Decreasing beta-lactam resistance in Pneumococci from the Memphis region: analysis of 2,152 isolates From 1996 to 2001

Long-term effects of an educational seminar on antibiotic prescribing by GPs: a randomised controlled trial

BACKGROUND

High levels of outpatient antibiotic use remain observed in many European countries. Several studies have shown a strong relationship between antibiotic use and bacterial resistance.

AIM

To assess the long-term effect of a standardised educational seminar on antibiotic prescriptions by GPs.

DESIGN AND SETTING

Randomised controlled trial of 171 GPs (of 203 initially randomised) in France.

METHOD

GPs in the control group (n = 99) received no antibiotic prescription recommendation. Intervention group GPs (n = 72) attended an interactive seminar presenting evidence-based guidelines on antibiotic prescription for respiratory infections. The proportion of prescriptions containing an antibiotic in each group and related costs were compared to the baseline up to 30 months following the intervention. Data were obtained from the National Health Insurance System database.

RESULTS

In the intervention group, 4-6 months after the intervention, there was a significant decrease in the proportion of prescriptions containing an antibiotic from 15.2 ± 5.4% to 12.3 ± 5.8% (-2.8% [95% CI = -3.8 to -1.9], P<0.001). By contrast, an increase was observed in controls from 15.3 ± 6.0 to 16.4 ± 6.7% (+1.1% [95% CI = +0.4 to +1.8], P<0.01), resulting in a between-group difference of 3.93% ([95% CI = 2.75 to 5.11], P<0.001). The between-group difference was maintained 30 months after intervention (1.99% [95% CI = 0.56 to 3.42], P<0.01). Persistence of the intervention effect over the entire study period was confirmed in a hierarchical multivariate analysis.

CONCLUSION

This randomised trial shows that a standardised and interactive educational seminar results in a long-term reduction in antibiotic prescribing and could justify a large-scale implementation of this intervention.

Fluoroquinolones in the management of community-acquired pneumonia in primary care

A literature search was conducted to evaluate the pharmacokinetic and pharmacodynamic profile of the respiratory fluoroquinolones (gemifloxacin, levofloxacin and moxifloxacin) and their efficacy and safety in the management of community-acquired pneumonia (CAP). Data show that CAP is a common presentation in primary care practice, and is associated with high rates of morbidity and mortality, particularly in the elderly. Although the causative pathogens differ depending on treatment setting and patient factors, Streptococcus pneumoniae is the primary pathogen in all treatment settings. As a class, the respiratory fluoroquinolones have a very favorable pharmacokinetic and pharmacodynamic profile. Pharmacodynamic criteria suggest that moxifloxacin and gemifloxacin are more potent against S. pneumoniae, which may have the added benefit of reducing resistance selection and enhancing bacterial eradication. The respiratory fluoroquinolones are also generally well tolerated, and are first-line options for outpatient treatment of CAP in patients with comorbidities or previous antibiotic use.

Mortality in ICU patients with bacterial community-acquired pneumonia: when antibiotics are not enough

BACKGROUND

It remains uncertain why immunocompetent patients with bacterial community-acquired pneumonia (CAP) die, in spite of adequate antibiotics.

METHODS

This is a secondary analysis of the CAPUCI database which was a prospective observational multicentre study. Two hundred and twelve immunocompetent patients admitted to 33 Spanish ICUs for CAP were analyzed. Comparisons were made for lifestyle risk factors, comorbidities and severity of illness. ICU mortality was the principal outcome variable.

RESULTS

Bacteremic CAP (43.3 vs. 21.1%) and empyema (11.5 vs. 2.2%) were more frequent (P < 0.05) in patients with Streptococcus pneumoniae CAP. Higher rates of adequate empiric therapy (95.8 vs. 75.5%, P < 0.05) were observed in patients with S. pneumoniae CAP. Patients with non-pneumococcal CAP experienced more shock (66.7 vs. 50.8%, P < 0.05), and need for mechanical ventilation (83.3 vs. 61.5%, P < 0.05). ICU mortality was 20.7 and 28% [OR 1.49(0.74-2.98)] among immunocompetent patients with S. pneumoniae (n = 122) and non-pneumococci (n = 90), in spite of initial adequate antibiotic. Multivariable regression analysis in these 184 immunocompetent patients with adequate empirical antibiotic treatment identified the following variables as independently associated with mortality: shock (HR 13.03); acute renal failure (HR 4.79), and APACHE II score higher than 24 (HR 2.22).

