A comparative clinical study of pneumonia by penicillin-resistant and -sensitive Streptococcus pneumoniae in a community hospital

Serotype Replacement in Adult Pneumococcal Pneumonia after the Introduction of Seven-Valent Pneumococcal Conjugate Vaccines for Children in Japan: a Systematic Literature Review and Pooled Data Analysis

Streptococcus pneumoniae is the major causative agent for adult pneumonia. Following the introduction of pneumococcal conjugate vaccines (PCV) for children, serotype replacement has been reported in adult invasive pneumococcal diseases but has not been well studied for cases of pneumococcal pneumonia in adults in Asia. To investigate serotype replacement in adult pneumococcal pneumonia in Japan, we conducted a systematic review of the literature across 5 databases using terms, including pneumococcus, serotype, their synonyms, and derivatives. After the assessment of the identified articles, data on the pneumococcal serotype distribution among adult pneumonia cases were extracted from relevant studies. Twenty-two studies were reviewed, and 4 relevant articles were included in the pooled data analysis. The proportion of the 7-valent PCV (PCV7)-covered serotypes from before and after the introduction of PCV7 for children (－18.1%, p ＜ 0.001) significantly decreased; moreover, the proportions of serotypes covered by PCV13 but not PCV7 (＋9.9%, p = 0.003) and those covered by the 23-valent polysaccharide vaccine but not PCV7 (＋9.4%, p = 0.007) significantly increased. Serotype replacement occurred in adult cases of pneumococcal pneumonia following vaccination of children with PCV7 in Japan. Further nationwide surveillance is warranted to investigate serotype replacement in the post-PCV13 phase.

Antibiotic Resistance in PathogenicStreptococcus pneumoniaeIsolates in Turkey

Streptococcus pneumoniae causes various human infections such as meningitis, septicemia, otitis media, sinusitis, and pneumonia. Antibiotic resistance has already been reported with increasing frequency worldwide and is spreading. The earliest studies on pneumococcal antibiotic resistance go back to the late 1980s in Turkey. The resistance patterns have elevated with stepwise increments since then. By the beginning of 2005, approximately 40% of pneumococci were resistant to penicillin and nearly one-fifth of resistant isolates present high-level penicillin resistance. This proves that penicillin is still a good alternative for nonmeningeal infections. In addition, no ceftriaxone resistance have been reported in local Turkish studies, but cefuroxime, a second-generation cephalosporin, was recorded to have (10.8-20%) resistance rates. The most frequently assessed antibiotics other than penicillin in Turkish studies include erythromycin (4-19.4%), chloramphenicol (2-10%), clindamycin (2.5-13%) and tetracycline (13-28.6%) and all have various resistance profiles. On the other hand, nearly all or almost all of the isolates evaluated in Turkish studies are susceptible to rifampicin, quinolones, linezolid, quinupristin-dalfopristin and telithromycin. All these non-beta-lactam antibiotics except the tetracyclines are within acceptable limits of empirical approaches. Tetracycline must be used cautiously. In addition, trimethoprim sulfamethoxazole cannot be prescribed in probable pneumococcal infections since more than half of the isolates are nonsusceptible.

Trends in antimicrobial susceptibility of Streptococcus pneumoniae in the Tohoku district of Japan: a longitudinal analysis from 1998 to 2007

Streptococcus pneumoniae is a common cause of respiratory tract infections (RTIs). The prevalence of Streptococcus pneumoniae strains with reduced susceptibility to antimicrobial agents has dramatically increased worldwide. Susceptibility to nine antimicrobial agents and serotypes were determined among 1,644 Streptococcus pneumoniae strains isolated from patients with RTIs in the Tohoku district of Japan from October to December every year from 1998 to 2007. The prevalence of penicillin G-nonsusceptible Streptococcus pneumoniae (PNSP) strains increased gradually from 48.5% in 1998, reached a statistical peak in 2004 (65.1%) and then decreased to 51.5% in 2007. Streptococcus pneumoniae strains with each serotype 3, 6, 19 and 23 were constantly detected, and the distribution of these serotypes in PNSP strains did not significantly change during the study period. A trend of Streptococcus pneumoniae strains nonsusceptible to other beta-lactams tested was similar to that of PNSP strains, except for cefditoren, to which the resistance rate was < 20% throughout the analysis period. The prevalence of strains nonsusceptible to erythromycin and minocycline were consistently > 60%. Almost all penicillin G-resistant Streptococcus pneumoniae (PRSP) strains were resistant to both erythromycin and minocycline throughout the analysis period. The prevalence of strains resistant to fluoroquinolones tested were < 3% over the study period. Our longitudinal surveillance demonstrated for the first time that decreased prevalence of both beta-lactam- and multidrug-resistant strains has been occurring since 2004 in a region of Japan. Careful monitoring of antimicrobial susceptibility of Streptococcus pneumoniae should be continued.

