Yellow fever (YF) remains endemic in parts of Africa and South America. Although the YF vaccine, derived from the 17D strain, is highly effective, concerns remain regarding its safety and immunogenicity in elderly individuals over 60 years old. WHO classifies YF vaccination in this age group as a relative contraindication, recommending that healthcare providers carefully weigh the risks and benefits with recipients. As international travel from Korea to YF-endemic areas rises, including among older adults, data are needed to guide vaccination in this population.Figure 1.Comparison of (A) Humoral (YFV-gE Ab Titer) and (B) Cellular (IFN-γ ELISPOT) Immune Response Between in <60 and ≥60 age groups at a time point exceeding five years post-vaccination.. We retrospectively reviewed adults vaccinated against YF at Pusan National University Hospital between September 2016 and January 2020. Adverse events (AEs) were assessed via telephone interviews. A subset of recipients underwent blood sampling for humoral and cellular immune response testing in 2024. Anti-YFV envelope IgG titers were measured by ELISA, and cellular responses were assessed via IFN-γ ELISPOT assays. Participants were grouped by age (< 60 vs. ≥60 years) for comparative analysis. A comparison of each group was performed using the Mann–Whitney Wilcoxon unpaired test and results were considered significant at P < 0.05. Among 1,021 vaccinees, 691 (67.7%) were aged ≥60 years. No serious AEs were reported at the time of vaccination. Of the 454 individuals (44.5%) who completed telephone follow-up, 6 (1.3%) reported mild AEs (febrile sensation in 4; myalgia in 2) and no serious AE. Seventy-one individuals underwent immunogenicity assessment at a time point exceeding five years post-vaccination, with a median age of 62 years (49.3% male), including 44 individuals aged ≥60 years. Median log anti-YFV IgG titer was 3.83 (IQR, 3.55–4.25) in the elderly vs. 3.77 (IQR, 3.47–3.94) in the non-elderly (P = 0.55) (Figure 1). Median IFN-γ ELISPOT responses were 17.50 (IQR, 0–50.83) in the elderly vs. 15.00 (IQR, 1.67–146.7) in the non-elderly (P = 0.67) (Figure 1B). Yellow fever vaccination was well tolerated with no serious adverse events and preserved humoral and cellular immune responses in older adults. These findings support the safe use of YF vaccine in elderly Korean travelers, particularly when benefits outweigh risks in endemic-area travel. All Authors: No reported disclosures

OBJECTIVE:Antimicrobial resistance is a global health problem, with methicillin-resistant Staphylococcus aureus (MRSA) causing significant morbidity and mortality. As antibiotic options dwindle, (bacterio) phage therapy is re-emerging as a promising alternative. METHODS:We characterised a novel lytic S. aureus phage, PBSA08, and evaluated its host range using a reference panel of 39 MRSA isolates selected from the 2021 Australian Group on Antimicrobial Resistance repository. Phage susceptibility was tested by efficiency of plating (EOP) and growth kinetics assays (GKA). Factors associated with phage susceptibility were evaluated. RESULTS:Phage PBSA08, classified under the genus Silviavirus, revealed an icosahedral head and long tail structure using transmission electron microscopy. Adsorption assays indicated efficient bacterial binding, with a burst size of approximately 120 plaque forming units (PFU) per infected cell. EOP testing revealed 51.3% of the MRSA reference panel isolates were susceptible (EOP ≥10%). GKA results correlated strongly with EOP. In univariate analysis, phage PBSA08 susceptibility was associated with multilocus sequence type (ST), ciprofloxacin susceptibility, and the presence of the Panton-Valentine leucocidin-associated genes, with all ST30-IV and ST93-IV isolates susceptible to PBSA08 and all ST45-V isolates resistant to PBSA08. Firth logistic regression showed that ST30/93 isolates had significantly higher odds of susceptibility (aOR 68.9, 95% CI 2.0-2378.5; P = 0.0191), as did ciprofloxacin-susceptible strains (aOR 15.4, 95% CI 1.7-143.0; P = 0.0160). CONCLUSIONS:PBSA08 demonstrates potential as a therapeutic phage, particularly against community-associated MRSA lineages such as ST93. Its inclusion in phage cocktails targeting prevalent MRSA clones warrants further investigation.

