Safety and outcome of treatment of latent tuberculosis infection in liver transplant recipients.

PURPOSE: Liver transplant (LT) recipients have an increased risk of tuberculosis (TB), which is associated with higher mortality rates. This retrospective cohort study assessed the outcome and tolerability of screening and treatment of latent tuberculosis infection (LTBI) in LT recipients. METHODS: Between March 2020 and February 2022, all adult LT candidates at our institution were screened for LTBI. The candidates who tested positive for interferon-γ-releasing assay or met epidemiological or clinical-radiological criteria for LTBI were treated and monitored. RESULTS: Among the 857 LT recipients, 199 (23.2%) were diagnosed with LTBI, of which 171 (85.9%) initiated LTBI treatment. The median duration of follow-up was 677 days. Adequate LTBI treatment occurred in 141/171 (82.5%) patients and was discontinued prematurely in 30/171 (17.5%) patients. The most common reason for discontinuation was liver enzyme elevation (11/30, 36.7%), although only five discontinued treatment due to suspicion of isoniazid-associated hepatotoxicity. None of the LTBI-treated patients developed active TB during the follow-up period, while 3.6% (1/28) of untreated LTBI patients and 0.6% (4/658) of patients without LTBI developed TB. CONCLUSION: These findings demonstrate that LTBI screening and treatment is a safe and effective strategy to prevent TB in LT recipients. However, monitoring for adverse events and liver enzyme elevation is recommended.

Clinical significance and outcomes of Clostridium tertium bacteremia: analysis of 62 cases in neutropenic and non-neutropenic patients.

The clinical significance of Clostridium tertium bacteremia is still uncertain. We evaluated the incidence, clinical characteristics, and outcomes of C. tertium bacteremia and identified differences between neutropenia and non-neutropenia. All adult patients with C. tertium bacteremia in a 2700-bed tertiary center between January 2004 and November 2021 were retrospectively enrolled. The first episode of C. tertium bacteremia in each patient was included in the analysis. Among 601 patients with Clostridium species bacteremia, 62 (10%) had C. tertium bacteremia, and of these 62 patients, 39 (63%) had had recent chemotherapy, and 31 (50%) had neutropenia or hematologic malignancy. C. tertium bacteremia originated frequently from a gastrointestinal tract infection such as enterocolitis (34%), primary bacteremia (29%), and secondary peritonitis (18%), and 34% of patients had polymicrobial bacteremia. Hematologic malignancy, prior antibiotic treatment, neutropenic enterocolitis, and primary bacteremia were significantly associated with C. tertium bacteremia in neutropenic patients, whereas solid tumor, hepatobiliary disease, secondary peritonitis, polymicrobial bacteremia, and a higher frequency of eradicable infection foci were significantly associated with C. tertium bacteremia in non-neutropenic patients. There was 15% 30-day mortality. APACHE II score (adjusted odds ratio [aOR], 1.5; 95% confidence interval [CI], 1.1-2.1) and secondary peritonitis (aOR, 25.9; 95% CI, 3.0-224.7) were independent risk factors for 30-day mortality. The prevalence of C. tertium bacteremia is low, and the characteristics of C. tertium bacteremia are significantly different between neutropenic and non-neutropenic patients. Appropriate investigation for gastrointestinal mucosal injury should be performed to improve treatment outcomes in this form of bacteremia.

Risk Factors of Recurrent Infection in Patients with Staphylococcus aureus Bacteremia: a Competing Risk Analysis.

