Evaluation of the synergistic effect of eravacycline and tigecycline against carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a substantial healthcare challenge. This study assessed the in vitro efficacy of selected antibiotic combinations against CRKP infections. METHODS: Our research involved the evaluation of 40 clinical isolates of CRKP, with half expressing Klebsiella pneumoniae carbapenemase (KPC) and half producing Metallo-ß-lactamase (MBL), two key enzymes contributing to carbapenem resistance. We determined the minimum inhibitory concentrations (MICs) of four antibiotics: eravacycline, tigecycline, polymyxin-B, and ceftazidime/avibactam. Synergistic interactions between these antibiotic combinations were examined using checkerboard and time-kill analyses. RESULTS: We noted significant differences in the MICs of ceftazidime/avibactam between KPC and MBL isolates. Checkerboard analysis revealed appreciable synergy between combinations of tigecycline (35%) or eravacycline (40%) with polymyxin-B. The synergy rates for the combination of tigecycline or eravacycline with polymyxin-B were similar among the KPC and MBL isolates. These combinations maintained a synergy rate of 70.6% even against polymyxin-B resistant isolates. In contrast, combinations of tigecycline (5%) or eravacycline (10%) with ceftazidime/avibactam showed significantly lower synergy than combinations with polymyxin-B (P < 0.001 and P = 0.002, respectively). Among the MBL CRKP isolates, only one exhibited synergy with eravacycline or tigecycline and ceftazidime/avibactam combinations, and no synergistic activity was identified in the time-kill analysis for these combinations. The combination of eravacycline and polymyxin-B demonstrated the most promising synergy in the time-kill analysis. CONCLUSION: This study provides substantial evidence of a significant synergy when combining tigecycline or eravacycline with polymyxin-B against CRKP strains, including those producing MBL. These results highlight potential therapeutic strategies against CRKP infections.

Clinical manifestations and risk factors for COVID-19 and its severity in patients with hematological malignancies.

BACKGROUND: Patients with hematological malignancies (HM) were at a high risk of developing severe disease from coronavirus disease 2019 (COVID-19). We aimed to assess the clinical outcome of COVID-19 in hospitalized patients with HM. METHODS: Adult patients with HM who were hospitalized with a laboratory-confirmed COVID-19 between May, 2021 and November, 2022 were retrospectively identified. Primary outcome was respiratory failure requiring mechanical ventilation or mortality within 60 days after hospitalization. We also analyzed associated factors for de-isolation (defined as defervescence with a consecutive serial cycle threshold value > 30) within 28 days. RESULTS: Of 152 eligible patients, 22 (14.5%) developed respiratory failure or mortality in 60 days. Factors associated with developing respiratory failure that required mechanical ventilation or mortality included receipt of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) (adjusted hazards ratio [aHR], 5.10; 95% confidence interval [CI], 1.64-15.85), type 2 diabetes mellitus (aHR, 2.47; 95% CI, 1.04-5.90), lymphopenia at admission (aHR, 6.85; 95% CI, 2.45-19.15), and receiving <2 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines (aHR, 3.00; 95% CI, 1.19-7.60). Ninety-nine (65.1%) patients were de-isolated in 28 days, against which two hazardous factors were identified: receipt of B-cell depletion therapies within one year prior to COVID-19 (aHR, 0.55, 95% CI, 0.35-0.87) and lymphopenia upon admission (aHR, 0.65; 95% CI, 0.43-1.00). CONCLUSION: We found a high rate of respiratory failure and mortality among patients with HM who contracted the SARS-CoV-2. Factors associated with developing respiratory failure or mortality in 60 days included receipt of allo-HSCT, type 2 diabetes mellitus and lymphopenia upon admission. Having received ≥2 doses of vaccination conferred protection against clinical progression.

Effect of early dexamethasone on outcomes of COVID-19: A quasi-experimental study using propensity score matching.