Background Carbapenem-resistant Enterobacterales (CRE) poses a significant public health threat. In Korea, the current surveillance systems do not distinguish between colonisation and infection. This study evaluated the clinical and socioeconomic burden of CRE infections in Korea. Methods This retrospective study was conducted at 15 medical institutions. All patients with CRE-positive clinical specimens in 2022 were classified as either ‘CRE-infected’ or ‘colonised’. Clinical data and medical costs were collected for the ‘CRE-infected’ cohort. A predictive logistic regression model based on sex, age, presence of bacteraemia, and bacterial species was developed to estimate the nationwide incidence of CRE infections. For cases of CRE bacteraemia, the clinical information of the matched control groups (no-infection, 3rd-generation-cephalosporin [3GC]-susceptible infection, and 3GC-resistant infection) was collected. Findings Among the 4,848 reported CRE cases, 1,087 (22.4%) were classified as infections, including 586 bacteraemia cases. The most common infection sites were intra-abdominal (34.0%) and pulmonary (31.3%). Carbapenemase-producing Enterobacterales accounted for 74.2% of cases, with Klebsiella pneumoniae carbapenemase (84.4%) being the most prevalent. The 30-day and 90-day mortality rates were 29.3% and 40.8%, respectively. The predictive model estimated 7,117 CRE infections nationwide, including 1,897 cases of bacteraemia. The economic burden of CRE infections in 2022 was estimated to be $517,738,296, with excess costs ranging from $108,382,302 to $401,186,712, compared with carbapenem-susceptible infections and cases without infection. Conclusions This study highlights the substantial clinical and socioeconomic burden of CRE infections in Korea. Given the continued increase in reported CRE cases even after 2022, urgent measures are required to address this growing public health challenge.

BACKGROUND:The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted the healthcare workforce. This study aimed to compare needlestick and sharp injuries (NSIs) incidence between the pre-pandemic period and the pandemic period and to assess how hospital responses influenced NSI incidence among healthcare workers. METHODS:This retrospective study was conducted at a tertiary care hospital designated for COVID-19 management. We compared the incidence of NSIs before (2017-2019) and after (2020-2022) the pandemic onset. The incidence, expressed as cases per 100 full-time equivalents (FTEs) per year, was analyzed using generalized linear regression with interrupted time series analysis based on the Prais-Winsten model. RESULTS:Hospital admissions (7.63%) and surgeries (7.01%) declined in the first pandemic year and continued to decrease, whereas the workforce steadily increased. A total of 844 NSIs were reported, with 475 (56.3%) before the pandemic and 369 (43.7%) during the pandemic. The overall NSI incidence (per 100 FTEs/year) declined both immediately after the outbreak (from 5.78 in 2019 to 4.58 in 2020, P = 0.530) and throughout the pandemic (from 4.58 in 2020 to 3.89 in 2022, P = 0.756). By occupation, incidence among nurses significantly decreased immediately after the outbreak (from 7.6 in 2019 to 5.2 in 2020, P = 0.035). Of the 369 NSIs during the pandemic, most occurred in non-COVID-19 care areas, with only 9 cases (2.4%) in COVID-19 care areas. CONCLUSION:Our study observed a declining trend in NSI incidence during the COVID-19 pandemic, likely related to reduced hospitalizations, adequate staffing, optimized patient contact and infection control measures.

