Penicillin resistance and other predictors of mortality in pneumococcal bacteremia in a population with high human immunodeficiency virus seroprevalence

Impact of previous macrolide use on invasive pneumococcal disease due to erythromycin-resistant serotypes in adults over 59 years of age

The major goals of the study were to describe the invasive pneumococcal disease (IPD) cases due to erythromycin-resistant serotypes and to evaluate the association between these cases and recent macrolide use in individuals aged over 59 years. We selected cases of IPD reported between 2007 and 2016 in persons aged over 59 years living in the Community of Madrid (CM). We followed the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The explanatory variables (age, sex, year of onset of symptoms, clinical presentation, serotypes, vaccination status) were taken from the Mandatory Notification System for Infectious Diseases System and from the Vaccination Information System. The cases were classified as either included in the 13-valent pneumococcal conjugate vaccine (PCV13) or not (nonPCV13). Associations between cases due to erythromycin-resistant serotypes and previous macrolide use (total, long and short-term) were adjusted with a logistic regression multivariate analysis. A total of 1,831 cases were identified, of whom 408 were erythromycin-resistant serotypes. PCV13 cases were associated with previous macrolide use (OR: 5.07), particularly long-acting types (OR: 8.61). NonPCV13 cases were associated with the use of total macrolides (OR: 3.48) and long-acting macrolides (OR: 4.26) suggesting that PCV13 did not reduce the IPD cases in patients with previous use of macrolides. Our results confirmed that previous macrolide consumption was associated with the presence of IPD due to erythromycin-resistant serotypes. The risk was higher with the use of long-term macrolides.

Pharmacist Impact on Pneumococcal Vaccination Rates through Incorporation of Immunization Assessment into Critical Pathways in an Acute Care Setting

Despite the availability of effective prevention and treatment measures, pneumococcal infection continues to be a significant source of morbidity and mortality. This study evaluated the impact of incorporating the assessment of pneumococcal vaccination status into selected critical pathways of at-risk patients. In a prospective, nonblinded, parallel-group trial, adult inpatients on four critical pathways were randomized into intervention or control groups. Nursing personnel screened all patients for previous pneumococcal vaccination. A pharmacist would then screen all patients for pneumococcal disease risk factors. If vaccination was indicated in the intervention group, the pharmacist educated the patient and/or caregiver, obtained patient consent, and asked the patient's physician for permission to immunize. No further action was undertaken with the control patients. A total of 231 patients were enrolled in the study (107 intervention, 124 control). Initial immunization rates were 46.8% in the control group and 56.1 % in the intervention group. Forty-six patients in the control group and 39 patients in the intervention group were eligible (unvaccinated with indication) for vaccination. Thirty-two (82.1%) of the patients in the intervention group were counseled and 19 (59.4%) were vaccinated. The overall vaccination rates were 73.8% in the intervention group and 56.1% in the control group (P < 0.001). Results indicate that incorporating assessment of pneumococcal immunization status into critical pathways is an effective way to improve immunization rates.

Predictors of Mortality Among U.S. Veterans With Streptococcus Pneumoniae Infections

INTRODUCTION

Serious Streptococcus pneumoniae infections, encompassing pneumonia, bacteremia, and meningitis, are a major cause of mortality. However, literature regarding mortality is often limited to invasive pneumococcal disease, excluding pneumonia. This study sought to identify predictors of mortality among adults with serious pneumococcal disease, including pneumonia and invasive pneumococcal disease.

METHODS

This was a nested case-control study of unvaccinated older Veterans with positive S. pneumoniae cultures (blood, cerebrospinal fluid, respiratory) admitted to Veterans Affairs medical centers nationally between 2002 and 2011. Patients vaccinated against pneumococcal disease were excluded. Using multivariable logistic regression, predictors of 30-day mortality were identified, including patient demographics, comorbidities during admission, and medical history within the previous year.

RESULTS

Among 9,468 patients, there were 9,730 serious pneumococcal infections; 1,764 (18.6%) resulted in death within 30 days (cases), whereas 7,966 did not (controls). Pneumonia accounted for half (49.4%, n=871) of all deaths. Mortality predictors consistent with vaccine recommendations included dialysis (during hospitalization, OR=3.35, 95% CI=2.37, 4.72), moderate to severe liver disease (during hospitalization, OR=2.47, 95% CI=1.53, 3.99; within 1 year, OR=1.49, 95% CI=1.01, 2.20), and neutropenia (during hospitalization, OR=2.67, 95% CI=1.32, 5.42). Predictors not included in current recommendations included dementia (during hospitalization, OR=1.8, 95% CI=1.23, 2.61) and neurologic disorders (during hospitalization, OR=1.86, 95% CI=1.42, 2.45; within 1 year, OR=1.28, 95% CI=1.02, 1.59).

CONCLUSIONS

Several mortality predictors among unvaccinated Veterans with serious pneumococcal disease were consistent with pneumococcal vaccine recommendations, including organ or immune system dysfunction-related conditions. Other predictors, including neurologic disorders or dementia, may warrant expanded vaccination recommendations.

Risk stacking of pneumococcal vaccination indications increases mortality in unvaccinated adults with Streptococcus pneumoniae infections

BACKGROUND

Several chronic disease states have been identified as pneumococcal vaccination indications due to their ability to increase pneumococcal disease development and subsequent mortality. However, the risk of mortality according to the number of these disease states present is unknown. We sought to determine the impact of concomitant, multiple risk factors (stacked risks) for pneumococcal disease on 30-day mortality in adults.

METHODS

This was a national case-control study of unvaccinated older Veterans (≥50years of age) admitted to Veterans Affairs medical centers from 2002 to 2011 with serious pneumococcal infections (pneumonia, bacteremia, meningitis) based on positive S. pneumoniae blood, cerebrospinal fluid, or respiratory cultures, respectively. Cases were those not alive 30days following culture, while controls were alive. Using logistic regression, we quantified risk of 30-day mortality among patients with stacked risk factors, including age ≥65years, alcohol abuse, chronic heart disease, chronic liver disease, chronic respiratory disease, diabetes mellitus, immunodeficiency, and smoking.

