Trends of antibiotic use at the end-of-life of cancer and non-cancer decedents: a nationwide population-based longitudinal study (2006-2018)

Objective

This study aimed to assess the actual burden of antibiotic use among end-of-life (EOL) patients in South Korea and to compare trends between cancer and non-cancer decedents.

Design

Population-based mortality follow-back study.

Setting

Data from the Korean National Health Insurance Database, covering the period from January1, 2006, to December 31, 2018, provided for research by the National Health Insurance Service (NHIS), were used.

Participants

All decedents from 2006 to 2018 were included and categorized as cancer decedents or non-cancer decedents.

Methods

Annual antibiotic consumption rates and prescription rates were calculated, and Poisson regression was used to estimate their trends.

Results

Overall antibiotic consumption rates decreased slightly among decedents in their final month with a less pronounced annual decrease rate among cancer decedents compared to non-cancer decedents (0.4% vs 2.3% per year, P <.001). Over the study period, although narrow spectrum antibiotics were used less, utilization and prescription of broad-spectrum antibiotics steadily increased, and prescription rates were higher in cancer decedents compared to non-cancer controls. Specifically, carbapenem prescription rates increased from 5.6% to 18.5%, (RR 1.087, 95% CI 1.085-1.088, P <.001) in cancer decedents and from 2.9% to 13.2% (RR 1.115, 95% CI 1.113-1.116, P <.001) in non-cancer decedents.

Conclusions

Our findings show that patients at the EOL, especially those with cancer, are increasingly and highly exposed to broad-spectrum antibiotics. Measures of antibiotic stewardship are required among this population.

Persistent differences in the immunogenicity of the two COVID-19 primary vaccines series, modulated by booster mRNA vaccination and breakthrough infection

INTRODUCTION

The long-term impact of initial immunogenicity induced by different primary COVID-19 vaccine series remains unclear.

METHODS

A prospective cohort study was conducted at 10 tertiary hospitals in Korea from March 2021 to September 2022. Immunogenicity assessments included anti-spike protein antibody (Sab), SARS-CoV-2-specific interferon-gamma releasing assay (IGRA), and multiplex cytokine assays for spike protein-stimulated plasma. Spike proteins derived from wild-type SARS-CoV-2 and alpha variant (Spike1) and beta and gamma variant (Spike2) were utilized.

RESULTS

A total of 235 healthcare workers who had received a two-dose primary vaccine series of either ChAdOx1 or BNT162b2, followed by a third booster dose of BNT162b2 (166 in the ChAdOx1/ChAdOx1/BNT162b2 (CCB) group and 69 in the BNT162b2/BNT162b2/BNT162b2 (BBB) group, based on the vaccine series) were included. Following the primary vaccine series, the BBB group exhibited significantly higher increases in Sab levels, IGRA responses, and multiple cytokines (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, interleukin (IL)-1ra, IFN-γ, IL-2, IL-4, and IL-10) compared to the CCB group (all P < 0.05). One month after the third BNT162b2 booster, the CCB group showed Sab levels comparable to those of the BBB group, and both groups exhibited lower levels after six months without breakthrough infections (BIs). However, among those who experienced BA.1/2 BIs after the third booster, Sab levels increased significantly more in the BBB group than in the CCB group (P < 0.001). IGRA responses to both Spike1 and Spike2 proteins were significantly stronger in the BBB group than the CCB group after the third booster, while only the Spike2 response were higher after BIs (P = 0.007). The BBB group exhibited stronger enhancement of T-cell cytokines (IL-2, IL-4, and IL-17A) after BIs than in the CCB group (P < 0.05).

CONCLUSION

Differences in immunogenicity induced by the two primary vaccine series persisted, modulated by subsequent booster vaccinations and BIs.

Incidence of Clostridioides difficile Infections in Republic of Korea: A Prospective Study With Active Surveillance vs. National Data From Health Insurance Review & Assessment Service

BACKGROUND

Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly.

METHODS

To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020.

RESULTS

In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patient-days was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25-12.05) and 4.18 per 1,000 admissions (range: 1.92-8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68-13.90) and 6.73 per 1,000 admissions (range: 3.18-15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively.

CONCLUSION

The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

Staphylococcus argenteus bacteremia in the Republic of Korea

In 2015, Staphylococcus argenteus and Staphylococcus schweitzeri were proposed as new species, distinct from Staphylococcus aureus and collectively referred to as the S. aureus complex. However, no clinical reports of these new species exist in Korea. Upon the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for all bloodstream isolates since September 2022, S. argenteus was identified in one patient. Therefore, we aimed to search for new species among the archives of the S. aureus bacteremia cohort and describe their clinical and microbiological characteristics. Among the 691 archived S. aureus isolates between 2012 and 2018, one was identified as S. argenteus via MALDI-TOF MS. Both S. argenteus isolates (one in 2022) were obtained from patients with extensive pneumonia accompanied by bacteremia and both cases had fatal outcomes. They harbored multiple virulence genes (clfA, clfB, fnbpA, sdrC, sdrD, sdrE, bbp, cna, see, seg, sei, blaZ, fnbpB, and map) but did not harbor mecA and pvl. No matched sequence type (ST) was found in either isolate, and both S. argenteus isolates were closely related to ST1594, ST1593, ST1793, and ST1303, which belonged to S. argenteus. S. argenteus accounted for <1% of the S. aureus complex but had clinical characteristics similar to S. aureus. Therefore, clinicians should be aware of these factors to avoid misidentifying these strains as coagulase-negative staphylococci, and appropriate reporting is required to minimize confusion.IMPORTANCEStaphylococcus argenteus, a member of Staphylococcus aureus complex, has been reported as an important pathogen that causes clinically invasive infections in humans similar to S. aureus. Clinical isolates of S. argenteus have been reported across the world, showing a large geographical difference in prevalence and genomic profile. However, there have been no clinical reports regarding this new species in Korea. This is the first report to investigate the clinical and genetic characteristics of S. argenteus identified in patients with bacteremia, and the proportion of S. argenteus bacteremia among S. aureus bacteremia cohort in Korea.

Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea

BACKGROUND

Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly.

AIM

To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea.

METHODS

A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs.

FINDINGS

In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024).

CONCLUSION

The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

False-positive results of galactomannan assays in patients administered glucose-containing solutions

Galactomannan (GM) is a polysaccharide cell wall component released by Aspergillus spp., and an immunoenzymatic GM assay is used for the diagnosis of invasive pulmonary aspergillosis. We evaluated the cause of strong positivity for GM in patients with no typical signs of aspergillosis. Repeat assays were performed using different instruments and reagent lots, but there were no differences in results among the assays. Patients with strongly positive GM results were investigated. Medication histories revealed that 14 of 23 patients had been administered total parenteral nutrition solution from one manufacturer and 4 patients had been administered dextrose solution from a different manufacturer before being tested. The results of GM assays conducted on samples of dextrose solution and the glucose fraction of the total parenteral nutrition solution were strongly positive, confirming the causes of the false-positive reactions. We hypothesize that a trace amount of GM was introduced into the glucose-containing solutions because glucoamylase, which is necessary for the saccharification step of glucose synthesis, was derived from Aspergillus niger. To enhance patient care and prevent unnecessary antifungal prescriptions, healthcare providers and manufacturers of healthcare products need to be aware of the possibility of false-positive reactions for GM.

Clinical Features of Mpox Patients in Korea: A Multicenter Retrospective Study

BACKGROUND

Mpox is a viral illness with a characteristic skin rash caused by the monkeypox virus. In 2022, Mpox spread throughout the world, and an epidemic through domestic transmission started in South Korea in early 2023. This study aimed to summarize the clinical features of Mpox patients in South Korea.

METHODS

This is a multicenter retrospective study conducted at four hospitals in South Korea. All adult patients diagnosed with Mpox who were admitted to the study hospitals between June 1, 2022 and May 26, 2023 and were discharged by June 30, 2023 were reviewed.

RESULTS

Sixty patients were included, accounting for 65.9% of Mpox cases reported in South Korea during the study period. Median age was 32 years and 97% (58/60) of patients were male. In total, 85% (51/60) of patients reported their sexual orientation as homosexual or bisexual. The most common route of transmission was sexual or close contact (55/60). Every patient had a skin rash and 88% (53/60) had constitutional symptoms. In total, 42% (25/60) of patients had human immunodeficiency virus and 25% (15/60) had concomitant sexually transmitted infections. Severe manifestations of Mpox were identified in only two patients.

CONCLUSION

Mpox patients in South Korea were mainly young adult males and were infected through sexual contact. The clinical outcomes were favorable.

Development of machine learning algorithms for scaling-up antibiotic stewardship

BACKGROUND

Antibiotic stewardship programs (ASP) aim to reduce inappropriate use of antibiotics, but their labor-intensive nature impedes their wide adoption. The present study introduces explainable machine learning (ML) models designed to prioritize inpatients who would benefit most from stewardship interventions.