BACKGROUND: The RECOVERY trial demonstrated that the use of dexamethasone is associated with a 36% lower 28-day mortality in hospitalized patients with COVID-19 on invasive mechanical ventilation. Nevertheless, the optimal timing to start dexamethasone remains uncertain. METHODS: We conducted a quasi-experimental study at National Taiwan University Hospital (Taipei, Taiwan) using propensity score matching to simulate a randomized controlled trial to receive or not to receive early dexamethasone (6 mg/day) during the first 7 days following the onset of symptoms. Treatment was standard protocol-based, except for the timing to start dexamethasone, which was left to physicians' decision. The primary outcome is 28-day mortality. Secondary outcomes include secondary infection within 60 days and fulfilling the criteria of de-isolation within 20 days. RESULTS: A total of 377 patients with COVID-19 were enrolled. Early dexamethasone did not decrease 28-day mortality in all patients (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.97-1.10) or in patients who required O2 for severe/critical disease at admission (aOR, 1.05; 95%CI, 0.94-1.18); but is associated with a 24% increase in superinfection in all patients (aOR, 1.24; 95% CI, 1.12-1.37) and a 23% increase in superinfection in patients of O2 for several/critical disease at admission (aOR, 1.23; 95% CI, 1.02-1.47). Moreover, early dexamethasone is associated with a 42% increase in likelihood of delayed clearance of SARS-CoV-2 virus (adjusted hazard ratio, 1.42; 95% CI, 1.01-1.98). CONCLUSION: An early start of dexamethasone (within 7 days after the onset of symptoms) could be harmful to hospitalized patients with COVID-19.

Achievements of COVID-19 vaccination programs: Taiwanese perspective.

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global health crisis. The specific characteristics of aerosol transmission in the latent period and the contagiousness of SARS-CoV-2 lead to rapid spread of infection in the community. Vaccination is the most effective method for preventing infection and severe outcomes. As of December 1, 2022, 88% of the Taiwanese population had received at least two doses of COVID-19 vaccines. Heterologous vaccination with ChAdOx1-mRNA-based or ChAdOx1-protein-based vaccines has been found to elicit higher immunogenicity than homologous vaccination with ChAdOx1-ChAdOx1 vaccines. A longitudinal cohort study revealed that 8-12-week intervals between the two heterologous vaccine doses of the primary series led to good immunogenicity and that the vaccines were safe. A third booster dose of mRNA vaccine is being encouraged to evoke effective immune responses against variants of concern. A novel domestic recombinant protein subunit vaccine (MVC-COV1901) was manufactured and authorized for emergency use in Taiwan. It has shown a good safety profile, with promising neutralizing antibody titers against SARS-CoV-2. Given the global pandemic due to emerging novel variants of SARS-CoV-2, booster COVID-19 vaccines and appropriate intervals between booster doses need to be investigated.

Preventing and controlling intra-hospital spread of COVID-19 in Taiwan - Looking back and moving forward.

COVID-19 has exposed major weaknesses in the healthcare settings. The surge in COVID-19 cases increases the demands of health care, endangers vulnerable patients, and threats occupational safety. In contrast to a hospital outbreak of SARS leading to a whole hospital quarantined, at least 54 hospital outbreaks following a COVID-19 surge in the community were controlled by strengthened infection prevention and control measures for preventing transmission from community to hospitals as well as within hospitals. Access control measures include establishing triage, epidemic clinics, and outdoor quarantine stations. Visitor access restriction is applied to inpatients to limit the number of visitors. Health monitoring and surveillance is applied to healthcare personnel, including self-reporting travel declaration, temperature, predefined symptoms, and test results. Isolation of the confirmed cases during the contagious period and quarantine of the close contacts during the incubation period are critical for containment. The target populations and frequency of SARS-CoV-2 PCR and rapid antigen testing depend on the level of transmission. Case investigation and contact tracing should be comprehensive to identify the close contacts to prevent further transmission. These facility-based infection prevention and control strategies help reduce hospital transmission of SARS-CoV-2 to a minimum in Taiwan.

Antiviral therapy of coronavirus disease 2019 (COVID-19).