Carbapenem-resistant Enterobacterales (CRE) pose a significant public health threat. While CRE isolation from clinical specimens is a mandatory national notifiable event in Korea, current surveillance systems do not differentiate between colonization and infection, hindering accurate estimation of the disease burden. This study aimed to assess the clinical and socio-economic burden of CRE infections in Korea. A retrospective study was conducted across fifteen geographically diverse medical institutions. Medical records from all cases with CRE-positive clinical specimens in 2022 were reviewed and classified as “CRE-infected” or “colonized.” For the “CRE-infected” cohort, clinical data and medical costs were collected. A predictive logistic regression model was developed using sex, age, presence of bacteremia, and bacterial species to estimate the nationwide CRE infections. For cases of CRE bacteremia, matched control groups (no-infection, 3rd generation-cephalosporin-susceptible [3GC-S], and 3GC-resistant [3GC-R] infections) were used to assess the incremental burden of CRE. Of 4,848 reported CRE cases, accounting for 15.9% of the 30,548 reported in Korea, 1,087 (22.4%) were classified as infections, including 586 bacteremic cases. Intra-abdominal infection (34.0%) and pneumonia (31.3%) were the most common infection sites. Klebsiella pneumoniae was the most frequent pathogen (77.0%) of CRE infections. Carbapenemase-producing Enterobacterales accounted for 74.2%, with KPC (84.4%) being the most common type. The 30-day and 90-day mortality rates were 29.3% and 40.8%, respectively. Nationwide, 7,117 CRE infections were estimated by the predictive logistic regression model, including 1,897 bacteremia. The total cost per CRE infection was estimated at $78,071. The economic burden of CRE infections in 2022 was estimated at $517,610,261, exceeding that of no-infection, 3GC-S, and 3GC-R infections by $108,355,500 to $401,087,500. This study confirmed the profound clinical and socioeconomic burden of CRE infections in Korea. Considering the rapidly increasing number of reported CRE cases even after 2022, it is urgent to prepare corresponding measures against CRE infections. Kyoung-Ho Song, MD, PhD, PhAST Corp.: Advisor/Consultant|PhAST Corp.: Grant/Research Support

OBJECTIVES:This study compared the efficacy of cefazolin in a mouse pneumonia model caused by a methicillin-susceptible Staphylococcus aureus (MSSA) strain with cefazolin inoculum effect (CIE) and its blaZ-eliminated derivative. METHODS:An isogenic blaZ gene-eliminated strain was derived from type A blaZ-positive MSSA blood isolates exhibiting CIE: PNIDSA230 (parental strain, CIE+) and PNIDSA230c (blaZ-eliminated strain, CIE-). Mice were inoculated with 2 × 10⁶ to 2 × 10⁷ cfu of MSSA via endotracheal tubes and treated with intraperitoneal cefazolin or oxacillin 5 h post-inoculation. Bacterial loads in the lungs (primary sites), liver, and kidneys (metastatic foci) were measured 24 h later. RESULTS:Cefazolin reduced bacterial densities in the lungs of CIE-positive MSSA-infected mice (n = 11) compared with untreated controls (n = 11) (mean log10 cfu/g ± SD, 6.0 ± 1.6 versus 9.4 ± 2.7; P = 0.006). However, the efficacy of cefazolin was significantly lower in CIE+ infections than in CIE- infections (mean log10 cfu/g ± SD, 6.0 ± 1.6 versus 4.4 ± 0.8, P = 0.0258). Cefazolin-treated CIE- MSSA-infected mice showed no metastatic infections, while 7 of the 11 CIE+ MSSA-infected mice developed liver or kidney infections despite cefazolin treatment. Oxacillin treatment significantly reduced bacterial densities of the lungs, liver, and kidney in CIE-positive (n = 4) and CIE-negative (n = 4) MSSA-infected mice, with no significant differences between CIE-positive and CIE-negative MSSA infections. CONCLUSIONS:CIE may diminish cefazolin's efficacy in severe MSSA infections and contribute to the development of metastatic infection foci. Oxacillin remains effective regardless of CIE status.

This retrospective study analyzed data from 1,192 men living with HIV (MWH) between 2002 and 2023, and identified 76 anogenital wart cases (6.4%), which were predominantly anal (n=67). Among 20 individuals with anal warts who underwent biopsy, 25% had high-grade squamous intraepithelial lesions (SILs). Of 15 individuals with low-grade SILs, one progressed to high-grade SIL after 5 years, and two developed anal cancer at 5 and 15 years. High-risk human papillomavirus genotypes were detected in 42.9% of tested specimens. These findings highlight the importance of routine screening and early detection of precancerous lesions in MWH in Korea.

Plasmids containing the wild-type (WT) or mutant type A blaZ (blaZ(A)) gene (mutations at codons 226, 229, or both 226 and 229) were constructed and transformed into Staphylococcus aureus RN4220, yielding the strains WT-blaZ, M226-blaZ, M229-blaZ, and MB-blaZ. The high-inoculum cefazolin MIC was significantly lower in MB-blaZ and M226-blaZ than in WT-blaZ but not in M229-blaZ, suggesting that the single nucleotide polymorphism at codon 226 in blaZ(A) contributes to the cefazolin inoculum effect.

