Invasive meningococcal disease: Impact of short course therapy. A DOOR/RADAR study

Progression of antibiotic resistance in Neisseria meningitidis

SUMMARYThe human pathogen Neisseria meningitidis (Nm) is the causative agent of invasive meningococcal disease (IMD), usually presenting as meningitis, bacteremia, or sepsis. Unlike Neisseria gonorrhoeae, antibiotic resistance in Nm has developed slowly. However, in the last two decades and with the reemergence of IMD following the COVID-19 pandemic, antibiotic-resistant Nm isolates, especially to penicillin and fluoroquinolones, have progressively increased. Recent worldwide studies of penicillin intermediate and resistant Nm isolates and the PubMLST global database reveal a notable increase in fully penicillin-resistant isolates since 2016, mediated by mosaic penA alleles or the β-lactamase genes blaROB-1 and blaTEM-1. Fluoroquinolone-resistant isolates, mediated by gyrA mutations, have increased since 2005. Also, while still exceptionally rare, four Nm isolates have been identified with third-generation cephalosporin-resistance since 2011. We review the emergence of antibiotic resistance determinants and lineages in Nm, the resistance to agents previously or currently used in treatment or chemoprophylaxis, and summarize updated treatment and prevention guidelines for IMD. Special populations (e.g., individuals on complement inhibitors) and antibiotic resistance in Nm urethritis isolates are also reviewed. The increasing number of resistant Nm isolates worldwide affects chemoprophylaxis and treatment options for IMD and emphasizes the need for enhanced global surveillance of antibiotic resistance in Nm.

Combination of Antistaphylococcal β-Lactam With Standard Therapy Compared to Standard Therapy Alone for the Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia: A Post Hoc Analysis of the CAMERA2 Trial Using a Desirability of Outcome Ranking Approach

Background

Desirability of outcome ranking (DOOR) is an emerging approach to clinical trial outcome measurement using an ordinal scale to incorporate efficacy and safety endpoints.

Methods

We applied a previously validated DOOR endpoint to a cohort of CAMERA2 trial participants with methicillin-resistant Staphylococcus aureus bacteremia (MRSAB). Participants were randomly assigned to standard therapy, or to standard therapy plus an antistaphylococcal β-lactam (combination therapy). Each participant was assigned a DOOR category, within which they were further ranked according to their hospital length of stay (LOS) and duration of intravenous antibiotic treatment. We calculated the probability and the generalized odds ratio of participants receiving combination therapy having worse outcomes than those receiving standard therapy.

Results

Participants assigned combination therapy had a 54.5% (95% confidence interval [CI], 48.9%-60.1%; P = .11) probability and a 1.2-fold odds (95% CI, .95-1.50; P = .12) of having a worse outcome than participants on standard therapy. When further ranked according to LOS and duration of antibiotic treatment, participants in the combination group had a 55.6% (95% CI, 49.5%-61.7%) and 55.3% (95% CI, 49.2%-61.4%) probability of having a worse outcome than participants in the standard treatment group, respectively.

Conclusions

When considering both efficacy and safety, treatment of MRSAB with a combination of standard therapy and a β-lactam likely results in a worse clinical outcome than standard therapy. However, a small benefit of combination therapy cannot be excluded. Most likely the toxicity of combination therapy outweighed any benefit from faster clearance of bacteremia.

Study protocol for a randomized clinical trial to assess 7 versus 14-days of treatment for Pseudomonas aeruginosa bloodstream infections (SHORTEN-2 trial)

BACKGROUND

Research priorities in Antimicrobial Stewardship (AMS) have rapidly evolved in the last decade. The need for a more efficient use of antimicrobials have fueled plenty of studies to define the optimal duration for antibiotic treatments, and yet, there still are large areas of uncertainty in common clinical scenarios. Pseudomonas aeruginosa has been pointed as a priority for clinical research, but it has been unattended by most randomized trials tackling the effectiveness of short treatments. The study protocol of the SHORTEN-2 trial is presented as a practical example of new ways to approach common obstacles for clinical research in AMS.