The coronavirus disease 2019 (COVID-19) pandemic has reached a turning point. The non-pharmaceutical interventions for preventing COVID-19 are lifting. Vaccination uptake is increasing in general, but this strategy is continuously challenged by the rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of note, the Omicron subvariants spread globally for at least one year, and the most recently developed subvariants show strong immune evasion to preexisting immunity, either from previous infection, vaccination or both. Therefore, early and appropriate antiviral agents to treat patients at risk for severe COVID-19 or death is crucial to decrease morbidities and mortalities, to restore the healthcare capacities and to facilitate a return to the new normal. Current antiviral therapy for COVID-19 consist of neutralizing monoclonal antibodies (mAbs) and direct antiviral agents. Each agent has been proved for early ambulatory treatment of COIVD-19, but suffer from variable effectiveness and limitations due to patients' comorbidities, drug properties, or antiviral resistance. Besides, some specific mAbs are indicated for prophylaxis of COVID-19 before or after close contact with confirmed COVID-19 patients. This review article summarizes the evidence and unmet needs of the currently available antiviral agents for management of COVID-19 in the context of the Omicron subvariants.

Coronavirus disease 2019 (COVID-19) universal admission screening in patients and companions in Taiwan from May 2021 to June 2022: A nationwide multicenter study.

OBJECTIVE: Universal admission screening and follow-up symptom-based testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play critical roles in controlling nosocomial transmission. We describe the performance of test strategies for inpatients and their companions during various disease incidences in Taiwan. DESIGN: Retrospective population-based cohort study. SETTING: The study was conducted across 476 hospitals in Taiwan. METHODS: The data for both testing strategies by reverse transcription-polymerase chain reaction for SARS-CoV-2 in newly admitted patients and their companions during May 2021-June 2022 were extracted and analyzed. RESULTS: The positivity rate of universal admission screening was 0.76% (14,640 of 1,928,676) for patients and 0.37% (5,372 of 1,438,944) for companions. The weekly community incidences of period 1 (May 2021-June 2021), period 2 (July 2021-March 2022), and period 3 (April 2022-June 2022) were 6.57, 0.27, and 1,261, respectively, per 100,000 population. The positivity rates of universal admission screening for patients and companions (4.39% and 2.18%) in period 3 were higher than those in periods 1 (0.29% and 0.04%) and 2 (0.03% and 0.003%) (all P < .01). Among the 22,201 confirmed cases, 9.86% were identified by symptom-based testing. The costs and potential savings of universal admission screening for patients and companions achieved a breakeven point when the test strategy was implemented in a period with weekly community incidences of 27 and 358 per 100,000 population, respectively. CONCLUSIONS: Universal admission screening and follow-up symptom-based testing is important for reducing nosocomial transmission. Implementing universal admission screening at an appropriate time would balance the benefits with costs and potential unintended harms.

CXCL9 as a Reliable Biomarker for Discriminating Anti-IFN-γ-Autoantibody-Associated Lymphadenopathy that Mimics Lymphoma.

The diagnosis of adult-onset immunodeficiency syndrome associated with neutralizing anti-interferon γ autoantibodies (AIGA) presents substantial challenges to clinicians and pathologists due to its nonspecific clinical presentation, absence of routine laboratory tests, and resemblance to certain lymphoma types, notably nodal T follicular helper cell lymphoma, angioimmunoblastic type (nTFHL-AI). Some patients undergo lymphadenectomy for histopathological examination to rule out lymphoma, even in the absence of a preceding clinical suspicion of AIGA. This study aimed to identify reliable methods to prevent misdiagnosis of AIGA in this scenario through a retrospective case-control analysis of clinical and pathological data, along with immune gene transcriptomes using the NanoString nCounter platform, to compare AIGA and nTFHL-AI. The investigation revealed a downregulation of the C-X-C motif chemokine ligand 9 (CXCL9) gene in AIGA, prompting an exploration of its diagnostic utility. Immunohistochemistry (IHC) targeting CXCL9 was performed on lymph node specimens to assess its potential as a diagnostic biomarker. The findings exhibited a significantly lower density of CXCL9-positive cells in AIGA compared to nTFHL-AI, displaying a high diagnostic accuracy of 92.3% sensitivity and 100% specificity. Furthermore, CXCL9 IHC demonstrated its ability to differentiate AIGA from various lymphomas sharing similar characteristics. In conclusion, CXCL9 IHC emerges as a robust biomarker for differentiating AIGA from nTFHL-AI and other similar conditions. This reliable diagnostic approach holds the potential to avert misdiagnosis of AIGA as lymphoma, providing timely and accurate diagnosis.