Background: A healthcare system's collapse due to a pandemic, such as the coronavirus disease 2019 (COVID-19), can expose healthcare workers (HCWs) to various mental health problems. This study aimed to investigate the impact of the COVID-19 pandemic on the depression and anxiety of HCWs. Methods: A nationwide questionnaire -based survey was conducted on HCWs who worked in healthcare facilities and public health centers in Korea in December 2020. Patient Health Questionnaire -9 (PHQ-9) and Generalized Anxiety Disorder -7 (GAD -7) were used to measure depression and anxiety. To investigate factors associated with depression and anxiety, stepwise multiple logistic regression analysis was performed. Results: A total of 1,425 participating HCWs were included. The mean depression score (PHQ-9) of HCWs before and after COVID-19 increased from 2.37 to 5.39, and the mean anxiety score (GAD -7) increased from 1.41 to 3.41. The proportion of HCWs with moderate to severe depression (PHQ-9 >= 10) increased from 3.8% before COVID-19 to 19.5% after COVID-19, whereas that of HCWs with moderate to severe anxiety (GAD -7 >= 10) increased from 2.0% to 10.1%. In our study, insomnia, chronic fatigue symptoms and physical symptoms after COVID-19, anxiety score (GAD -7) after COVID-19, living alone, and exhaustion were positively correlated with depression. Furthermore, post -traumatic stress symptoms, stress score (Global Assessment of Recent Stress), depression score (PHQ-9) after COVID-19, and exhaustion were positively correlated with anxiety. Conclusion: In Korea, during the COVID-19 pandemic, HCWs commonly suffered from mental health problems, including depression and anxiety. Regularly checking the physical and mental health problems of HCWs during the COVID-19 pandemic is crucial, and social support and strategy are needed to reduce the heavy workload and psychological distress of HCWs.

BACKGROUND:Concerns about the rise in antimicrobial resistance have led to renewed interest in phage therapy worldwide, but perceptions among relevant medical professionals in Korea remain largely unknown.MATERIALS AND METHODS:We conducted a semi-quantitative online survey to evaluate the Korean infectious disease specialists' perception of phage therapy.RESULTS:We sent out the link to the questionnaire to 380 subjects and received 91 replies, with 90/91 respondents identifying as Korean infectious diseases specialists or trainees. Ten out of 91 (11.0%) respondents scored themselves as well-informed about phage therapy. The majority (93.4%) of respondents would consider using phage therapy if the safety of the phage formulation is guaranteed, and 80% of respondents would consider participating in clinical trials with phage therapy given adequate support. The biggest concern was uncertainty about safety (73.6%) and efficacy (65.9%). Acinetobacter baumannii was ranked as a high priority for phage therapy research, as were bone and joint infections.CONCLUSION:Korean infectious diseases specialists are receptive to phage therapy, but a better understanding of safety, efficacy and clinical trials are warranted to progress phage therapy within the Korean healthcare system.

Despite widespread application during the coronavirus disease-19 pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection using patient-performed rapid antigen tests (RATs) is limited, especially regarding the Delta and Omicron variants. Therefore, in this study, we evaluated the performance of RATs in identifying Delta and Omicron infections in self-test settings. In this multicenter clinical performance study conducted in Korea between November 2021 and February 2022, we included participants without prior diagnostic device experience. Using 2 RAT types, we compared the results with real-time reverse transcriptase-polymerase chain reaction testing, focusing on clinical sensitivity and specificity. Reverse transcriptase-polymerase chain reaction helped confirm 77 SARS-CoV-2 infections among 280 participants. RATs exhibited high positive agreement for Omicron detection but lower rates for Delta, especially among partially vaccinated individuals. This study provides direct evidence that RATs, originally developed for ancestral strains of SARS-CoV-2, effectively detect major variants such as Delta and Omicron in real patient/clinical settings. By confirming variant presence through sequencing, our research offers significant and novel insights into the performance of RATs, particularly in the context of breakthrough infections postvaccination, with precise data on vaccination status and timing obtained from government records.

