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Although CD4+CD25+FOXP3+ regulatory T (TREG) cells have been studied in patients with COVID-19, changes in the TREG cell population have not been longitudinally examined during the course of COVID-19. In this study, we longitudinally investigated the quantitative and qualitative changes in the TREG cell population in patients with COVID-19. We found that the frequencies of total TREG cells and CD45RA−FOXP3hi activated TREG cells were significantly increased 15–28 d postsymptom onset in severe patients, but not in mild patients. TREG cells from severe patients exhibited not only increased proliferation but also enhanced apoptosis, suggesting functional derangement of the TREG cell population during severe COVID-19. The suppressive functions of the TREG cell population did not differ between patients with severe versus mild COVID-19. The frequency of TREG cells inversely correlated with SARS-CoV-2–specific cytokine production by CD4+ T cells and their polyfunctionality in patients with mild disease, suggesting that TREG cells are major regulators of virus-specific CD4+ T cell responses during mild COVID-19. However, such correlations were not observed in patients with severe disease. Thus, in this study, we describe distinctive changes in the TREG cell population in patients with severe and mild COVID-19. Our study provides a deep understanding of host immune responses upon SARS-CoV-2 infection in regard to TREG cells.

A majority (70%) of Q fever patients in South Korea do not have a history of animal contact. Therefore, unconscious environmental exposure is suspected. The aim of this study was to investigate exposure of Q fever patients to environmental contamination and animal shedding.Two goat farmers were enrolled. One was diagnosed with Q fever 3 years ago (Farm 1). Among 20 goats on Farm 1, five were tested randomly and found to be Q fever PCR-positive. Three of the five were Q fever ELISA-positive. Two of five environmental samples taken in 2015 were PCR-positive. In 2018, 17 of 18 environmental samples were PCR-positive. On Farm 2, 54 of the 77 goats were PCR-positive, and 63 were ELISA-positive. Twelve of 14 environmental samples were PCR-positive. Repeat administration of oxytetracycline to goats led to a gradual reduction in PCR-positive tests over a 5-month period. However, PCR-positivity of the farm environment persisted for 5 months.The environment on farms owned by Q fever patients was contaminated extensively and persistently, even after antibiotic treatment of goats and environmental decontamination. Undetected environmental contamination can be a major source of sporadic Q fever infection in South Korea.

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 ( 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.

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 (ND

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.Study flow diagram Results A total of 2697 cases of ABU or UTI were included. The appropriateness of antibiotic use was assessed in 1157 cases with asymptomatic bacteriuria, 677 and 863 cases with lower and upper UTI (Figure 1). Antibiotics were prescribed in 21.7% (251 of 1157) of ABU without appropriate indication. Of 66 ABU cases with appropriate indication in which prophylactic antibiotics were prescribed, the duration of antibiotics was adequate in only 34.8% (Table 1). For lower UTI, the appropriateness of empirical and definite antibiotics was 77.8% (527 of 677) and 68.0% (353 of 519). In terms of upper UTI, 86.3% (745 of 863) and 78.2% (583 of 746) was appropriate, respectively. The duration of antibiotics was adequate in 65.7% (421 of 641) of lower UTI and 77.9% (592 of 760) in upper UTI (Table 2, 3). Conclusion This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that a significant proportion of antibiotics were prescribed inappropriately and, furthermore the duration of antibiotics was prolonged unnecessarily. Interventions for appropriate antibiotic use in ABU and UTI at the national level are required. Disclosures All Authors: No reported disclosures.

Studies on methods to share nursing and learning experiences with preceptors are lacking. This study was conducted to determine the preliminary effects of developing and applying a reflective practice program for preceptor nurses who experience stressful situations to convert negative emotions into positive ones. This study was conducted over 12 weeks from March to May 2022 on 47 participant nurses in South Korea. Preceptor Reflective Practice Program (PRPP) was conducted in parallel with writing a reflective journal and a reflective practice workshop. Data collection was integrated through quantitative and qualitative approaches. Quantitative data were collected through questionnaires on stress coping, the burden of preceptors, social support, and emotional intelligence, and analyzed by SPSS WIN 26.0 program. The questionnaire data were analyzed after the preceptor nurses had written a reflective journal. Stress coping, social support, and emotional intelligence significantly increased in preceptor nurses after participating in the PRPP. This study found that the PRPP helped nurses improve their emotional intelligence through reflective practice and convert stress into a more positive direction. Therefore, at the organizational and national levels, a reasonable compensation system to provide support workforce and to the work of preceptor nurses should be established.

