/- 1.5; P = 0.009) than those receiving nirmatrelvir/ritonavir. Three patients required hospitalization (nirmatrelvir/ritonavir group, n = 1 [0.4%]; molnupiravir group, n = 2 [0.8%]; P = 1.000). Nirmatrelvir/ritonavir was associated with a higher risk of adverse events than molnupiravir (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.27-3.03), especially for patients aged 65 years and older (OR, 3.04; 95% CI, 1.71-5.39). The severity of adverse events in both groups was mild to moderate and improved after discontinuation of medication. In the molnupiravir group, age >= 65 years (OR, 0.43 95% CI, 0.22-0.86) and appropriate vaccination (OR, 0.37; 95% CI, 0.15-0.91) reduced the occurrence of adverse events.Conclusion: The rates of hospitalization and death were low and not significantly different between high-risk patients who received either nirmatrelvir/ritonavir or molnupiravir. Although adverse events were more frequent with nirmatrelvir/ritonavir than with molnupiravir, none were severe. Nirmatrelvir/ritonavir can be safely used to treat COVID-19, while molnupiravir could be considered as an alternative treatment option for high-risk groups.

Candida auris (C.auris) is a pathogen that causes severe infections, particularly in healthcare settings, and is resistant to common antifungal agents, leading to a global public health threat.Infections of the cavernous sinus are rare but potentially fatal.We report a rare case of cavernous sinus infection caused by drug-resistant C. auris.A 60-year-old woman with chronic otitis media underwent a mastoidectomy and tympanoplasty.The patient developed a surgical site infection with methicillin-resistant Staphylococcus aureus after the surgery, which improved with antibiotic treatment.However, she developed purulent otorrhea, ear pain, and a limitation of eye movement.Cultures of ear discharge repeatedly identified C. auris, and brain magnetic resonance imaging (MRI) findings were consistent with the presence of cavernous sinus infection and pachymeningitis.Therefore, amphotericin B and micafungin combination therapy was initiated for the C. auris infection.The patient showed no clinical improvement despite combination therapy with amphotericin B and micafungin; therefore, flucytosine was added to the treatment regimen.Symptoms improved after the triple-agent combination therapy, and a follow-up MRI showed improvement in the cavernous sinus infection and pachymeningitis.

AbstractObjectives:To evaluate the efficacy of selective digestive decolonization (SDD) therapy using oral gentamicin against carbapenem-resistant Enterobacteriaceae (CRE) colonization and to compare the incidence of novel gentamicin resistance between SDD and non-SDD patient groups.Design:Retrospective cohort study.Setting:Acute-care referral center hospital in South Korea.Methods:Adults aged ≥20 years identified as rectal CRE carriers hospitalized between October 2019 and June 2020 were enrolled. Patients with a <30-day follow-up were excluded. Among CRE carriers, those who received 80 mg oral gentamicin sulfate (Shin Poong Pharmaceutical, Seoul, South Korea) 4 times daily comprised the SDD group and those who did not receive SDD therapy comprised the non-SDD group. CRE decolonization was compared between groups within 15 days, and new gentamicin resistance was assessed.Results:In total, 73 rectal CRE carriers were identified; 11 patients were lost to follow-up within 30 days and were excluded. Oral gentamicin was administered to 20 of 62 patients. We detected no differences in the basic demographic features between groups. The rate of decolonization within 15 days was higher in the SDD group than in the non-SDD group (70.0% vs 23.8%; P = .001). The time to decolonization was significantly shorter in the SDD group. We detected no difference in acquisition of new gentamicin resistance between the groups. No serious adverse events due to oral gentamicin SDD therapy were reported.Conclusions:SDD therapy using oral gentamicin for CRE-colonized patients may be effective for the decolonization of gut CRE and for the prevention of transmission and subsequent CRE infection.

The increasing resistance of gram-negative bacteria is a serious global public health concern. One way to prevent increasing antibiotic resistance is by implementing the antibiotic stewardship program. This study aimed to assess the changes in the consumption of antimicrobials and antimicrobial resistance rates after implementing piperacillin/tazobactam restriction. This study was conducted at Kandong Sacred Heart Hospital. We retrospectively collected and analysed data between October 2018 and May 2021 to evaluate antibiotic consumption and resistance patterns after restricting piperacillin/tazobactam. This study included two periods, a 16-month pre-restriction period and a 16-month post-restriction period. During the study period, there was a significant decrease in the consumption of piperacillin/tazobactam after implementing the restriction policy (127.82 ± 9.39 to 104.82 ± 15.66 defined daily doses/1000 patient days, p < 0.001). A significant decrease in the resistance rate of Acinetobacter spp. was observed for cefepime ( p = 0.001), ceftazidime ( p = 0.004), levofloxacin ( p = 0.021), meropenem ( p = 0.002) and piperacillin ( p = 0.028). The introduction of piperacillin/tazobactam restriction reduced their use and positively impacted the resistance rates of Acinetobacter spp., carbapenem-resistant Pseudomonas spp. and carbapenem-resistant Enterobacteriaceae which are major threats to nosocomial infections.