We aimed to assess the temporal trends of incident syphilis and its associated risk factors among men with HIV (Human Immunodeficiency Virus) in Korea during the COVID-19 pandemic. We conducted a retrospective cohort study of men with HIV attending an HIV clinic in Korea between 2005 and 2022. Of 767 men with HIV, 499 were included and contributed 3220 person-years (PY) of the observation period. Eighty-two patients were diagnosed with incident syphilis, with an overall incidence of 2.55/100 PY (95% confidence interval [CI] 20.56–31.53). The incidence of syphilis per 100 PY gradually decreased from 2.43 (0.79–7.42) in 2005–2007 to 1.85 (1.08–3.17) in 2014–2016; however, it increased to 3.0 (1.99–4.53) in 2017–2019, and further to 3.33 (2.26–4.89) in 2020–2022. A multivariate analysis identified young age (≤30 years versus >50, adjusted HR 6.27, 95% CI 2.38–16.56, p < 0.001), treponemal test positive at baseline (2.33, 1.48–3.67, p < 0.001), men who have sex with men (2.36, 1.34–4.16, p = 0.003), and history of incarceration (2.62, 1.21–5.67, p = 0.015) as risk factors for incident syphilis. Recently, syphilis incidence in men with HIV has increased in Korea, especially in young patients and at-risk groups, highlighting the need for enhanced regular screening and targeted behavioral interventions among these populations.

Abstract Background Despite the importance of multidrug-resistant organisms (MDRO) bacteremia, especially extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) or carbapenem-resistant Enterobacteriaceae (CRE), the disease burden of those has not been investigated in detail. Thus, we tried to evaluate the clinical outcomes and estimate the socioeconomic burden of those MDROs bacteremia at a nationwide level in the Republic of Korea. Methods We retrospectively searched for all cases of ESBL-E or CRE bacteremia, as well as matched control patients, in ten hospitals representing regions across the country over a six-month period. Patients with ESBL-E or CRE bacteremia were classified as the R group, while matched controls with antibiotic-susceptible bacteremia or those without infection were classified as the S and N groups, respectively. Patients’ clinical data, including demographic data, underlying medical conditions, and microbiologic data were collected. We estimated economic burden by considering medical expenses, loss of productivity, and total costs. Results We identified a total of 795 patients, including 265 cases with ESBL-E or CRE bacteremia, and their matched controls after propensity-score matching. The mean total length of stay for ESBL-E and CRE matching in the R group were 7.8 days and 18.3 days longer compared to the S group, and 12.2 days and 14.5 days longer compared to the N group. The 90-day mortality rates for ESBL-E and CRE matching in the R, S, and N groups were 12.1%, 5.6%, 3.4%, and 24.0%, 12.0%, 0.0%, respectively. The total costs of the R, S, and N groups showed significant differences in both ESBL-E and CRE matching ($11,151 vs. $8,712 vs. $6,063, P = 0.004; $40,464 vs. $8,748 vs. $7,279, P = 0.024). Conclusion The mortality rates of ESBL-E or CRE bacteremia were found to be tremendously high. Furthermore, the economic burden imposed by ESBL-E or CRE bacteremia, compared to controls without infection, were approximately two and five times higher, respectively. These findings suggest that ESBL-E and CRE bacteremia impose a significant clinical and economic burden, and adequate efforts to control these resistant bacteremia might be necessary to reduce this burden. This Study is sponsored by Pfizer Pharmaceuticals Korea Ltd. Disclosures All Authors: No reported disclosures

Background: Limited information is available on the clinical course and treatment outcomes of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection in Korea. Materials and Methods: A retrospective case series was conducted of patients with HIV-HCV coinfection who received interferon (IFN)-based or direct-acting antiviral (DAA) treatment for HCV at a tertiary care hospital between 2000 and 2023. Early virological response (EVR) was defined as a 2-log reduction in HCV RNA levels or undetectable HCV RNA levels at treatment week 12. A sustained virologic response (SVR) was defined as undetectable HCV RNA at 12 weeks after treatment completion. Results: Of the 33 patients with HIV-HCV coinfection, 19 received anti-HCV treatment, of whom 12 received IFNbased treatment and 10 received DAA treatment. The median age at the time of anti-HCV treatment was 49 years (interquartile range, 42-57 years) and 15 patients (79%) were male. Of the 12 patients who received IFN-based antiHCV treatment, 10 showed EVR and 8 achieved SVR. However, 2 patients who achieved SVR experienced recurrence of HCV infection during follow-up; therefore, the overall success rate of IFN-based treatment was 50% (6/12). All 10 patients (including 3 in whom IFN-based treatment failed) who received DAA treatment (5 with previous anti-HCV treatment and 5 treatment-na & iuml;ve), achieved SVR and did not experience recurrence of HCV infection during followup; therefore, the overall success rate of DAA treatment was 100%. Conclusion: In Korean patients with HIV-HCV coinfection, treatment outcomes were better with DAA treatment than with IFN-based treatment.