Immunogenicity and safety of heterologous booster with protein-based COVID-19 vaccine (NVX-CoV2373) in healthy adults: A comparative analysis with mRNA vaccines.

BACKGROUND: Information on the protein-based severe acute respiratory syndrome (SARS-CoV-2) vaccine-NVX-CoV2373 (Novavax), as a heterologous booster remains limited. We investigated the immunogenicity and adverse events of NVX-CoV2373 as a second booster and compared them with those of mRNA vaccines in healthy adults. METHODS: Healthcare workers who had received an mRNA vaccine (mRNA-1273 or BNT-162b2) as the first booster (third dose) 12 weeks prior were recruited. Participants voluntarily received either NVX-CoV2373 or an mRNA vaccine as a second booster. Participants with a history of SARS-CoV-2 infection were excluded. The primary outcomes included serum anti-SARS-CoV-2 spike protein (SP) and neutralizing antibody titers against B.1.1.7 (Alpha), B.1.1.529 (Omicron) BA2, and BA5 variants on the 28th day after the boost. Secondary outcomes included new SARS-CoV-2 infections and adverse events reported during the study period. RESULTS: A total of 160 participants were enrolled in this study. Compared with the mRNA vaccination group (n = 59), the NVX-CoV2373 vaccination group (n = 101) had significantly lower anti-SARS-CoV-2 SP antibody titers and neutralizing antibody titers against all variants tested after the boost. During the study period, higher rates of new SARS-CoV-2 infections and a lower incidence of adverse events were observed in the NVX-CoV2373 vaccination group. No significant differences in cellular immune responses were observed between the two groups. CONCLUSION: Compared to a homologous mRNA booster vaccination, heterologous boosters with NVX-CoV2373 showed lower antibody responses, a higher incidence of new SARS-CoV-2 infections, and fewer adverse events.

Excess mortality and long-term disability from healthcare-associated carbapenem-resistant Acinetobacter baumannii infections: A nationwide population-based matched cohort study.

BACKGROUND: Carbapenem resistance is perceived as a clinical challenge in the management of debilitated and immunocompromised patients who eventually will die from underlying diseases. We aimed to examine whether carbapenem resistance per se, rather than the underlying diseases, negatively affect outcomes, by comparing the excess mortality and morbidity from healthcare-associated infections (HAIs) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-susceptible A. baumannii (CSAB). METHODS: This was a nationwide retrospective matched cohort study of hospitalized patients in 96 hospitals which participated in Taiwan Nosocomial Infection Surveillance (TNIS). A total of 2,213 patients with A. baumannii HAIs were individually matched to 4,426 patients without HAIs. Main outcomes were excess risks for one-year all-cause mortality and one-year new-onset chronic ventilator dependence or dialysis-dependent end-stage renal disease. RESULTS: Excess one-year mortality was 27.2% in CRAB patients, compared with their matched uninfected inpatients, as well as 15.4% in CSAB patients (also compared with their matched uninfected inpatients), resulting in an attributable mortality of 11.8% (P <0.001) associated with carbapenem resistance. The excess risk associated with carbapenem resistance for new-onset chronic ventilator dependence was 5.2% (P <0.001). Carbapenem resistance was also associated with an extra cost of $2,511 per case of A. baumannii HAIs (P <0.001). CONCLUSION: Carbapenem resistance is associated with a significant disease burden in terms of excess mortality, long-term ventilator dependence, and medical cost. Further studies on effects of antimicrobial stewardship programs in decreasing this burden are warranted.

Single-Center Experience of Control of Ventilator-Circuit-Transmitted Burkholderia cepacia Outbreak in an Intensive Care Unit.