METHODS

A cohort of inpatients who received systemic antibiotics and were monitored by a multidisciplinary ASP team at a tertiary hospital in the Republic of Korea was assembled. Data encompassing over 130,000 patient-days and comprising more than 160 features from multiple domains, including prescription records, laboratory, microbiology results, and patient conditions was collected.Outcome labels were generated using medication administration history: discontinuation, switching from intravenous to oral medication (IV to PO), and early or late de-escalation. The models were trained using Extreme Gradient Boosting (XGB) and light Gradient Boosting Machine (LGBM), with SHapley Additive exPlanations (SHAP) analysis used to explain the model's predictions.

RESULTS

The models demonstrated strong discrimination when evaluated on a hold-out test set(AUROC - IV to PO: 0.81, Early de-escalation: 0.78, Late de-escalation: 0.72, Discontinue: 0.80). The models identified 41%, 16%, 22%, and 17% more cases requiring discontinuation, IV to PO, early and late de-escalation, respectively, compared to the conventional length of therapy strategy, given that the same number of patients were reviewed by the ASP team. The SHAP results explain how each model makes their predictions, highlighting a unique set of important features that are well-aligned with the clinical intuitions of the ASP team.

CONCLUSIONS

The models are expected to improve the efficiency of ASP activities by prioritizing cases that would benefit from different types of ASP interventions along with detailed explanations.

Clinical utility of quantitative immunoassays and surrogate virus neutralization tests for predicting neutralizing activity against the SARS-CoV-2 Omicron BA.1 and BA.5 variants

Developing new antibody assays for emerging SARS-CoV-2 variants is challenging. SARS-CoV-2 surrogate virus neutralization tests (sVNT) targeting Omicron BA.1 and BA.5 have been devised, but their performance needs to be validated in comparison with quantitative immunoassays. First, using 1749 PRNT-positive sera, we noticed that log-transformed optical density (OD) ratio of wild-type (WT) sVNT exhibited better titer-correlation with plaque reduction neutralization test (PRNT) than % inhibition value. Second, we tried 798 dilutional titration tests with 103 sera, but nonlinear correlation between OD ratio and antibody concentration limited titration of sVNT. Third, the titer-correlations of two sVNT kits for BA.1 and two quantitative immunoassays for WT were evaluated with BA.1 and BA.5 PRNT. All tested kits exhibited a linear correlation with PRNT titers, but the sVNT kits exhibited high false-negative rates (cPass-BA.1 kit, 45.4% for BA.1 and 44.2% for BA.5; STANDARD F-BA.1 kit, 1.9% for BA.1 and 2.2% for BA.5), while quantitative immunoassays showed 100% sensitivity. Linear mixed-effects model suggested superior titer-correlation with PRNT for quantitative immunoassays compared to sVNT kits. Taken together, the use of quantitative immunoassays for WT, rather than rapid development of new kits, would be practical for predicting neutralizing activities against emerging new variants.

Possibility of Decreasing Incidence of Human Immunodeficiency Virus Infection in Korea

BACKGROUND

The number of newly diagnosed cases of human immunodeficiency virus (HIV) infection in Korea, which had increased until 2019, has markedly decreased since the coronavirus disease 2019 pandemic started. This study evaluated whether the decrease is due to a reduction in the incidence of HIV infection and/or delayed diagnosis during the pandemic.

MATERIALS AND METHODS

We reviewed the medical records of 587 newly diagnosed patients with HIV infection between February 2018 and January 2022 from four general hospitals, and their characteristics were compared between the pre-pandemic and pandemic periods. The lapse time from infection to diagnosis was estimated using an HIV modeling tool.

RESULTS

The estimated mean times to diagnosis were 5.68 years (95% confidence interval [CI]: 4.45 - 6.51 years) and 5.41 years (95% CI: 4.09 - 7.03 years) before and during the pandemic, respectively (P = 0.016). The proportion of patients with acquired immunodeficiency syndrome-defining illnesses, expected to visit hospitals regardless of the pandemic, decreased from 17.2% before the pandemic to 11.9% during the pandemic (P = 0.086).

CONCLUSION

The decrease in the number of newly diagnosed cases of HIV infection in Korea might have resulted from an actual decrease in the incidence of HIV infection rather than a worsening of underdiagnosis or delayed diagnosis.

Tracking antigen-specific TCR clonotypes in SARS-CoV-2 infection reveals distinct severity trajectories

Despite the importance of antigen-specific T cells in infectious disease, characterizing and tracking clonally amplified T cells during the progression of a patient's symptoms remain unclear. Here, we performed a longitudinal, in-depth single-cell multiomics analysis of samples from asymptomatic, mild, usual severe, and delayed severe patients of SARS-CoV-2 infection. Our in-depth analysis revealed that hyperactive or improper T-cell responses were more aggressive in delayed severe patients. Interestingly, tracking of antigen-specific T-cell receptor (TCR) clonotypes along the developmental trajectory indicated an attenuation in functional T cells upon severity. In addition, increased glycolysis and interleukin-6 signaling in the cytotoxic T cells were markedly distinct in delayed severe patients compared to usual severe patients, particularly in the middle and late stages of infection. Tracking B-cell receptor clonotypes also revealed distinct transitions and somatic hypermutations within B cells across different levels of disease severity. Our results suggest that single-cell TCR clonotype tracking can distinguish the severity of patients through immunological hallmarks, leading to a better understanding of the severity differences in and improving the management of infectious diseases by analyzing the dynamics of immune responses over time.

Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea

BACKGROUND

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes.

AIM

To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI).

METHODS

Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI.

RESULTS

This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI.

CONCLUSIONS

This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Coinfection With Severe Fever With Thrombocytopenia Syndrome and Scrub Typhus in Korea

Background

Scrub typhus and severe fever with thrombocytopenia syndrome (SFTS) are the 2 most common tick-borne infectious diseases in Korea. Every year, an increasing number of cases are reported, which is a public health concern. Therefore, we aimed to investigate the prevalence of SFTS-scrub typhus coinfection in patients with SFTS.

Methods

Clinical samples were collected from 129 patients with SFTS. One-step reverse-transcription polymerase chain reaction (PCR) was performed to identify the SFTS virus (SFTSV), and real-time PCR followed by nested PCR was performed to detect the Orientia tsutsugamushi gene for scrub typhus. Phylogenetic analysis was conducted to confirm the evolutionary relationships among different species.

Results

Among 129 SFTS cases, 2 patients with SFTSV were positive for O. tsutsugamushi with a prevalence of coinfection of 1.6% (95% confidence interval, .001-.06). Phylogenetic analysis confirmed these as O. tsutsugamushi strain Boryong.

Conclusions

Our study found that 1.6% of patients were coinfected with SFTS and scrub typhus infection. We believe that this information will add a new dimension to clinical diagnosis, which should be considered for better public health management. Further research is needed to better understand the ecological transmission dynamics and geographical distribution of SFTSV and O. tsutsugamushi in endemic countries.

Applicability and limitations of quality indicator-based assessment of appropriateness in antimicrobial use: a comparison with expert opinion

BACKGROUND

The effective implementation of antimicrobial stewardship requires an a-priori assessment of the appropriateness of antimicrobial prescriptions.

AIM

To evaluate the effectiveness of quality indicators (QIs) in determining the appropriateness of antimicrobial prescriptions compared to that of expert opinions.

METHODS

The study assessed antimicrobial use in 20 hospitals in Korea, with infectious disease specialists rating the appropriateness based on QIs and expert opinions. The selected QIs were (1) taking two blood cultures, (2) taking cultures from suspected sites of infection, (3) prescribing empirical antimicrobials according to guidelines, and (4) changing from empirical to pathogen-directed therapy for hospitalized patients and (2, 3, and 4) for ambulatory patients. Applicability, compliance with QIs, and agreement between QIs and expert opinions were investigated.

FINDINGS

Overall, 7999 therapeutic uses of antimicrobials were investigated at the study hospitals. The experts rated 20.5% (1636/7999) as inappropriate use. For hospitalized patients, antimicrobial use was assessed based on all four QIs in 28.8% (1798/6234) of the cases. For ambulatory care patients, only 7.5% (102/1351) of the antimicrobial use cases were assessed using all three QIs. The agreement between expert opinions and all four QIs for hospitalized patients was minimal (κ = 0.332), whereas that between expert opinions and all three QIs for ambulatory patients was weak (κ = 0.598).

CONCLUSION

QIs have limitations in determining the appropriateness of antimicrobial use, and the degree of agreement with expert opinions was low. Therefore, these QI limitations should be considered when determining the appropriateness of antimicrobial use.

Immune Response Kinetics Following a Third Heterologous BNT162b2 Booster Dose After Primary 2-Dose ChAdOx1 Vaccination in Relation to Omicron Breakthrough Infection: A Prospective Nationwide Cohort Study in South Korea

Background

Immune responses to each vaccine must be investigated to establish effective vaccination strategies for the ongoing coronavirus disease (COVID-19) pandemic. We investigated the long-term kinetics of immune responses after heterologous booster vaccination in relation to Omicron breakthrough infection (BI).