OBJECTIVE

To determine whether a 7-day course of antibiotics is superior to 14-day schemes for treating bloodstream infections by P. aeruginosa (BSI-PA).

METHODS

A superiority, open-label, randomized controlled trial will be performed across 30 Spanish hospitals. Adult patients with uncomplicated BSI-PA will be randomized to receive a 7 versus 14-day course of any active antibiotic. The primary endpoint will be the probability for the 7-day group of achieving better outcomes than the control group, assessing altogether clinical effectiveness, severe adverse events, and antibiotic exposure through a DOOR/RADAR analysis. Main secondary endpoints include treatment failure, BSI-PA relapses, and mortality. A superiority design was set for the primary endpoint and non-inferiority for treatment failure, resulting in a sample size of 304 patients.

CONCLUSIONS

SHORTEN-2 trial aligns with some of the priorities for clinical research in AMS. The implementation of several methodological innovations allowed overcoming common obstacles, like feasible sample sizes or measuring the clinical impact and unintended effects.

TRIAL REGISTRATION

EudraCt: 2021-003847-10; ClinicalTrials.gov: NCT05210439.

Outcomes of adults with invasive meningococcal disease with reduced penicillin susceptibility in Auckland 2004-2017

PURPOSE

The purpose of this study was to assess the clinical outcomes of adults with invasive meningococcal disease (IMD) and to compare the outcomes of patients with IMD caused by a penicillin susceptible isolate (minimum inhibitory concentration (MIC) ≤ 0.06 mg/L) with patients with IMD caused by an isolate with reduced penicillin susceptibility (MIC > 0.06 mg/L). We also assessed the outcomes of patients with IMD caused by an isolate with reduced penicillin susceptibility who were treated exclusively with intravenous (IV) benzylpenicillin.

METHODS

Retrospective study of all culture positive IMD in adult patients (age ≥ 15 years) in the Auckland region from 2004 to 2017.

RESULTS

One hundred and thirty-nine patients were included; 94 had penicillin susceptible isolates (88 cured, 6 died), and 45 had an isolate with reduced penicillin susceptibility (41 cured, 1 possible relapse, 3 died). The median benzylpenicillin/ceftriaxone treatment duration was 3 days for both groups. There was no difference in the patient outcomes of both groups. Eighteen patients with IMD caused by an isolate with reduced penicillin susceptibility received benzylpenicillin alone and were cured.

CONCLUSIONS

This study provides further support to existing data that has shown that short duration IV beta-lactam treatment is effective for IMD in adults. Only a small number of patients with meningitis caused by an isolate with reduced penicillin susceptibility received benzylpenicillin alone, limiting its evaluation. For Neisseria meningitidis meningitis, we recommend ceftriaxone as empiric treatment and as definitive treatment when this is caused by an isolate with reduced penicillin susceptibility.

Outcomes of Restricted versus Liberal Post-Operative Antibiotic Use in Patients Undergoing Appendectomy: A DOOR/RADAR Post Hoc Analysis of the EAST Appendicitis MUSTANG Study