Interactions among colloidal particles govern the hierarchical microstructure and its physical properties. Here, optical laser tweezers and Monte Carlo simulations are used to evaluate the effects of azimuthal rotation of Janus particles at the oil-water interface on interparticle interactions. We find that the capillary-induced attractive force between two Janus particles at the interface can be relaxed by azimuthal rotation around the critical separation region, at which the capillary force is ∼0.053 pN. Force relaxation leads to a decrease in capillary force around the critical separation region, resulting in a slight increase in the scaling exponent, compared to the theoretical prediction.

IntroductionDespite 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.MethodsWe 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.ResultsWe 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 <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).ConclusionDecreased 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.

We designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients’ blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset.

To compare the standardized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence of high epicenter region with non-epicenter region, serological studies were performed with a total of 3,268 sera from Daegu City and 3,981 sera from Chungbuk Province. Indirect immunofluorescence assay (IFA) for SARS-CoV-2 IgG results showed a high seroprevalence rate in the Daegu City (epicenter) compared with a non-epicenter area (Chungbuk Province) (1.27% vs. 0.91%, P = 0.0358). It is noteworthy that the highest seroprevalence in Daegu City was found in elderly patients (70’s) whereas young adult patients (20’s) in Chungbuk Province showed the highest seroprevalence. Neutralizing antibody (NAb) titers were found in three samples from Daegu City (3/3, 268, 0.09%) while none of the samples from Chungbuk Province were NAb positive. These results demonstrated that even following the large outbreak, the seropositive rate of SARS-CoV-2 in the general population remained low in South Korea.

Background Iliotibial band friction syndrome (ITBFS) is a common disorder of the lateral knee. Previous research has reported that the iliotibial band (ITB) thickness (ITBT) is correlated with ITBFS, and ITBT has been considered to be a key morphologic parameter of ITBFS. However, the thickness is different from inflammatory hypertrophy. Thus, we made the ITB cross-sectional area (ITBCSA) a new morphological parameter to assess ITBFS. Methods Forty-three patients with ITBFS group and from 43 normal group who underwent T1W magnetic resonance imaging were enrolled. The ITBCSA was measured as the cross-sectional area of the ITB that was most hypertrophied in the magnetic resonance axial images. The ITBT was measured as the thickest site of ITB. Results The mean ITBCSA was 25.24 ± 6.59 mm2 in the normal group and 38.75 ± 9.11 mm2 in the ITBFS group. The mean ITBT was 1.94 ± 0.41 mm in the normal group and 2.62 ± 0.46 mm in the ITBFS group. Patients in ITBFS group had significantly higher ITBCSA (P < 0.001) and ITBT (P < 0.001) than the normal group. A receiver operator characteristic curve analysis demonstrated that the best cut-off value of the ITBT was 2.29 mm, with 76.7% sensitivity, 79.1% specificity, and area under the curve (AUC) 0.88. The optimal cut-off score of the ITBCSA was 30.66 mm2, with 79.1% sensitivity, 79.1% specificity, and AUC 0.87. Conclusions ITBCSA is a new and sensitive morphological parameter for diagnosing ITBFS, and may even be more accurate than ITBT.

We report a massive outbreak of human Q fever cases, which occurred at totally 11 humans. The occurrence was related to a goat farm where Coxiella burnetii infection was diagnosed from goat tissues and environmental specimens. From January of 2018, continuous abortions from 6 goats occurred. Laboratory tests from 77 goat specimens for C. burnetii showed that 54 (70.1%) and 63 (81.8%) goats were positive by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The infection was also confirmed from the farmer, his wife and 9 persons from all 16 veterinary officials who had visited the farm for protective measures and preparing goat specimens for laboratory tests. The farm was found to be extensively contaminated with C. burnetii from the examination to the environmental specimens and epidemiological inspections, which might be the main source of C. burnetii infection to humans. The extensive contamination to the farm was derived from the uncareful handling of postpartum animal tissues or discharges by the farm owner. This report will contribute to the establishment of educational system on the biosecurity to novice farmers.

We report a case of human granulocytic anaplasmosis (HGA) in a 76-year-old woman, diagnosed rapidly based on the characteristic peripheral blood smear finding of intragranulocytic morulae. The smear was prepared on the day of hospitalization, which was 1-2 weeks before results of the serology test or polymerase chain reaction (PCR) became available. Owing to the blood smear test, we could start timely and appropriate antimicrobial treatment. The sensitivity of peripheral blood smear is lower compared to that of serology or PCR for the diagnosis of HGA but may increase with the examiner's experience. In our case, the diagnosis of HGA was confirmed based on PCR and serology 7 and 14 days after the positive peripheral blood smear test, respectively. Morulae in neutrophils are a diagnostic indicator of HGA, particularly for febrile patients with a history of tick bites or outdoor activities in rural areas.