Although several clinical variables have been reported as risk factors for recurrence of Staphylococcus aureus infection, most studies have not considered competing risk events that may overestimate the risk. In this study, we performed competing risk analysis to identify risk factors related to 90-day recurrence in patients with S. aureus bacteremia (SAB) using a large cohort data from a single tertiary hospital in South Korea. All adults who experienced SAB during admission were prospectively enrolled from August 2008 to December 2019. After the day of the first positive blood culture, recurrence and all-cause mortality were assessed for 90 days. Recurrence was defined as a development of symptoms or signs of infection with or without repeated bacteremia after >7 days of negative blood culture and clinically apparent improvement. Subdistribution hazard ratios (sHR) for recurrence and all-cause mortality were estimated using Fine and Gray models. Of 1,725 SAB patients, including 885 cases (51.3%) of methicillin-resistant S. aureus (MRSA) bacteremia, 85 (5.0%) experienced recurrence during the study period. In a multivariate Fine and Gray regression model, the presence of a vascular graft (subdistribution HR [sHR], 3.48; 95% confidence interval [CI], 1.90-6.40), nasal MRSA carriage (sHR, 2.10; 95% CI, 1.28-3.44), methicillin resistance (sHR, 1.69; 95% CI, 1.00-2.84), and rifampicin resistance (sHR, 2.20; 95% CI, 1.12-4.33) were significantly associated with 90-day recurrence. In a large cohort of SAB patients with a high prevalence of MRSA, indwelling vascular graft, nasal MRSA carriage, methicillin resistance, and rifampicin resistance were potential risk factors for recurrence of S. aureus infection.

Bedside risk prediction for positive follow-up blood culture in Gram-negative bacilli bacteremia: for whom is follow-up blood culture useful?

PURPOSE: The value of follow-up blood culture (FUBC) in Gram-negative bacteremia (GNB) management is controversial. We evaluated bedside risk predictors and their probabilities of yielding positive FUBCs in GNB. METHODS: All adult patients with GNB in a 2700-bed tertiary center were retrospectively enrolled between January 2019 and December 2019. Only one initial GNB episode was included per patient. Positive FUBC was defined as isolation of the same organism in blood culture 48-72 h after the initial blood culture. RESULTS: A total of 2216 patients with GNB were identified, of whom 34.4% underwent FUBC. Of the 645 patients with FUBCs analyzed in the study, 89 (13.8%) had positive FUBCs. In multivariate analysis, hemodialysis [adjusted odds ratio (aOR), 2.6], fever on the day of FUBCs (aOR 3.6), intravascular device (aOR 2.4), no use of in vitro active antibiotic within 24 h (aOR 2.5), non-fermenting bacteria (aOR 4.7), and multidrug resistance (aOR 5.4) were independent risk factors for positive FUBCs. If microbiological results were excluded in multivariate analysis, hemodialysis, immunosuppressive treatment, fever on the day of FUBCs, and intravascular device were independent bedside risk predictors for positive FUBCs. The yield of FUBCs increased from 3.0% (95% CI 1.0-7.0) to 63.6% (95% CI 25.6-100) as the number of bedside risk predictors increased from 0 to 4. In addition, positive FUBCs were significantly associated with 30 day mortality. CONCLUSIONS: FUBCs may not need to be routinely used for patients with GNB bacteremia, and bedside risk predictors could be helpful in identifying patients for whom FUBC is likely to be useful.

C-reactive protein predicts persistent bacteremia caused by community-acquired methicillin-resistant Staphylococcus aureus strain.

There is limited data on persistent bacteremia (PB) caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, we aimed to investigate the clinical and microbiological characteristics of PB caused by the major CA-MRSA strain in Korea (ST72-SCCmecIV). All adult patients with S. aureus bacteremia were prospectively investigated from August 2008 to December 2018. Patients with ST72 MRSA bacteremia were included in the study. Patients were stratified into the PB group (defined as positive blood cultures for ≥ 3 days) and short bacteremia (SB) group. A total of 291 patients were included, comprising 115 (39.5%) with PB and 176 (60.5%) with SB. Although the 30-day mortality did not differ between PB and SB, recurrent bacteremia within 12 weeks was significantly more common in PB (8.7% vs 1.7%; P = 0.01). Multivariate analysis showed risk factors of PB were liver cirrhosis (adjusted odds ratio [aOR], 3.27; 95% confidence interval [CI], 1.50-7.12), infective endocarditis (aOR, 7.13; 95% CI, 1.37-37.12), bone and joint infections (aOR, 3.76; 95% CI, 1.62-8.77), C-reactive protein ≥ 10 mg/dL (aOR, 2.20; 95% CI, 1.22-3.95), metastatic infection (aOR, 7.35; 95% CI, 3.53-15.29), and agr dysfunction (aOR, 2.47; 95% CI, 1.05-5.81). PB occurred in approximately 40% of bacteremia caused by ST72 MRSA with a significantly higher recurrence rate. Patients with risk factors of PB, including liver cirrhosis, high initial CRP, infective endocarditis, or bone and joint infections, might require early aggressive treatment.