Background: There is no consensus on the duration of antibiotic use after appendectomy. We hypothesized that restricted antibiotic use is associated with better clinical outcomes. Patients and Methods: We performed a post hoc analysis of the Eastern Association for the Surgery of Trauma (EAST) Multicenter Study of the Treatment of Appendicitis in America-Acute, Perforated, and Gangrenous (MUSTANG) study using the desirability of outcome ranking/response adjusted for duration of antibiotic risk (DOOR/RADAR) framework. Three separate datasets were analyzed based on restricted versus liberal post-operative antibiotic groups: simple appendicitis (no vs. yes); complicated appendicitis, only four days (≤24 hours vs. 4 days); and complicated appendicitis, four or more days (≤24 hours vs. ≥4 days). Patients were assigned to one of seven mutually exclusive DOOR categories RADAR ranked within each category. DOOR/RADAR score pairwise comparisons were performed between all patients. Each patient was assigned either 1, 0, or -1 if they had better, same, or worse outcomes than the other patient in the pair, respectively. The sum of these numbers (cumulative comparison score) was calculated for each patient and the group medians of individual sums were compared by Wilcoxon rank sum. Results: For simple appendicitis, the restricted group had higher median sums than the liberal group (552 [552,552] vs. -1,353 [-1,353, -1,353], p < 0.001). For both complicated appendicitis analyses, the restricted group had higher median sums than the liberal: only 4 (196 [23,196] vs. -121 [-121, -121], p < 0.02) and 4 or more (660 [484,660] vs -169 [-444,181], p < 0.001). Conclusions: Restricted post-operative antibiotic use in patients after appendectomy is a dominant strategy when considering treatment effectiveness and antibiotic exposure.

Antibiotic treatment of common infections: more evidence to support shorter durations

PURPOSE OF REVIEW

Although there is increasing recognition of the link between antibiotic overuse and antimicrobial resistance, clinician prescribing is often unnecessarily long and motivated by fear of clinical relapse. High-quality evidence supporting shorter treatment durations is needed to give clinicians confidence to change prescribing habits. Here we summarize recent randomized controlled trials investigating antibiotic short courses for common infections in adult patients.

RECENT FINDINGS

Randomized trials in the last five years have demonstrated noninferiority of short-course therapy for a range of conditions including community acquired pneumonia, intraabdominal sepsis, gram-negative bacteraemia and vertebral osteomyelitis.

SUMMARY

Treatment durations for many common infections have been based on expert opinion rather than randomized trials. There is now evidence to support shorter courses of antibiotic therapy for many conditions.

Impact of unit-specific metrics and prescribing tools on a family medicine ward

Objective:

Prescribing metrics, cost, and surrogate markers are often used to describe the value of antimicrobial stewardship (AMS) programs. However, process measures are only indirectly related to clinical outcomes and may not represent the total effect of an intervention. We determined the global impact of a multifaceted AMS initiative for hospitalized adults with common infections.

Design:

Single center, quasi-experimental study.

Methods:

Hospitalized adults with urinary, skin, and respiratory tract infections discharged from family medicine and internal medicine wards before (January 2017–June 2017) and after (January 2018–June 2018) an AMS initiative on a family medicine ward were included. A series of AMS-focused initiatives comprised the development and dissemination of: handheld prescribing tools, AMS positive feedback cases, and academic modules. We compared the effect on an ordinal end point consisting of clinical resolution, adverse drug events, and antimicrobial optimization between the preintervention and postintervention periods.

Results:

In total, 256 subjects were included before and after an AMS intervention. Excessive durations of therapy were reduced from 40.3% to 22% (P < .001). Patients without an optimized antimicrobial course were more likely to experience clinical failure (OR, 2.35; 95% CI, 1.17–4.72). The likelihood of a better global outcome was greater in the family medicine intervention arm (62.0%, 95% CI, 59.6–67.1) than in the preintervention family medicine arm.

Conclusion:

Collaborative, targeted feedback with prescribing metrics, AMS cases, and education improved global outcomes for hospitalized adults on a family medicine ward.

An approach to antibiotic treatment in patients with sepsis

Sepsis is a medical emergency and life-threatening condition due to a dysregulated host response to infection, which is time-dependent and associated with unacceptably high mortality. Thus, when treating suspicious or confirmed cases of sepsis, clinicians must initiate broad-spectrum antimicrobials within the first hour of diagnosis. Optimizing antibiotic use is essential to ensure successful outcomes and to reduce adverse antibiotic effects, as well as preventing drug resistance. All likely pathogens involved should be considered to provide an appropriate antibiotic coverage. Clinicians must investigate on the previous risk of multidrug-resistant (MDR) pathogens, and the principle of individualized dosing should replace the principle of standard dosing. The loading dose is an initial higher dose of an antibiotic for all patients, yet an individualized treatment approach for further doses should be implemented according to pharmacokinetics (PK)/pharmacodynamics (PD) and the presence of renal/liver dysfunction. Extended or continuous infusion of beta-lactams and therapeutic drug monitoring (TDM) can help to achieve therapeutic levels of antimicrobials. Reevaluation of duration and appropriateness of treatment at regular intervals are also necessary. De-escalation and shortened courses of antimicrobials must be considered for most patients, except in some justified circumstances. Leadership, teamwork, antimicrobial stewardship (AS) frameworks, guideline’s recommendations on the optimal duration of treatments, de-escalation, and novel diagnostic stewardship approaches will help us to improve patients’ quality of care.