The purpose of this study was to determine whether the fluoroquinolone (FQ) minimum inhibitory concentration (MIC) for the causative agent Escherichia coli influences the clinical response of FQ treatment at 72 h in patients with community-acquired acute pyelonephritis (CA-APN). We prospectively collected the clinical data of women with CA-APN from 11 university hospitals from March 2010 to February 2012 as well as E. coli isolates from the urine or blood. In total, 78 patients included in this study received FQ during the initial 72 h, and the causative E. coli was detected. The clinical response at 72 h was significantly higher in patients with a levofloxacin MIC ≤ 16 mg/L than in those with an MIC > 16 mg/L (70.4% vs. 28.6%, p = 0.038). No difference was observed in clinical response at 72 h based on ciprofloxacin MIC. To summarize, FQ can be an effective treatment option for CA-APN when levofloxacin MIC against E. coli is ≤16 mg/L.

OBJECTIVES:Wound infection is the most common complication associated with percutaneous endoscopic gastrostomy (PEG) placement, with an incidence between 4% and 30%. In this study, we compared the characteristics of PEG site infection between the head and neck cancer (HNC) group and the non-HNC group.METHODS:This study was conducted at Kangdong Sacred Heart Hospital at the Ilsong Head and Neck Cancer Center. We retrospectively collected and analyzed data on patients who underwent PEG insertion from October 2003 to May 2019 to evaluate the risk factors and microbiological etiologies of PEG site infection.RESULTS:A total of 316 (HNC group [n = 129] and non-HNC group [n = 187]) patients undergoing PEG insertion were included in this study. Moreover, 67 episodes of PEG site infection were diagnosed, with an overall prevalence of 21.2%. PEG site infections were significantly higher in the HNC group than in the non-HNC group (32.6% vs 13.4%, P <.001). Pseudomonas aeruginosa is the most common pathogen associated with a PEG site infection. Multidrug-resistant (MDR) P aeruginosa was more frequent in the HNC group than in the non-HNC group (78.6% vs 25.0%, P = .006).CONCLUSIONS:For appropriate treatment, P aeruginosa, especially MDR P aeruginosa, should be considered when selecting empirical antibiotics for PEG site infection in patients with HNC.Level of Evidence: 4.

BackgroundDelayed antifungal therapy for candidemia leads to increased mortality. Differentiating bacterial infection from candidemia in systemic inflammatory response syndrome (SIRS) patients is complex and difficult. The Delta Neutrophil Index (DNI) has recently been considered a new factor to distinguish infections from non-infections and predict the severity of sepsis. We aimed to assess if the DNI can predict and provide a prognosis for candidemia in SIRS patients.MethodsA matched case-control study was conducted from July 2016 to June 2017 at Kangdong Sacred Heart Hospital. Among patients with a comorbidity of SIRS, those with candidemia were classified as the case group, whereas those with negative blood culture results were classified as the control group. The matching conditions included age, blood culture date, and SIRS onset location. Multivariate logistic regression was performed to evaluate DNI as a predictive and prognostic factor for candidemia.ResultsThe 140 included patients were assigned to each group in a 1:1 ratio. The DNI_D1 values measured on the blood culture date were higher in the case group than in the control group (p< 0.001). The results of multivariate analyses confirmed DNI_D1 (odds ratio [ORs] 2.138, 95% confidential interval [CI] 1.421-3.217, p< 0.001) and Candida colonization as predictive factors for candidemia. The cutoff value of DNI for predicting candidemia was 2.75%. The area under the curve for the DNI value was 0.804 (95% CI, 0.719-0.890, p<0.001), with a sensitivity and specificity of 72.9 and 78.6%, respectively. Analysis of 14-day mortality in patients with candidemia showed significantly higher DNI_D1 and DNI_48 in the non-survivor group than in the survivor group.ConclusionsDNI was identified as a predictive factor for candidemia in patients with SIRS and a prognostic factor in predicting 14-day mortality in candidemia patients. DNI, along with clinical patient characteristics, was useful in determining the occurrence of candidemia in patients with SIRS.