Background South Korea has been providing 10-valent pneumococcal conjugate vaccine/(PCV10)/13-valent pneumococcal conjugate vaccine (PCV13) to children and 23-valent pneumococcal polysaccharide vaccine (PPSV23) to older adults as part of a national immunization program. Methods From September 2015 to August 2017, a prospective cohort study was conducted for adults aged ≥19 years with community-acquired pneumonia (CAP) at four university hospitals. All-cause and pneumococcal CAP incidence and mortality rates were evaluated on the basis of hospital catchment population. Serotype distribution of pneumococcal CAP was also evaluated. Results Among 2669 patients with CAP, 252 cases (9.4%) were pneumococcal CAP cases. The annual incidences of all-cause and pneumococcal CAP were 194.3 cases and 18.3 cases respectively, per 100,000 persons. Serotyped Streptococcus pneumoniae was identified in 107 cases (42.5%) through culture or a serotype-specific urinary antigen detection assay. Pneumococcal CAP caused by the PCV13 and PPSV23 serotypes were 50 cases (46.7% of serotyped pneumococcal CAP and 19.8% of pneumococcal CAP), and 83 cases (77.6% of serotyped pneumococcal CAP and 32.9% of pneumococcal CAP), respectively. The most prevalent serotype was 3 (n = 21, 19.6% of serotyped pneumococcal CAP), followed by 19A (n = 10, 9.3% of serotyped pneumococcal CAP) and 11A (n = 10, 9.3% of serotyped pneumococcal CAP). Compared with non-pneumococcal CAP patients, pneumococcal CAP patients were more likely to have a higher CURB-65 scores (P = 0.002). The overall 30-day mortality rate of pneumococcal CAP was higher than that of non-pneumococcal CAP (6.3% versus 5.6%; odds ratio [OR], 1.15; 95% confidence interval [CI], 0.67–1.96), but this trend was reversed in patients aged 65–74 years (4.2% versus 8.6%; OR, 0.47; 95% CI, 0.14–1.54). Conclusions The disease burden of PCV13-serotype pneumococcal CAP remains significantly high in Korean adults, particularly among elderly people, even after a high uptake of pediatric PCVs.

Background Hemorrhagic fever with renal syndrome is a serious health problem in Eurasian countries. This study aimed to evaluate the immunogenicity and safety of formalin-inactivated Hantaan virus vaccine (Hantavax®) with a 3 + 1 vaccination schedule. Methods A phase III, multi-center clinical trial was conducted to evaluate the immunogenicity and safety of Hantavax® (three primary doses and a booster dose schedule at 0, 1, 2 and 13 months) among healthy adults. Immune responses were assessed using the plaque reduction neutralizing antibody test (PRNT) and immunofluorescent antibody assay (IFA). Systemic and local adverse events were assessed. Results A total of 320 healthy subjects aged ≥19 years were enrolled. Following three primary doses of Hantavax®, the seroconversion rate was 80.97% and 92.81% by PRNT and IFA, respectively. With booster administration, seropositive rates were 67.47% and 95.68% at one-month post-vaccination according to PRNT and IFA, respectively. Solicited local and systemic adverse events were reported in 30.50–42.81% and 16.67–33.75% during the three primary dose vaccination, while those were reported 36.57% and 21.36% after the booster doses. Both local and systemic adverse events did not increase with repeated vaccinations. Conclusion Hantavax® showed a high seroconversion rate after the three-dose priming, and additional dose administration with 11-month interval induced good booster effects. (ClinicalTrials.gov Identifier: NCT02553837).