Impact of pre-hospital antibiotic therapy on mortality in invasive meningococcal disease: a propensity score study

The role of pre-hospital antibiotic therapy in invasive meningococcal diseases remains unclear with contradictory data. The aim was to determine this role in the outcome of invasive meningococcal disease. Observational cohort study of patients with/without pre-hospital antibiotic therapy in invasive meningococcal disease attended at the Hospital Universitari de Bellvitge (Barcelona) during the period 1977-2013. Univariate and multivariate analyses of mortality, corrected by propensity score used as a covariate to adjust for potential confounding, were performed. Patients with pre-hospital antibiotic therapy were also analyzed according to whether they had received oral (group A) or parenteral antibiotics (early therapy) (group B). Five hundred twenty-seven cases of invasive meningococcal disease were recorded and 125 (24%) of them received pre-hospital antibiotic therapy. Shock and age were the risk factors independently related to mortality. Mortality differed between patients with/without pre-hospital antibiotic therapy (0.8% vs. 8%, p = 0.003). Pre-hospital antibiotic therapy seemed to be a protective factor in the multivariate analysis of mortality (p = 0.038; OR, 0.188; 95% CI, 0.013-0.882). However, it was no longer protective when the propensity score was included in the analysis (p = 0.103; OR, 0.173; 95% CI, 0.021-1.423). Analysis of the oral and parenteral pre-hospital antibiotic groups revealed that there were no deaths in early therapy group. Patients able to receive oral antibiotics had less severe symptoms than those who did not receive pre-hospital antibiotics. Age and shock were the factors independently related to mortality. Early parenteral therapy was not associated with death. Oral antibiotic therapy in patients able to take it was associated with a beneficial effect in the prognosis of invasive meningococcal disease.

Invasive Meningococcal Disease: What We Should Know, Before It Comes Back

Background

Invasive meningococcal disease (IMD), sepsis and/or meningitis continues to be a public health problem, with mortality rates ranging from 5% to 16%. The aim of our study was to further knowledge about IMD with a large series of cases occurring over a long period of time, in a cohort with a high percentage of adult patients.

Methods

Observational cohort study of patients with IMD between 1977 hand 2013 at our hospital, comparing patients with only sepsis and those with meningitis and several degrees of sepsis. The impact of dexamethasone and prophylactic phenytoin was determined, and an analysis of cutaneous and neurological sequelae was performed.

Results

A total of 527 episodes of IMD were recorded, comprising 57 cases of sepsis (11%) and 470 of meningitis with or without sepsis (89%). The number of episodes of IMD decreased from 352 of 527 (67%) in the first to 20 of 527 (4%) in the last quarter (P < .001). Thirty-three patients died (6%): 8 with sepsis (14%) and 25 with meningitis (5%) (P = .02). Cutaneous and neurological sequelae were present in 3% and 5% of survivors of sepsis and meningitis, respectively. The use of dexamethasone was safe and resulted in less arthritis, and patients given prophylactic phenytoin avoided seizures.

Conclusions

The frequency of IMD has decreased sharply since 1977. Patients with sepsis only have the highest mortality and complication rates, dexamethasone use is safe and can prevent some arthritis episodes, and prophylactic phenytoin might be useful in a selected population. A rapid response and antibiotic therapy may help improve the prognosis.