Sepsis is one of the significant causes of morbidity and mortality.The burden caused by sepsis has continued to increase in recent years in the Korea, highlighting the urgent need for the implementation of strategies to improve sepsis treatment outcomes.We therefore designed a web-based sepsis registry system ("Korean Registry for Improving Sepsis Survival" [KISS]) protocol to be used in hospitals in the Korea for evaluation of the epidemiology and clinical characteristics of patients with sepsis, via an analysis of outcome predictors.The inclusion criteria of this registry are as follows: adult patients ≥18 years admitted to the participating hospitals who are diagnosed with sepsis or septic shock.Demographic and clinical information data of the patients will be collected from hospital medical records and will be recorded in a case report form, which will be entered into a web-based data management system.The analysis of the collected data will be performed as follows: (1) epidemiological and clinical characteristics of sepsis and septic shock, (2) application of sepsis bundles and antibiotic stewardship, and (3) audit and feedback.In conclusion, we aim to build the comprehensive web-based sepsis registry in the Korea through a nation-wide network of participating hospitals.Information collected and analyzed through the KISS can be used for further improvements in the clinical management of sepsis.Furthermore, the KISS will facilitate research leading to the formulation of public health policies regarding sepsis bundle and antibiotic stewardship strategies in the Korea.

The dramatic spread of Coronavirus Disease 2019 (COVID-19) has profound impacts on every continent and life. Due to human-to-human transmission of COVID-19, nuclear medicine staffs also cannot escape the risk of infection from workplaces. Every staff in the nuclear medicine department must prepare for and respond to COVID-19 pandemic which tailored to the characteristics of our profession. This article provided the guidance prepared by the Korean Society of Nuclear Medicine (KSNM) in cooperation with the Korean Society of Infectious Disease (KSID) and Korean Society for Healthcare-Associated Infection Control and Prevention (KOSHIC) in managing the COVID-19 pandemic for the nuclear medicine department. We hope that this guidance will support every practice in nuclear medicine during this chaotic period.

Coronavirus disease 2019 (COVID-19) has spread widely across the world since January 2020. There are many challenges when caring for patients with COVID-19, one of which is infection prevention and control. In particular, in cases where surgery must absolutely be performed, special infection control may be required in order to perform surgery without spreading infection within the hospital. We aim to present potentially useful recommendations for non-deferrable surgery for COVID-19 patients based on in vivo and in vitro research and clinical experiences from many countries.

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.

BACKGROUND:Escherichia coli is the predominant causative pathogen for community-acquired urinary tract infections (UTIs), and the increase in fluoroquinolone-resistant E. coli is of great concern in Korea. The objectives of this study were to investigate the genotypic characteristics and molecular epidemiology of ciprofloxacin-resistant (CIP-R) E. coli isolated from community-acquired UTIs in Korea.MATERIALS AND METHODS:E. coli samples isolated from the blood or urine were collected from patients with community-acquired acute pyelonephritis aged 15 years and more who were admitted to 12 Korean hospitals from 1st April 2010 to 29th February 2012. Phylogenetic typing, multilocus sequence typing, and molecular characterization of β-lactamase and plasmid-mediated quinolone resistance determinants were performed for CIP-R E. coli isolates.RESULTS:A total of 569 E. coli isolates were collected, and 122 (21.4%) isolates were CIP-R isolates. The most prevalent sequence type (ST) was ST131 (28.7%, 35/122), followed by ST393 (14.7%, 18/122), ST1193 (13.1%, 16/122), ST38 (9.0%, 11/122), and ST405 (8.2%, 10/122). The antimicrobial resistance rates of ST131 to cefepime (22.9%, 8/35), ST38 to gentamicin (100%, 11/11), and ST405 to cefotaxime (66.7%, 6/9) were significantly higher than the resistance rates of all other STs combined. Notably, 40% (4/10) of ST405 clones produced extended-spectrum β-lactamases and were co-resistant to trimethoprim/sulfamethoxazole. aac(6')-1b-cr (20%, 7/35) and CTX-M-14 (40%, 4/10) were more frequently observed in ST131 and ST405 compared with other clones, respectively.CONCLUSIONS:Among the CIP-R uropathogenic E. coli isolates in this study, ST131, ST38, and ST405 were specifically associated with antimicrobial resistance.