RESULTS

We identified 9730 serious pneumococcal infections, with an overall 30-day mortality rate of 18.6% (1764 cases, 7966 controls). Infection types included pneumonia (62%), bacteremia (26%), and bacteremic pneumonia (11%). Along with eight individual risk factors, we assessed 247 combinations of risk factors. Most cases (85%) and controls (74%) had at least two risk factors. Mortality increased as risks were stacked, up to six risk factors (one: OR 1.5, CI 1.08-2.07; two: OR 2.01, CI 1.47-2.75; three: OR 2.71, CI 1.99-3.69; four: OR 3.27, CI 2.39-4.47; five: OR 3.63, CI 2.60-5.07; six: OR 4.23, CI 2.69-6.65), with each additional risk factor increasing mortality an average of 55% (±13%).

CONCLUSIONS

Among adults ≥50years with serious pneumococcal disease, mortality risk increased approximately 55% as vaccination indications present increased. Mortality with six stacked indications was double that of two indications.

The rate of antibiotic utilization in Iranian under 5-year-old children with acute respiratory tract illness: A nationwide community-based study

Background:

To investigate the prevalence of antibiotic usage in children aged <5 years with acute respiratory tract illness (ARTI) in Iran.

Materials and Methods:

Data were collected from a national health survey conducted in 2010 (Iran's Multiple Indicator Demographic and Health Survey). Participants of this cross-sectional study were selected by multistage stratified cluster-random sampling from 31 provinces of Iran. Parents of children with <5 years of age responded to questions about the occurrence of any cough during the previous 2 weeks, referral to private/governmental/other health care systems, and utilization of any oral/injection form of antibiotics. Data were analyzed using SPSS software18. The chi-square test was used to determine antibiotic consumption in various gender and residency groups and also a place of residence with the referral health care system.

Results:

Of the 9345 children under 5 years who participated in the study, 1506 cases (16.2%) had ARTI during 2 weeks prior to the interview, in whom 1143 (75.9%) were referred to urban or rural health care centers (43.4 vs. 30.4%; P < 0.001). Antibiotics were utilized by 715 (62.6%) of affected children. Injection formulations were used for 150 (13.1%) patients. The frequency of receiving antibiotics was higher in urban than in rural inhabitants (66.0% vs. 57.7% P < 0.05).

Conclusion:

The prevalence of total and injection antibiotics usage in children <5 years with ARTI is alarmingly high in Iran. Therefore, interventions to reduce antibiotic use are urgently needed.

Increased risk for and mortality from invasive pneumococcal disease in HIV-exposed but uninfected infants aged <1 year in South Africa, 2009-2013

BACKGROUND

High antenatal human immunodeficiency virus (HIV) seroprevalence rates (∼ 30%) with low perinatal HIV transmission rates (2.5%), due to HIV prevention of mother-to-child transmission program improvements in South Africa, has resulted in increasing numbers of HIV-exposed but uninfected (HEU) children. We aimed to describe the epidemiology of invasive pneumococcal disease (IPD) in HEU infants.

METHODS

We conducted a cross-sectional study of infants aged <1 year with IPD enrolled in a national, laboratory-based surveillance program for incidence estimations. Incidence was reported for 2 time points, 2009 and 2013. At enhanced sites we collected additional data including HIV status and in-hospital outcome.

RESULTS

We identified 2099 IPD cases in infants from 2009 to 2013 from all sites. In infants from enhanced sites (n = 1015), 92% had known HIV exposure status and 86% had known outcomes. IPD incidence was highest in HIV-infected infants, ranging from 272 to 654 per 100,000 population between time points (2013 and 2009), followed by HEU (33-88 per 100,000) and HIV-unexposed and uninfected (HUU) infants (18-28 per 100,000). The case-fatality rate in HEU infants (29% [74/253]) was intermediate between HUU (25% [94/377]) and HIV-infected infants (34% [81/242]). When restricted to infants <6 months of age, HEU infants (37% [59/175]) were at significantly higher risk of dying than HUU infants (32% [51/228]; adjusted relative risk ratio, 1.76 [95% confidence interval, 1.09-2.85]).

DISCUSSION

HEU infants are at increased risk of IPD and mortality from IPD compared with HUU children, especially as young infants. HEU infants, whose numbers will likely continue to increase, should be prioritized for interventions such as pneumococcal vaccination along with HIV-infected infants and children.

High prevalence of antibiotic resistance in nasopharyngeal bacterial isolates from healthy children in rural Uganda: A cross-sectional study

BACKGROUND

In Uganda, the main causes of death in children under 5 years of age are malaria and pneumonia--often due to delayed diagnosis and treatment. In preparation for a community case management intervention for pneumonia and malaria, the bacterial composition of the nasopharyngeal flora and its in vitro resistance were determined in children aged five or under to establish baseline resistance to commonly used antibiotics.

METHODS

In a population-based survey in April 2008, nasopharyngeal specimens were collected from 152 randomly selected healthy children under 5 years of age in the Iganga/Mayuge Health and Demographic Surveillance Site (HDSS). Medical history and prior treatment were recorded. Demographic characteristics and risk factors for carriage of resistant strains were obtained from the HDSS census. Bacteria were isolated and analysed for antibiotic susceptibility using disk diffusion and E test.

RESULTS

Streptococcus pneumoniae (S. pneumoniae) carriage was 58.6%, and, while most (80.9%) isolates had intermediate resistance to penicillin, none was highly resistant. Whereas no isolate was resistant to erythromycin, 98.9% were resistant to trimethoprim-sulphamethoxazole (co-trimoxazole).