During the coronavirus disease 2019 (COVID-19) pandemic, frontline healthcare workers (HCWs) suffered more distress from the possibility of contracting the virus, quarantine, social stigma, and prejudice against their families. Many studies have investigated the impact of the pandemic on HCWs; however, studies or guidelines presenting strategies to overcome these challenges are lacking. As part of a 2020 research project supported by the Ministry of Health and Welfare, titled "Health impact assessment of healthcare workers undertaking coronavirus disease 2019 treatment and management in Korea: Identifying problems and researching effective solutions" (HC20C0003), we created guidelines to respond to serious problems posed by infection control. and burnout among HCWs during COVID-19 response measures throughout the extended pandemic period. We formulated the guidelines by means of a systematic review and collated them with the latest literature. The guidelines will highlight the gravity and impact of infection control and burnout among HCWs responding to COVID-19 and include potential prevention strategies, and they can be used as a reference in the event of another emerging infectious disease outbreak in the future.

The appropriate use of carbapenem is a critical concern for patient safety and public health, and is a national priority. We investigated the nationwide status of carbapenem prescription in patients within their last 14 days of life to guide judicious-use protocols from the previous study comprised of 1350 decedents. Carbapenem use was universally controlled through computerised authorisation system at all centres during the study period. Carbapenem prescribing patterns and their optimality were evaluated. A total of 1201 patients received antimicrobial agents within the last two weeks of their lives, of whom 533 (44.4%) received at least one carbapenem. The median carbapenem treatment duration was seven days. Of the 533 patients receiving carbapenems, 510 (95.7%) patients had microbiological samples drawn and 196 (36.8%) yielded carbapenem-resistant pathogens. A total of 200 (37.5%) patients were referred to infectious disease (ID) specialists. Of the 333 patients (62.5%) who did not have ID consultations, 194 (58.2%) were assessed as "not optimal", 79 (23.7%) required escalation, 100 (30.0%) required de-escalation, and 15 (4.5%) were discontinued. Notwithstanding the existing antibiotic restriction program system, carbapenems are commonly prescribed to patients in their last days of life.

Abstract Background Timely access is a major concern when considering phage therapy. Using susceptible phage is critical for the outcomes of phage therapy. For timely access to susceptible phages, identifying factors associated with phage susceptibility and building a reference set (RS) to compare host ranges is needed. Methods Phage K, which was a well-documented lytic S. aureus phage, and phage PBSA02, which was a new S. aureus phage from the Korean phage biobank, were used. The efficiency of plating (EOP), the relative activity of phage against specific strain/host strain, and growth kinetics assays were used to determine phage susceptibility. The isolates with high lytic activity (HLA) were defined as susceptible (EOP > 1%). The phage PBSA02 and phage K susceptible groups were compared to the non-susceptible groups to determine the associating factors of phage susceptibility. Results We constructed a methicillin-resistant S. aureus (MRSA) RS using the Australian Group on Antimicrobial Resistance (AGAR) repository. We determined the predominant sequence types (ST) of MRSA in Australia in 2021; ST22 accounted for 90.1% of HA-MRSA and 5 STs for 67.9% of CA-MRSA (figure 1). Then, we randomly selected 39 AGAR MRSA isolates corresponding to each ST from each region in Australia (figure 1). Phage PBSA02 exhibited HLA against 56.4% of the 39 RS isolates, while phage K exhibited HLA against 30.8%. Phage PBSA02 showed HLA against 100% of ST93 and ST30 isolates following ST1 (62.5%), ST22 (37.5%), ST5 (20%) and ST45 (16.7%); phage K showed HLA against 100% of ST30 and 62.5% of ST22 isolates but against none of the ST93 isolates. Phage PBSA02 susceptibility correlated with the ST of MRSA isolates and ciprofloxacin susceptibility (table 1). Isolates from pneumonia/empyema tended to show phage PBSA02 susceptibility (table 1). Phage K susceptibility was also significantly associated with the ST (table 2). Conclusion Our study demonstrated that phage susceptibility was associated with the STs of MRSA, and the RS could be useful for a standardised comparison of the phage host range. Phage PBSA02 with broad susceptibility to the RS could be useful for phage therapy. Further work includes antibiotic synergy testing and resistance mechanism identification in these isolates. Disclosures All Authors: No reported disclosures