Background After pandemic, A(H1N1)pdm09 is generally known to be associated with younger adults' infection and greater severity than seasonal A(H3N2) but some inconsistences between recent studies exist. Objectives We aimed to compare the epidemiology and clinical outcomes of A(H1N1)pdm09 and A(H3N2) to verify and consolidate about the knowledge of known differences of subtypes. Methods Data were retrospectively collected from the hospital‐based influenza morbidity and mortality surveillance in South Korea in nine tertiary care hospitals, from August 31, 2014, to August 25, 2018. Patients with H1N1pdm09 or H3N2 infection admitted in the emergency room or ward were recruited. Results A total of 1747 patients had influenza A and were divided into two groups those with A(H1N1)pdm09 (n = 240) and those with A(H3N2) (n = 1507). A(H1N1)pdm09 group had younger age (mean age ± standard deviation 50.0 ± 18.8 in H1N1 vs 53.4 ± 21.1 in H3N2, P = .030), lower influenza vaccination (27.9% vs 43.9%, P

Background The number of human Q fever cases in South Korea has been rapidly increasing since 2015. We report the first isolation of Coxiella burnetii in Korea in two patients who initially presented with non-specific febrile illness and were finally diagnosed with acute Q fever in South Korea. Case presentation Two adult patients with fever had serologic tests against C. burnetii initially negative, and polymerase chain reaction against 16S rRNA using whole blood was also negative. After bacterial amplification of C. burnetii in immune-depressed mice, we isolated C. burnetii from patients with acute Q fever. The isolates KZQ2 and KZQ3 were confirmed by polymerase chain reaction, nucleotide sequence analysis, and morphologic observation using a transmission electron microscope. Conclusions These results can help us understand the clinical and epidemiologic features of Q fever in South Korea.

The threat of severe fever with thrombocytopenia syndrome (SFTS) to public health has been increasing due to the rapid spread of the ticks that carry the causative viral agent. The SFTS virus (SFTSV) was first identified in China and subsequently detected in neighboring countries, including South Korea, Japan, and Vietnam. In addition to the tick-mediated infection, human-to-human transmission has been recently reported with a high mortality rate; however, differential study of the pathogen has been limited by the route of infection. In this study, we investigated the pathogenic potential of SFTSV based on the infection route in aged ferrets, which show clinical signs similar to that of human infections. Ferrets inoculated with SFTSV via the intramuscular and subcutaneous routes show clinical signs comparable to those of severe human infections, with a mortality rate of 100%. Contrastingly, intravascularly infected ferrets exhibit a comparatively lower mortality rate of 25%, although their early clinical signs are similar to those observed following infection via the other routes. These results indicate that the infection route could influence the onset of SFTS symptoms and the pathogenicity of SFTSV. Thus, infection route should be considered in future studies on the pathogenesis of SFTSV infection.

Objective This study aimed to investigate the mediation effect of depressive symptoms on the relationship between white matter hyperintensities and the basic activities of daily living (BADL) using an integrated approach to overcome the limitations of previous studies and examine the relationship among the three variables simultaneously.Methods We performed structural equation modeling using cross-sectional data from 497 Alzheimer’s disease (AD), AD with small vessel disease, and subcortical ischemic vascular dementia patients enrolled in the Clinical Research for Dementia of South Korea registry who were diagnosed with mild-to-moderate dementia. Periventricular white matter hyperintensities (PWMHs) and deep white matter hyperintensities (DWMHs) were visualized separately at baseline using magnetic resonance imaging. Depressive symptoms were assessed using the Korean Form of the Geriatric Depression Scale at the follow-up assessment conducted after 1 year. BADL were assessed using the Barthel Index at the follow-up assessment conducted after 2 years.Results The direct and indirect effects of DWMHs on the BADL as mediated via depression were significant. However, neither the direct effect of PWMHs on the BADL nor the indirect effect of PWMHs on the BADL via depression were significant.Conclusion This study presented a mediation model that included a longitudinal developmental pathway from DWMHs to deterioration in the BADL mediated via depressive symptoms. Moreover, the mediation model of depressive symptoms could not be applied to the longitudinal developmental pathway from DWMHs to the deterioration in BADL.

Personal digital assistants can perform multiple functions such as Internet search, documentation, calculating, and barcode scanning. This study examined nurses' perceptions of personal digital assistants used as a barcode scanner for medication administration, blood transfusions, and blood collection. A total of 236 nurses participated in the survey using the instrument developed by the researchers. The data collected were analyzed using descriptive statistics, one-way analysis of variance, and the Scheffe test. Written responses to the advantages and drawbacks of using personal digital assistants were categorized by meaning. The results showed that the nurses perceived more drawbacks than advantages in using personal digital assistants because of nonworking barcodes, prescription practice requiring additional scanning, poor interfacing between personal digital assistants and the EMR, and frequent Wi-Fi disconnection. The drawbacks resulted in delays in nursing workflow for patient care. Therefore, increasing the availability of barcode scanning for all medications applicable to personal digital assistant use, redesigning the practice of current prescriptions to eliminate additional scanning, and seamless interfacing between personal digital assistants and EMRs should be considered. This enables the nurses to use personal digital assistants more efficiently and effectively for patient care.

