We performed a point seroprevalence survey of measles among healthcare workers (HCWs) at two Korean teaching hospitals in 2019. A total of 2,830 HCWs underwent an antibody test.The overall seropositivity of measles was 93.1%. The seroprevalence of measles was lowest in HCWs aged 20 - 24 years (81.2%), followed by those aged 25 - 29 years (90.1%). The rates of anti-measles IgG positivity were significantly different between the two hospitals (97.0% vs.89.4%, P <0.001). These results suggest that the seropositivity of measles in HCWs may differ depending on the hospital's vaccination policy.

Background: Staphylococcus aureus bacteremia (SAB) is a common and serious infection with a high mortality. Patients with chronic kidney disease (CKD) are vulnerable to SAB, but there have been few studies performed on the clinical characteristics and outcomes of SAB in CKD patients stratified by dialysis. We aimed to estimate the all-cause mortality and identify its predictors in patients with CKD. Materials and Methods: We conducted a retrospective study on the patients with SAB hospitalized in a tertiary care center in Korea between March 2014 and December 2018.Kaplan-Meier analysis was performed to compare all-cause mortality following SAB among patients with non-dialysis dependent CKD (ND-CKD), those receiving dialysis, and those without CKD (non-CKD). The predictors of mortality among CKD patients were analyzed by Cox proportional hazards regression. Results: As a total, 278 SAB of 43 ND-CKD (31 males), 58 dialysis (39 males), and 177 nonCKD (112 males) patients were included. The 30-day mortality was 39.5% in ND-CKD, 27.6% in dialysis, and 7.9% in non-CKD patients. The hazard ratio of all-cause mortality following SAB in ND-CKD was 2.335 (95% confidence interval, 1.203 – 4.531; P = 0.003), compared to non-CKD patients. For methicillin-resistant S. aureus bacteremia (MRSAB), the hazard ratio of all-cause mortality in ND-CKD was 2.628 (95% CI, 1.074 – 6.435; P = 0.011), compared to dialysis patients. Appropriate antibiotics <48 h was independently related to improved survival following SAB among ND-CKD (adjusted HR, 0.304; 95% CI, 0,108 – 0.857; P = 0.024) and dialysis (adjusted HR, 0.323; 95% CI, 0,116 – 0.897; P = 0.030) patients. Conclusion ND-CKD patients demonstrated poor outcome following SAB and administration of appropriate antibiotics within 48 h could reduce the risk for mortality.

Background: To identify the differences in the vancomycin pharmacokinetics between multiple trauma patients and medically ill patients in the intensive care unit (ICU) stratified by the use of continuous renal replacement therapy (CRRT), and the factors affecting vancomycin clearance (CLvan ). Materials and Methods: All the included patients received at least three consecutive doses of vancomycin, then, therapeutic drug monitoring was conducted. Patients' serum vancomycin trough levels and other clinical variables were identified retrospectively. The vancomycin pharmacokinetics and associated factors were compared and analyzed between trauma ICU (TICU) and medical ICU (MICU) patients. Results: In the non-dialyzed group, the CLvan was higher among the TICU patients than the MICU patients. However, in the continuous renal replacement therapy group, there was no significant difference in the CLvan between the multiple trauma and medically ill patients. The only factor associated with CLvan in the non-dialyzed group was creatinine clearance; none of the factors was associated with CLvan in the CRRT group. Conclusion In the case of non-dialyzed patients in the TICU, vancomycin dosages must be adjusted, depending on the patient's actual body weight changes. In the case of patients undergoing CRRT in both ICUs, vancomycin can be infused with fixed doses regardless of the patients' characteristics.

Background: Carbapenemase-producing Enterobacteriaceae (CPE) are highly drug-resistant pathogens. Screening the contacts of newly-identified CPE patients is crucial for nosocomial transmission control. We evaluated the acquisition rate of CPE in close contacts as a function of CPE genotype. Materials and Methods: This study was conducted in Asan Medical Center, a 2,700-bed, tertiary teaching hospital in Seoul, Korea, between November 2010 and October 2017. Index cases were defined as patients with positive tests for CPE from any infected or colonized site during hospitalization who had no direct epidemiologic linkage with existing CPE patients; close contact patients were defined as those whose hospital stay overlapped with the stay of an index case for at least one day and who occupied the same room or intensive care unit (ICU). Secondary patients were defined as those who produced positive CPE culture isolates from surveillance cultures that had the same CPE enzyme as that of the index case patients. Results: A total of 211 index case patients and 2,689 corresponding contact patients were identified. Of the contact patients, 1,369 (50.9%) including 649 New-Delhi metallo-betalactamase-1 (NDM-1) and 448 Klebsiella pneumoniae carbaepenamse (KPC)-producing CPE exposures were screened, and 44 secondary patients (3.2%; 95% confidence interval 2.3 -4.3%) were positive for NDM-1-producing CPE (16 patients) and KPC-producing (24 patients) CPE. The CPE acquisition rate (5.4%) for KPC-producing CPE exposures was significantly higher than that for NDM-1 exposures (2.7%) (P = 0.01). Conclusion The CPE acquisition rate was 3.2% among close contacts sharing a multi-patient room, with about a two-fold higher risk of KPC-producing CPE than NDM-1-producing CPE.

