Population antibiotic susceptibility for Streptococcus pneumoniae and treatment outcomes in common respiratory tract infections

Streptococcus pneumoniae vaccination strategies and its expected impact on penicillin non-susceptibility in children under the age of five: Let's recap!

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The efficacy of PCVs currently used in children under 5 years of age is threatened by the emergence of invasive and resistant non-vaccine serotypes worldwide.

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Resistant NVT strains are emerging in IPD in children < 5 years mainly serotypes 24F, 15A, 11A and 33F along with serotype 19A in PCV-10 settings.

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Continuous surveillance is necessary in IPD in children under five to monitor the long-term effect of PCV-10 and PCV-13 on penicillin resistance trends.

The impact of pneumococcal conjugate vaccines (PCVs) on invasive pneumococcal disease (IPD) burden has been extensively studied in children aged<5 years; however, a pooled estimation of the effect of PCVs on penicillin non-susceptible pneumococci (PNSP) has not yet been performed. We aimed to identify whether the introduction of PCV-10 and PCV-13 had led to the decrease of the overall PNSP rate in children < 5 years. We conducted a systematic review of published surveillance studies reporting the rate of PNSP rates in children < 5 in countries where PCV10/13 were introduced. The overall observed trend onwards the introduction of PCV-10 and PCV-13 is a decrease in PNSP among children < 5 years in surveillance sites located in PCV-13 countries. We identified an increase of PNSP rates (serotype 19A) in PCV-10 settings. Resistant NVT strains are emerging in IPD in children < 5 years mainly serotypes 24F, 15A, 11A and 33F along with serotype 19A in PCV-10 settings. Continuous surveillance is necessary in IPD in children under five to monitor the long-term effect of PCV-10 and PCV-13 on penicillin resistance trends.

Macrolide Treatment Failure due to Drug–Drug Interactions: Real-World Evidence to Evaluate a Pharmacological Hypothesis

Macrolide antibiotics have received criticism concerning their use and risk of treatment failure. Nevertheless, they are an important class of antibiotics and are frequently used in clinical practice for treating a variety of infections. This study sought to utilize pharmacoepidemiology methods and pharmacology principles to estimate the risk of macrolide treatment failure and quantify the influence of their pharmacokinetics on the risk of treatment failure, using clinically reported drug–drug interaction data. Using a large, commercial claims database (2006–2015), inclusion and exclusion criteria were applied to create a cohort of patients who received a macrolide for three common acute infections. Furthermore, an additional analysis examining only bacterial pneumonia events treated with macrolides was conducted. These criteria were formulated specifically to ensure treatment failure would not be expected nor influenced by intrinsic or extrinsic factors. Treatment failure rates were 6% within the common acute infections and 8% in the bacterial pneumonia populations. Regression results indicated that macrolide AUC changes greater than 50% had a significant effect on treatment failure risk, particularly for azithromycin. In fact, our results show that decreased or increased exposure change can influence failure risk, by 35% or 12%, respectively, for the acute infection scenarios. The bacterial pneumonia results were less significant with respect to the regression analyses. This integration of pharmacoepidemiology and clinical pharmacology provides a framework for utilizing real-world data to provide insight into pharmacokinetic mechanisms and support future study development related to antibiotic treatments.

Treatment failure in pediatric acute otitis media: How do you define?

INTRODUCTION

Reaching the point of treatment failure in the management of pediatric acute otitis media (AOM) is decision-changing, and is often associated with switching to a broader coverage antibiotic with/without middle ear surgical drainage. Yet, still there is no consensus on the definition of what is treatment failure, which may lead to confusion for clinical decision-making purposes. We sought to review the heterogeneity of treatment failure definitions in AOM.

METHODS

We searched for relevant English language manuscripts using the following key-words: ['otitis media' (OM) or (AOM)] AND ['treatment failure' or 'failure' or 'response failure' or 'response'] AND 'human' in various electronic databases from 1/1/2005 through 10/31/2020.

RESULTS

In the 60 retrieved papers, treatment failure was considered only when antibiotics had been prescribed beforehand, but not when watchful waiting had been adopted. We categorized the manuscripts into 5 major treatment failure definition subgroups, which occasionally overlapped: unimprovement or worsening of symptoms or signs of failure in otoscopy (n = 36), specialist(s) referral or hospital admission (n = 12), changing or adding antibiotic treatment (n = 22), failure to eradicate causative bacteria (n = 7) and failure as perceived by parents (n = 4).

CONCLUSIONS

We suggest a broader definition of AOM treatment failure including physical examination findings and degree of initial treatment response, which will enable an unbiased, uniform comparison of treatments for pediatric AOM.