Severe pneumococcal pneumonia: new strategies for management

PURPOSE OF REVIEW

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia worldwide and is the most likely causative pathogen in patients with community-acquired pneumonia admitted to the intensive care unit. Bacteremic pneumococcal pneumonia is an advanced stage of severe pneumococcal pneumonia. Improvement in the management of bacteremic pneumococcal pneumonia has the potential for improving the survival for severe pneumococcal pneumonia.

RECENT FINDINGS

Non-culture methods, especially the Binax urinary antigen test, can increase the diagnostic yield for pneumococcal pneumonia, allowing targeted antimicrobial therapy (specifically penicillin). In-vitro resistance to penicillin has increased over the past decade; however, it has not led to clinical failure when used for pneumococcal pneumonia.

SUMMARY

Hospitalized patients with community-acquired pneumonia should have blood cultures obtained to confirm the possibility of bacteremic pneumococcal pneumonia. Based on pharmacodynamic properties, parenteral penicillin remains the drug of choice to treat pneumococcal pneumonia regardless of in-vitro resistance. Combination antimicrobial therapy will likely improve survival of patients with bacteremic pneumococcal pneumonia among the subset of critically ill patients.

Drug-resistant genes and serotypes of pneumococcal strains of community-acquired pneumonia among adults in Japan

BACKGROUND

A high frequency of drug-resistant pneumococci has been reported in Asian countries. Few data on the drug-resistance or serotype of pneumococcal strains responsible for community-acquired pneumonia (CAP), however, are available for the past two decades in Japan.

METHODOLOGY

Susceptibility to antibiotics and the genotype of antibiotic-resistant genes and serotypes of Streptococcus pneumoniae isolates from 114 adult patients with CAP were examined in a nationwide study in Japan between 2001 and 2003.

RESULTS

Most of the cases were non-bacteraemic pneumonia and the case fatality rate was 4.4%. The most frequent genotype of the pbp gene was pbp1a + 2x + 2b (gPRSP; 36.8%) followed by pbp 2x (28.1%) and of the macrolide-resistant gene, it was ermB (50.0%). The most common serotype was 19F (29.1%), followed by serotype 23F (13.2%), 6B (12.3%) and 3 (11.4%). The coverage of serotypes of isolates by a 23-valent pneumococcal polysaccharide vaccine (PPV) would be 82.5% in these patients with CAP. Most of strains with serotypes 19F and 23F were gPRSP. A cluster of serotype 3 strains associated with the pbp 2x and ermB gene was also noted.

CONCLUSION

A high frequency of altered pbp gene mutations or of macrolide-related genes and a high serotype coverage by the 23-valent PPV found in our study of pneumococcal pneumonia facilitates attempts to increase the coverage rate of the 23-valent PPV in adults older than 65 years in Japan.

Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae isolated from patients with community-acquired pneumonia and molecular analysis of multidrug-resistant serotype 19F and 23F strains in Japan