The clinical characteristics and the effect of viral RNA loads on fatality in 56 patients with severe fever with thrombocytopenia syndrome (SFTS) were analyzed. The non-survival group (12 patients) demonstrated a significantly higher mean age (77 years) than the survival group (44 patients, 65 years) (p = 0.003). The survival rates were 91.7% and 8.3% in patients with Ct values ≥30 and differed significantly (p = 0.001) in the survival and non-survival groups, respectively. The survival rates were 52.4% and 47.6% in patients with viral copy numbers ≥10,000 and 94.3% and 5.7% in patients with viral copy numbers

Severe fever with thrombocytopenia syndrome (SFTS) and scrub typhus are disorders with similar clinical features; therefore, differentiating between them is difficult. We retrospectively collected data from 183 SFTS and 178 scrub typhus patients and validated an existing scoring system to develop a more sensitive, specific, and objective scoring system. We first applied the scoring systems proposed by Kim et al. to differentiate SFTS from scrub typhus. Multivariable logistic regression revealed that altered mental status, leukopenia, prolonged activated partial thromboplastin time (aPTT), and normal C-reactive protein (CRP) level (≤1.0 mg/dL) were significantly associated with SFTS. We changed the normal CRP level from ≤1.0 mg/dL to ≤3.0 mg/dL and replaced altered mental status with the creatine kinase (CK) level. The modified scoring system showed 97% sensitivity and 96% specificity for SFTS (area under the curve (AUC): 0.983) and a higher accuracy than the original scoring system (p = 0.0308). This study’s scoring system had 97% sensitivity and 98% specificity for SFTS (AUC: 0.992) and a higher accuracy than Kim et al.’s original scoring system (p = 0.0308). Our scoring system that incorporated leukopenia, prolonged aPTT, normal CRP level (≤3.0 mg/dL), and elevated CK level (>1000 IU/L) easily differentiated SFTS from scrub typhus in an endemic area.

Background: During in-hospital cardiac arrest events, clinical nurses are often the first responders; therefore, nurses require sufficient advanced cardiac life support (ACLS) competency. This study aimed to verify the effects of a hybrid team-based ACLS simulation (HTAS) program (developed in this study) on nurses’ ACLS performance, specifically ACLS knowledge, cardiopulmonary resuscitation (CPR) self-efficacy, and CPR-related stress. Methods: The developed HTAS comprised four lecture videos, one team-based skills training video, and a team-based ACLS simulation. A quasi-experimental pretest-posttest design with a comparison group (CG) was used to evaluate the effectiveness of the HTAS. Of the 226 general ward nurses with more than 6 months of clinical experience, 117 were allocated to the intervention group (IG), which attended the HTAS, and 109 to the CG, which attended only basic ACLS training. Results: The IG’s ACLS performance significantly improved (t = 50.8, p < 0.001) after the training. Relative to the respective pretest conditions, posttest ACLS knowledge (t = 6.92, p < 0.001) and CPR self-efficacy (t = 6.97, p < 0.001) of the IG also significantly increased. However, when the mean difference values were compared, there was no significant difference between the two groups with respect to ACLS knowledge (t = 1.52, p = 0.130), CPR self-efficacy (t = -0.42, p = 0.673), and CPR stress (t = -0.88, p = 0.378). Conclusion: The HTAS for ward nurses was effective at enhancing the nurses’ ACLS performance. It is necessary to develop effective training methods for team-based ACLS and verify the sustained effects of such training.

While the seroprevalence of SARS-CoV-2 in healthy people does not differ significantly among age groups, those aged 65 years or older exhibit strikingly higher COVID-19 mortality compared to younger individuals. To further understand differing COVID-19 manifestations in patients of different ages, three age groups of ferrets are infected with SARS-CoV-2. Although SARS-CoV-2 is isolated from all ferrets regardless of age, aged ferrets (≥3 years old) show higher viral loads, longer nasal virus shedding, and more severe lung inflammatory cell infiltration, and clinical symptoms compared to juvenile (≤6 months) and young adult (1–2 years) groups. Furthermore, direct contact ferrets co-housed with the virus-infected aged group shed more virus than direct-contact ferrets co-housed with virus-infected juvenile or young adult ferrets. Transcriptome analysis of aged ferret lungs reveals strong enrichment of gene sets related to type I interferon, activated T cells, and M1 macrophage responses, mimicking the gene expression profile of severe COVID-19 patients. Thus, SARS-CoV-2-infected aged ferrets highly recapitulate COVID-19 patients with severe symptoms and are useful for understanding age-associated infection, transmission, and pathogenesis of SARS-CoV-2., Here, Kim et al. characterize SARS-CoV-2 infection in juvenile, young, and old aged ferrets to provide a further understanding of differences in COVID-19 severity in humans at different ages. Aged ferrets have higher viral loads, shed virus longer, and mimic the transcriptomic profile of severely infected patients.