Methods

Our study included 373 healthcare workers who received primary ChAdOx1 vaccine doses and a third BNT162b2 vaccine dose. BIs that occurred after the third vaccine were investigated. Blood specimens were collected before and 3 months after the booster dose from participants without BI and 1, 4, and 6 months after BI from participants who experienced BI. Spike-specific binding and neutralizing antibody levels against the wild-type virus, Omicron BA.1, and Omicron BA.5, as well as cellular responses, were analyzed.

Results

A total of 346 participants (82 in the no BI group; 192 in the BI group during the BA.1/BA.2 period; 72 in the BI group during the BA.5 period) were included in the analysis. Participants without BI exhibited the highest binding and neutralizing antibody concentrations and greatest cellular response 1 month after the third vaccination, which reached a nadir by the ninth month. Antibody and cellular responses in participants who experienced BI substantially increased postinfection. Neutralizing antibody titers in individuals who experienced BI during the BA.1/BA.2 period showed more robust increase against wild-type virus than against BA.1 and BA.5.

Conclusions

Our findings provide evidence of antigenic imprinting in participants who received a heterologous booster vaccination, thereby serving as a foundation for further studies on the impact of BIs on immune responses.

Antibiotic Prescription in Patients With Coronavirus Disease 2019: Analysis of National Health Insurance System Data in the Republic of Korea

BACKGROUND

Although coronavirus disease 2019 (COVID-19) is a viral infection, antibiotics are often prescribed due to concerns about accompanying bacterial infection. Therefore, we aimed to analyze the number of patients with COVID-19 who received antibiotic prescriptions, as well as factors that influenced antibiotics prescription, using the National Health Insurance System database.

METHODS

We retrospectively reviewed claims data for adults aged ≥ 19 years hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to the National Institutes of Health guidelines for severity classification, we calculated the proportion of patients who received antibiotics and the number of days of therapy per 1,000 patient-days. Factors contributing to antibiotic use were determined using linear regression analysis. In addition, antibiotic prescription data for patients with influenza hospitalized from 2018 to 2021 were compared with those for patients with COVID-19, using an integrated database from Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service cohort (K-COV-N cohort), which was partially adjusted and obtained from October 2020 to December 2021.

RESULTS

Of the 55,228 patients, 46.6% were males, 55.9% were aged ≥ 50 years, and most patients (88.7%) had no underlying diseases. The majority (84.3%; n = 46,576) were classified as having mild-to-moderate illness, with 11.2% (n = 6,168) and 4.5% (n = 2,484) having severe and critical illness, respectively. Antibiotics were prescribed to 27.3% (n = 15,081) of the total study population, and to 73.8%, 87.6%, and 17.9% of patients with severe, critical, and mild-to-moderate illness, respectively. Fluoroquinolones were the most commonly prescribed antibiotics (15.1%; n = 8,348), followed by third-generation cephalosporins (10.4%; n = 5,729) and beta-lactam/beta-lactamase inhibitors (6.9%; n = 3,822). Older age, COVID-19 severity, and underlying medical conditions contributed significantly to antibiotic prescription requirement. The antibiotic use rate was higher in the influenza group (57.1%) than in the total COVID-19 patient group (21.2%), and higher in severe-to-critical COVID-19 cases (66.6%) than in influenza cases.

CONCLUSION

Although most patients with COVID-19 had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of antibiotics is necessary for patients with COVID-19, considering the severity of disease and risk of bacterial co-infection.

Clinically differential diagnosis of human granulocytic anaplasmosis and severe fever with thrombocytopenia syndrome

This study analyzed HGA and SFTS in patients with suspected tick-borne infection by focusing on key differences that clinicians can easily recognize. A retrospective analysis was performed on confirmed patients with HGA or SFTS in 21 Korean hospitals from 2013 to 2020. A scoring system was developed by multivariate regression analysis and accuracy assessment of clinically easily discriminable parameters was performed. The multivariate logistic regression analysis revealed that sex (especially male sex) (odds ratio [OR] 11.45, P = 0.012), neutropenia (< 1500) (OR 41.64, P < 0.001), prolonged activated partial thromboplastin time (OR 80.133, P < 0.001), and normal C-reactive protein concentration (≤ 1.0 mg/dL; OR 166.855, P = 0.001) were significantly associated with SFTS but not with HGA. Each factor, such as meaningful variables, was given 1 point, and a receiver-operating characteristic curve with a cutoff value (> 1) in a 5-point scoring system (0-4 points) was analyzed to evaluate the accuracy of differentiation between HGA and SFTS. The system showed 94.5% sensitivity, 92.6% specificity, and an area under the receiver-operating characteristic curve of 0.971 (0.949-0.9). Where HGA and SFTS are endemic, the scoring system based on these four parameters such as sex, neutrophil count, activated partial thromboplastin time, and C-reactive protein concentration will facilitate the differential diagnosis of HGA and SFTS in the emergency room in patients with suspected tick-borne infectious diseases.

Anti-Alpha-Toxin Antibody Responses and Clinical Outcomes of Staphylococcus aureus Bacteremia

BACKGROUND

Alpha-toxin (AT), a major virulence factor of Staphylococcus aureus, is an important immunotherapeutic target to prevent or treat invasive S. aureus infections. Previous studies have suggested that anti-AT antibodies (Abs) may have a protective role against S. aureus bacteremia (SAB), but their function remains unclear. Therefore, we aimed to investigate the association between serum anti-AT Ab levels and clinical outcomes of SAB.

METHODS

Patients from a prospective SAB cohort at a tertiary-care medical center (n = 51) were enrolled in the study from July 2016 to January 2019. Patients without symptoms or signs of infection were enrolled as controls (n = 100). Blood samples were collected before the onset of SAB and at 2- and 4-weeks post-bacteremia. Anti-AT immunoglobin G (IgG) levels were measured using an enzyme-linked immunosorbent assay. All clinical S. aureus isolates were tested for the presence of hla using polymerase chain reaction.

RESULTS

Anti-AT IgG levels in patients with SAB before the onset of bacteremia did not differ significantly from those in non-infectious controls. Pre-bacteremic anti-AT IgG levels tended to be lower in patients with worse clinical outcomes (7-day mortality, persistent bacteremia, metastatic infection, septic shock), although the differences were not statistically significant. Patients who needed intensive care unit care had significantly lower anti-AT IgG levels at 2 weeks post-bacteremia (P = 0.020).

CONCLUSION

The study findings suggest that lower anti-AT Ab responses before and during SAB, reflective of immune dysfunction, are associated with more severe clinical presentations of infection.

Evaluation of Vancomycin TDM Strategies: Prediction and Prevention of Kidney Injuries Based on Vancomycin TDM Results

The current guidelines for therapeutic drug monitoring (TDM) of vancomycin suggest a target 24-hour area under the curve (AUC_0-24) of 400 to 600 mg*h/L for serious methicillin-resistant Staphylococcus aureus infections. In this study, the predictabilities of acute kidney injury (AKI) of various TDM target parameters, target levels, and sampling methods were evaluated in patients who underwent TDM from January 2020 to December 2020. The AUC_0-24 and trough values were calculated by both one- and two-point sampling methods, and were evaluated for the predictability of AKI. Among the AUC_0-24 cutoff comparisons, the threshold value of 500 mg*h/L in the two sampling methods was statistically significant (P = 0.042) when evaluated for the predictability of AKI. Analysis by an receiver operating characteristic curve estimated an AUC_0-24 cutoff value of 563.45 mg*h/L as a predictor of AKI, and was proposed as the upper limit of TDM target.

Exercise With a Novel Digital Device Increased Serum Anti-influenza Antibody Titers After Influenza Vaccination

It has been reported that some exercise could enhance the anti-viral antibody titers after vaccination including influenza and coronavirus disease 2019 vaccines. We developed SAT-008, a novel digital device, consists of physical activities and activities related to the autonomic nervous system. We assessed the feasibility of SAT-008 to boost host immunity after an influenza vaccination by a randomized, open-label, and controlled study on adults administered influenza vaccines in the previous year. Among 32 participants, the SAT-008 showed a significant increase in the anti-influenza antibody titers assessed by hemagglutination-inhibition test against antigen subtype B Yamagata lineage after 4 wk of vaccination and subtype B Victoria lineage after 12 wk (p<0.05). There was no difference in the antibody titers against subtype "A." The SAT-008 also showed significant increase in the plasma cytokine levels of IL-10, IL-1β, and IL-6 at weeks 4 and 12 after the vaccination (p<0.05). A new approach using the digital device may boost host immunity against virus via vaccine adjuvant-like effects.

Trial Registration

ClinicalTrials.gov Identifier: NCT04916145.

Case Report and Literature Review of Occupational Transmission of Monkeypox Virus to Healthcare Workers, South Korea

We report a case of occupational monkeypox virus infection from a needlestick injury in a healthcare worker in South Korea and review similar reports in the literature during 2022. Postexposure prophylactic treatment with a third-generation smallpox vaccine and antiviral agent tecovirimat inhibited local virus spread and alleviated lesion pain.

Development of diagnostic tests for pathogen identification and detection of antimicrobial resistance on WHO global priority pathogens using modular real-time nucleic acid amplification test

BACKGROUND

Concerns regarding antimicrobial resistance (AMR) have resulted in the World Health Organization (WHO) designating so-called global priority pathogens (GPPs). However, little discussion has focused on the diagnosis of GPPs. To enable the simultaneous identification of pathogens and AMR, we developed a modular real-time nucleic acid amplification test (MRT-NAAT).