A nationwide study was undertaken to determine the susceptibility to penicillin and serotypes of Streptococcus pneumoniae in Japan. S. pneumoniae was isolated from 114 adult patients with community-acquired pneumonia over 22 months at 20 hospitals and medical centres in different regions in Japan. All but five isolates were from sputum. Forty-eight isolates (42.1%) were susceptible, 40 (35.1%) showed intermediate resistance (MIC, 0.12-1.0 microg/ml) and 26 (22.8%) were resistant (MIC, >or=2.0 microg/ml) to penicillin G. All isolates were susceptible to ceftriaxone (breakpoint 1 microg/ml), imipenem (4 microg/ml) and vancomycin (4 microg/ml). Most were resistant to erythromycin, clarithromycin and azithromycin; only two were resistant to levofloxacin. Differences were found in the distribution of serotypes among isolates showing susceptibility to penicillin (predominant types 3, 6B, and 19F), intermediate resistance (6B, 14, 19F, and 23F) and full resistance (19F and 23F). PFGE typing showed that 14 of the 25 strains of serotype 19F had a single DNA profile, pattern A, a pattern closely similar to that of the Taiwan multidrug-resistant 19F clone. Twelve pattern A strains were not susceptible to penicillin but carried the macrolide resistance gene mef(A). The DNA profiles of the 15 strains of 23F were also heterogeneous but six were highly similar (pattern b) yet distinct from the Spanish multidrug-resistant 23F clone although possibly related to the Taiwan multidrug-resistant 23F clone. The pattern b strains were not susceptible to penicillin and also harboured either mef(A) or erm(B). Our results indicate that multidrug-resistant pneumococci are spreading rapidly in Japan. Efforts to prevent the spread of the pandemic multidrug-resistant serotypes should be intensified.

The Impact of Penicillin Resistance on Short-Term Mortality in Hospitalized Adults with Pneumococcal Pneumonia: A Systematic Review and Meta-Analysis

BACKGROUND

The clinical impact of penicillin resistance on the outcome of pneumococcal pneumonia has remained controversial. We performed a meta-analysis of prospective cohort studies to examine the association between penicillin resistance and short-term all-cause mortality for pneumococcal pneumonia.

METHODS

We retrieved studies published in any language by a comprehensive search of the Medline, Current Contents, and Embase databases for all appropriate articles published up to January 2005. We also manually reviewed bibliographies of retrieved articles, recent national treatment guidelines, and review articles. We included prospective cohort studies that involved adult subjects, and we examined the association between penicillin resistance and short-term mortality for pneumococcal pneumonia. Two reviewers independently extracted data on crude and adjusted risk estimates of all-cause mortality for pneumococcal infections with different levels of penicillin resistance and assessed the methodological quality of selected studies. We also contacted authors to obtain additional information. We performed meta-analyses using a random-effect model.

RESULTS

Of 1152 articles identified in the search, 10 studies that involved 3430 patients (most of whom were hospitalized) were included. The mortality rate was 19.4% in the penicillin-nonsusceptible Streptococcus pneumoniae group and 15.7% in the penicillin-susceptible S. pneumoniae group. The combined relative risks of all-cause mortality for the penicillin-nonsusceptible, -intermediate, and -resistant S. pneumoniae groups, compared with the penicillin-susceptible S. pneumoniae group, were 1.31 (95% confidence interval [CI], 1.08-1.59), 1.34 (95% CI, 1.13-1.60), and 1.29 (95% CI, 1.01-1.66), respectively. The combined adjusted relative risks of mortality for penicillin-nonsusceptible versus penicillin-susceptible S. pneumoniae group was 1.29 (95% CI, 1.04-1.59) for the 6 studies that adjusted for age, comorbidities, and severity of illness. There was minimal between-study heterogeneity in these analyses.

CONCLUSION

Penicillin resistance is associated with a higher mortality rate than is penicillin susceptibility in hospitalized patients with pneumococcal pneumonia. Additional efforts are needed to understand the mechanisms of this association.

Streptococcus pneumoniae bacteremia in patients with cancer: disease characteristics and outcomes in the era of escalating drug resistance (1998-2002)