CONCLUSIONS

Mortality remains unacceptably high in immunocompetent patients admitted to the ICU with bacterial pneumonia, despite adequate initial antibiotics and comorbidities management. Patients with shock, acute renal failure and APACHE II score higher than 24 should be considered for inclusion in trials of adjunctive therapy in order to improve CAP survival.

Improving outcomes of elderly patients with community-acquired pneumonia

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality in elderly patients. Therefore, efforts to optimize the healthcare process for patients with CAP are warranted. An organized approach to management is likely to improve clinical results. Assessing the severity of CAP is crucial to predicting outcome, deciding the site of care, and selecting appropriate empirical therapy. Unfortunately, current prognostic scoring systems for CAP such as CURB-65 (confusion, uraemia, respiratory rate, low blood pressure and 65 years of age) or the Pneumonia Severity Index have not been validated specifically in older adults, in whom assessment of mortality risk alone might not be adequate for predicting outcomes. Obtaining a microbial diagnosis remains problematic and may be particularly challenging in frail elderly persons, who may have greater difficulties producing sputum. Effective empirical treatment involves selection of a regimen with a spectrum of activity that includes the causative pathogen. Although most cases of CAP are probably caused by a single pathogen, dual and multiple infections are increasingly being reported. Streptococcus pneumoniae remains the overriding aetiological agent, particularly in very elderly people. However, respiratory viruses and 'atypical' organisms such as Chlamydia pneumoniae are being described with increasing frequency in old patients, and aspiration pneumonia should also be taken into consideration, particularly in very elderly subjects and those with dementia. Age >65 years is a well established risk factor for infection with drug-resistant S. pneumoniae. Clinicians should be aware of additional risk factors for acquiring less common pathogens or antibacterial-resistant organisms that may suggest that additions or modifications to the basic empirical regimen are warranted. In addition to administration of antibacterials, appropriate supportive therapy, covering management of severe sepsis and septic shock, respiratory failure, as well as management of any decompensated underlying disease, may be critical to improving outcomes in elderly patients with CAP. Immunization with pneumococcal and influenza vaccines has also been demonstrated to be beneficial in numerous large studies. There is good evidence that implementation of guidelines leads to improvement in clinical outcomes in elderly patients with CAP, including a reduction in mortality. Protocols should address a comprehensive set of elements in the process of care and should periodically be evaluated to measure their effects on clinically relevant outcomes. Assessment of functional clinical outcome variables, in addition to survival, is strongly recommended for this population.

Invasive pneumococcal disease in New Zealand 1998-2005: capsular serotypes and antimicrobial resistance

Isolates from 3903 cases of invasive pneumococcal disease (IPD) were referred to the national reference laboratory over the 8 years, 1998-2005, as part of the laboratory-based surveillance of this disease in New Zealand. All isolates were serotyped and their antimicrobial susceptibility was tested. The incidence of IPD was highest in young children, with an average annual incidence of 100.8/100,000 in infants aged <2 years. There were changes in the prevalence of several of the serotypes during the 8-year period. Overall the seven serotypes included in the 7-valent pneumococcal conjugate vaccine, 4, 6B, 9V, 14, 18C, 19F and 23F, were the most common serotypes and accounted for 80.9% of the disease in infants aged <2 years. There was no overall change in penicillin resistance or non-susceptibility during the 8 years, and rates were 7.1% and 17.1%, respectively, in 2005. In contrast, cefotaxime and erythromycin resistance increased to reach 3.1% and 12.2%, respectively, by 2005.