The First Case of Multisystem Inflammatory Syndrome in Adult after COVID-19 in Korea.

Multisystem inflammatory disease in children is a Kawasaki disease like illness occurring after severe acute respiratory syndrome coronavirus 2 infection in children. As the pandemic progresses, similar syndromes were also reported in adult with a decreased incidence. Multisystem inflammatory syndrome in adults (MIS-A) can be characterized with shock, heart failure, and gastrointestinal symptoms with elevated inflammatory markers after coronavirus disease 2019 (COVID-19) infection. Herein, we describe the first case of MIS-A in South Korea. A 38-year-old man presented to our hospital with a 5-day history of abdominal pain and fever. He had been treated with antibiotics for 5 days at the previous hospital, but symptoms had worsened and he had developed orthopnea on the day of presentation. He suffered COVID-19 six weeks ago. Laboratory data revealed elevated white blood cell counts with neutrophil dominance, C-reactive protein, and B-type natriuretic peptide. Chest X-ray showed normal lung parenchyme and echocardiography showed severe biventricular failure with normal chamber size. We diagnosed him as MIS-A and treated with intravenous immunoglobulin and steroid.

Clinical characteristics and prognostic factors of extraintestinal infection caused by Clostridioides difficile: analysis of 60 consecutive cases.

Data regarding extraintestinal Clostridioides difficile infections (ECDIs) remain scarce and anecdotal. We conducted a retrospective cohort study to investigate characteristics and prognostic factors in patients with ECDI. From January 1997 through December 2018, 60 patients were enrolled and divided into three groups as follows: group A (gastrointestinal [GI] disruption caused by malignancy, n = 13); group B (GI disruption from causes other than malignancy, n = 25); group C (no GI disruption, n = 22). GI disruption was defined as compromised integrity of the GI tract caused by abdominal surgery, perforation, malignancy, enterocolitis, or bleeding. The incidence of ECDI was 2.53 per 100,000 admissions. The most common specimens yielded C. difficile were blood (36.7%), peritoneal fluid (20.0%), and abscesses (16.7%). Six patients (10.0%) had confirmed C. difficile enterocolitis, and 36 patients (60.0%) had a polymicrobial infection. C. difficile bacteremia was significantly more common in group A patients than those in groups B or C (53.8% vs. 48.0% vs. 13.6%, p = 0.02), as was the 30-day mortality rate (69.2% vs. 12.0% vs. 18.2%, respectively; p < 0.001). In multivariate analysis, group A (adjusted odds ratio [aOR], 17.32; 95% confidence interval [CI], 2.96-101.21; p = 0.002) and an age of > 65 years (aOR, 7.09; 95% CI, 1.31-38.45; p = 0.02) were independent risk factors for 30-day mortality. ECDI was uncommonly associated with C. difficile enterocolitis. Two factors, GI disruption caused by malignancy, and old age, were associated with significantly poorer short-term outcomes.

Clinical characteristics and outcomes of Staphylococcus aureus bacteremia from a biliary source.

Staphylococcus aureus is a virulent gram-positive organism, which rarely involves the biliary tract. This study aimed to analyze the clinical characteristics and outcomes of S. aureus bacteremia (SAB) originating from the biliary tract by comparing them with those of catheter-related SAB and biliary Klebsiella pneumoniae bacteremia. A matched case-control study within a prospective observational cohort of patients with SAB was conducted. Biliary SAB was defined as the isolation of S. aureus from blood cultures with symptoms and signs of biliary infection. Biliary SAB patients were matched (1:3) with the control groups: patients with catheter-related SAB and biliary Klebsiella pneumoniae bacteremia. Out of 1818 patients with SAB enrolled in the cohort, 42 (2%) had biliary SAB. Majority of these patients had solid tumors involving the pancreaticobiliary tract or liver, biliary drainage stent, and/or recent broad-spectrum antibiotic exposure. Patients with biliary SAB were more likely to have community-onset SAB, solid tumors, and lower APACHE II score than those with catheter-related SAB. They were less likely to have community-acquired infection and solid tumors and more likely to have lower Charlson comorbidity index and higher APACHE II score as compared with biliary K. pneumoniae bacteremia. The 12-week mortality in the biliary SAB group was higher than those in other control groups (60% vs. 20% and 14%). After adjusting for confounding factors, biliary SAB was independently associated with higher mortality. Biliary SAB is relatively rare. When it is clinically suspected, early aggressive treatment should be considered due to high mortality.