In the current era of multidrug-resistant organisms, the clinical spectrum of Streptococcus pneumoniae infection remains unclear, especially in immunosuppressed patients with cancer. We sought to define the characteristics of pneumococcal bacteremia in patients who were receiving care at a comprehensive cancer center. All consecutive episodes of S. pneumoniae bacteremia between January 1998 and December 2002 were evaluated retrospectively. One hundred thirty-five episodes of pneumococcal bacteremia occurred in 122 patients. Sixty-three (52%) of 122 patients had hematologic malignancies; the others had solid tumors. The median Acute Physiology and Chronic Health Evaluation II score was 14 +/- 5. Twenty-four episodes (18%) occurred during neutropenia (<500 cells/microL). Sixty-five patients (53%) were receiving antineoplastic therapy, and 36 (30%) were receiving systemic corticosteroids. Twelve (41%) of 29 hematopoietic stem cell transplant (HSCT) recipients had received transplantation within 12 months of the infection diagnosis; 11 patients had graft-versus-host disease (chronic in 10). In 27 episodes (22%), S. pneumoniae bacteremia was considered as a breakthrough infection. Nine (56%) of 16 hospital-acquired episodes of S. pneumoniae bloodstream infection occurred in patients with profound neutropenia, whereas 15 (13%) of 119 episodes of community-acquired infection occurred during neutropenia (p < 0.0002). In 91 episodes (67%), patients had radiographic evidence of pneumonia. Infected catheters were associated with 21 episodes (16%). Forty-eight (36%) of 135 isolates were not susceptible to penicillin (minimum inhibitory concentration [MIC] > or = 2 microg/mL); 9 (7%) showed intermediate susceptibility to ceftriaxone (MIC >0.5 and <2.0 microg/mL). Nineteen patients (16%) died within 2 weeks of diagnosis; 18 deaths were attributed to systemic pneumococcal infection. Univariate analysis showed no significant increase in the risk of short-term death in patients with infection due to penicillin non-susceptible organisms (OR [odds ratio], 1.47; 95% confidence intervals [CI], 0.53-4.05; p < 0.46), initially discordant treatment (OR, 1.0; 95% CI, 0.62-665.4; p < 0.16), presence of pneumonia (OR, 1.19; 95% CI, 0.39-3.62; p < 0.76), neutropenia (OR, 1.0; 95% CI, 0.28-4.09; p < 0.92), systemic corticosteroid use (OR, 1.96; 95% CI, 0.69-5.60; p < 0.21), or antineoplastic therapy (OR, 1.45; 95% CI, 1.52-4.05; p < 0.47). Similarly, patients with hematologic cancers compared to those with solid cancers (OR, 1.0; 95% CI, 0.49-3.70; p < 0.56) and recipients of HSCT compared to those with no history of transplantation (OR, 1.0; 95% CI 0.59-12.71; p < 0.20) did not have a less favorable outcome. In conclusion, most pneumococcal bloodstream infections were community acquired, although hospital-acquired infections were common in neutropenic patients. It is noteworthy that initially discordant therapy, penicillin non-susceptible S. pneumoniae, and other conventional predictors of unfavorable outcome were not associated with increased mortality rates in these high-risk patients with cancer.

Non-antibiotic treatment recommendations: delivery formats and implications for parent resistance

This study draws on a database of 570 community-based acute pediatric encounters in the USA and uses conversation analysis as a methodology to identify two formats physicians use to recommend non-antibiotic treatment in acute pediatric care (using a subset of 309 cases): recommendations for particular treatment (e.g., "I'm gonna give her some cough medicine.") and recommendations against particular treatment (e.g., "She doesn't need any antibiotics."). The findings are that the presentation of a specific affirmative recommendation for treatment is less likely to engender parent resistance to a non-antibiotic treatment recommendation than a recommendation against particular treatment even if the physician later offers a recommendation for particular treatment. It is suggested that physicians who provide a specific positive treatment recommendation followed by a negative recommendation are most likely to attain parent alignment and acceptance when recommending a non-antibiotic treatment for a viral upper respiratory illness.

Usefulness of the Japanese Respiratory Society guidelines for community pneumonia: a retrospective analysis of community-acquired pneumonia between 2000 and 2002 in a general hospital

OBJECTIVE

The aim of this study was to investigate the causative organisms of community-acquired pneumonia (CAP) diagnosed between 2000 and 2002 and to evaluate the Japanese Respiratory Society (JRS) guidelines.

METHODOLOGY

A total of 124 cases of CAP diagnosed during the study period were analyzed, and the results were compared with those of a previous study by the authors' research group. Determination of the causative organisms of CAP was based on Gram stain, morphology of colonies, quantitative culture of sputum, identification of bacterial isolates, and serological tests.

RESULTS

During the study period, the causative organisms were identified in 42 cases (33.8%). Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were the major causative organisms. Patients were classified into three groups based on the severity of CAP according to the JRS guidelines. The survival rates of patients with moderate and severe CAP were significantly lower than those of the mild group as evaluated by the Kaplan-Meier method (moderate vs mild, 70% vs 100%; severe vs mild, 40% vs 100%; P < 0.001 for both). Seven patients died during the study, and the risk factors were old age, bedridden status with cerebral infarction, and microaspiration, which was associated with recurrent pneumonia within 17 days.

