Catching the Culprit: Benzylpenicillin Neurotoxicity Confirmed by Therapeutic Drug Monitoring in a Critically Ill Patient with Continuous Venovenous Hemofiltration.

ABSTRACT: We present the case of a 65-year-old patient who was treated with high-dose benzylpenicillin for severe invasive pneumococcal pneumonia, complicated by acute renal failure managed with continuous venovenous hemofiltration. After cessation of continuous venovenous hemofiltration, the patient experienced multiple tonic-clonic seizures. Therapeutic drug monitoring revealed high total serum concentrations of benzylpenicillin, identifying it as the likely cause of the neurotoxicity. This case study presents the first documented total serum benzylpenicillin concentration associated with neurotoxicity.

Comparison of MBT biotargets with MBT steel targets for matrix-assisted laser desorption/ionization time of flight mass spectrometry identifications of microorganisms in a clinical microbiology laboratory.

MALDI-TOF MS identifications of microorganisms in a clinical laboratory were investigated, comparing steel targets with MBT Biotargets. By using MBT Biotargets, the score values of yeast identifications increased, whereas the score values of Gram-negative bacteria decreased. Switching to MBT Biotargets did not negatively impact overall frequencies of high confidence identifications.

Performance of point-of care molecular and antigen-based tests for SARS-CoV-2: a living systematic review and meta-analysis.

BACKGROUND: Molecular and antigen point-of-care tests (POCTs) have augmented our ability to rapidly identify and manage SARS-CoV-2 infection. However, their clinical performance varies among individual studies. OBJECTIVES: The evaluation of the performance of molecular and antigen-based POCTs in confirmed, suspected, or probable COVID-19 cases compared with that of laboratory-based RT-PCR in real-life settings. DATA SOURCES: MEDLINE/PubMed, Scopus, Embase, Web of Science, Cochrane Library, Cochrane COVID-19 study register, and COVID-19 Living Evidence Database from the University of Bern. STUDY ELIGIBILITY CRITERIA: Peer-reviewed or preprint observational studies or randomized controlled trials that evaluated any type of commercially available antigen and/or molecular POCTs for SARS-CoV-2, including multiplex PCR panels, approved by the United States Food and Drug Administration, with Emergency Use Authorization, and/or marked with Conformitè Europëenne from European Commission/European Union. PARTICIPANTS: Close contacts and/or patients with symptomatic and/or asymptomatic confirmed, suspected, or probable COVID-19 infection of any age. TEST/S: Molecular and/or antigen-based SARS-CoV-2 POCTs. REFERENCE STANDARD: Laboratory-based SARS-CoV-2 RT-PCR. ASSESSMENT OF RISK OF BIAS: Eligible studies were subjected to quality-control and risk-of-bias assessment using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. METHODS OF DATA SYNTHESIS: Summary sensitivities and specificities with their 95% CIs were estimated using a bivariate model. Subgroup analysis was performed when at least three studies informed the outcome. RESULTS: A total of 123 eligible publications (97 and 26 studies assessing antigen-based and molecular POCTs, respectively) were retrieved from 4674 initial records. The pooled sensitivity and specificity for 13 molecular-based POCTs were 92.8% (95% CI, 88.9-95.4%) and 97.6% (95% CI, 96.6-98.3%), respectively. The sensitivity of antigen-based POCTs pooled from 138 individual evaluations was considerably lower than that of molecular POCTs; the pooled sensitivity and specificity rates were 70.6% (95% CI, 67.2-73.8%) and 98.9% (95% CI, 98.5-99.2%), respectively. DISCUSSION: Further studies are needed to evaluate the performance of molecular and antigen-based POCTs in underrepresented patient subgroups and different respiratory samples.

Does plasmid-based beta-lactam resistance increase E. coli infections: Modelling addition and replacement mechanisms.