METHODS

Sequence-specific primers for each modular unit for MRT-NAAT pathogen identification and AMR sets were designed. The composition of the reaction mixture and the real-time PCR program were unified irrespective of primer type so to give MRT-NAAT modularity. Standard strains and clinical isolates were used to evaluate the performance of MRT-NAAT by real-time PCR and melting curve analysis. Probit analysis for the MRT-NAAT pathogen identification set was used to assess the limit of detection (LoD).

RESULTS

The MRT-NAAT pathogen identification set was made up of 15 modular units 109-199 bp in product size and with a T_ms of 75.5-87.5 °C. The LoD was < 15.548 fg/μL, and nine modular units successfully detected the target pathogens. The MRT-NAAT AMR set included 24 modular units 65-785 bp in product size with a T_ms of 75.5-87.5 °C; it showed high performance for detecting GPP target genes and variants.

CONCLUSIONS

MRT-NAAT enables pathogen identification and AMR gene detection and is time-effective. By unifying the reaction settings of each modular unit, the modularity where combinations of primers can be used according to need could be achieved. This would greatly help in reflecting the researcher's need and the AMR status of a certain region while successfully detecting pathogens and AMR genes.

Estimation of SARS-CoV-2 Neutralizing Activity and Protective Immunity in Different Vaccine Types Using Three Surrogate Virus Neutralization Test Assays and Two Semiquantitative Binding Assays Targeting the Receptor-Binding Domain

Estimating neutralizing activity in vaccinees is crucial for predicting the protective effect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the plaque reduction neutralization test (PRNT) requires a biosafety level 3 facility, it would be advantageous if surrogate virus neutralization test (sVNT) assays and binding assays could predict neutralizing activity. Here, five different assays were evaluated with respect to the PRNT in vaccinees: three sVNT assays from GenScript, Boditech Med, and SD Biosensor and two semiquantitative binding assays from Roche and Abbott. The vaccinees were subjected to three vaccination protocols: homologous ChAdOx1, homologous BNT162b2, and heterologous administration. The ability to predict a 50% neutralizing dose (ND50) of ≥20 largely varied among the assays, with the binding assays showing substantial agreement (kappa, ~0.90) and the sVNT assays showing relatively poor performance, especially in the ChAdOx1 group (kappa, 0.33 to 0.97). The ability to predict an ND50 value of ≥118.25, indicating a protective effect, was comparable among different assays. Applying optimal cutoffs based on Youden's index, the kappa agreements were greater than 0.60 for all assays in the total group. Overall, relatively poor performance was demonstrated in the ChAdOx1 group, owing to low antibody titers. Although there were intra-assay differences related to the vaccination protocols, as well as interassay differences, all assays demonstrated fair performance in predicting the protective effect using the new cutoffs. This study demonstrates the need for a different cutoff for each assay to appropriately determine a higher neutralizing titer and suggests the clinical feasibility of using various assays for estimation of the protective effect. IMPORTANCE The coronavirus disease 2019 (COVID-19) pandemic continues to last, despite high COVID-19 vaccination rates. As many people experience breakthrough infection after prior infection and/or vaccination, estimating the neutralization activity and predicting the protective effect are major issues of concern. However, since standard neutralization tests are not available in most clinical laboratories, it would be beneficial if commercial assays could predict these aspects. In this study, we evaluated the performance of three sVNT assays and two semiquantitative binding assays targeting the receptor-binding domain with respect to the PRNT. Our results suggest that these assays could be used for predicting the protective effect by adjusting the cutoffs.

Current Status of Outpatient Parenteral Antimicrobial Therapy in Korea: Experience of a Single University-Affiliated Acute-Care Hospital

BACKGROUND

Systematic protocols for the management of outpatient parenteral antimicrobial therapy (OPAT) and information on the current status of a prescription of parenteral antibiotics for outpatients and referred patients are lacking in the Republic of Korea. This study aimed to describe the current status of OPAT at a tertiary care hospital in Korea.

MATERIALS AND METHODS

This was a retrospective study of outpatients and referral patients who were prescribed parenteral antibiotics from July to December 2019. We reviewed the prescribed antimicrobials, indications for antimicrobial therapy, institution administering the antimicrobial injections, and pre- and post-prescription management.

RESULTS

Of the 577 prescriptions assessed in this study, 399 (69.2%) and 178 (30.8%) were delivered using the referral and outpatient models, respectively. About 70% of OPATs were prescribed in the pulmonology, infectious diseases, orthopedics, gastroenterology, and hematology departments. Five antibiotics (ertapenem [26.0%], ceftriaxone [12.8%], kanamycin [11.8%], amikacin [10.1%], and cefazolin [8.5%]) accounted for 69.2% of the total OPATs. Urinary tract (27.3%), respiratory (20.8%), and intra-abdominal (15.9%) infections were the most frequent indications for OPAT. After prescription, there were 295 (73.9%) and 150 (84.3%) follow-up visits in the referral and outpatient models, respectively (P <0.05). Laboratory tests necessary for monitoring were fully performed for 274 (47.5%) prescriptions.

CONCLUSION

We found that a significant number of OPATs were prescribed, follow-up visits were not performed in the case of about a quarter of prescriptions, and laboratory monitoring was not fully conducted in more than half of the cases. Therefore, it is necessary to establish an appropriate management program for OPAT. Considering the limited resources and the distribution of OPAT prescriptions, an effective strategy may be to select the frequently-used antibiotics or frequently-prescribing departments and start the program with them.

1781. Antibiotic Prescription Trends of Patients with COVID-19: Analysis of National Health Insurance Data in Republic of Korea

Background

Although COVID-19 is a viral infection, it is known that antibiotics are often prescribed due to concerns about combined bacterial infection. Therefore, we aimed to analyze how many patients with COVID-19 received the antibiotic prescription as well as what kinds of factors contributed to it using the National Health Insurance database.

Methods

We retrospectively reviewed claims data for adults 19 years of age and older hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to severity classification of the National Institutes of Health guidelines, we calculated not only the proportion of patients receiving antibiotics but also days of treatment per 1000 patient days. In addition, we investigated the factors contributing to antibiotic use by linear regression analysis.

Results

Of the 55,228 patients, 47% were male, 55% were older than 50 years of age, and most patients (89%) had no underlying diseases. The majority (84%, 46,576) were classified as having mild to moderate illness, with 11% (6,168) and 5% (2,484) having severe and critical, respectively. Antibiotics were prescribed in a total of 27% (15,081). While 74% of patients with severe illness and 88% of those with critical illness received antibiotic treatment, even 18% of mild to moderate cases were prescribed antibiotics. Fluoroquinolones were the most commonly prescribed antibiotics (8,348), followed by third generation cephalosporins (5,729) and beta-lactam/beta-lactamase inhibitors (3,822) as shown in Figure 1. Older age, severity of disease and underlying medical conditions contributed to overall prescription rates as well as days of antibiotic use significantly (Table 1).

Conclusion

Although most of COVID-19 patients had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of broad-spectrum antibiotics is necessary for COVID-19 patients, considering the severity of disease and the risk of bacterial co-infection.

Disclosures

All Authors: No reported disclosures.

208. Clinical outcomes of empirical versus pre-emptive broad spectrum antifungal therapy in patients with acute myelogenous leukemia receiving antimold prophylaxis

Background

Since antimold prophylaxis has been widely used in induction chemotherapy for acute myelogenous leukemia (AML), it should be re-evaluated whether broad spectrum antifungal therapy should be empirically used in prolonged febrile neutropenia. Therefore, we compared clinical outcomes of empirical versus pre-emptive antifungal therapy in patients with AML receiving antimold prophylaxis.

Methods

From September 2016 to December 2020, all adult AML patients (≥ 18 years) receiving antimold prophylaxis who had febrile neutropenia for ≥ 4 days during induction or re-induction chemotherapy at Seoul National University Hospital were retrospectively reviewed. They were classified into the empirical group (therapeutic broad spectrum antifungal agents had been used without evidence of invasive fungal infection [IFI]) or the pre-emptive group (antimold prophylaxis had been maintained until the emergence of IFI’s evidence). We compared clinical outcomes between the two groups after propensity score matching.

Results

A total of 229 chemotherapy episodes, 36 in the empirical group and 193 in the pre-emptive group, were analyzed. In the pre-emptive group, broad spectrum antifungal therapy was administered in 45 (23.3%) episodes. After 1:3 matching with age, gender, induction or re-induction chemotherapy, and worst qSOFA score at febrile neutropenia, incidence of proven or probable IFI (0/36 [0%] in the empirical group vs. 5/97 [5.2%] in the pre-emptive group, P=0.323) and all-cause mortality (3/36 [8.3%] in the empirical group vs. 4/97 [4.1%] in the pre-emptive group, P=0.388) were not different between the two groups.