Susceptibility testing practices for Streptococcus pneumoniae: results of a proficiency testing survey of clinical laboratories

In June 2003, a test sample was sent to 355 laboratories enrolled in a proficiency testing program to assess their ability to detect low-level penicillin resistance in a strain of Streptococcus pneumoniae. One hundred fifty participants reported results for antimicrobial susceptibility testing. Of the 62 respondents using disk diffusion, 34 (55%) failed to report a result that was acceptable for detecting penicillin resistance and 30 (48%) reported a result for one or more drugs not approved for testing S. pneumoniae. Moreover, 12 (14%) of the 88 respondents using minimum inhibitory concentration methods reported results for at least one unapproved drug. These findings support the conclusions of other studies that antimicrobial susceptibility testing practices are suboptimal in many laboratories. Resolution of this problem will require continued educational initiatives, studies to discover the reasons why laboratories fail to follow published standards, and enforcement of the use of standards by regulatory and credentialing agencies.

Reduction in High Rates of Antibiotic-Nonsusceptible Invasive Pneumococcal Disease in Tennessee after Introduction of the Pneumococcal Conjugate Vaccine

BACKGROUND

Invasive pneumococcal disease (IPD) is a burgeoning problem, with rates of antibiotic-nonsusceptible IPD, in particular, increasing during the past decade. One measure to combat IPD is vaccination with the recently introduced 7-valent pneumococcal conjugate vaccine (PCV).

METHODS

To evaluate the effects of the introduction of PCV in 2000 on the epidemiology of antibiotic-nonsusceptible IPD, a database of IPD cases from January 1995 through December 2002 identified through active surveillance in 5 Tennessee counties was examined. For each case, clinical data were collected, and antibiotic susceptibility testing and serotyping were performed on available isolates.

RESULTS

Among children younger than 2 years, IPD rates peaked at 235 cases per 100,000 in 1999 before decreasing, after PCV licensure, to 46 cases per 100,000 in 2002 (P<.001). The proportion of penicillin-nonsusceptible IPD isolates from this age group declined from 59.8% in 1999 to 30.4% in 2002 (P<.01). After 2001, similar decreases in IPD rates and in the proportion of antibiotic-nonsusceptible isolates recovered were seen among persons aged 2 years and older (P<.01). Rates of IPD due to PCV-associated serotypes declined after PCV introduction in all age groups (P<.001), whereas the rate of IPD due to nonvaccine serotypes increased among persons aged 2 years and older.

CONCLUSIONS

In the 2 years since licensure, widespread PCV vaccination of children has resulted in dramatic declines in the proportion of antibiotic-nonsusceptible isolates in Tennessee. PCV vaccination of children also appears to be a highly effective method for reducing the burden of IPD in adults.

Pneumococcal resistance in perspective: how well are we combating it?

Because Streptococcus pneumoniae is the most commonly isolated community-acquired respiratory tract pathogen, the reports of high rates of antibiotic resistance throughout the world highlight the need for intervention to stem any further increases in resistance. Efforts to reduce the incidence of pneumococcal resistance have been mainly 2-fold, involving attempts to reduce unnecessary antibiotic prescribing, as well as to assure early childhood immunization with the pneumococcal heptavalent conjugate vaccine. To reduce unnecessary prescribing for infections that are typically viral in etiology, such as acute bronchitis, education efforts have been focused not only on clinicians but also on parents and patients. These education efforts significantly reduce unnecessary antibiotic prescribing, and initial evidence suggests that they may stabilize, if not reduce, the incidence of penicillin and macrolide-resistant pneumococcal isolates. Utilization of the relatively new pneumococcal heptavalent conjugate vaccine not only reduces the incidence of acute otitis media caused by pneumococcal serotypes included in the vaccine as well as disease caused by related serotypes but also has a highly significant effect on reducing the incidence of invasive pneumococcal disease in children and potential adult contacts. In addition more recent data have established that vaccination is also decreasing the carriage and transmission of antibiotic-resistant pneumococcal isolates. Education and vaccine programs that attempt to stabilize and/or reduce the rate of pneumococcal resistance are at least as important as having effective antibiotic treatments for pneumococcal disease. These efforts to address pneumococcal resistance have been highly successful to date.