Neutropenic enterocolitis is a fatal enterocolitis occurring in neutropenic patients with immunocompromised diseases including hematologic malignancies. Gastrointestinal (GI) mucormycosis in hematologic malignancies has been rarely reported. Especially, in myelodysplastic syndrome (MDS), GI mucormycosis has never been reported. We report a case of GI mucormocysis manifesting as neutropenic enterocolitis in a patient with MDS.

Coronaviruses have caused serious Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and Coronavirus Disease 2019 (COVID-19) outbreaks, and only remdesivir has been recently indicated for the treatment of COVID-19. In the line of therapeutic options for SARS and MERS, this study aims to summarize the current clinical evidence of treatment options for COVID-19. In general, the combination of antibiotics, ribavirin, and corticosteroids was considered as a standard treatment for patients with SARS. The addition of this conventional treatment with lopinavir/ritonavir, interferon, and convalescent plasma showed potential clinical improvement. For patients with MERS, ribavirin, lopinavir/ritonavir, interferon, and convalescent plasma were continuously recommended. However, a high-dose of corticosteroid was suggested for severe cases only.The use of lopinavir/ritonavir and convalescent plasma was commonly reported. There was limited evidence for the effect of corticosteroids, other antiviral drugs like ribavirin, and favipiravir. Monoclonal antibody of tocilizumab and antimalarial agents of chloroquine and hydroxychloroquine were also introduced. Among antibiotics for infection therapy, azithromycin was suggested. In conclusion, this study showed the up-to-date evidence of treatment options for COVID-19 that is helpful for the therapy selection and the development of further guidelines and recommendations. Updates of on-going clinical trials and observational studies may confirm the current findings.

Tigecycline was previously considered to have activity against vancomycin-resistant Enterococcus (VRE) isolates, but the optimal dose was not clarified. Thus, this study assessed the in vitro activity of tigecycline against clinical VRE isolates to determine its optimal regimens for complicated intra-abdominal (cIAIs) and complicated skin/soft tissue infections (cSSTIs). We used Monte Carlo simulation to calculate the probability of target attainment (PTA) and the cumulative fraction of response for the ratio of the free area under the curve to the minimum inhibitory concentration (MIC) (fAUIC 24 ), which were 17.9 and 6.9 for treating cSSTIs and cIAIs, respectively. All clinical isolates were Enterococcus faecium. Only a maintenance dose of 200 mg/day tigecycline gave the target attainment of fAUIC 24>17.9, and PTA exceeded 90% for MIC ≤0.38 µg/mL. Meanwhile, this dose gave the target attainment of fAUIC 24>6.9, and PTA exceeded 90% for MIC ≤1 µg/mL. All simulated tigecycline dosing regimens met the fAUIC 24 targets more than 90% of the cumulative fraction of response.Despite its apparent efficacy, a daily tigecycline dose of 200 mg is recommended for VRE isolates with MICs of ≤0.38 µg/mL and ≤1 µg/mL for treating cSSTIs and cIAIs, respectively.

Convalescent plasma has been used for decades to prevent and treat a wide range of infectious diseases for which no specific treatment is available. The use of convalescent plasma involves transfusing plasma collected from patients who have recovered from a viral illness, in an attempt to transfer virus-neutralizing antibodies and confer passive immunity.In addition to the antiviral mechanisms of neutralizing antibodies, the immunomodulatory effects of plasma components could have benefits. Several small and large-scale studies have shown the effects of convalescent plasma for the treatment of severe coronavirus disease 2019 (COVID-19). In addition to transfusion-related side effects, unexpected side effects such as antibody-dependent enhancement (ADE) may occur during convalescent plasma therapy, but early safety studies have not found any cases of ADE among more than 5,000 participants.With historical precedents and recent clinical studies, convalescent plasma therapy should be considered as a candidate therapy for COVID-19 given the limited effectiveness of antiviral drugs and lack of a vaccine. A system to secure safe collection and use of convalescent plasma should be developed as a response to the pandemic. Further clinical trials should be conducted to determine the safety and efficacy of convalescent plasma therapy concurrently with its clinical use.