Burkholderia cepacia is an emerging nosocomial pathogen frequently associated with outbreaks, but the exact transmission route of this pathogen can at times be elusive in spite of extensive environmental investigative cultures. Active surveillance for sputum cultures was performed for all patients from September 2008 to September 2009 in an intensive care unit (ICU) with B. cepacia outbreak. With evidence of persistent positive conversion of sputum cultures (colonization) and infections among patients, discontinuing re-usable ventilator circuits was introduced. A total of 689 patients were admitted to this unit for a mean duration of 8.7 ± 7.5 days. There were 489 patients (71.0%) with a stay for one to ten days; 161 (23.4%) patients for 11 to 20 days; and 39 (5.7%) with over 20 days. In the first group, 13.5% of patients had cultures converting from negative to positive, in contrast to 66.7% in the last group (p < 0.01). With intervention of using disposable ventilator circuits since June 2009, the incidence of isolated B. cepacia decreased gradually. The estimated 30-day isolation-free probabilities of the groups before, during, one month (August 2009) after, and two months (September 2009) after this intervention were 38.5%, 47.3%, 66.5%, and 96.0%, respectively (p < 0.01). Furthermore, the effect of discontinuing reusable ventilator circuit persisted in the following 6 years; both total isolates of B. cepacia and the infection caused by it were much lower compared to the outbreak period. In summary, this six-year outbreak in a medical ICU persisted until reusable ventilator circuits were discontinued in 2009. The effect of disposable circuits on the decreased incidence of B. cepacia infection maintained in the following years.

COVID-19 outbreaks in long-term care facilities-a nationwide population-based cohort study in Taiwan, May-July 2021.

BACKGROUND/PURPOSE: Long-term care facilities (LTCFs) are high-risk settings for the novel coronavirus disease (COVID-19). The aim of the study was to describe the extent and the impacts of 2021 COVID-19 outbreaks on LTCFs in Taiwan. METHODS: We retrospectively analyzed the data of each COVID-19 outbreak in LTCFs from May 15 to July 31, 2021 in Taiwan. We characterized the features of LTCFs with outbreaks and compared the characteristics of infected staff members and residents of the affected LTCFs. RESULTS: COVID-19 outbreaks were reported in 16 LTCFs (0.9%). The outbreak was significantly associated with LTCFs with ≥50 beds [adjusted odds ratio (aOR), 6.3; 95%confidence interval [CI], 1.9-21.1] and location of Taipei metropolitan area (aOR, 4.6; 95%CI, 1.7-12.8). Resident cases accounted for 75.4% (203/269) of confirmed cases affected by outbreaks. The 30-day all-cause mortality was 24.2% for residents only and was significantly associated with age ≥65 years [adjusted hazard ratio (aHR, 4.3; 95%CI, 1.7-10.5)], presence of symptoms on diagnosis (aHR, 2.2; 95%CI, 1.3-3.7), and LTCF occupancy rate ≥80% (aHR, 3.0, 95%CI, 1.3-7.4). CONCLUSION: COVID-19 outbreaks have a critical impact on residents in LTCFs owing to the advanced age and high prevalence of chronic comorbidities in this population. Multi-pronged infection control measures and mass testing are vital for mitigating COVID-19 transmission in LTCFs.

Factors associated with viral rebound among COVID-19 patients receiving oral antivirals.