CONCLUSIONS

In vitro resistance in S. pneumoniae to co-trimoxazole treatment was high, and the majority of isolates had intermediate resistance to penicillin. To inform treatment policies on the clinical efficacy of current treatment protocols for pneumonia in health facilities and at the community level, routine surveillance of resistance in pneumonia pathogens is needed as well as research on treatment efficacy in cases with resistant strains. Improved clinical algorithms and diagnostics for pneumonia should be developed.

What is the relevance of antimicrobial resistance on the outcome of community-acquired pneumonia caused by Streptococcus pneumoniae? (should macrolide monotherapy be used for mild pneumonia?)

Multidrug-resistant pneumococci continue to increase worldwide. Although there are still questions regarding the relevance of β-lactam resistance, the recommendation for the use of the macrolides as monotherapy for mild community-acquired pneumonia should be revisited in view of high rates of resistance, the association of clinical failures with low-level and high-level resistance, and the lack of clinical data to support their need for empirical therapy for the atypicals.

Pharmacotherapy for pneumococcal infections: an update

INTRODUCTION

The management of pneumococcal diseases still places a significant burden on medical and economic resources. The subjects at greatest risk of pneumococcal infections are children.

AREAS COVERED

The aim of this review is to analyse the best current therapeutic approach to pneumococcal resistance, taking into account the level of susceptibility of Streptococcus pneumoniae, and the pharmacokinetics and pharmacodynamics of different antibiotics in the various pneumococcal diseases.

EXPERT OPINION

Antibiotic treatment of a number of pneumococcal diseases remains difficult or impossible due to the presence of strains resistant to commonly used antibiotics. In children the problem is significantly more important than in adults due to the reduced number of licenced drugs for subjects in the first years of life. The new conjugate pneumococcal vaccines containing 10 (PCV10) and 13 serotypes (PCV13), which include most of the recently emerging strains, might reduce the incidence of pneumococcal infections and the circulation of resistant pathogens. However, it is likely that optimal results will only be reached after the development of effective vaccines based on conserved proteins that are capable of preventing all pneumococcal infections, regardless of the serotype of the causative organism.

Impact of penicillin nonsusceptibility on clinical outcomes of patients with nonmeningeal Streptococcus pneumoniae bacteremia in the era of the 2008 clinical and laboratory standards institute penicillin breakpoints

To investigate the impact of penicillin nonsusceptibility on clinical outcomes of patients with nonmeningeal Streptococcus pneumoniae bacteremia (SPB), a retrospective cohort study was performed. The characteristics of 39 patients with penicillin-nonsusceptible SPB (PNSPB) were compared to those of a group of age- and sex-matched patients (n = 78) with penicillin-susceptible SPB (PSSPB). Susceptibility to penicillin was redetermined by using the revised Clinical and Laboratory Standards Institute (CLSI) penicillin breakpoints in CLSI document M100-S18. Although the PNSPB group tended to have more serious initial manifestations than the PSSPB group, the two groups did not differ significantly in terms of their 30-day mortality rates (30.8% versus 23.1%; P = 0.37) or the duration of hospital stay (median number of days, 14 versus 12; P = 0.89). Broad-spectrum antimicrobial agents, such as extended-spectrum cephalosporins, vancomycin, and carbapenem, were frequently used in both the PNSPB and PSSPB groups. Multivariate analysis revealed that ceftriaxone nonsusceptibility (adjusted odds ratio [aOR] = 4.88; 95% confidence interval [CI] = 1.07 to 22.27; P = 0.041) was one of the independent risk factors for 30-day mortality. Thus, when the 2008 CLSI penicillin breakpoints are applied and the current clinical practice of using wide-spectrum empirical antimicrobial agents is pursued, fatal outcomes in patients with nonmeningeal SPB that can be attributed to penicillin nonsusceptibility are likely to be rare. Further studies that examine the clinical impact of ceftriaxone nonsusceptibility in nonmningeal SPB may be warranted.

Risk factors for 30-day mortality in adult patients with pneumococcal bacteraemia, and the impact of antimicrobial resistance on clinical outcomes

The clinical impact of antimicrobial resistance on the outcome of pneumococcal bacteraemia has remained unclear. This study aimed to evaluate risk factors for mortality and determine the impact of antimicrobial resistance on clinical outcomes. A total of 150 adult patients with pneumococcal bacteraemia were identified over a period of 11 years at Seoul National University Hospital. Of the 150 patients, 122 (81·3%) had penicillin-susceptible (Pen-S) strains and 28 (18·7%) penicillin-non-susceptible (Pen-NS) strains; 43 (28·7%) had erythromycin-susceptible (EM-S) strains and 107 (71·3%) erythromycin-non-susceptible (EM-NS) strains. On multivariate analysis, elevated APACHE II score [odds ratio (OR) 1·24, 95% confidence interval (CI) 1·14–1·34, P<0·001) and presence of solid organ tumour (OR 2·99, 95% CI 1·15–7·80, P=0·025) were independent risk factors for mortality. Neither erythromycin resistance nor penicillin resistance had a significant effect on clinical outcomes. However, for the 76 patients with pneumococcal pneumonia, the time required for defervescence was significantly longer in the EM-NS group than in the EM-S group (5·45±4·39 vs. 2·93±2·56, P=0·03 by log rank test). In conclusion, antimicrobial resistance does not have an effect on mortality in adult patients with pneumococcal bacteraemia.

Health Alliance for prudent antibiotic prescribing in patients with respiratory tract infections (HAPPY AUDIT) -impact of a non-randomised multifaceted intervention programme

Background

Excessive use of antibiotics is worldwide the most important reason for development of antimicrobial resistance. As antibiotic resistance may spread across borders, high prevalence countries may serve as a source of bacterial resistance for countries with a low prevalence. Therefore, bacterial resistance is an important issue with a potential serious impact on all countries. Initiatives have been taken to improve the quality of antibiotic prescribing in primary care, but only few studies have been designed to determine the effectiveness of multifaceted strategies across countries with different practice setting. The aim of this study was to evaluate the impact of a multifaceted intervention targeting general practitioners (GPs) and patients in six countries with different health organization and different prevalence of antibiotic resistance.