CONCLUSION

This study indicates that the JRS guidelines for CAP are useful for treating patients with CAP in Japan.

[Guidelines for the management of community pneumonia in adult who needs hospitalization]

Community acquired pneumonia is still an important health problem. In Spain the year incidence is 162 cases per 100,000 inhabitants with 53,000 hospital admission costing 115 millions of euros per year. In the last years there have been significant advances in the knowledge of: aetiology, diagnostic tools, treatment alternatives and antibiotic resistance. The Spanish Societies of Intensive and Critical Care (SEMICYUC), Infectious Diseases and Clinical Microbiology (SEIMC) and Pulmonology and Thoracic Surgery (SEPAR) have produced these evidence-based Guidelines for the management of community acquired pneumonia in Adults. The main objective is to help physicians to make decisions about this disease. The different points that have been developed are: aetiology, diagnosis, treatment and prevention.

Antibacterial drug resistance: implications for the treatment of patients with community-acquired pneumonia

In contrast to the tremendous number of articles and meetings devoted to elucidating the mechanisms of antibacterial drug resistance and describing the emergence of drug resistance patterns, little research has been completed on the impact of bacterial drug resistance on clinical outcomes. Moreover.among the studies that have been completed, the better-designed studies generally have failed to detect an effect of most current levels of antibacterial drug resistance on clinical outcomes for patients who have CAP. Yet, practice patterns are shifting in response to the perception that current levels of drug resistance necessitate changes in treatment patterns. This is unfortunate because it severely limits one's ability to continue to monitor the effectiveness of available therapies in light of changing patterns of antibacterial drug resistance. If levels of drug resistance continue to rise, it is likely that outcomes from those drug treatments will be affected adversely. In this regard, the recent licensing of a 7-valent pneumococcal conjugate vaccine for infants and young children may have an important effect on future trends in antibacterial drug resistance. The vaccine reduces childhood carriage of vaccine serotypes,which are among the most common serotypes found among drug-resistant isolates, and may reduce transmission of these serotypes to adults [65]. In conclusion, antibacterial drug resistance has not reduced substantially the effectiveness of first-line treatments for CAP. Whether levels of drug resistance will continue to increase or decline is unknown. Therefore,carefully designed outcomes studies likely will continue to be essential to help define optimal therapy for patients who have CAP.

Parent resistance to physicians' treatment recommendations: one resource for initiating a negotiation of the treatment decision

This article examines pediatrician-parent interaction in the context of acute pediatric encounters for children with upper respiratory infections. Parents and physicians orient to treatment recommendations as normatively requiring parent acceptance for physicians to close the activity. Through acceptance, withholding of acceptance, or active resistance, parents have resources with which to negotiate for a treatment outcome that is in line with their own wants. This article offers evidence that even in acute care, shared decision making not only occurs but, through normative constraints, is mandated for parents and physicians to reach accord in the treatment decision.

Penicillin and macrolide resistance in pneumococcal pneumonia: does in vitro resistance affect clinical outcomes?

In vitro resistance to antimicrobial agents is escalating among pathogens responsible for the most serious respiratory tract infections. Some reports have suggested that this has direct clinical implications. Because of penicillin and macrolide resistance in Streptococcus pneumoniae, current guidelines for the initial treatment of respiratory tract infections advocate less reliance on the use of either of these classes of drugs in single-agent therapy. Recent studies that have assessed the impact of beta -lactam and macrolide resistance on clinical outcomes in community-acquired pneumonia fail to provide incontrovertible evidence for a direct link between in vitro resistance and treatment failure. However, there are anecdotal reports of breakthrough bacteremia due to macrolide-resistant pneumococci among patients receiving macrolide therapy, unlike the situation for beta -lactams and penicillin-resistant pneumococci. Continued efforts, including in vitro surveillance, appropriate antibiotic use campaigns, and immunization programs, will be important in limiting the spread of drug-resistant S. pneumoniae.