Purpose: To compare the clinical efficacy between peramivir and oseltamivir in hospitalized patients with influenza. Patients and Methods: Retrospective cohort study examined data from 542 adult patients with laboratory-confirmed seasonal influenza hospitalized in five teaching hospitals and one secondary hospital between August 2017 and May 2018. The main outcome was the defervescence rate within 3 days from the first administration of peramivir or oseltamivir. The secondary outcomes were mortality and duration of hospitalization/intensive care unit (ICU) stay. Results: Of the 542 enrolled patients, 251 were administered the standard dose of peramivir (300 mg, single dose), 42 were administered peramivir at doses exceeding 300 mg, and 249 were administered oseltamivir (75 mg, twice daily for 5 days). There were more ICU and pneumonia cases and older patients in the peramivir group, especially the high-dose group. The Charlson comorbidity index (CCI) scores were similar among the three groups. There were no significant differences in defervescence rates within 3 days between the three groups. The mortality and duration of hospital and ICU stays also did not differ significantly. The factors associated with 30-day mortality were ICU admission, high CCI score, and pneumonia. Conclusion: Treatment of influenza with either peramivir or oseltamivir in hospitalized adults resulted in generally similar clinical outcomes. Peramivir treatment showed good clinical response in influenza patients with pneumonia or admitted to the ICU.

An effective post-exposure prophylaxis (PEP) strategy may limit the spread of infection. However, there is no consensus regarding PEP for Middle East respiratory syndrome coronavirus (MERS-CoV) infection. This study assessed the efficacy of ribavirin and lopinavir/ritonavir as PEP for healthcare workers (HCWs) exposed to patients with severe MERS-CoV pre-isolation pneumonia. The safety of the PEP regimen was assessed. HCWs with high-risk exposure to MERS-CoV pre-isolation pneumonia were retrospectively enrolled. HCWs who received PEP therapy were classified into the PEP group. PEP therapy was associated with a 40% decrease in the risk of infection. There were no severe adverse events during PEP therapy.

Purpose: Colistin alone may not be sufficient for treating carbapenem-resistant Acinetobacter baumannii (CRAB); thus, efforts are needed to increase treatment success rates. We compared the effects of colistin plus carbapenem therapy versus colistin monotherapy in treating pneumonia caused by CRAB and attempted to identify specific populations or factors that could benefit from combination therapy. Methods: We retrospectively collected data on cases of CRAB pneumonia. The patients were divided into colistin plus carbapenem therapy and colistin monotherapy groups. The primary outcome was 14-day mortality. The secondary outcomes were in-hospital mortality, clinical improvement at days 2 and 14, and microbiological improvement at day 14. Results: Of 160 cases meeting criteria for CRAB pneumonia, 83 (52%) and 77 (48.0%) were treated with carbapenem combination therapy or colistin monotherapy, respectively. Among these patients, 50 (63.3%) in the combination group and 27 (39.7%) in the monotherapy group had Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) II scores >24 points (p=0.010). Overall, there was no significant difference in 14-day mortality between the combination and monotherapy groups (24.1% vs 20.8%, p=0.616). Clinical improvement and sputum-negative conversion also showed no significant difference. After adjusting for disease severity according to APACHE II score, the 14-day mortality was significantly lower in the combination group than in the monotherapy group among patients with APACHE II scores of 25-29 points (9.1% vs 53.8%, P=0.020). Conclusion: Despite more severe conditions, compared with colistin monotherapy, colistin plus carbapenem combination therapy showed equivalent primary mortality outcome in treating CRAB pneumonia. Combination therapy was more effective in patients with APACHE II score ranging from 25 to 29 points.

Objective The aim of this study was to compare clinical outcomes between patients with carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia treated with colistin monotherapy and those treated with colistin plus meropenem. Methods We retrospectively evaluated data from 71 patients with CRAB bacteremia treated from November 2006 to February 2018. Predictors of 14-day mortality were determined through logistic regression analysis. Results Our study cohort included 40 bacteremia patients (44.6 %) treated with colistin monotherapy and 31 (55.4 %) treated with colistin plus meropenem. Overall 14-day mortality tended to be higher with monotherapy rather than combination therapy (47.5% vs 25.8%). The latter also showed a tendency for higher clinical success rate compared with monotherapy (61.3% vs 40.0%). Logistic regression analysis showed that Pitt bacteremia score, pneumonia, and combination therapy were significantly associated with mortality. In patients with higher Pitt bacteremia score (≥4), mortality was significantly higher with monotherapy compared with combination therapy (66.7% vs 27.8%). In patients with lower Pitt bacteremia score (≤3), mortality was similar between the two treatment groups (26.3% vs 23.1%). Conclusion Treatment with colistin plus meropenem improves survival in critically-ill patients with CRAB.