Methods

GPs from two Nordic countries, two Baltic Countries and two Hispano-American countries registered patients with respiratory tract infections (RTIs) in 2008 and 2009. After first registration they received individual prescriber feedback and they were offered an intervention programme that included training courses, clinical guidelines, posters for waiting rooms, patient brochures and access to point of care tests (Strep A and C-Reactive Protein). Antibiotic prescribing rates were compared before and after the intervention.

Results

A total of 440 GPs registered 47011 consultations; 24436 before the intervention (2008) and 22575 after the intervention (2009). After the intervention, the GPs significantly reduced the percentage of consultations resulting in an antibiotic prescription. In patients with lower RTI the GPs in Lithuania reduced the prescribing rate by 42%, in Russia by 25%, in Spain by 25%, and in Argentina by 9%. In patients with upper RTIs, the corresponding reductions in the antibiotic prescribing rates were in Lithania 20%, in Russia 15%, in Spain 9%, and in Argentina 5%.

Conclusion

A multifaceted intervention programme targeting GPs and patients and focusing on improving diagnostic procedures in patients with RTIs may lead to a marked reduction in antibiotic prescribing. The pragmatic before-after design used may suffer from some limitations and the reduction in antibiotic prescribing could be influenced by factors not related to the intervention.

Health Alliance for Prudent Prescribing, Yield and Use of Antimicrobial Drugs in the Treatment of Respiratory Tract Infections (HAPPY AUDIT)

Background

Excessive and inappropriate use of antibiotics is considered to be the most important reason for development of bacterial resistance to antibiotics. As antibiotic resistance may spread across borders, high prevalence countries may serve as a source of bacterial resistance for countries with a low prevalence. Therefore, bacterial resistance is an important issue with a potential serious impact on all countries.

The majority of respiratory tract infections (RTIs) are treated in general practice. Most infections are caused by virus and antibiotics are therefore unlikely to have any clinical benefit. Several intervention initiatives have been taken to reduce the inappropriate use of antibiotics in primary health care, but the effectiveness of these interventions is only modest. Only few studies have been designed to determine the effectiveness of multifaceted strategies in countries with different practice setting. The aim of this study is to evaluate the impact of a multifaceted intervention targeting general practitioners (GPs) and patients in six countries with different prevalence of antibiotic resistance: Two Nordic countries (Denmark and Sweden), two Baltic Countries (Lithuania and Kaliningrad-Russia) and two Hispano-American countries (Spain and Argentina).

Methods/Design

HAPPY AUDIT was initiated in 2008 and the project is still ongoing. The project includes 15 partners from 9 countries. GPs participating in HAPPY AUDIT will be audited by the Audit Project Odense (APO) method. The APO method will be used at a multinational level involving GPs from six countries with different cultural background and different organisation of primary health care. Research on the effect of the intervention will be performed by analysing audit registrations carried out before and after the intervention. The intervention includes training courses on management of RTIs, dissemination of clinical guidelines with recommendations for diagnosis and treatment, posters for the waiting room, brochures to patients and implementation of point of care tests (Strep A and CRP) to be used in the GPs'surgeries.

To ensure public awareness of the risk of resistant bacteria, media campaigns targeting both professionals and the public will be developed and the results will be published and widely disseminated at a Working Conference hosted by the World Association of Family Doctors (WONCA-Europe) at the end of the project period.

Discussion

HAPPY AUDIT is an EU-financed project with the aim of contributing to the battle against antibiotic resistance through quality improvement of GPs' diagnosis and treatment of RTIs through development of intervention programmes targeting GPs, parents of young children and healthy adults. It is hypothesized that the use of multifaceted strategies combining active intervention by GPs will be effective in reducing prescribing of unnecessary antibiotics for RTIs and improving the use of appropriate antibiotics in suspected bacterial infections.

Clinical characteristics and outcomes of pneumococcal bacteremia in adult patients with liver cirrhosis

Few studies have assessed the clinical characteristics and outcomes of invasive pneumococcal diseases in cirrhotic patients. We reviewed the medical records of adult cirrhotic patients with pneumococcal bacteremia from January 1997 to April 2006. During this time, 62 episodes of pneumococcal bacteremia occurred in 59 patients with liver cirrhosis, 45 (76.3%) of whom were classified as Child-Pugh grade C. The most common source of infection was spontaneous bacterial peritonitis (SBP) (45.8%), followed by primary bacteremia (40.7%) and pneumonia (10.1%). The 30-day mortality rate was 16.9%, with all fatalities in patients classified as Child-Pugh grade C. The median model for end-stage liver disease score of patients who died was significantly higher than that of survivors (26.5 versus 17.0, P=0.001). Pneumococcal bacteremia in adult cirrhotic patients was more commonly associated with SBP than with pneumonia. Most cases of bacteremia and fatal outcomes occurred in patients with advanced cirrhosis.