Invasive pneumococcal disease (IPD) is associated with substantial morbidity and mortality in children and elderly populations. Serotype distribution and antibiotic susceptibility of IPD isolates are changing with the implementation of pneumococcal vaccination and increasing antibiotic use worldwide. We aimed to determine serotype distribution, antibiogram, and molecular epidemiology of pneumococci in the late stage of PCV13 era.Prospective multicenter IPD surveillance study was conducted for adults aged ≥ 19 years from July 2019 to June 2021. Clinical and epidemiologic data were collected. In addition, antibiotic susceptibility test, serotype identification and multi-locus sequence typing (MLST) was taken for pneumococcal isolates.A total of 160 IPD cases were collected with mean age of 65.1 years (male, 72.5%). Serotyping was taken for 116 available pneumococcal isolates. PCV13 and PPSV23 serotypes were 32.8% (n = 38) and 56.0% (n = 65), respectively. Serotype 3 (13.8%) and 19A (9.5%) were the most common causative agents of IPD, followed by serogroup 11 (6.9%), 23A (6.9%), 10A (4.3%), and 15B (4.3%). Notably, 32.5% of invasive pneumococcal isolates were non-susceptible to ceftriaxone. Serotypes 11A, 11E and 19A pneumococci showed high ceftriaxone non-susceptible rate (80%, 100% and 81.8% respectively), and they were related to sequence type (ST) 166 and ST320. In comparison, most serotype 3 isolates were ceftriaxone susceptible and related to ST180.PCV serotypes, especially 3 and 19A, are still prevalent in adult IPDs, suggesting that individual PCV13 immunization would be necessary for the elderly people and chronically ill patients. Ceftriaxone non-susceptible rate was remarkably high in invasive pneumococcal isolates.

This participatory action research study was conducted to confirm the implementation process and effect of developing and applying a preceptor education program based on the One-Minute Preceptor Model to foster the competence of preceptor clinical nurses. The study was conducted for eight weeks from March 2020 on 30 preceptor nurses in South Korea. Nursing standards were developed for two weeks and six cycles (comprising four stages) were performed. Data collection was integrated using both quantitative and qualitative approaches. For quantitative data, the Clinical Core Competency of Preceptor (CCCP) and General Communication Competence Scale (GICC-15) results were collected from preceptor nurses through questionnaires. Reflection journals of nurses’ experiences were also analyzed through content analysis and frequency of keywords using WordClouds. There was no significant change in CCCP or GICC-15 results among preceptor nurses. However, nurses’ experiences were associated with the growth and development of competencies such as evidence-based practice, quality feedback, and self-reflection. The program was effective in developing nurse competencies. Therefore, it is necessary to encourage One-Minute Preceptor Model activities among preceptors through an action research approach and to actively support research and practice in clinical settings, as well as to provide organizational and systematic support.

Background Annually, about 80% of the Korean elderly aged ≥65 years receive influenza vaccination. Repeated annual vaccination has been suggested as an important factor of poor influenza vaccine effectiveness (VE), though reported conflicting results. Methods During the consecutive A/H3N2-dominant influenza seasons between 2012 and 2015, we comparatively evaluated the VE (repeated vs. current season only) against laboratory-confirmed influenza, pneumonia and hospitalization in the elderly aged ≥65 years with influenza-like illness (ILI). Clinical and demographic data were collected prospectively, and vaccination status of prior and current seasons was verified using the immunization registry data of Korean Centers for Disease Control and Prevention. Results During the first A/H3N2-dominant season in 2012–2013, influenza vaccine showed statistically significant effectiveness against influenza A infection only and when vaccinated in the current season only (VE 53%, 95% CI 15–77). In the latter two seasons (2013–2015 years), the adjusted VE for influenza A was indistinguishable between repeated vaccination and vaccination in the current season only. Conclusion During consecutive influenza A/H3N2 epidemics, poor influenza vaccine effectiveness may be more pronounced among the elderly population with a high annual vaccine uptake rate.