Variability in pediatric infectious disease consultants' recommendations for management of community-acquired pneumonia

Background

Community-acquired pneumonia (CAP) is a common childhood infection. CAP complications, such as parapneumonic empyema (PPE), are increasing and are frequently caused by antibiotic-resistant organisms. No clinical guidelines currently exist for management of pediatric CAP and no published data exist about variations in antibiotic prescribing patterns. Our objectives were to describe variation in CAP clinical management for hospitalized children by pediatric infectious disease consultants and to examine associations between recommended antibiotic regimens and local antibiotic resistance levels.

Methods

We surveyed pediatric members of the Emerging Infections Network, which consists of 259 pediatric infectious disease physicians. Participants responded regarding their recommended empiric antibiotic regimens for hospitalized children with CAP with and without PPE and their recommendations for duration of therapy. Participants also provided information about the prevalence of penicillin non-susceptible S. pneumoniae and methicillin-resistant S. aureus (MRSA) in their community.

Results

We received 148 responses (57%). For uncomplicated CAP, respondents were divided between recommending beta-lactams alone (55%) versus beta-lactams in combination with another class (40%). For PPE, most recommended a combination of a beta-lactam plus an anti-MRSA agent, however, they were divided between clindamycin (44%) and vancomycin (57%). The relationship between reported antibiotic resistance and empiric regimen was mixed. We found no relationship between aminopenicillin use and prevalence of penicillin non-suscepetible S. pneumoniae or clindamycin use and clindamycin resistance, however, respondents were more likely to recommend an anti-MRSA agent when MRSA prevalence increased.

Conclusions

Substantial variability exists in recommendations for CAP management. Development of clinical guidelines via antimicrobial stewardship programs and dissemination of data about local antibiotic resistance patterns represent opportunities to improve care.

Ambulatory visit rates and antibiotic prescribing for children with pneumonia, 1994-2007

BACKGROUND

The incidence of pediatric hospitalizations for community-acquired pneumonia (CAP) has declined after the widespread use of the heptavalent pneumococcal conjugate vaccine. The national incidence of outpatient visits for CAP, however, is not well established. Although no pediatric CAP treatment guidelines are available, current data support narrow-spectrum antibiotics as the first-line treatment for most patients with CAP.

OBJECTIVE

To estimate the incidence rates of outpatient CAP, examine time trends in antibiotics prescribed for CAP, and determine factors associated with broad-spectrum antibiotic prescribing for CAP.

PATIENTS AND METHODS

The National Ambulatory and National Hospital Ambulatory Medical Care Surveys (1994-2007) were used to identify children aged 1 to 18 years with CAP using a validated algorithm. We determined age group-specific rates of outpatient CAP and examined trends in antibiotic prescribing for CAP. Data from 2006-2007 were used to study factors associated with broad-spectrum antibiotic prescribing.

RESULTS

Overall, annual CAP visit rates ranged from 16.9 to 22.4 per 1000 population, with the highest rates occurring in children aged 1 to 5 years (range: 32.3-49.6 per 1000). Ambulatory CAP visit rates did not change between 1994 and 2007. Antibiotics commonly prescribed for CAP included macrolides (34% of patients overall), cephalosporins (22% overall), and penicillins (14% overall). Cephalosporin use increased significantly between 2000 and 2007 (P = .002). Increasing age, a visit to a nonemergency department office, and obtaining a radiograph or complete blood count were associated with broad-spectrum antibiotic prescribing.

CONCLUSIONS

The incidence of pediatric ambulatory CAP visits has not changed significantly between 1994 and 2007, despite the introduction of heptavalent pneumococcal conjugate vaccine in 2000. Broad-spectrum antibiotics, particularly macrolides, were frequently prescribed despite evidence that they provide little benefit over penicillins.

Oral garenoxacin in the treatment of acute bacterial maxillary sinusitis: a Phase II, multicenter, noncomparative, open-label study in adult patients undergoing sinus aspiration

BACKGROUND

Garenoxacin is a des-F(6)-quinolone with in vitro activity against key respiratory pathogens, including Streptococcus pneumoniae, Hemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis. Limited data are available regarding the effect of garenoxacin in the treatment of acute bacterial sinusitis.

OBJECTIVE

The aim of this study was to assess the efficacy and tolerability of garenoxacin in adults with acute bacterial maxillary sinusitis undergoing a pre-treatment diagnostic sinus aspirate.

METHODS

This Phase II, multicenter, noncomparative, open-label study was conducted at 30 centers in the United States, Mexico, Argentina, and Europe. Male and female patients aged 18 to 80 years with clinical signs and symptoms lasting >or=5 but <or=28 days and radiologic signs (air-fluid level, opacification, mucosal thickening) of acute maxillary sinusitis were eligible. The entry criteria for the 5-day treatment regimen did not include mucosal thickening of >or=5 mm because it was believed that improvement in mucosal thickening might not be reliably measurable at the 5-day time point. All patients received garenoxacin 400 mg QD for 5 or 10 days. Maxillary sinus needle aspiration for Gram stain, routine culture, and susceptibility testing were performed before treatment, and, if clinically indicated, during and after treatment. Bacteriologic eradication (negative culture on repeat sinus aspiration) and cure rates (complete resolution of all signs and symptoms) were assessed at a test-of-cure visit 5 to 18 days after the end of treatment. The occurrence of adverse events was recorded by the investigators up to 30 days after the last administration of garenoxacin by questioning patients.