Pneumococcal antimicrobial resistance: therapeutic strategy and management in community-acquired pneumonia

Streptococcus pneumoniae has been consistently shown to represent the most frequent causative agent of community-acquired pneumonia (CAP) and pneumococcal antibiotic resistance towards different families of antibiotics continues to be a much-debated issue. Microbial resistance causes a great deal of confusion in choosing an empirical treatment for pneumonia and this makes it necessary to know which factors actually determine the real impact of antimicrobial resistance on the outcome of pneumococcal infections. Several different aspects have to be taken into account when analyzing this matter, such as the study design, the condition of the patient at the time of diagnosis, the choice of the initial antimicrobial regimen (combination or monotherapy) and the pharmacokinetic/pharmacodynamic variables of the chosen antibiotic. It is generally accepted that in the treatment of beta-lactam-resistant pneumococcal infections, the use of standard antipneumococcal beta-lactam agents is unlikely to impact negatively on the outcome of CAP when appropriate agents are given in sufficient doses. As a general rule, for infections with penicillin-sensitive strains, penicillin or an aminopenicillin in a standard dosage will be effective; in the cases of strains with intermediate resistance, beta-lactam agents are still considered appropriate treatment although higher dosages are recommended; finally, 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 areas of high prevalence of high-level macrolide resistance, empirical monotherapy with a macrolide is not optimal for the treatment of hospitalised patients with moderate or moderately-severe CAP. Fluoroquinolones are considered to be excellent antibiotics in the treatment of pneumococcal CAP in adults, but their general recommendation has been withheld due to fears of a widespread development of resistance. Most international guidelines recommend combination therapy (beta-lactam plus a macrolide) for the treatment of hospitalised patients with CAP.

The evidence for using conjugate vaccines to protect HIV-infected children against pneumococcal disease

Pneumococcal conjugate vaccines (PCVs) are a potentially useful complement to existing treatment strategies in HIV-infected children, for whom pneumococcal infections are common and serious. This Review summarises available data on the burden of pneumococcal disease and the safety and efficacy of PCVs in HIV-infected children. The data demonstrate that children with HIV have significantly increased risk of pneumococcal disease compared with uninfected children; the serotypes included in currently licensed or near-licensure conjugate vaccines include most serotypes that cause invasive pneumococcal disease (IPD) in HIV-infected children and adults; PCVs provide substantial protection against IPD and clinical pneumonia when given to HIV-infected infants; and HIV-infected adults gain an indirect benefit when children in the community are vaccinated. PCV should be considered as an important intervention for improving the lives of HIV-infected children.

Antimicrobial resistance among invasive isolates of Streptococcus pneumoniae collected across Canada

Between 2002 and 2003, 736 nonduplicate Streptococcus pneumoniae isolated from blood cultures were collected from 7 of 10 Canadian provinces (10 tertiary care centers). Microdilution broth susceptibility testing was performed using the method prescribed by the Clinical Laboratory Standards Institute. Of the isolates, 16.85% were nonsusceptible to penicillin and 5.4% were highly resistant. Of the S.pneumoniae, 14.1% had reduced susceptibility to erythromycin and 47% had been accounted for by the M phenotype. No isolates were recovered that were resistant to telithromycin. Only 6 isolates were resistant to levofloxacin and gatifloxacin. Of these, 5 strains had intermediate susceptibility to moxifloxacin and 1 was considered susceptible. The rates observed in this study are in keeping with previous surveillance studies among noninvasive isolates.

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.

Amoxicillin is effective against penicillin-resistant Streptococcus pneumoniae strains in a mouse pneumonia model simulating human pharmacokinetics

High-dose oral amoxicillin (3 g/day) is the recommended empirical outpatient treatment of community-acquired pneumonia (CAP) in many European guidelines. To investigate the clinical efficacy of this treatment in CAP caused by Streptococcus pneumoniae strains with MICs of amoxicillin > or =2 microg/ml, we used a lethal bacteremic pneumonia model in leukopenic female Swiss mice with induced renal failure to replicate amoxicillin kinetics in humans given 1 g/8 h orally. Amoxicillin (15 mg/kg of body weight/8 h subcutaneously) was given for 3 days. We used four S. pneumoniae strains with differing amoxicillin susceptibility and tolerance profiles. Rapid bacterial killing occurred with an amoxicillin-susceptible nontolerant strain: after 4 h, blood cultures were negative and lung homogenate counts under the 2 log(10) CFU/ml detection threshold (6.5 log(10) CFU/ml in controls, P < 0.01). With an amoxicillin-intermediate nontolerant strain, significant pulmonary bacterial clearance was observed after 24 h (4.3 versus 7.9 log(10) CFU/ml, P < 0.01), and counts were undetectable 12 h after treatment completion. With an amoxicillin-intermediate tolerant strain, 24-h bacterial clearance was similar (5.4 versus 8.3 log(10) CFU/ml, P < 0.05), but 12 h after treatment completion, lung homogenates contained 3.3 log(10) CFU/ml. Similar results were obtained with an amoxicillin-resistant and -tolerant strain. Day 10 survival rates were usually similar across strains. Amoxicillin with pharmacokinetics simulating 1 g/8 h orally in humans is bactericidal in mice with pneumonia due to S. pneumoniae for which MICs were 2 to 4 microg/ml. The killing rate depends not only on resistance but also on tolerance of the S. pneumoniae strains.

[Antibiotherapy for acute CAP in adults]

Community acquired pneumonia is one of the most frequent infections. With time, bacterial epidemiology and bacterial resistance evolve and new antibiotics become available. So an up-date on adequate antibiotic use is necessary. We reviewed the epidemiology of pneumonia and the evolution of bacterial resistance. We also collected data on new antibiotics which can be used for this infection such as levofloxacin, moxifloxacin, telithromycin, and pristinamycin. All these drugs are effective on bacteria involved in pneumonia. At this time, only few Streptococcus pneumoniae strains have developed resistance to these drugs. However, resistance to fluoroquinolones is not easily detected with common laboratory techniques. There is no effectiveness difference between the 2 new fluoroquinolones (levofloxacin, moxifloxacin) in clinical studies. However, in bacteriological and pharmacological studies, moxifloxacin seems to be more effective than levofloxacin (500 mg/day). For the treatment of pneumonia due to Legionella pneumophila, fluoroquinolones are now widely recommended. For Streptococcus pneumonia, amoxicillin remain the drug of choice, even for bacteria with a decreased susceptibility to penicillin. The importance of treating atypical pathogens remains to be documented.