Infections caused by antibiotic-resistant bacteria have become more prevalent during past decades. Yet, it is unknown whether such infections occur in addition to infections with antibiotic-susceptible bacteria, thereby increasing the incidence of infections, or whether they replace such infections, leaving the total incidence unaffected. Observational longitudinal studies cannot separate both mechanisms. Using plasmid-based beta-lactam resistant E. coli as example we applied mathematical modelling to investigate whether seven biological mechanisms would lead to replacement or addition of infections. We use a mathematical neutral null model of individuals colonized with susceptible and/or resistant E. coli, with two mechanisms implying a fitness cost, i.e., increased clearance and decreased growth of resistant strains, and five mechanisms benefitting resistance, i.e., 1) increased virulence, 2) increased transmission, 3) decreased clearance of resistant strains, 4) increased rate of horizontal plasmid transfer, and 5) increased clearance of susceptible E. coli due to antibiotics. Each mechanism is modelled separately to estimate addition to or replacement of antibiotic-susceptible infections. Fitness costs cause resistant strains to die out if other strain characteristics are maintained equal. Under the assumptions tested, increased virulence is the only mechanism that increases the total number of infections. Other benefits of resistance lead to replacement of susceptible infections without changing the total number of infections. As there is no biological evidence that plasmid-based beta-lactam resistance increases virulence, these findings suggest that the burden of disease is determined by attributable effects of resistance rather than by an increase in the number of infections.

Narrow-spectrum antibiotics for community-acquired pneumonia in Dutch adults (CAP-PACT): a cross-sectional, stepped-wedge, cluster-randomised, non-inferiority, antimicrobial stewardship intervention trial.

BACKGROUND: Adults hospitalised to a non-intensive care unit (ICU) ward with moderately severe community-acquired pneumonia are frequently treated with broad-spectrum antibiotics, despite Dutch guidelines recommending narrow-spectrum antibiotics. Therefore, we investigated whether an antibiotic stewardship intervention would reduce the use of broad-spectrum antibiotics in patients with moderately severe community-acquired pneumonia without compromising their safety. METHODS: In this cross-sectional, stepped-wedge, cluster-randomised, non-inferiority trial (CAP-PACT) done in 12 hospitals in the Netherlands, we enrolled immunocompetent adults (≥18 years) who were admitted to a non-ICU ward and had a working diagnosis of moderately severe community-acquired pneumonia. All participating hospitals started in a control period and every 3 months a block of two hospitals transitioned from the control to the intervention period, with all hospitals eventually ending in the intervention period. The unit of randomisation was the hospital (cluster), and electronic randomisation (by an independent data manager) decided the sequence (the time of intervention) by which hospitals would cross over from the control period to the intervention period. Blinding was not possible. The antimicrobial stewardship intervention was a bundle targeting health-care providers and comprised education, engaging opinion leaders, and prospective audit and feedback of antibiotic use. The co-primary outcomes were broad-spectrum days of therapy per patient, tested by superiority, and 90-day all-cause mortality, tested by non-inferiority with a non-inferiority margin of 3%, and were analysed in the intention-to-treat population, comprising all patients who were enrolled in the control and intervention periods. This trial was prospectively registered at ClinicalTrials.gov, NCT02604628. FINDINGS: Between Nov 1, 2015, and Nov 1, 2017, 5683 patients were assessed for eligibility, of whom 4084 (2235 in the control period and 1849 in the intervention period) were included in the intention-to-treat analysis. The adjusted mean broad-spectrum days of therapy per patient were reduced from 6·5 days in the control period to 4·8 days in the intervention period, yielding an absolute reduction of -1·7 days (95% CI -2·4 to -1·1) and a relative reduction of 26·6% (95% CI 18·0-35·3). Crude 90-day mortality was 10·9% (242 of 2228 died) in the control period and 10·8% (199 of 1841) in the intervention period, yielding an adjusted absolute risk difference of 0·4% (90% CI -2·7 to 2·4), indicating non-inferiority. INTERPRETATION: In patients hospitalised with moderately severe community-acquired pneumonia, a multifaceted antibiotic stewardship intervention might safely reduce broad-spectrum antibiotic use. FUNDING: None.

How to interpret and use COVID-19 serology and immunology tests.