Risk of COVID-19 Transmission from Infected Outpatients to Healthcare Workers in an Outpatient Clinic.

From January to September 2020, we conducted contact-tracing for confirmed coronavirus disease 2019 (COVID-19) patients who visited our outpatient clinic to evaluate the risk of COVID-19 transmission from infected patients to healthcare workers (HCWs). COVID-19 was diagnosed in 8 outpatients. Per the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) polymerase chain reaction test results, none of the 317 HCWs who came in contact had a confirmed COVID-19 diagnosis (0.00%; 95% confidence interval, 0.00%-0.01%). This low rate of transmission from infected outpatients to HCWs suggests that standard precaution such as using surgical mask and hand hygiene protects HCWs from SARS-CoV-2 in a low-risk, outpatient clinic setting.

Trueness, physical properties, and surface characteristics of additive-manufactured zirconia crown.

OBJECTIVE: This study aimed to conduct a comparison of trueness and physical and surface properties among five distinct types of additive manufactured (AM) zirconia crowns and zirconia crowns produced using the subtractive manufacturing (SM). MATERIAL AND METHODS: Zirconia crowns were fabricated using five distinct techniques, each varying in the method of slurry transfer and photocuring source. Each experimental group utilized either one of the four digital light processing (DLP)-based techniques (DLP spreading, DLP spreading gradation, DLP vat and DLP circular spreading) or the stereolithography (SLA)-based technique (SLA spreading). The control (CON) group employed SM. To assess accuracy, trueness was measured between the scan and reference data. To analyze the physical properties, voids were examined using high-energy spiral micro-computed tomography scans, and the crystal structure analysis was performed using X-ray diffraction (XRD). Surface roughness was assessed through laser scanning microscopy. RESULTS: Differences in the trueness of internal surfaces of crowns were found among the groups (P < 0.05). Trueness varied across the measurement surfaces (occlusal, lateral, and marginal) in all the groups except for the DLP spreading gradation group (P < 0.05). Voids were observed in all AM groups. All groups showed similar XRD patterns. All AM groups showed significantly greater surface roughness compared to the CON group (P < 0.001). CONCLUSION: The AM zirconia crowns showed bubbles and a rougher surface compared to the SM crowns. All groups exhibited typical zirconia traits and trueness levels within clinically acceptable limits, suggesting that current zirconia AM techniques could be suitable for dental applications.

Dimensional changes after horizontal and vertical guided bone regeneration without membrane fixation using the retentive flap technique: A 1-year retrospective study.

AIM: To evaluate the dimensional changes after horizontal and vertical guided bone regeneration (GBR) without membrane fixation using the retentive flap technique. METHODS: This study retrospectively examined two cohorts that received vertical or horizontal ridge augmentations (VA or HA groups). GBR was performed using particulate bone substitutes and resorbable collagen membranes. The augmented sites were stabilized using the retentive flap technique without any additional membrane fixation. The augmented tissue dimensions were assessed using cone-beam computed tomography at preoperative, immediately postoperative (IP), 4 months (4M), and 1 year (1Y). RESULTS: Postoperative vertical bone gain in 11 participants of VA group amounted to 5.96 ± 1.88 mm at IP, which decreased to 5.53 ± 1.62 at 4M and to 5.26 ± 1.52 mm at 1Y (intragroup p < 0.05). The horizontal bone gain at IP in 12 participants amounted to 3.98 ± 2.06 mm, which decreased to 3.02 ± 2.06 at 4M and to 2.48 ± 2.09 mm at 1Y (intragroup p < 0.05). The mean implant dehiscence defect height after 1Y was 0.19 ± 0.50 mm in the VA group, and 0.57 ± 0.93 mm in the HA group. CONCLUSION: GBR without membrane fixation using the retentive flap technique seems to preserve the radiographic bone dimensions of vertically augmented sites. This technique may be less effective at preserving the width of the augmented tissue.