Antibiothérapie des pneumonies aiguës communautaires à Streptococcus pneumoniae : impact clinique de la résistance bactérienne

The emergence of Streptococcus pneumoniae strains with reduced susceptibility to beta-lactams and with multiple drug resistance has not led to major changes in recommendations for antibiotic therapy in patients with acute community-acquired pneumococcal pneumonia. Numerous factors explain the limited clinical impact of this major microbiological change. The frequency of intermediate strains is high but the frequency of resistant strains to beta-lactams is very low. There is a complex relation between the acquisition of resistance to beta-lactams and the decreased virulence of S. pneumoniae strains. The only finding in studies of humanized experimental animal models of lethal bacteremic pneumonia caused by resistance and tolerant strains was a slowing in the kinetics of beta-lactams bactericidal activity, especially for amoxicillin. Taken together, this preclinical data shows that microbiological resistance of pneumococci to beta-lactams has very little influence on a possible failure of recommanded treatment regimens for pneumococcal pneumonia. The high rate of multiple drug resistance, particularly among beta-lactam resistant strains, rules out the probabilistic use of macrolides. Conversely, fluoroquinolone (FQ) resistance remains low, inferior to 3%, and the same is true for ketolides (<1%). Only a global strategy of patient management in the use of these new drugs could ensure their long-term activity. The high mortality rate of hospitalized S. pneumoniae pneumonia will only be improved with a better understanding of the complex host-bacteria interactions.

Controversies in the treatment of pneumococcal community-acquired pneumonia

Community-acquired pneumonia remains an important cause of disease and death both in the developed and the developing worlds, despite the ready availability of potent antimicrobial agents to which the organisms remain susceptible. Furthermore, disease management is complicated by emerging resistance of the common pathogens to the various classes of commonly prescribed antimicrobial agents. Much recent research in the field of community-acquired pneumonia has focused attention on optimal treatment, evaluating the impact of antibiotic resistance, as well as of antimicrobial choices, on the outcome of these infections. In addition, efforts have been directed towards finding adjunctive therapies to antibiotics that may improve the prognosis of these patients. This article reviews some of these research areas, highlighting controversies that still exist with regard to final recommendations, and in particular with regard to infections with Streptococcus pneumoniae, the most common bacterial cause of community-acquired pneumonia.

Drug-resistant pneumococcal pneumonia: clinical relevance and approach to management

Community-acquired pneumonia is the most common infectious disease that causes death, with Streptococcus pneumoniae remaining the leading causative pathogen. The worldwide incidence of infections caused by pneumococci resistant to penicillin, macrolides, and other antimicrobial agents has increased at an alarming rate during the past 2 decades. Yet, these agents are still used as first-line empirical therapy in the outpatient setting. There are several reasons for this, including the infrequency of making a pathogen-specific diagnosis, the failure of studies to demonstrate the relevance of resistance, and the infrequency with which clinicians recognize clinical failures. Despite this, there is mounting evidence that supports the practice of using high doses of some antimicrobial agents, a more active antimicrobial agent within a class, or switching to another class of antimicrobial agents when a patient is identified as being at an increased risk of infection with a resistant pneumococcus. There is now information that will allow the physician to identify not only the patient at risk for infection with a resistant pneumococcus but also the antimicrobial class and, in some cases, the agent within the class to which the organism is more likely to be resistant. This will allow clinicians to better define optimal therapy for patients with community-acquired pneumonia.

Clinical outcomes of bacteremic pneumococcal infections in an area with high resistance

In a retrospective study designed to gather information in a region with high antimicrobial resistance, the outcomes of 216 episodes of laboratory-confirmed pneumococcal bacteremia treated in Hong Kong between 1995 and 2001 were assessed. The patients had a mean age (+/-standard deviation) of 40+/-33.7 years. In all patients, the clinical diagnosis was confirmed by isolation of Streptococcus pneumoniae from blood (n=216), cerebrospinal fluid (n=7) and/or other sterile sites (n=12). Penicillin nonsusceptibility was found in 37.5% of the isolates (20.8% intermediate and 16.7% resistant). Penicillin nonsusceptibility was not a risk factor for inpatient mortality (p=0.7), nor did it affect duration of fever (p=0.4), requirement for intensive care unit admission (p=0.4) or development of suppurative complications (p=0.2). Advanced age (OR 11.3, 95%CI 4.5-28.2, p<0.01), critical illness (OR 11.3, 95%CI 4.5-28.2, p<0.001) and discordant therapy (OR 4.3, 95%CI 1.7-10.9, p<0.002) involving agents with poor anti-pneumococcal activity (but not penicillins and broad-spectrum beta-lactam agents) were significantly associated with mortality.

Penicillins for Treatment of Pneumococcal Pneumonia: Does In Vitro Resistance Really Matter?

BACKGROUND

The rate of in vitro bacterial resistance to antimicrobial agents is escalating among pathogens that cause the most serious respiratory tract infections. Many reports published during the past few years suggest that this has direct clinical implications. In particular, resistance of Streptococcus pneumoniae to beta-lactam antibiotic therapy has assumed a prominent role in the evolution of guidelines for the initial treatment of respiratory tract infection.

METHODS

I conducted a critical review of the published medical literature.

RESULTS

There is only a single report of documented microbiologic failure of parenteral penicillin-class antibiotics in the treatment of pneumococcal pneumonia in patients with or without bacteremia, whereas there are numerous well-documented reports of treatment failure with quinolone-class (n > or = 21) and macrolide-class (n > or = 33) antibiotics in the treatment of pneumococcal pneumonia.

CONCLUSION

The recommended optimal in-hospital therapy for community-acquired pneumonia should continue to be a beta-lactam antibiotic (penicillin, aminopenicillin, cefotaxime, or ceftriaxone) administered with a macrolide or a fluoroquinolone agent for adjunctive treatment of infection with potential atypical pathogens.