RESULTS

A total of 546 patients were enrolled and 543 were randomized (5-day cohort: mean age, 40 years; mean weight, 76 kg; 56% women; 10-day cohort: mean age, 41 years; mean weight, 77 kg; 58% women). Clinically evaluable patients included 253 in the 5-day cohort and 266 in the 10-day cohort. Cure rates were 93% (236/253; 95% CI, 89%-96%) and 91% (243/266; 95% CI, 87%-94%) for evaluable patients in the 5- and 10-day cohorts, respectively. Bacteriologic eradication rates in microbiologically evaluable patients were 94% in both cohorts (5 days, 204/217; 10 days, 182/193). Eradication rates in the 5- and 10-day cohorts were as follows: S pneumoniae, 94% (62/66) and 93% (39/42); H influenzae, 100% (30/30) and 93% (26/28); S aureus, 96% (23/24) and 91% (31/34); and M catarrhalis, 89% (8/9) and 86% (12/14). Of the 9 patients with acute bacterial sinusitis due to multidrug-resistant S pneumoniae, 8 achieved clinical cure with garenoxacin treatment. Adverse events (AEs) most frequently reported were diarrhea (<or=2%), nausea (2%-6%), headache (2%-6%), and dizziness (<or=2%). Two percent of patients withdrew because of an AE (allergic reaction, adverse gastrointestinal effects, dyspnea, dizziness, headache, or elevation in liver enzymes).

CONCLUSION

In this population of patients with signs and symptoms of acute maxillary sinusitis, oral garenoxacin 400 mg QD for 5 or 10 days eradicated 94% of bacterial pathogens associated with acute bacterial sinusitis in this population and appeared to be well tolerated in adults.

A naturalistic comparison of amoxicillin/clavulanate extended release versus immediate release in the treatment of acute bacterial sinusitis in adults: A retrospective data analysis

BACKGROUND

Choosing the most effective treatment for acute bacterial sinusitis (ABS) is helpful to avoid treatment failure. To date, studies comparing antibiotic options for ABS have compared amoxicillin/clavulanate (AMX/CA) immediate release (IR) versus other antibiotics, but have not included AMX/CA extended release (XR).

OBJECTIVE

The purpose of this study was to determine whether the clinical advantages of AMX/CA XR found in a clinical trial setting translate to a naturalistic setting, relative to AMX/CA IR.

METHODS

Data for this retrospective analysis were obtained from a managed care benchmark database that included >25 million patients from >30 health plans covering 7 US census divisions. Data from all patients aged > or =18 years with an index diagnosis of ABS between July 1, 2001, and December 31, 2003, were included. Episodes of ABS were classified as treatment successes (no additional prescriptions for antibiotics, ABS-related emergency department [ED] visits, or ABS-related inpatient hospitalizations within 30 days after the index prescription) or failures (> or =1 subsequent antibiotic prescription, an ABS-related ED visit, or an ABS-related inpatient hospitalization within 30 days after the index prescription). Treatment failures were subclassified as early or late. Mean costs were assessed for medical claims linked with a primary diagnosis of ABS and antibiotic pharmacy claims within the follow-up time period (through February 28, 2004). Descriptive statistics for demographic characteristics, utilization patterns, and success rates were calculated for each cohort. A multivariate general linear regression model was developed to assess differences in costs between the 2 cohorts.

RESULTS

: Of the patients with an index antibiotic prescription filled within 3 days of ABS diagnosis (n = 241,511), a total of 3224 in the AMX/CA XR cohort (mean [SD] age, 41.8 [11.6] years; women, 57.7%) and 23,638 in the AMX/CA IR cohort (mean [SD] age, 41.9 [11.6] years; women, 62.7%) were included in the analysis. The rate of treatment success in patients treated with AMX/CA XR was 82.8% versus 81.0% in patients treated with AMX/CA IR (P < 0.015). Treatment success costs were significantly lower than treatment failure costs regardless of an early or late designation and ranged from 98 dollars to 110 dollars per episode (P < 0.001). After adjustment for background covariates, the mean cost of treating an episode of ABS was significantly lower for patients receiving AMX/CA XR versus those receiving AMX/CA IR (166.32 dollars vs 177.34 dollars [US 2004 dollars]; P < 0.001), representing a mean cost savings of 11.02 dollars per patient treated with AMX/CA XR over AMX/CA IR for ABS, regardless of treatment outcome.

CONCLUSIONS

The results from this data analysis suggest that AMX/CA XR had significantly higher treatment success in ABS relative to AMX/CA IR in this naturalistic setting. AMX/CA XR was associated with significantly decreased total ABS-related costs in these adults.