Causes of a Low Measles Seroprevalence among Young Healthcare Workers in Korea.

BACKGROUND: Sporadic measles outbreaks have continued to occur in Korea, mainly in adults in their 20s and 30s, most notably in 2014 and 2019. We here evaluated the possible causes of a low seroprevalance of measles by testing young healthcare workers (HCWs). MATERIALS AND METHODS: This study was conducted in a 2,743-bed tertiary-care hospital in Seoul between 2020 and 2021. We performed a measles antibody test (chemiluminescence immunoassay), measured the IgM/IgG index ratio, and conducted an avidity test at 1-month after Measles-Mumps-Rubella (MMR) vaccination in HCWs who had been seronegative for measles. Measles vaccination histories were obtained from the national vaccine registry. RESULTS: Of the 3,173 HCWs newly employed in our hospital during the study period, 54 with a negative measles IgG at commencement were enrolled. Thirty six (67%) of these subjects were female, and the median age was 25 years (interquartile range [IQR]: 24 - 27). Fourty nine (91%) showed seroconversion at 1 month after the first vaccination. Of these individuals, 38 received both measles IgM and IgG test, and all had an IgM/IgG index <1. Of the 49 seroconverters, all HCWs showed a high avidity index. According to the national immunization registry, 45 (83%) received at least 2 doses of an MMR vaccination. CONCLUSION: Secondary vaccine failure may underlie vaccine failure in young Korean adults. HCWs born after 1985 with a negative measles antibody may need only a single dose booster vaccination rather than a 2-dose vaccination regimen.

Risk and Outcome of Infective Endocarditis in Streptococcal Bloodstream Infections according to Streptococcal Species.

This study aimed to identify which streptococcal species are closely associated with infective endocarditis (IE) and to evaluate risk factors for mortality in patients with streptococcal IE. We performed a retrospective cohort study of all patients with streptococcal bloodstream infection (BSI) from January 2010 to June 2020 in a tertiary hospital in South Korea. We compared clinical and microbiological characteristics of streptococcal BSIs according to the diagnosis of IE. We performed multivariate analysis to evaluate the risk of IE according to streptococcal species and risk factors for mortality in streptococcal IE. A total of 2,737 patients were identified during the study period, and 174 (6.4%) were diagnosed with IE. The highest IE prevalence was in patients with Streptococcus mutans BSI (33% [9/27]) followed by S. sanguinis (31% [20/64]), S. gordonii (23% [5/22]), S. gallolyticus (16% [12/77]), and S. oralis (12% [14/115]). In multivariate analysis, previous IE, high-grade BSI, native valve disease, prosthetic valve, congenital heart disease, and community-onset BSI were independent risk factors for IE. After adjusting for these factors, S. sanguinis (adjusted OR [aOR], 7.75), S. mutans (aOR, 5.50), and S. gallolyticus (aOR, 2.57) were significantly associated with higher risk of IE, whereas S. pneumoniae (aOR, 0.23) and S. constellatus (aOR, 0.37) were associated with lower risk of IE. Age, hospital-acquired BSI, ischemic heart disease, and chronic kidney disease were independent risk factors for mortality in streptococcal IE. Our study points to significant differences in the prevalence of IE in streptococcal BSI according to species. IMPORTANCE Our study of risk of infective endocarditis in patients with streptococcal bloodstream infection demonstrated that Streptococcus sanguinis, S. mutans, and S. gallolyticus were significantly associated with higher risk of infective endocarditis. However, when we evaluated the performance of echocardiography in patients with streptococcal bloodstream infection, patients with S. mutans and S. gordonii bloodstream infection had a tendency of low performance in echocardiography. There are significant differences in the prevalence of infective endocarditis in streptococcal bloodstream infection according to species. Therefore, performing echocardiography in streptococcal bloodstream infection with a high prevalence of, and significant association with, infective endocarditis is desirable.

Vertical ridge augmentation feasibility using unfixed collagen membranes and particulate bone substitutes: A 1- to 7-year retrospective single-cohort observational study.