Conclusion

Clinical outcomes of empirical versus pre-emptive broad spectrum antifungal therapy were comparable in patients with AML receiving antimold prophylaxis. Broad spectrum antifungal therapy could be delayed until the emergence of evidence of IFI, in the current era of antimold prophylaxis.

Disclosures

All Authors: No reported disclosures.

1855. Risk factors for early mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteremia

Background

Although many deaths due to carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia occur within a few days after the onset of bacteremia, risk factors for early mortality (EM) have not been deeply investigated. We aimed to determine the risk factors for EM and the difference between risk factors associated with EM and late mortality (LM) in CRAB bacteremia.

Methods

All patients with CRAB bacteremia in 10 hospitals during a 1-year study period were identified. We prospectively collected patients’ clinical data, including microbiological and demographic data, underlying comorbidities, origin of bacteremia, severity of illness, antibiotic therapy, and mortality. Among the cases with mortality within 30 days, EM and LM were defined as death within 3 and more than 5 calendar days from the first positive blood culture, respectively.

Results

A total of 212 CRAB bacteremia cases were included in the analysis. Of 122 (57.5%) patients with 30-day mortality, EM was observed in 75 (61.5%) patients and LM in 39 (32.0%) patients. The proportion of severe sepsis or septic shock, Pitt score, and Sequential Organ Failure Assessment (SOFA) score were significantly higher in 30-day deaths than 30-day survivors. These factors of clinical severity were also significantly higher in patients with EM than those with LM. While urinary tract infection as the factor of site of infection and the severity of illness were independent predictors of LM, only factors representing the severity of illness were independent risk factors for EM. Appropriate empirical antibiotic therapy was associated with reduced risk of EM.

Conclusion

The difference between risk factors for EM and LM was identified in this study. Our data suggest that a large proportion of CRAB bacteremia with high severity progress to a rapidly fatal course, regardless of the underlying diseases or source of infection. Further studies might be needed to investigate the microbiological factors associated with CRAB and pathogen-host interaction in patients with EM.

Disclosures

All Authors: No reported disclosures.

1783. Appropriateness of antibiotics use for patients with asymptomatic bacteriuria or urinary tract infection: A retrospective observational multicenter study in Korea

Background

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes. Antibiotic use for asymptomatic bacteriuria (ABU) has been defined as “antibiotics never events”, and urinary tract infection (UTI) is one of the most common infectious diseases for which antibiotics are prescribed in Korea. To establish an effective antimicrobial stewardship strategy, a qualitative assessment of antibiotic use in actual clinical syndrome is necessary.

Methods

Cases of positive urine cultures (≥10⁵ CFU/ml), performed in inpatient, outpatient, and emergency departments in April 2021 were screened in 26 hospitals located throughout Korea. Cases were classified into ABU, lower UTI, and upper UTI. The appropriateness of antibiotic use was retrospectively evaluated by infectious disease specialists using quality indicators based on the domestic clinical guideline for ABU and UTI. Figure 1.

Prevalence of and factors associated with inappropriate Clostridioides difficile testing in a teaching hospital in Korea

Background

Given the increasing incidence of Clostridioides difficile infections in Korea, there has been an increase in inappropriate testing for C. difficile, which has rendered overdiagnosis of asymptomatic colonisers common. We aimed to investigate the appropriateness of C. difficile testing and the related factors.

Methods

We retrospectively reviewed the medical records of patients who were admitted to a 1300-bed tertiary-care teaching hospital in Korea and were tested for C. difficile infection from September 2019 to November 2019. We performed logistic regression analysis to investigate factors related to inappropriate testing. Further, a survey was conducted on physicians to assess the knowledge and ordering patterns of C. difficile testing.

Results

We included 715 tests from 520 patients in the analysis. Testing was classified as hospital-onset and community-onset and subclassified as appropriate and inappropriate following an algorithmic method. Among the 715 tests, 576 (80.6%) and 139 (19.6%) tests were classified as hospital-onset and community-onset, respectively. Among the hospital-onset tests, 297 (52%) were considered inappropriate. The risk of inappropriate testing increased when C. difficile tests were conducted in the emergency room (OR 24.96; 95% CI 3.12–199.98) but decreased in intensive care units (OR 0.36, 95% CI 0.19–0.67). The survey was conducted on 61 physicians. Internal medicine physicians had significantly higher scores than non-internal medicine physicians (7.1 vs. 5.7, p = 0.001). The most frequently ordered combination of tests was toxin + glutamate dehydrogenase (47.5%), which was consistent with the ordered tests.

Conclusion

Almost half of the C. difficile tests were performed inappropriately. The patient being located in the emergency room and intensive care unit increased and decreased the risk of inappropriate testing, respectively. In a questionnaire survey, we showed that internal medicine physicians were more knowledgeable about C. difficile testing than non-internal medicine physicians. There is a need to implement the diagnostic stewardship for C. difficile, especially through educational interventions for emergency room and non-internal medicine physicians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01111-0.

Clinical and economic burden of bacteremia due to multidrug-resistant organisms in Korea: a prospective case control study

OBJECTIVES

The socioeconomic and clinical burden of multidrug-resistant organisms (MDRO), including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), multidrug-resistant Acinetobacter baumannii (MRAB), multidrug-resistant Pseudomonas aeruginosa (MRPA), and carbapenem-resistant Enterobacteriaceae (CRE) have not yet been adequately addressed.

METHODS

We prospectively searched for MDRO bacteremia cases with matched controls from 10 hospitals across Korea during a 6-month period in 2017. Patients were classified into the MDRO, susceptible organism, and no-infection groups. The corresponding susceptible or no-infection controls had been selected according to predefined criteria. We collected clinical information and estimated the total additional medical cost due to MDRO infections using the multistate model.

RESULTS

During the 6-month period, a total of 486 MDRO bacteremia cases (260, 87, 18, 20, and 101 cases of MRSA, MRAB, MRPA, CRE, and VRE, respectively) were identified. The 90-d mortality rates were 30.4%, 63.2%, 16.7%, 55.0%, and 47.5%, respectively. The additional costs caused by bacteremia were $15 768, $35 682, $39 908, $72 051, and $33 662 per MDRO type, respectively. Based on these 6-month data, the estimated annual number of bacteremia cases due to these five MDRO in Korea were 7979 (4070, 1396, 218, 461, and 1834 cases, respectively). Overall, this caused an estimated 3280 (1237, 882, 36, 254, and 871, respectively) deaths and cost $294 505 002 ($84 707 359, $74 387 364, $10 344 370, $45 850 215, and $79 215 694, respectively) (range $170,627,020-$416,094,679) in socioeconomic loss.

CONCLUSIONS

A tremendous clinical and economic burden is caused by MDRO bacteremia compared with antibiotic-susceptible and no-infection groups. Substantial investment and efforts by related government agencies and medical staffs are needed.

Risk factors for early mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteraemia

OBJECTIVES

Although many deaths due to carbapenem-resistant Acinetobacter baumannii (CRAB) bacteraemia occur within a few days after the onset of bacteraemia, risk factors for early mortality (EM) have not been deeply investigated. We aimed to determine the risk factors for EM and the difference between risk factors associated with EM and late mortality (LM) in CRAB bacteraemia.

METHODS

Clinical information on all patients with CRAB bacteraemia in 10 hospitals during a 1-year period was collected. Among the cases with mortality within 30 days, EM and LM were defined as death within 3 and more than 5 calendar days from the first positive blood culture, respectively.

RESULTS

In total, 212 CRAB bacteraemia cases were included in the analysis. Of 122 (57.5%) patients with 30-day mortality, EM was observed in 75 (61.5%) patients and LM in 39 (32.0%) patients. The proportion of severe sepsis or septic shock, Pitt score, and Sequential Organ Failure Assessment (SOFA) score was significantly higher in patients with EM than those with LM. Although urinary tract infection as the site of infection and the severity of illness were independent predictors of LM, only factors representing the severity of illness were independent risk factors for EM.

CONCLUSION

Our results suggest that a large proportion of CRAB bacteraemia with high severity progresses to a rapidly fatal course, regardless of the underlying diseases or source of infection. Further studies might be needed to investigate the microbiological factors associated with CRAB and pathogen-host interaction in patients with EM.

Maternal and Neonatal Outcomes in Pregnant Women With Coronavirus Disease 2019 in Korea

BACKGROUND

This study aimed to describe the maternal, obstetrical, and neonatal outcomes in pregnant women with coronavirus disease 2019 (COVID-19) and identify the predictors associated with the severity of COVID-19.

METHODS

This multicenter observational study included consecutive pregnant women admitted because of COVID-19 confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR) test at 15 hospitals in the Republic of Korea between January 2020 and December 2021.

RESULTS

A total of 257 women with COVID-19 and 62 newborns were included in this study. Most of the patients developed this disease during the third trimester. Nine patients (7.4%) developed pregnancy-related complications. All pregnant women received inpatient treatment, of whom 9 (3.5%) required intensive care, but none of them died. The gestational age at COVID-19 diagnosis (odds ratio [OR], 1.096, 95% confidence interval [CI], 1.04-1.15) and parity (OR, 1.703, 95% CI, 1.13-2.57) were identified as significant risk factors of severe diseases. Among women who delivered, 78.5% underwent cesarean section. Preterm birth (38.5%), premature rupture of membranes (7.7%), and miscarriage (4.6%) occurred, but there was no stillbirth or neonatal death. The RT-PCR test of newborns' amniotic fluid and umbilical cord blood samples was negative for severe acute respiratory syndrome coronavirus 2.