BACKGROUND: Although molecular tests are considered the reference standard for coronavirus disease 2019 (COVID-19) diagnostics, serological and immunological tests may be useful in specific settings. OBJECTIVES: This review summarizes the underlying principles and performance of COVID-19 serological and immunological testing. SOURCES: Selected peer-reviewed publications on COVID-19 related serology and immunology published between December 2019 and March 2021. CONTENT: Serological tests are highly specific but heterogeneous in their sensitivity for the diagnosis of COVID-19. For certain indications, including delayed disease presentations, serological tests can have added value. The presence of antibodies against SARS-CoV-2 may indicate a recent or past COVID-19 infection. Lateral flow immunoassay (LFIA) antibody tests have the advantages of being easy and fast to perform, but many have a low sensitivity in acute settings. Enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassays (CLIAs) have higher sensitivities. Besides humoral immunity, cellular immunity is also essential for successful host defences against viruses. Enzyme-linked immunospot (ELISpot) assays can be used to measure T-cell responses against SARS-CoV-2. The presence of cross-reactive SARS-CoV-2-specific T cells in never exposed patients suggests the possibility of cellular immunity induced by other circulating coronaviruses. T-cell responses against SARS-CoV-2 have also been detected in recovered COVID-19 patients with no detectable antibodies. IMPLICATIONS: Serological and immunological tests are primarily applied for population-based seroprevalence studies to evaluate the effectiveness of COVID-19 control measures and increase our understanding of the immunology behind COVID-19. Combining molecular diagnostics with serological tests may optimize the detection of COVID-19. As not all infected patients will develop antibodies against SARS-CoV-2, assessment of cellular immunity may provide complementary information on whether a patient has been previously infected with COVID-19. More studies are needed to understand the correlations of these serological and immunological parameters with protective immunity, taking into account the different circulating virus variants.

Incidence and costs of hospitalized adult influenza patients in The Netherlands: a retrospective observational study.

OBJECTIVE: Influenza virus infections cause a high disease and economic burden during seasonal epidemics. However, there is still a need for reliable disease burden estimates to provide a more detailed picture of the impact of influenza. Therefore, the objectives of this study is to estimate the incidence of hospitalisation for influenza virus infection and associated hospitalisation costs in adult patients in the Netherlands during two consecutive influenza seasons. METHODS: We conducted a retrospective study in adult patients with a laboratory confirmed influenza virus infection in three Dutch hospitals during respiratory seasons 2014-2015 and 2015-2016. Incidence was calculated as the weekly number of hospitalised influenza patients divided by the total population in the catchment populations of the three hospitals. Arithmetic mean hospitalisation costs per patient were estimated and included costs for emergency department consultation, diagnostics, general ward and/or intensive care unit admission, isolation, antibiotic and/or antiviral treatment. These hospitalisation costs were extrapolated to national level and expressed in 2017 euros. RESULTS: The study population consisted of 380 hospitalised adult influenza patients. The seasonal cumulative incidence was 3.5 cases per 10,000 persons in respiratory season 2014-2015, compared to 1.8 cases per 10,000 persons in 2015-2016. The arithmetic mean hospitalisation cost per influenza patient was €6128 (95% CI €4934-€7737) per patient in 2014-2015 and €8280 (95% CI €6254-€10,665) in 2015-2016, potentially reaching total hospitalisation costs of €28 million in 2014-2015 and €20 million in 2015-2016. CONCLUSIONS: Influenza virus infections lead to 1.8-3.5 hospitalised patients per 10,000 persons, with mean hospitalisation costs of €6100-€8300 per adult patient, resulting in 20-28 million euros annually in The Netherlands. The highest arithmetic mean hospitalisation costs per patient were found in the 45-64 year age group. These influenza burden estimates could be used for future influenza cost-effectiveness and impact studies.

Impact of antimicrobial de-escalation on mortality: a literature review of study methodology and recommendations for observational studies.

Introduction: The safety of de-escalation of empirical antimicrobial therapy is largely based on observational data, with many reporting protective effects on mortality. As there is no plausible biological explanation for this phenomenon, it is most probably caused by confounding by indication.Areas covered: We evaluate the methodology used in observational studies on the effects of de-escalation of antimicrobial therapy on mortality. We extended the search for a recent systematic review and identified 52 observational studies. The heterogeneity in study populations was large. Only 19 (36.5%) studies adjusted for confounders and four (8%) adjusted for clinical stability during admission, all as a fixed variable. All studies had methodological limitations, most importantly the lack of adjustment for clinical stability, causing bias toward a protective effect.Expert opinion: The methodology used in studies evaluating the effects of de-escalation on mortality requires improvement. We depicted all potential confounders in a directed acyclic graph to illustrate all associations between exposure (de-escalation) and outcome (mortality). Clinical stability is an important confounder in this association and should be modeled as a time-varying variable. We recommend to include de-escalation as time-varying exposure and use inverse-probability-of-treatment weighted marginal structural models to properly adjust for time-varying confounders.

Confounding by indication of the safety of de-escalation in community-acquired pneumonia: A simulation study embedded in a prospective cohort.