Clinical relevance of antimicrobial resistance in the management of pneumococcal community-acquired pneumonia

Streptococcus pneumoniae remains the most common bacterial cause of community-acquired pneumonia, and these infections are associated with significant morbidity and mortality worldwide. A major concern is the increasing incidence of antibiotic resistance among pneumococcal isolates, which, in the case of certain of the antibiotic classes, has been associated with treatment failure. Yet despite multiple reports of infections with penicillin-resistant pneumococcal isolates, no cases of bacteriologic failure have been documented with the use of penicillin or ampicillin in the treatment of pneumonia caused by penicillin-resistant pneumococci. Current prevalence and levels of penicillin resistance among pneumococal isolates in most areas of the world do not indicate a need for substantial treatment changes with regard to the use of the penicillins. For infections with penicillin-sensitive strains, penicillin or an aminopenicillin in a standard dosage will still be effective for treatment. In the cases of strains with intermediate resistance, beta-lactam agents are still considered appropriate treatment, although higher dosages are recommended. Infections with isolates of high-level penicillin resistance should be treated with alternative agents such as the third-generation cephalosporins or the new antipneumococcal fluoroquinolones. In the case of the cephalosporins, pharmacodynamic/pharmacokinetic parameters help predict which of those agents are likely to be successful, and the less active agents should not be used. Debate continues in the literature with regard to the impact of macrolide resistance on the outcome of pneumococcal pneumonia, with some investigators providing evidence of an "in vivo-in vitro paradox," referring to discordance between reported in vitro resistance and clinical success of macrolides/azalide in vivo. However, several cases of macrolide/azalide treatment failure have been documented, and many clinicians recommend that these agents not be used on their own in areas with a high prevalence and levels of macrolide/azalide resistance. However, evidence is emerging to show beneficial effects on outcome with combination therapy, especially that of a beta-lactam agent and a macrolide given together to sicker, hospitalized patients with pneumococcal pneumonia. In an attempt to prevent the emergence of resistance, it has been recommended by some that the new fluoroquinolones not be used routinely as first-line agents in the treatment of community-acquired pneumonia; instead, they say, these agents should be reserved for patients who are allergic to the commonly used beta-lactam agents, for infections known to be or suspected of being caused by highly resistant strains, and for patients in whom initial therapy has failed.

Community-acquired pneumonia

This seminar reviews important features and management issues of community-acquired pneumonia (CAP) that are especially relevant to immunocompetent adults in light of new information about cause, clinical course, diagnostic testing, treatment, and prevention. Streptococcus pneumoniae remains the most important pathogen; however, emerging resistance of this organism to antimicrobial agents has affected empirical treatment of CAP. Atypical pathogens have been quite commonly identified in several prospective studies. The clinical significance of these pathogens (with the exception of Legionella spp) is not clear, partly because of the lack of rapid, standardised tests. Diagnostic evaluation of CAP is important for appropriate assessment of severity of illness and for establishment of the causative agent in the disease. Until better rapid diagnostic methods are developed, most patients will be treated empirically. Antimicrobials continue to be the mainstay of treatment, and decisions about specific agents are guided by several considerations that include spectrum of activity, and pharmacokinetic and pharmacodynamic principles. Several factors have been shown to be associated with a beneficial clinical outcome in patients with CAP. These factors include administration of antimicrobials in a timely manner, choice of antibiotic therapy, and the use of a critical pneumonia pathway. The appropriate use of vaccines against pneumococcal disease and influenza should be encouraged. Several guidelines for management of CAP have recently been published, the recommendations of which are reviewed.

An international prospective study of pneumococcal bacteremia: correlation with in vitro resistance, antibiotics administered, and clinical outcome

We performed a prospective, international, observational study of 844 hospitalized patients with blood cultures positive for Streptococcus pneumoniae. Fifteen percent of isolates had in vitro intermediate susceptibility to penicillin (minimum inhibitory concentration [MIC], 0.12-1 microg/mL), and 9.6% of isolates were resistant (MIC, >or=2 microg/mL). Age, severity of illness, and underlying disease with immunosuppression were significantly associated with mortality; penicillin resistance was not a risk factor for mortality. The impact of concordant antibiotic therapy (i.e., receipt of a single antibiotic with in vitro activity against S. pneumoniae) versus discordant therapy (inactive in vitro) on mortality was assessed at 14 days. Discordant therapy with penicillins, cefotaxime, and ceftriaxone (but not cefuroxime) did not result in a higher mortality rate. Similarly, time required for defervescence and frequency of suppurative complications were not associated with concordance of beta-lactam antibiotic therapy. beta-Lactam antibiotics should still be useful for treatment of pneumococcal infections that do not involve cerebrospinal fluid, regardless of in vitro susceptibility, as determined by current NCCLS breakpoints.