CONCLUSION

At the time of COVID-19 diagnosis, gestational age and parity of pregnant women were the risk factors of disease severity. Vertical transmission of COVID-19 was not observed, and maternal severity did not significantly affect the neonatal prognosis.

Interspecies differences in clinical characteristics and risk factors for third-generation cephalosporin resistance between Escherichia coli and Klebsiella pneumoniae bloodstream infection in patients with liver cirrhosis

This retrospective study aimed to clarify the interspecies differences in the clinical characteristics and risk factors of bloodstream infection (BSI) due to third-generation cephalosporin-resistant (3GC-R) Escherichia coli (EC) and Klebsiella pneumoniae (KP) in patients with liver cirrhosis (LC). KP BSI had more comorbidities and higher treatment failure rate than EC BSI. Non-alcoholic LC was a risk factor for treatment failure in EC, whereas it was not associated with KP. Risk factors for BSI due to 3GC-R strain were nosocomial infection in EC, and β-lactam/fluoroquinolone treatment ≤ 30 days in KP. These results could help predict outcomes of BSI and improve clinical practice.

Clinical and molecular epidemiology of invasive group B Streptococcus infections in adults in a referral center in Korea

Invasive group B Streptococcus (GBS) infections are increasing among adults with underlying health conditions; however, clinical manifestations and serotype distribution remain unclear. This study investigated the molecular characteristics and antimicrobial resistance of invasive GBS in Korean adults. GBS isolates from patients with invasive diseases during 2006–2015 were investigated for capsular serotype, multilocus sequence type (ST), antimicrobial susceptibility, and resistance genes. Among the 74 isolates analyzed, the most common serotype was Ib (31.1%), followed by III (21.6%), V (20.3%), Ia (12.2%), and VI (12.2%). Thirteen STs were detected, with ST1, ST10, ST19, and ST23 as the most prevalent. The dominant capsular serotype exhibited by ST1 was V, and those expressed by ST10, ST19, and ST23 were Ib, III, and Ia, respectively. Erythromycin and levofloxacin resistance were observed in 33.8% and 31.1% of the isolates, respectively. ST10-Ib (n = 11/11, 100%) and ST654-Ib (n = 3/3, 100%) were dominant levofloxacin-resistant strains. Serotypes Ib, III, and V were most common among adults, which is inconsistent with recent reports in Korea where III, V, and Ia were predominant in infants. The difference in the serotype distribution between adults and children may be associated with the selective pressure imparted by antibiotics.

Real-world eligibility and cost-effectiveness analysis for empagliflozin in patients with heart failure

Background/Introduction

Empagliflozin was approved by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) for reducing cardiovascular mortality and heart failure (HF) hospitalization in both patients with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF).

Purpose

Limited data are available on the generalizability of empagliflozin to clinical practice. Therefore, we evaluated real-world eligibility and cost-effectiveness based on a nationwide prospective HF registry.

Methods

For the study, 3108 HFrEF and 2070 HFpEF patients from the Korean Acute Heart Failure (KorAHF) registry were analysed. Eligibility was estimated by FDA and EMA label criteria and by inclusion and exclusion criteria of EMPEROR-Reduced and EMPEROR-Preserved trials. The cost-effectiveness analysis was performed using the decision tree model, where effectiveness was the avoidance of the first hospitalization.

Results

Among the KorAHF patients, 91.4% met FDA & EMA label criteria, while 44.7% met the clinical trial criteria. The main factor for exclusion in the clinical trial-based empagliflozin eligibility was low systolic blood pressure, including 18.7% of HFrEF and 11.0% of HFpEF patients. Other factors were acute (&lt;4 weeks) myocardial infarction and impaired renal function (eGFR &lt;20 mL/min/1.73 m2 or requiring dialysis). The overall expected hospitalization rate and cost reduction were 3.6 and US$ 14,885 per 100 eligible HF patients per year. In HFrEF patients, hospitalization rate and cost reduction were 4.8 and US$ 28,442. However, in HFpEF, the cost was increased by US$ 7,576, while hospitalization reduction was 1.7.

Conclusion(s)

There is a large discrepancy of real-world eligibility for empagliflozin between FDA & EMA labels and clinical trial criteria. The cost-effectiveness benefit was more evident in patients with HFrEF than HFpEF. The efficacy and safety of empagliflozin in real-world patients should be further investigated for a broader range of clinical applications.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Minister of Science and Information and Communication Technologies (NRF-2021R1F1A1063430), by the Catholic Medical Center Research Foundation (2022), and by the Research of Korea Centers for Disease Control and Prevention (2010-E63003-00, 2011-E63002-00, 2012-E63005-00, 2013-E6300300, 2014-E63003-01, 2015-E63003-02, 2016-ER6303-00, and 2017-ER6303-01).

Characterization of myocardial proteomics in biopsy proven cardiomyopathies

Background

Difference in proteomic expression according to the etiology of cardiomyopathies is not well known.

Purpose

We aimed to identify proteome based pathogenesis in patients with biopsy proven cardiomyopathies.

Methods

Comparative proteomic analysis of biopsy specimens were performed from 9 patients with cardiomyopathy (3 dilated cardiomyopathy (DCM), 2 hypertrophic cardiomyopathy (HCM) and 4 myocarditis) as well as 5 controls (normal endomyocardial biopsy specimen from one-year surveillance of heart transplant recipients) by tandem mass tag combined with liquid chromatography-mass spectrometry. Differential expression protein analysis, gene ontology analysis and Ingenuity pathway analysis were done to discover molecular mechanism for the differentially expressed proteins in each cardiomyopathy compared to the control.

Results

Differential expression protein analysis showed higher proportion of significantly increased proteins (Log2 fold change ≥1) in HCM and myocarditis, whereas higher proportion of significantly decreased proteins (Log2 fold change ≤−1) in DCM compared to controls (Figure). According to the gene ontology analysis, upregulation of neutrophil degranulation, and down-regulation of mitochondrial translation protein was noted in patients with DCM. In patients with HCM, platelet degranulation protein was increased, and mitochondrial ATP synthesis coupled electron transport, was decreased. In patients with myocarditis, neutrophil related proteins and calcium ion binding protein was increased, but muscle cell development, protein was decreased. Ingenuity pathway analysis revealed downregulation of oxidative phosphorylation and upregulation of sirtuin signalling pathway both in DCM and HCM. In myocarditis, various pathways related to inflammation were upregulated with only RHO GDP dissociation inhibitors downregulated.

Conclusions

This study showed that each cardiomyopathy exhibited different proteomic expression compared to normal heart. Further large detailed study is needed to understand the association between proteomic expression and disease pathophysiology.

Funding Acknowledgement

Type of funding sources: None.

Isolated Tuberculous Myositis: A Systematic Review and Multicenter Cases

Objective

To investigate the clinical features and associated underlying conditions of isolated tuberculous myositis (ITBM), a rare extrapulmonary tuberculosis (TB).

Methods

A systematic literature search and a multicenter survey were performed using a triangulation strategy. Data from the identified ITBM cases were extracted and analyzed to determine the underlying conditions, clinical presentations, treatments, and outcomes.

Results

Based on the systematic review, we identified 58 ITBM, including 9 pediatric, cases in the literature published from 1981 to 2021 25 (43.1%) immunocompromised and 33 (56.9%) non-immunocompromised patients. Immunocompromised cases had a significant shorter symptom duration (median 30.0 vs. 75.0 days) and a higher prevalence of multilocular involvement (20.8% vs. 0%). Among 24 immunocompromised adult patients, dermatomyositis/polymyositis (DM/PM; n=10, 41.7%) were the most common underlying diseases in adults with ITBM identified in the systematic review. Over the past 20 years, 11 Korean adults with ITBM were identified in the multicenter survey. Of 7 immunocompromised cases, two (28.6%) were DM/PM patients. TB death rate of immunocompromised patients was 0.0% and 5/23 (21.7%) in the pediatric and adult ITBM cases identified in the systematic review, respectively, and 3/7 (42.9%) in survey-identified ITBM cases.

Conclusion

ITBM has a unique clinical presentation including fever, tenderness, local swelling, overlying erythema, abscess formation and was associated with a grave outcome, especially in immunocompromised hosts. DM/PM was a highly prevalent underlying disease in both systematic review-identified and survey-identified immunocompromised ITBM patients.

Kinetics of vaccine-induced neutralizing antibody titers and estimated protective immunity against wild-type SARS-CoV-2 and the Delta variant: A prospective nationwide cohort study comparing three COVID-19 vaccination protocols in South Korea

Introduction

Despite vaccine development, the COVID-19 pandemic is ongoing due to immunity-escaping variants of concern (VOCs). Estimations of vaccine-induced protective immunity against VOCs are essential for setting proper COVID-19 vaccination policy.