AIM: To determine whether vertical ridge augmentation (VRA) can be obtained through guided bone regeneration (GBR) using exclusively resorbable collagen membranes and particulate bone substitutes without additional stabilization. MATERIALS AND METHODS: This study retrospectively examined 22 participants who underwent VRA with staged or simultaneous implant placement. The vertical defects of all participants were filled with particulate bone substitutes and covered with resorbable collagen membranes. The augmented sites were stabilized with unfixed collagen membranes and the flap without any additional fixation. The augmented tissue height was assessed using cone-beam computed tomography at baseline, immediately after surgery, and at annual follow-ups. RESULTS: The vertical bone gain of the 22 augmented sites amounted to 6.48 ± 2.19 mm (mean ± SD) immediately after surgery and 5.78 ± 1.72 mm at 1- to 7-year follow-up. Of the 22 augmented sites, 18 exhibited changes of less than 1 mm, while the other 4 showed changes of greater than 1 mm. Histological observation of three representative cases revealed new bone apposition on the remaining material. CONCLUSION: The present findings indicate that GBR procedures using exclusively collagen membranes and particulate biomaterials without any additional fixation are feasible options for VRA.

Immune Responses against the Omicron Variant of SARS-CoV-2 after a Third Dose of COVID-19 Vaccine in Patients Living with Human Immunodeficiency Virus (PLWH): Comparison with Healthcare Workers.

We compared immune responses against the omicron variant of SARS-CoV-2 after a third dose of the coronavirus disease 2019 (COVID-19) vaccine between people living with human immunodeficiency (PLWH) and healthcare workers (HCWs). In this prospective observational study, PLWH and HCWs vaccinated with at least two doses of vaccine were enrolled. We analyzed neutralizing responses using the GenScript SARS-CoV-2 surrogate virus neutralization test kit. Twenty-nine PLWH and 114 HCWs were included to analyze immune responses after the third vaccination. Most PLWH (86.2%) had fully suppressed viral loads and CD4 T cell counts were well-controlled (median 670.0 cells/µL). The neutralizing responses against the omicron variant in PLWH were not significantly different from those in HCWs (43.94% vs. 51.77%, p = 0.42). However, neutralizing responses against the omicron variant were significantly impaired by about 50% compared with wild type SARS-CoV-2 in PLWH (43.94% vs. 97.46%, p < 0.001) and HCWs (51.77% vs. 97.74%, p < 0.001). Although neutralizing responses against the omicron variant in well-controlled PLWH were comparable to those of HCWs, the responses were much lower than those against wild type in both PLWH and HCWs. Therefore, the risk of breakthrough SARS-CoV-2 infection due to the currently circulating omicron variant is still high despite three doses of vaccine in PLWH and will not differ from HCWs.

Periodontal probing on digital images compared to clinical measurements in periodontitis patients.

The aim of the study was to compare the supra-alveolar gingival dimension (GD) and the clinical pocket probing depth (PD) by combining data from an intraoral scanner (IOS) and cone-beam computed tomography (CBCT) and identify the clinical features affecting the clinical PD. 1,071 sites from 11 patients were selected for whom CBCT, IOS images, and periodontal charts were recorded at the same visit. CBCT and IOS data were superimposed. GD was measured on cross-sectional images of the probed sites. The level of agreement and correlation between GD and PD were assessed for the entire population and within groups (treated vs untreated, bleeding on probing [BOP] vs no BOP, and PDs of 0-3 mm vs 4-5 mm vs ≥ 6 mm). The mean [± SD] difference between GD and PD was 0.82 [± 0.69] mm, and they were positively correlated (r = 0.790, p < 0.001). The correlations between GD and PD were stronger for untreated sites, sites with BOP, and sites with a larger PD. Within the limitations of this study, the similarity between GD and PD may suggest a possible tendency of overestimation when recording PD.

Immunogenicity against the Omicron Variant after mRNA-Based COVID-19 Booster Vaccination in Medical Students Who Received Two Primary Doses of the mRNA-1273 Vaccine.