Deciding not to measure performance: the case of acute otitis media

BACKGROUND

No Health Plan Employer Data and Information Set (HEDIS) performance measures evaluate health plans for possible overuse or inappropriate use of antibiotics. Acute otitis media (AOM), or infection of the middle ear, is one of the most common infections in children. The antibiotic resistance of the bacteria that cause AOM and the general overuse and inappropriate use of antibiotics for this condition are taking center stage as a major public health threat. An effort was undertaken to develop a new HEDIS performance measure that evaluates appropriate antibiotic use in children with AOM.

THE MEASURE DEVELOPMENT PROCESS

The measure development process has three major phases: the initial development phase, the field-testing and analysis phase, and the measure refinement phase. With AOM, the measure development process could not proceed beyond the first phase for reasons that are be discussed in detail.

CONCLUSIONS

Additional difficulties beyond feasibility issues may arise in developing a quality of care performance measure. The measure development process discussed in this article failed primarily because of issues related to relevance as well as the scientific soundness of the proposed measures. If the evidence base related to the diagnosis and management of a particular condition is sparse, no standard can be developed against which to measure performance, and the criterion of scientific soundness cannot be met. This is the case with AOM. Unfortunately, the evidence base will likely remain inadequate to support the development of such a measure in the future.

Online commentary during the physical examination: a communication tool for avoiding inappropriate antibiotic prescribing?

A previously identified communication behavior, online commentary, is physician talk that describes what he/she is seeing, feeling, or hearing during the physical examination of the patient. The investigators who identified this communication behavior hypothesized that its use may be associated with successful physician resistance to perceived or actual patient expectations for inappropriate antibiotic medication. This paper examines the relationship between actual and perceived parental expectations for antibiotics and physician use of online commentary as well as the relationship between online commentary use and the physician's prescribing decision. We conducted a prospective observational study in two private pediatric practices. Study procedures included a pre-visit parent survey, audiotaping of study consultations, and post-visit surveys of the participating physicians. Ten pediatricians participated (participation rate=77%) and 306 eligible parents participated (participation rate=86%) who were attending sick visits for their children with upper respiratory tract infections between October 1996 and March 1997. The main outcomes measured were the proportion of consultations with online commentary and the proportion of consultations where antibiotics were prescribed. Two primary types of online commentaries were observed: (1) online commentary suggestive of a problematic finding on physical examination that might require antibiotic treatment ('problem' online commentary), e.g., "That cough sounds very chesty"; and (2) online commentary that indicated the physical examination findings were not problematic and antibiotics were probably not necessary ('no problem' online commentary), e.g., "Her throat is only slightly red". For presumed viral cases where the physician thought the parent expected to receive antibiotics, if the physician used at least some 'problem' online commentary, he/she prescribed antibiotics in 91% (10/11) of cases. Conversely, when the physician exclusively employed 'no problem' online commentary, antibiotics were prescribed 27% (4/15) of the time (p = 0.07). Use of 'no problem' online commentary did not add significantly to visit length. 'No problem' online commentary is a communication technique that may provide an effective and efficient method for resisting perceived expectations to prescribe antibiotics.

Nosocomial pneumonia: emerging concepts in diagnosis, management, and prophylaxis

Nosocomial pneumonia is a dynamic disease with multiple etiologic agents and a changing natural history. The highest attack rates and mortality occur in patients with ventilator-associated pneumonia. Diagnosis of nosocomial pneumonia is often made by clinical criteria that are sensitive but lack specificity. The use of quantitative endotracheal aspirates or bronchoscopy with bronchoalveolar lavage and protected specimen brush clearly improve diagnostic specificity and outcome in patients who are mechanically ventilated. The rapid spread of multidrug-resistant, spp, and has made initial empiric therapy more difficult. Management principles include the use of techniques for more accurate diagnosis and early antimicrobial therapy with appropriate agents along with careful analysis of culture results, clinical response, and potential complications of pneumonia and therapy. Strategies for prophylaxis are of critical importance for risk reduction, improvement in patient outcome, and reduction of hospital costs.