BACKGROUND: COVID-19 rebound is usually reported among patients experiencing concurrent symptomatic and viral rebound. But longitudinal viral RT-PCR results from early stage to rebound of COVID-19 was less characterized. Further, identifying the factors associated with viral rebound after nirmatrelvir-ritonavir (NMV/r) and molnupiravir may expand understanding of COVID-19 rebound. METHODS: We retrospectively analyzed clinical data and sequential viral RT-PCR results from COVID-19 patients receiving oral antivirals between April and May, 2022. Viral rebound was defined by the degree of viral load increase (ΔCt ≥ 5 units). RESULTS: A total of 58 and 27 COVID-19 patients taking NMV/r and molnupiravir, respectively, were enrolled. Patients receiving NMV/r were younger, had fewer risk factors for disease progression and faster viral clearance rate compared to those receiving molnupiravr (All P < 0.05). The overall proportion of viral rebound (n = 11) was 12.9%, which was more common among patients receiving NMV/r (10 [17.2%] vs. 1 [3.7%], P = 0.16). Of them, 5 patients experienced symptomatic rebound, suggesting the proportion of COVID-19 rebound was 5.9%. The median interval to viral rebound was 5.0 (interquartile range, 2.0-8.0) days after completion of antivirals. Initial lymphopenia (<0.8 × 109/L) was associated with viral rebound among overall population (adjusted odds ratio [aOR], 5.34; 95% confidence interval [CI], 1.33-21.71), and remained significant (aOR, 4.50; 95% CI, 1.05-19.25) even when patients receiving NMV/r were considered. CONCLUSION: Our data suggest viral rebound after oral antivirals may be more commonly observed among lymphopenic individuals in the context of SARS-CoV-2 Omicron BA.2 variant.

Risk factors for mortality after linezolid treatment of vancomycin-resistant Enterococcus bloodstream infection.

OBJECTIVES: We analyzed the risk factors affecting linezolid treatment outcome in vancomycin-resistant Enterococcus (VRE) bloodstream infection (BSI). METHODS: We conducted a multicenter observational study of patients who received linezolid 600 mg every 12 hours for VRE BSI. The primary outcome was 28-day mortality. The estimated area under the concentration-time curve and trough concentration were calculated. Multivariable logistic regression was used for the outcome analysis. RESULTS: A total of 170 patients were included: 114 (67.1%) survived and 56 (32.9%) did not. A total of 26 (18.2%) isolates showed a linezolid minimum inhibitory concentration (MIC) of ≤1 mg/l, 113 (79.0%) of 2 mg/l, and 4 (2.8%) of 4 mg/l. The univariable analysis showed that the linezolid MIC and concentration-time curve/MIC were not associated with mortality (P = 0.95 and P = 0.42, respectively). After adjusting for underlying comorbidity and disease severity, the linezolid dose per body weight (LDBW), body height, and interaction between them were independent risks for mortality. Marginal analysis showed that increasing the LDBW was protective in patients with a body height <160 cm. A trough concentration of >12.2 mg/l was a risk factor for thrombocytopenia. CONCLUSION: The LDBW and body height were interactively associated with clinical outcomes of linezolid treatment for VRE BSI.

Molnupiravir for the treatment of COVID-19 in immunocompromised participants: efficacy, safety, and virology results from the phase 3 randomized, placebo-controlled MOVe-OUT trial.

PURPOSE: Immunocompromised patients have a potentially increased risk for progression to severe COVID-19 and prolonged replication of SARS-CoV-2. This post hoc analysis examined outcomes among immunocompromised participants in the MOVe-OUT trial. METHODS: In phase 3 of MOVe-OUT, non-hospitalized at-risk adults with mild-to-moderate COVID-19 were randomized to receive molnupiravir 800 mg or placebo twice daily for 5 days. Immunocompromised participants were identified based on prior/concomitant medications and/or medical history. All-cause hospitalization/death, adverse events, SARS-CoV-2 titers, infectivity, and RNA sequences were compared between immunocompromised participants who received molnupiravir or placebo and with non-immunocompromised participants. RESULTS: Fifty-five of 1408 participants were considered immunocompromised. Compared to placebo, fewer molnupiravir-treated immunocompromised participants were hospitalized/died through Day 29 (22.6% [7/31] vs. 8.3% [2/24]), with fewer adverse events (45.2% [14/31] vs. 25.0% [6/24]). A larger mean change from baseline in SARS-CoV-2 RNA was observed with molnupiravir compared to placebo in non-immunocompromised participants (least squares mean [LSM] difference Day 5: - 0.31, 95% confidence interval [CI] - 0.47 to - 0.15), while the mean change was comparable between treatment groups in immunocompromised participants (LSM difference Day 5: 0.23, 95% CI - 0.71 to 1.17). Molnupiravir treatment was associated with increased clearance of infectious virus. Increased errors in viral nucleotide sequences in post-baseline samples compared to placebo support molnupiravir's mechanism of action and were not associated with observation of novel treatment-emergent amino acid substitutions in immunocompromised participants. CONCLUSION: Although the study population was small, these data suggest that molnupiravir treatment for mild-to-moderate COVID-19 in non-hospitalized immunocompromised adults is efficacious and safe and quickly reduces infectious SARS-CoV-2. GOV REGISTRATION NUMBER: NCT04575597.