We evaluated the immune response against the Omicron variant after mRNA-based COVID-19 booster vaccination in medical students. We prospectively enrolled medical students who received two primary doses of the mRNA-1273 vaccine. The neutralizing response and the SARS-CoV-2-specific T-cell response was evaluated. A total of 56 serum samples were obtained before booster vaccination. Nineteen students (33.9%) developed COVID-19 two months after booster vaccination. Of 56 students, 35 students (12 infected and 23 uninfected) were available for blood sampling four months after booster vaccination. In comparison with uninfected students, infected students showed a significantly higher level of SARS-CoV-2-specific IgG (5.23 AU/mL vs. 5.12 AU/mL, p < 0.001) and rate of neutralizing response (96.22% vs. 27.18%, p < 0.001) four months after booster vaccination. There was no significant difference in the SARS-CoV-2-specific T-cell response. Among 23 infection-naive students, the neutralizing response was significantly higher in those who received the mRNA-1273 booster than in those who received the BNT162b2 booster (69.07% vs. 26.43%, p = 0.02). In our study, booster vaccination with mRNA-1273 instead of BNT162b2 was significantly associated with a higher neutralizing response.

Kinetics of Glycoprotein-Specific Antibody Response in Patients with Severe Fever with Thrombocytopenia Syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tickborne disease in East Asia that is causing high mortality. The Gn glycoprotein of the SFTS virus (SFTSV) has been considered to be an essential target for virus neutralization. However, data on anti-Gn glycoprotein antibody kinetics are limited. Therefore, we investigated the kinetics of Gn-specific antibodies compared to those of nucleocapsid protein (NP)-specific antibodies. A multicenter prospective study was performed in South Korea from January 2018 to September 2021. Adult patients with SFTS were enrolled. Anti-Gn-specific IgM and IgG were measured using an enzyme-linked immunosorbent assay. A total of 111 samples from 34 patients with confirmed SFTS were analyzed. Anti-Gn-specific IgM was detected at days 5-9 and peaked at day 15-19 from symptom onset, whereas the anti-NP-specific IgM titers peaked at days 5-9. Median seroconversion times of both anti-Gn- and NP-specific IgG were 7.0 days. High anti-Gn-specific IgG titers were maintained until 35-39 months after symptom onset. Only one patient lost their anti-Gn-specific antibodies at 41 days after symptom onset. Our data suggested that the anti-Gn-specific IgM titer peaked later than anti-NP-specific IgM, and that anti-Gn-specific IgG remain for at least 3 years from symptom onset.

Fluvoxamine Treatment of Patients with Symptomatic COVID-19 in a Community Treatment Center: A Preliminary Result of Randomized Controlled Trial.

BACKGROUND: This study aimed to evaluate whether fluvoxamine reduces clinical deterioration in adult patients with mild to moderate coronavirus disease 2019 (COVID-19), and to identify risk factors for clinical deterioration in patients admitted to a community treatment center (CTC). MATERIALS AND METHODS: A randomized, placebo-controlled trial was conducted in a CTC, in Seoul, Korea from January 15, 2021, to February 19, 2021. Symptomatic adult patients with positive results of severe acute respiratory syndrome coronavirus 2 real time-polymerase chain reaction within 3 days of randomization were assigned at random to receive 100 mg of fluvoxamine or placebo twice daily for 10 days. The primary outcome was clinical deterioration defined by any of the following criteria: oxygen requirement to keep oxygen saturation over 94.0%, aggravation of pneumonia with dyspnea, or World Health Organization clinical progression scale 4 or greater. RESULTS: Of 52 randomized participants [median (interquartile range) age, 53.5 (43.3 - 60.0) years; 31 (60.0%) men], 44 (85.0%) completed the trial. Clinical deterioration occurred in 2 of 26 patients in each group (P >0.99). There were no serious adverse events in either group. Clinical deterioration occurred in 15 (6.0%) of 271 patients admitted to the CTC, and all of them were transferred to a hospital. In multivariate analysis, age between 55 and 64, fever and pneumonia at admission were independent risk factors for clinical deterioration. CONCLUSION: In this study of adult patients with symptomatic COVID-19 who were admitted to the CTC, there was no significant differences in clinical deterioration between patients treated with fluvoxamine and placebo (ClinicalTrials.gov Identifier: NCT04711863).