Clinical implications and treatment of multiresistant Streptococcus pneumoniae pneumonia

Streptococcus pneumoniae is the leading bacterial cause of community-acquired respiratory tract infections. Prior to the 1970s this pathogen was uniformly susceptible to penicillin and most other antimicrobials. However, since the 1990s there has been a significant increase in drug-resistant Streptococcus pneumoniae (DRSP) due, in large part, to increased use of antimicrobials. The clinical significance of this resistance is not definitely established, but appears to be most relevant to specific MICs for specific antimicrobials. Certain beta-lactams (amoxicillin, cefotaxime, ceftriaxone), the respiratory fluoroquinolones, and telithromycin are among several agents that remain effective against DRSP. Continued surveillance studies, appropriate antimicrobial usage campaigns, stratification of patients based on known risk factors for resistance, and vaccination programmes are needed to appropriately manage DRSP and limit its spread.

Application of Pharmacokinetics and Pharmacodynamics to Antimicrobial Therapy of Community-Acquired Respiratory Tract Infections

To achieve bacteriologic and clinical success, sufficient concentrations of antimicrobial at the site of infection must be maintained for an adequate period of time. These dynamics are determined by combining drug pharmacokinetic and pharmacodynamic (PK/PD) data with minimum inhibitory concentrations. Bacteriologically confirmed failures have been reported in otitis media and, with a lesser degree of evidence, in pneumococcal pneumonia with a variety of agents that include beta-lactams, macrolides and fluoroquinolones. These failures have been shown to be due to infection by resistant pathogens or suboptimal therapy. However, no clinical failure has been reported during therapy for bacteremic pneumococcal pneumonia with adequate doses of beta-lactams. The failures reported with macrolides or fluoroquinolones have been due to either preexisting resistance to these agents that cannot be overcome by increasing the dose of the antimicrobial or, more rarely, the emergence of resistance during therapy. In this review, we offer an overview of the most important attributes of the main antimicrobials that are currently used in the treatment of community-acquired respiratory tract infections from a PK/PD perspective.

Efficacy of moxifloxacin for treatment of penicillin-, macrolide- and multidrug-resistant Streptococcus pneumoniae in community-acquired pneumonia

This pooled analysis of six prospective, multicentre trials aimed to determine the efficacy of moxifloxacin in community-acquired pneumonia (CAP) due to penicillin-, macrolide- and multidrug-resistant Streptococcus pneumoniae (MDRSP). At a central laboratory, isolates were identified and antimicrobial susceptibility determined (microbroth dilution). MDRSP was defined as resistance > or =3 drug classes. Patients received oral or sequential intravenous/oral 400 mg moxifloxacin once daily for 7-14 days. The primary endpoint was clinical success at test-of-cure for efficacy-valid patients with proven pretherapy S. pneumoniae infection. Of 140 S. pneumoniae isolated (112 respiratory, 28 blood), 23 (16.4%) were penicillin resistant, 26 (18.6%) macrolide resistant and 31 (22.1%) MDRSP. The moxifloxacin MIC90 was 0.25 microg/ml. Clinical cure with moxifloxacin was 95.4% (125/131) overall, and 100% (21/21) for penicillin-, 95.7% (22/23) for macrolide- and 96.4% (27/28) for multidrug-resistant strains. Moxifloxacin provided excellent clinical and bacteriological cure rates in CAP due to drug-resistant pneumococci.

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.

Community-acquired bacteraemic pneumococcal pneumonia in adults: effect of diminished penicillin susceptibility on clinical outcome

Pneumococcal pneumonia remains a common disease with a high mortality rate. Between 1995 and 2000, we prospectively analyzed 95 consecutive adult cases of community-acquired bacteraemic pneumococcal pneumonia treated in a single centre. The incidence of pneumococcal resistance to penicillin increased from 19 to 50% during the study period. Multivariate analysis showed that only age and recent hospitalization were independently associated with fatal outcome. The proportion of penicillin-resistant strains was slightly but not significantly higher among patients who died before the fourth hospital day than among those who died later. Patients who died before D4 were more likely to have a recent history of hospitalization, cancer and/or chemotherapy. It thus appears that infection by a resistant pneumococcal strain is not in itself a gravity factor in this setting, but that their acquisition is associated with pejorative clinical features.

Role of beta-lactam agents in the treatment of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a common illness associated with high rates of morbidity and mortality worldwide. The beta-lactam antibacterial agents have been the mainstay of therapy for CAP for over four decades and remain as first-line therapy. However, the impact of the substantial prevalence of resistance seen among the common respiratory pathogens, particularly penicillin and macrolide resistance among Streptococcus pneumoniae, is now an area for concern. CAP treatment guidelines often recommend the use of a macrolide or fluoroquinolone in conjunction with, or as an alternative to, beta-lactam agents, but whether this is necessary is uncertain. This review outlines the historical use of beta-lactam antibacterial agents in the treatment of CAP along with their ongoing therapeutic utility.