The Combination of Daptomycin with Fosfomycin is More Effective than Daptomycin Alone in Reducing Mortality of Vancomycin-Resistant Enterococcal Bloodstream Infections: A Retrospective, Comparative Cohort Study.

INTRODUCTION: High-dose daptomycin-based combinations are recommended for vancomycin-resistant Enterococcus (VRE) bloodstream infection (BSI). Preclinical data have shown a synergistic effect of daptomycin/fosfomycin combinations against VRE. However, clinical studies comparing daptomycin monotherapy with daptomycin/fosfomycin combinations are unavailable. METHODS: An observational study of VRE-BSI was performed between 2010-2021 on patients receiving daptomycin monotherapy (≥ 8 mg/kg) or daptomycin combined with intravenous fosfomycin. Patients treated with concomitant ß-lactam combinations were excluded. The primary outcome was in-hospital mortality. Outcomes were analyzed using multivariable logistic regression and augmented inverse probability weighting (AIPW) analyses. RESULTS: Among 224 patients, 176 received daptomycin monotherapy, and 48 received fosfomycin combinations. The median daptomycin and fosfomycin doses were 9.8 mg/kg and 12 g/day, respectively. In-hospital mortality was 77.3% and 47.9% in the daptomycin monotherapy and fosfomycin combination groups (P < 0.001), respectively. Multivariable logistic regression analysis predicted lower mortality with fosfomycin combination treatment (adjusted odds ratio, 0.35; 95% confidence interval (CI), 0.17-0.73; P = 0.005). AIPW demonstrated a 17.8% reduced mortality with fosfomycin combinations (95% CI, - 30.6- - 4.9%; P = 0.007). The survival benefit was significant, especially among patients with a lower Pitt bacteremia score or fosfomycin minimum inhibitory concentration (MIC) ≤ 64 mg/l. Fosfomycin combination resulted in higher hypernatremia (10.4% vs. 2.8%, P = 0.04) and hypokalemia (33.3% vs. 15.3%, P = 0.009) compared to daptomycin monotherapy. CONCLUSION: The combination of high-dose daptomycin with fosfomycin improved the survival rate of patients with VRE-BSI compared to daptomycin alone. The benefit of the combination was most pronounced for VRE with fosfomycin MIC ≤ 64 mg/l and for patients with a low Pitt bacteremia score.

Serological response and safety of heterologous ChAdOx1-nCoV-19/mRNA-1273 prime-boost vaccination with a twelve-week interval.

The appropriate interval between heterologous prime adenoviral vectored vaccination and boost mRNA vaccination remains unclear. We recruited 100 adult participants to receive a prime adenoviral vectored vaccine (ChAdOx1, AstraZeneca) and a boost mRNA vaccine (mRNA-1273, Moderna) 12 weeks apart and checked their serum SARS-CoV-2 anti-spike IgG titers and neutralizing antibody titers against B.1.1.7 (alpha) and B.1.617.2 (delta) variants on the 28th day after the boost dose. Results were compared with our previous study cohorts who received the same prime-boost vaccinations at 4- and 8-week intervals. Compared to other heterologous vaccination groups, the 12-week interval group had higher neutralizing antibody titers against SARS-CoV-2 variants than the 4-week interval group and was similar to the 8-week interval group at day 28. Adverse reactions after the boost dose were mild and transient. Our results support deploying viral vectored and mRNA vaccines in a flexible schedule with intervals from 8 to 12 weeks.