Burnout is a form of negative emotional and physical response to job stress. This study aimed to investigate the prevalence of burnout among healthcare workers responding to the coronavirus disease 2019 (COVID-19) outbreak in Korea and to explore correlates of burnout among healthcare workers. A nationwide questionnaire-based survey was conducted from December 1, 2020, to January 29, 2021 on 1425 healthcare workers who worked in one of the 16 healthcare facilities designated for COVID-19 care, in public health centers, or as paramedics in Korea. Burnout was assessed using 16 Korean-adapted items based on the Oldenburg Burnout Inventory (OLBI). Data were collected using a structured questionnaire and analyzed using the R version 4.1.1 software program. OLBI results indicate clinically exhaustion in 84.5% (1204/1425) and clinically disengagement in 91.1% (1298/1425), and 77.3% (1102/1425) met the score criteria for both the exhaustion and disengagement subscales for burnout. Burnout rate was significantly increased in the group with chronic fatigue symptoms (Fatigue Severity Scale ≥ 3.22) after the outbreak of COVID-19 (OR, 3.94; 95% CI 2.80–5.56), in the female group (OR, 2.05; 95% CI 1.46–2.86), in the group with physical symptoms (Patient Health Questionnaire-15 ≥ 10) after the outbreak of COVID-19 (OR, 2.03; 95% CI 1.14–3.60), in the group with a higher Global Assessment of Recent Stress scale (OR, 1.71; 95% CI 1.46–2.01), in the group with post-traumatic stress symptoms (Primary Care Post-Traumatic Stress Disorder-5 ≥ 2) (OR, 1.47; 95% CI 1.08–2.01), and in the younger age group(OR, 1.45; 95% CI 1.22–1.72). The chronic fatigue symptoms were correlated with cumulative days of care (OR, 1.18; 95% CI 1.02–1.37). The physical symptoms were correlated with average contact hours with COVID-19 patients per day (OR, 1.34; 95% CI 1.17–1.54), and cumulative days of care (OR, 1.21; 95% CI 1.06–1.38). Most Korean healthcare workers suffered from burnout related to excessive workload during the COVID-19 pandemic. During a widespread health crisis like COVID-19, it is necessary to regularly check the burnout status in healthcare workers and reduce their excessive workload by supplementing the workforce and providing appropriate working hours sufficient rest hours.

BACKGROUND:Antimicrobial prescriptions for serious chronic or acute illness nearing its end stages raise concerns about the potential for futile use, adverse events, increased multidrug-resistant organisms, and significant patient and social cost burdens. This study investigated the nationwide situation of how antibiotics are prescribed to patients during the last 14 days of life to guide future actions.METHODS:This nationwide multicenter retrospective cohort study was conducted at 13 hospitals in South Korea from November 1 to December 31, 2018. All decedents were included in the study. Antibiotic use during the last two weeks of their lives was investigated.RESULTS:A total of 1,201 (88.9%) patients received a median of two antimicrobial agents during the last two weeks of their lives. Carbapenems were prescribed to approximately half of the patients (44.4%) in the highest amount (301.2 days of therapy per 1,000 patient-days). Among the patients receiving antimicrobial agents, 63.6% were inappropriate and only 327 patients (27.2%) were referred by infectious disease specialists. The use of carbapenem (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.13-2.03; P = 0.006), underlying cancer (OR, 1.56; 95% CI, 1.20-2.01, P = 0.047), underlying cerebrovascular disease (OR, 1.88; 95% CI, 1.23-2.89, P = 0.004), and no microbiological testing (OR, 1.79; 95% CI, 1.15-2.73; P = 0.010) were independent predictors for inappropriate antibiotic prescribing.CONCLUSION:A considerable number of antimicrobial agents are administered to patients with chronic or acute illnesses nearing their end-of-life, a high proportion of which are prescribed inappropriately. Consultation with an infectious disease specialist, in addition to an antimicrobial stewardship program, may be necessary to induce the optimal use of antibiotics.