Drug treatment of pneumococcal pneumonia in the elderly

Streptococcus pneumoniae has been recognised as a major cause of pneumonia since the time of Sir William Osler. Drug-resistant S. pneumoniae (DRSP), which have gradually become resistant to penicillins as well as more recently developed macrolides and fluoroquinolones, have emerged as a consequence of indiscriminate use of antibacterials coupled with the ability of the pneumococcus to adapt to a changing antibacterial milieu. Pneumococci use cell wall choline components to bind platelet-activating factor receptors, colonise mucosal surfaces and evade innate immune defenses. Numerous virulence factors that include hyaluronidase, neuraminidase, iron-binding proteins, pneumolysin and autolysin then facilitate cytolysis of host cells and allow tissue invasion and bloodstream dissemination. Changes in pneumococcal cell wall penicillin-binding proteins account for resistance to penicillins, mutations in the ermB gene cause high-level macrolide resistance and mutations in topoisomerase IV genes coupled with GyrA gene mutations alter DNA gyrase and lead to high-level fluoroquinolone resistance. Risk factors for lower respiratory tract infections in the elderly include age-associated changes in oral clearance, mucociliary clearance and immune function. Other risks for developing pneumonia include poor nutrition, hypoalbuminaemia, bedridden status, aspiration, recent viral infection, the presence of chronic organ dysfunction syndromes including parenchymal lung disease and recent antibacterial therapy. Although the incidence of infections caused by DRSP is rising, the effect of an increase in the prevalence of resistant pneumococci on mortality is not clear. When respiratory infections occur, rapid diagnosis and prompt, empirical administration of appropriate antibacterial therapy that ensures adequate coverage of DRSP is likely to increase the probability of a successful outcome when treating community-acquired pneumonia in elderly patients, particularly those with multiple risk factors for DRSP. A chest x-ray is recommended for all patients, but other testing such as obtaining a sputum Gram's smear is not necessary and should not prolong the time gap between clinical suspicion of pneumonia and antibacterial administration. The selection of antibacterials should be based upon local resistance patterns of suspected organisms and the bactericidal efficacy of the chosen drugs. If time-dependent agents are chosen and DRSP are possible pathogens, dosing should keep drug concentrations above the minimal inhibitory concentration that is effective for DRSP. Treatment guidelines and recent studies suggest that combination therapy with a beta-lactam and macrolide may be associated with a better outcome in hospitalised patients, and overuse of fluoroquinolones as a single agent may promote quinolone resistance. The ketolides represent a new class of macrolide-like antibacterials that are highly effective in vitro against macrolide- and azalide-resistant pneumococci. Pneumococcal vaccination with the currently available polysaccharide vaccine is thought to confer some preventive benefit (preventing invasive pneumococcal disease), but more effective vaccines, such as nonconjugate protein vaccines, need to be developed that provide broad protection against pneumococcal infection.

[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.

Nonresponses and treatment failures with conventional empiric regimens in patients with community-acquired pneumonia

Although most patients with suspected CAP respond to empiric therapy,a small number of patients do not respond in the expected fashion. Age and underlying comorbid conditions have a strong influence on the course of illness. Less common causes of treatment failures include overwhelming infection, antimicrobial resistance, and misdiagnosis. It is a common practice for empiric antimicrobial treatment of CAP to be initiated without microbiologic studies. Clinicians carefully should observe these patients for unusual or slow responses and should be ready to pursue a more extensive search for the cause of treatment failure.

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.

Epidemiology and etiology of community-acquired pneumonia

The seriousness of community-acquired pneumonia (CAP), despite being a reasonably common and potentially lethal disease, often is under estimated by physicians and patients alike. CAP results in more than 10 million visits to physicians, 64 million days of restricted activity, and 600,000 hospitalizations. This article discusses the epidemiology and bacterial causes of CAP in immunocompetent adults and the severe acute respiratory syndrome coronavirus.

Factores relacionados con la mortalidad de la enfermedad neumocócica invasiva

BACKGROUND AND OBJECTIVE

To analyze the risk factors associated with mortality in invasive pneumococcal disease in the university hospital Fundación Jiménez Díaz (Madrid, Spain) during 11 years.

PATIENTS AND METHOD

We performed a retrospective study of patients attending the emergency service of the hospital from January 1993 to August 2003. We registered data on mortality, clinical and microbiological evolution and relapses.

RESULTS

We studied 263 patients with pneumococcal baceteremia and invasive disease caused by Streptococcus pneumoniae (pneumonia, meningitis, sepsis, bacteremia of unknown origin and oligoarthritis). Mortality was 12.5%. Variables associated with mortality in a logistic regression analysis included absence of leukocytosis (p = 0.04), acidosis (p < 0.01), respiratory signs and symptoms (tachypnea, pleuritic pain) (p = 0.02), and neurologic manifestations (decreased consciousness level; (p < 0.01).

CONCLUSION

Patients at highest risk of death because of invasive pneumococcal disease are critically ill, with no leukocytosis, with severe respiratory or neurological symptoms and undergoing invasive procedures such as mechanical ventilation and tracheostomy.

Emergence of Streptococcus pneumoniae with very-high-level resistance to penicillin

Penicillin resistance threatens the treatment of pneumococcal infections. We used sentinel hospital surveillance (1978 to 2001) and population-based surveillance (1995 to 2001) in seven states in the Active Bacterial Core surveillance of the Emerging Infections Program Network to document the emergence in the United States of invasive pneumococcal isolates with very-high-level penicillin resistance (MIC > or = 8 microg/ml). Very-high-level penicillin resistance was first detected in 1995 in multiple pneumococcal serotypes in three regions of the United States. The prevalence increased from 0.56% (14 of 2,507) of isolates in 1995 to 0.87% in 2001 (P = 0.03), with peaks in 1996 and 2000 associated with epidemics in Georgia and Maryland. For a majority of the strains the MICs of amoxicillin (91%), cefuroxime (100%), and cefotaxime (68%), were > or =8 microg/ml and all were resistant to at least one other drug class. Pneumonia (50%) and bacteremia (36%) were the most common clinical presentations. Factors associated with very highly resistant infections included residence in Tennessee, age of <5 or > or =65 years, and resistance to at least three drug classes. Hospitalization and case fatality rates were not higher than those of other pneumococcal infection patients; length of hospital stay was longer, controlling for age. Among the strains from 2000 and 2001, 39% were related to Tennessee(23F)-4 and 35% were related to England(14-)9. After the introduction of the pneumococcal conjugate vaccine, the incidence of highly penicillin resistant infections decreased by 50% among children <5 years of age. The emergence, clonality, and association of very-high-level penicillin resistance with multiple drug resistance requires further monitoring and highlights the need for novel agents active against the pneumococcus.