Clinical aspects and cost of invasive Streptococcus pneumoniae infections in children: resistant vs. susceptible strains

Invasive Streptococcus pneumoniae infections in children are associated with serious consequences in terms of morbidity and mortality. The main objective of the study was to determine if invasive infections caused by penicillin-resistant Streptococcus pneumoniae (PRSP) differed in clinical presentation, outcome, risk factors, or cost from those caused by penicillin-susceptible strains (PSSP) in children. All patients aged 18 or less with invasive Streptococcus pneumoniae infections admitted to two teaching hospitals in Montreal between 1989 and 1998 were included in the study. We present a case-control study in which for each index case of PRSP, 3 controls with PSSP infections were matched for age, sex, and site of infection. One hundred and forty-four patients were included in the analysis (36 cases, 108 controls). There was no difference between the two groups in terms of initial clinical presentation (vital signs, laboratory results) or total length of stay. Mortality was 2.7% in both groups. Hospital antibiotic cost was higher in the PRSP group (211 Canadian dollars (CAD) vs. 74 CAD; P=0.02). Antibiotic consumption in the preceding month was significantly associated with PRSP infection. Underlying diseases or day-care attendance were not shown to be significant risk factors for acquiring invasive PRSP infection. There were no differences between invasive infections caused by PRSP and PSSP in terms of clinical presentation, morbidity or mortality in a paediatric population.

Update on community-acquired pneumonia: impact of antibiotic resistance on clinical outcomes

In contrast to the rapid expansion in the number of published studies reporting the increasing rate of antimicrobial drug resistance among common respiratory pathogens, there remain few controlled studies examining the impact of these trends on clinical outcomes. Those studies that are published are hampered by small sample sizes, biases inherent in observational designs, and the relative infrequency of isolates showing high-level resistance, particularly high-level beta-lactam resistance among clinical isolates of Streptococcus pneumoniae. This update summarizes recent published studies addressing the impact of drug resistance on outcomes for lower respiratory tract infections. The majority of these studies are retrospective cohort studies, focusing on the impact of beta-lactam-resistant pneumococcal infections in patients with community-acquired pneumonia. These studies support the conclusion that current levels of pneumococcal drug resistance do not result in clinical treatment failures for patients with community-acquired pneumonia. However, as patterns of drug resistance evolve, future studies will be needed to address the continued appropriateness of current empirical treatment guidelines for these patients.

Clinical relevance of macrolide-resistant Streptococcus pneumoniae for community-acquired pneumonia

Macrolides are often the first choice for empirical treatment of community-acquired pneumonia. However, macrolide resistance among Streptococcus pneumoniae has escalated at alarming rates in North America and worldwide. Macrolide resistance among pneumococci is primarily due to genetic mutations affecting the ribosomal target site (ermAM) or active drug efflux (mefE). Prior antibiotic exposure is the major risk factor for amplification and perpetuation of resistance. Clonal spread facilitates dissemination of drug-resistant strains. Data assessing the impact of macrolide resistance on clinical outcomes are spare. Many experts believe that the clinical impact is limited. Ribosomal mutations confer high-grade resistance, whereas efflux mutations can likely be overridden in vivo. Favorable pharmacokinetics and pharmacodynamics, high concentrations at sites of infections, and additional properties of macrolides may enhance their efficacy. In this article, we discuss the prevalence of macrolide resistance among S. pneumoniae, risk factors and mechanisms responsible for resistance, therapeutic strategies, and implications for the future.

Streptococcus pneumoniae respiratory tract infections

This review describes recent contributions to our understanding of pneumococcal pneumonia. Two genes have been described that encode enzymes involved with the biosynthesis of muropeptides. These enzymes may be novel antibiotic targets. The clinical impact of increasing antibiotic resistance on the treatment of pneumonia is the particular focus of the review. As resistant strains are more commonly associated with severe infections in patients with underlying disease, the interpretation of an association of resistance with poor clinical outcome is complicated.