Methods

We performed plaque-reduction neutralizing tests (PRNTs) using sera from healthcare workers (HCWs) collected from baseline to six months after COVID-19 vaccination and from convalescent COVID-19 patients. The 20.2% of the mean PRNT titer of convalescent sera was used as 50% protective value, and the percentage of HCWs with protective immunity for each week (percent-week) was compared among vaccination groups. A correlation equation was deduced between a PRNT 50% neutralizing dose (ND50) against wild type (WT) SARS-CoV-2 and that of the Delta variant.

Results

We conducted PRNTs on 1,287 serum samples from 297 HCWs (99 HCWs who received homologous ChAdOx1 vaccination (ChAd), 99 from HCWs who received homologous BNT162b2 (BNT), and 99 from HCWs who received heterologous ChAd followed by BNT (ChAd-BNT)). Using 365 serum samples from 116 convalescent COVID-19 patients, PRNT ND50 of 118.25 was derived as 50% protective value. The 6-month cumulative percentage of HCWs with protective immunity against WT SARS-CoV-2 was highest in the BNT group (2297.0 percent-week), followed by the ChAd-BNT (1576.8) and ChAd (1403.0) groups. In the inter-group comparison, protective percentage of the BNT group (median 96.0%, IQR 91.2–99.2%) was comparable to the ChAd-BNT group (median 85.4%, IQR 15.7–100%; P =0.117) and significantly higher than the ChAd group (median 60.1%, IQR 20.0–87.1%; P &lt;0.001). When Delta PRNT was estimated using the correlation equation, protective immunity at the 6-month waning point was markedly decreased (28.3% for ChAd group, 52.5% for BNT, and 66.7% for ChAd-BNT).

Conclusion

Decreased vaccine-induced protective immunity at the 6-month waning point and lesser response against the Delta variant may explain the Delta-dominated outbreak of late 2021. Follow-up studies for newly-emerging VOCs would also be needed.

Baricitinib versus dexamethasone for adults hospitalised with COVID-19 (ACTT-4): a randomised, double-blind, double placebo-controlled trial

BACKGROUND

Baricitinib and dexamethasone have randomised trials supporting their use for the treatment of patients with COVID-19. We assessed the combination of baricitinib plus remdesivir versus dexamethasone plus remdesivir in preventing progression to mechanical ventilation or death in hospitalised patients with COVID-19.

METHODS

In this randomised, double-blind, double placebo-controlled trial, patients were enrolled at 67 trial sites in the USA (60 sites), South Korea (two sites), Mexico (two sites), Singapore (two sites), and Japan (one site). Hospitalised adults (≥18 years) with COVID-19 who required supplemental oxygen administered by low-flow (≤15 L/min), high-flow (>15 L/min), or non-invasive mechanical ventilation modalities who met the study eligibility criteria (male or non-pregnant female adults ≥18 years old with laboratory-confirmed SARS-CoV-2 infection) were enrolled in the study. Patients were randomly assigned (1:1) to receive either baricitinib, remdesivir, and placebo, or dexamethasone, remdesivir, and placebo using a permuted block design. Randomisation was stratified by study site and baseline ordinal score at enrolment. All patients received remdesivir (≤10 days) and either baricitinib (or matching oral placebo) for a maximum of 14 days or dexamethasone (or matching intravenous placebo) for a maximum of 10 days. The primary outcome was the difference in mechanical ventilation-free survival by day 29 between the two treatment groups in the modified intention-to-treat population. Safety analyses were done in the as-treated population, comprising all participants who received one dose of the study drug. The trial is registered with ClinicalTrials.gov, NCT04640168.

FINDINGS

Between Dec 1, 2020, and April 13, 2021, 1047 patients were assessed for eligibility. 1010 patients were enrolled and randomly assigned, 516 (51%) to baricitinib plus remdesivir plus placebo and 494 (49%) to dexamethasone plus remdesivir plus placebo. The mean age of the patients was 58·3 years (SD 14·0) and 590 (58%) of 1010 patients were male. 588 (58%) of 1010 patients were White, 188 (19%) were Black, 70 (7%) were Asian, and 18 (2%) were American Indian or Alaska Native. 347 (34%) of 1010 patients were Hispanic or Latino. Mechanical ventilation-free survival by day 29 was similar between the study groups (Kaplan-Meier estimates of 87·0% [95% CI 83·7 to 89·6] in the baricitinib plus remdesivir plus placebo group and 87·6% [84·2 to 90·3] in the dexamethasone plus remdesivir plus placebo group; risk difference 0·6 [95% CI -3·6 to 4·8]; p=0·91). The odds ratio for improved status in the dexamethasone plus remdesivir plus placebo group compared with the baricitinib plus remdesivir plus placebo group was 1·01 (95% CI 0·80 to 1·27). At least one adverse event occurred in 149 (30%) of 503 patients in the baricitinib plus remdesivir plus placebo group and 179 (37%) of 482 patients in the dexamethasone plus remdesivir plus placebo group (risk difference 7·5% [1·6 to 13·3]; p=0·014). 21 (4%) of 503 patients in the baricitinib plus remdesivir plus placebo group had at least one treatment-related adverse event versus 49 (10%) of 482 patients in the dexamethasone plus remdesivir plus placebo group (risk difference 6·0% [2·8 to 9·3]; p=0·00041). Severe or life-threatening grade 3 or 4 adverse events occurred in 143 (28%) of 503 patients in the baricitinib plus remdesivir plus placebo group and 174 (36%) of 482 patients in the dexamethasone plus remdesivir plus placebo group (risk difference 7·7% [1·8 to 13·4]; p=0·012).

INTERPRETATION

In hospitalised patients with COVID-19 requiring supplemental oxygen by low-flow, high-flow, or non-invasive ventilation, baricitinib plus remdesivir and dexamethasone plus remdesivir resulted in similar mechanical ventilation-free survival by day 29, but dexamethasone was associated with significantly more adverse events, treatment-related adverse events, and severe or life-threatening adverse events. A more individually tailored choice of immunomodulation now appears possible, where side-effect profile, ease of administration, cost, and patient comorbidities can all be considered.

FUNDING

National Institute of Allergy and Infectious Diseases.

Comprehensive Rehabilitation in Severely Ill Inpatients With COVID-19: A Cohort Study in a Tertiary Hospital

BACKGROUND

This study aimed to investigate the effects of comprehensive rehabilitation management on functional recovery and examine the correlation between clinical parameters and improvements in functional outcomes in severe-to-critical inpatients with coronavirus disease 2019 (COVID-19) in a tertiary hospital.

METHODS

Post-acute COVID-19 patients who had a World Health Organization (WHO) ordinal scale of 5-7, underwent intensive care, and received comprehensive rehabilitation management, including exercise programs, nutritional support, dysphagia evaluation, and psychological care were included. The appendicular skeletal muscle mass index (SMI), Medical Research Council sum score, handgrip strength, number of repetitions in the 1-minute sit-to-stand test, gait speed, Berg Balance Scale (BBS), and Functional Ambulation Classification (FAC) were evaluated at hospital stay, discharge, and 1-month follow-up. The correlation between the rehabilitation dose and improvement in each outcome measure was analyzed.

RESULTS

Overall, 37 patients were enrolled, of whom 59.5% and 32.4% had a score of 6 and 7 on the WHO ordinal scale, respectively. Lengths of stay in the intensive care unit and hospital were 33.6 ± 23.9 and 63.8 ± 36.5 days. Outcome measures revealed significant improvements at discharge and 1-month follow-up. The SMI was significantly increased at the 1-month follow-up (6.13 [5.24-7.76]) compared with that during the hospital stay (5.80 [5.39-7.05]). We identified dose-response associations between the rehabilitation dose and FAC (ρ = 0.46) and BBS (ρ = 0.50) scores. Patients with older age, longer hospitalization, longer stay at the intensive care unit, longer duration of mechanical ventilation, tracheostomy, a more depressive mood, and poorer nutritional status revealed poorer improvement in gait speed at the 1-month follow-up.

CONCLUSION

Comprehensive rehabilitation management effectively improved muscle mass, muscle strength, and physical performance in severe-to-critical COVID-19 patients. Dose-response relationship of rehabilitation and functional improvement emphasizes the importance of intensive post-acute inpatient rehabilitation in COVID-19 survivors.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05104411.

Breakthrough COVID-19 Infection During the Delta Variant Dominant Period: Individualized Care Based on Vaccination Status Is Needed

BACKGROUND

The clinical features of coronavirus disease 2019 (COVID-19) patients in the COVID-19 vaccination era need to be clarified because breakthrough infection after vaccination is not uncommon.

METHODS

We retrospectively analyzed hospitalized COVID-19 patients during a delta variant-dominant period 6 months after the national COVID-19 vaccination rollout. The clinical characteristics and risk factors for severe progression were assessed and subclassified according to vaccination status.