Observational studies have demonstrated that de-escalation of antimicrobial therapy is independently associated with lower mortality. This most probably results from confounding by indication. Reaching clinical stability is associated with the decision to de-escalate and with survival. However, studies rarely adjust for this confounder. We quantified the potential confounding effect of clinical stability on the estimated impact of de-escalation on mortality in patients with community-acquired pneumonia. Data were used from the Community-Acquired Pneumonia immunization Trial in Adults (CAPiTA). The primary outcome was 30-day mortality. We performed Cox proportional-hazards regression with de-escalation as time-dependent variable and adjusted for baseline characteristics using propensity scores. The potential impact of unmeasured confounding was quantified through simulating a variable representing clinical stability on day three, using data on prevalence and associations with mortality from the literature. Of 1,536 included patients, 257 (16.7%) were de-escalated, 123 (8.0%) were escalated and in 1156 (75.3%) the antibiotic spectrum remained unchanged. Crude 30-day mortality was 3.5% (9/257) and 10.9% (107/986) in the de-escalation and continuation groups, respectively. The adjusted hazard ratio of de-escalation for 30-day mortality (compared to patients with unchanged coverage), without adjustment for clinical stability, was 0.39 (95%CI: 0.19-0.79). If 90% to 100% of de-escalated patients were clinically stable on day three, the fully adjusted hazard ratio would be 0.56 (95%CI: 0.27-1.12) to 1.04 (95%CI: 0.49-2.23), respectively. The simulated confounder was substantially stronger than any of the baseline confounders in our dataset. Quantification of effects of de-escalation on patient outcomes without proper adjustment for clinical stability results in strong negative bias. This study suggests the effect of de-escalation on mortality needs further well-designed prospective research to determine effect size more accurately.

Plasma cytokine profile on admission related to aetiology in community-acquired pneumonia.

BACKGROUND: Potentially unnecessary antibiotic use for community-acquired pneumonia (CAP) contributes to selection of antibiotic-resistant pathogens. Cytokine expression at the time that treatment is started may assist in identifying patients not requiring antibiotics. We determined plasma cytokine patterns in patients retrospectively categorized as strict viral, pneumococcal or combined viral-bacterial CAP. OBJECTIVE: To investigate whether cytokine-based prediction models can be used to differentiate strict viral CAP from other aetiologies at admission. METHODS: From 344 hospitalized CAP patients, 104 patients were categorized as viral CAP (n = 17), pneumococcal CAP (n = 48) and combined bacterial-viral CAP (n = 39). IL-6, IL-10, IL-27, IFN-γ and C-reactive protein (CRP) were determined on admission in plasma. Prediction of strict viral aetiology was explored with two multivariate regression models and ROC curves. RESULTS: Viral pneumonia was predicted by logistic regression using multiple cytokine levels (IL-6, IL-27 and CRP) with an AUC of 0.911 (95% CI: 0.852-0.971, P < .001). For the same patients the AUC of CRP was 0.813 (95% CI: 0.728-0.898, P < .001). CONCLUSIONS: This study demonstrated differences in cytokine expression in selected CAP patients between viral and bacterial aetiology. Prospective validation studies are warranted.

Inappropriate Use of Antimicrobials for Lower Respiratory Tract Infections in Elderly Patients: Patient- and Community-Related Implications and Possible Interventions.

The elderly are more susceptible to infections, which is reflected in the incidence and mortality of lower respiratory tract infections (LRTIs) increasing with age. Several aspects of antimicrobial use for LRTIs in elderly patients should be considered to determine appropriateness. We discuss possible differences in microbial etiology between elderly and younger adults, definitions of inappropriate antimicrobial use for LRTIs currently found in the literature, along with their results, and the possible negative impact of antimicrobial therapy at both an individual and community level. Finally, we propose that both antimicrobial stewardship interventions and novel rapid diagnostic techniques may optimize antimicrobial use in elderly patients with LRTIs.

Identification of Neisseria gonorrhoeae by the Bruker Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry System Is Improved by a Database Extension.

Identification ofNeisseria gonorrhoeaeby the Bruker matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system may be affected by "B consistency categorization." A supplementary database of 17N. gonorrhoeaemain spectra was constructed. Twelve of 64N. gonorrhoeaeidentifications were categorized with B consistency, which disappeared using the supplementary database. Database extension did not result in misidentification ofNeisseria meningitidis.