RESULTS

A total of 438 COVID-19 patients were included; the numbers of patients in the unvaccinated, partially vaccinated and fully vaccinated groups were 188 (42.9%), 117 (26.7%) and 133 (30.4%), respectively. The vaccinated group was older, less symptomatic and had a higher Charlson comorbidity index at presentation. The proportions of patients who experienced severe progression in the unvaccinated and fully vaccinated groups were 20.3% (31/153) and 10.8% (13/120), respectively. Older age, diabetes mellitus, solid cancer, elevated levels of lactate dehydrogenase and chest X-ray abnormalities were associated with severe progression, and the vaccination at least once was the only protective factor for severe progression. Chest X-ray abnormalities at presentation were the only predictor for severe progression among fully vaccinated patients.

CONCLUSION

In the hospitalized setting, vaccinated and unvaccinated COVID-19 patients showed different clinical features and risk of oxygen demand despite a relatively high proportion of patients in the two groups. Vaccination needs to be assessed as an initial checkpoint, and chest X-ray may be helpful for predicting severe progression in vaccinated patients.

The generation of stem cell-like memory cells early after BNT162b2 vaccination is associated with durability of memory CD8+ T cell responses

COVID-19 vaccines elicit humoral and cellular immune responses. Durable maintenance of vaccine-induced immunity is required for long-term protection of the host. Here, we examine activation and differentiation of vaccine-induced CD8⁺ T cells using MHC class I (MHC-I) multimers and correlations between early differentiation and the durability of CD8⁺ T cell responses among healthcare workers immunized with two doses of BNT162b2. The frequency of MHC-I multimer⁺ cells is robustly increased by BNT162b2 but decreases 6 months post-second vaccination to 2.4%-65.6% (23.0% on average) of the peak. MHC-I multimer⁺ cells dominantly exhibit phenotypes of activated effector cells 1-2 weeks post-second vaccination and gradually acquire phenotypes of long-term memory cells, including stem cell-like memory T (T_SCM) cells. Importantly, the frequency of T_SCM cells 1-2 weeks post-second vaccination significantly correlates with the 6-month durability of CD8⁺ T cells, indicating that early generation of T_SCM cells determines the longevity of vaccine-induced memory CD8⁺ T cell responses.

Different clinical characteristics and impact of carbapenem-resistance on outcomes between Acinetobacter baumannii and Pseudomonas aeruginosa bacteraemia: a prospective observational study

This study aimed to evaluate the differences in clinical characteristics and impact of carbapenem resistance (CR) on outcomes between Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) bacteraemia. We prospectively identified all patients with Ab and Pa bacteraemia in 10 hospitals over 1 year. Treatment failure was defined as all-cause 30-day mortality, persistent bacteraemia, or recurrent bacteraemia within 30 days. We included 304 Ab and 241 Pa bacteraemia cases. CR was detected in 216 patients (71%) with Ab bacteraemia and 55 patients (23%) with Pa bacteraemia. Treatment failure was significantly higher in CR-Ab than in CR-Pa (60.6% vs. 34.5%, P = 0.001). In Ab, severe sepsis or septic shock and high Pitt bacteraemia score were independent risk factors for treatment failure in the inappropriate empirical antibiotics group. In Pa, hospital-acquired infection and high Pitt bacteraemia score were independent risk factors for treatment failure in both groups. CR was an independent risk factor in Ab for treatment failure in both groups, but not in Pa bacteraemia. We demonstrated significant differences in clinical characteristics and impact of CR on clinical outcomes between Ab and Pa bacteraemia, suggesting that different treatment approaches may be needed.

Positivity rates of mycobacterial culture in patients with tuberculous spondylitis according to methods and sites of biopsies: An analysis of 206 cases

OBJECTIVES

We aimed to evaluate the mycobacterial culture positivity rates according to biopsy methods and sites in patients with tuberculous spondylitis (TS) and identify which tissues are the best sites for the diagnosis of TS.

METHODS

We retrospectively identified and reviewed medical records of all patients with TS in three university-affiliated hospitals in the Republic of Korea from January 2003 to December 2020. TS was diagnosed by culture or histopathologic examination of vertebral bodies or paraspinal tissues and characteristic clinical and radiologic features. Patients with TS who received a needle biopsy or underwent surgical biopsy were investigated. The sites of needle biopsy were classified as vertebral bodies or paraspinal tissues.

RESULTS

During the study period, 206 tissues from 200 patients with TS were included in the analysis. The culture positivity rates of vertebral bodies obtained by needle biopsy, paraspinal tissues obtained by needle biopsy, and tissues obtained by surgery were 69.0%, 85.3%, and 83.2%, respectively. Multivariate logistic regression identified that paraspinal tissues as biopsy sites were independently associated with mycobacterial culture positivity in TS undergoing needle biopsy (adjusted odds ratio, 3.68; 95% confidence interval: 1.13-11.99, P = 0.030).

CONCLUSIONS

We demonstrated that the positivity rates of mycobacterial culture in TS were 69.0-85.3%. Paraspinal tissues as biopsy sites were significantly associated with culture positivity in needle biopsy, suggesting that targeting paraspinal tissues during needle biopsy may be the best method for diagnosing TS.

A novel digital device-based adjuvant-like effect for influenza vaccine: A feasibility and pilot study

Viral infections such as influenza and COVID-19 have a huge impact on humans. Previous studies showed that some exercise could enhance the anti-viral antibody titers after vaccination. We developed a novel digital device designed to enhance host immune system against viral infection by acting like adjuvants. The digital device, SAT-008, is a mobile application based on an algorithm to regulate physical activity. To assess the feasibility of SAT-008, a randomized, open-label, and controlled study was conducted for 13 weeks (Oct 20 to Jan 21). A total of 42 healthy adults (mostly healthcare workers) aged 24 to 46 years were recruited and finally 32 subjects served for analysis. A single-dose of quadrivalent inactivated influenza vaccine was administered for each subject. The control group maintained daily life without using SAT-008, while the experimental group (Exp) used SAT-008 during the study. As a result, compared to the controls, the Exp showed a significant increase in hemagglutination-inhibition (HI) titers of antigen subtype B Yamagata lineage after 4 weeks of vaccination and antigen subtype B Victoria lineage after 12 weeks of vaccination (P &lt; 0.05), whereas the controls did not. As for type A influenza, there was no significant difference in HI titers between groups. In addition, the Exp was divided into high performers (HP) and low performers (LP) based on the adherence rate. The HP showed significantly higher HI titers of B Yamagata lineage in 12 weeks after vaccination than controls and LP (P &lt; 0.05) and of B Victoria lineage than controls (P &lt; 0.01). Our findings indicate a novel approach using digital device may play an important role to enhance host immune system to act as a vaccine adjuvant against viral diseases such as influenza.

Supported by grants from S-Alpha Therapeutics, Inc.

Changes in Anxiety Level and Personal Protective Equipment Use Among Healthcare Workers Exposed to COVID-19

BACKGROUND

The relationship between changes in anxiety levels and personal protective equipment (PPE) use is yet to be evaluated. The present study assessed this relationship among healthcare workers (HCWs) involved in the care of patients with coronavirus disease 2019 (COVID-19).

METHODS

An online survey was conducted in a municipal hospital with 195 nationally designated negative pressure isolation units in Korea. Anxiety level was measured using the self-rating anxiety scale (SAS), and changes in anxiety levels were assessed based on the time when COVID-19 vaccine was introduced in March 2021 in Korea. Monthly PPE usage between June 2020 and May 2021 was investigated.

RESULTS

The mean SAS score (33.25 ± 5.97) was within normal range and was lower than those reported in previous studies conducted before COVID-19 vaccination became available. Among the 93 HCWs who participated, 64 (68.8%) answered that their fear of contracting COVID-19 decreased after vaccination. The number of coveralls used per patient decreased from 33.6 to 0. However, a demand for more PPE than necessary was observed in situations where HCWs were exposed to body fluids and secretions (n = 38, 40.9%). Excessive demand for PPE was not related to age, working experience, or SAS score.

CONCLUSION

Anxiety in HCWs exposed to COVID-19 was lower than it was during the early period of the pandemic, and the period before vaccination was introduced. The number of coveralls used per patient also decreased although an excessive demand for PPE was observed.

Zika Virus Infection During Research Vaccine Development: Investigation of the Laboratory-Acquired Infection via Nanopore Whole-Genome Sequencing

Zika virus (ZIKV) emerged as a serious public health problem since the first major outbreak in 2007. Current ZIKV diagnostic methods can successfully identify known ZIKV but are impossible to track the origin of viruses and pathogens other than known ZIKV strains. We planned to determine the ability of Whole Genome Sequencing (WGS) in clinical epidemiology by evaluating whether it can successfully detect the origin of ZIKV in a suspected case of laboratory-acquired infection (LAI). ZIKV found in the patient sample was sequenced with nanopore sequencing technology, followed by the production of the phylogenetic tree, based on the alignment of 38 known ZIKV strains with the consensus sequence. The closest viral strain with the consensus sequence was the strain used in the laboratory, with a percent identity of 99.27%. We think WGS showed its time-effectiveness and ability to detect the difference between strains to the level of a single base. Additionally, to determine the global number of LAIs, a literature review of articles published in the last 10 years was performed, and 53 reports of 338 LAIs were found. The lack of a universal reporting system was worrisome, as in the majority of cases (81.1%), the exposure route was unknown.