Azithromycin vs cefuroxime plus erythromycin for empirical treatment of community-acquired pneumonia in hospitalized patients: a prospective, randomized, multicenter trial

A mini-review on anticancer-related properties of azithromycin and its potential activities in overcoming the challenges of glioblastoma

The resistance, plasticity and heterogeneity of cancer cells, including glioblastoma (GB) cells, have prompted the investigation of various agents for possible adjuncts and alternatives to existing therapies. This includes a macrolide antibiotic, azithromycin (AZI). It possesses intriguing anticancer properties in a range of cancer models in vitro, such as antiproliferative, pro-apoptotic, anti-autophagy and anti-angiogenic effects. In fact, AZI is renowned for its ability to eradicate cancer stem cells by inhibiting mitochondrial biogenesis and respiration. AZI-containing regimens in cancer patients for different purposes have shown favourable (i.e., attributed to its antibacterial activity) and unfavourable outcomes. Whilst its direct anticancer effects have yet to be clinically proven. To that end, this review provides a summary of AZI anticancer studies and delineates its potential activities in overcoming the challenges of GB.

Efficacy of erythromycin compared to clarithromycin and azithromycin in adults or adolescents with community-acquired pneumonia: A Systematic Review and meta-analysis of randomized controlled trials

BACKGROUND

It is debatable whether erythromycin has similar efficacy to other macrolides in treating community-acquired pneumonia (CAP). The aim of this meta-analysis is to compare the efficacy of erythromycin with clarithromycin and azithromycin.

METHODS

We performed this meta-analysis of randomized controlled trials (RCTs) of adults or adolescents with CAP which compared the efficacy of erythromycin monotherapy to either azithromycin or clarithromycin. We searched PubMed and EMBASE and Cochrane Library databases and three clinical trial registries up to November 02, 2021. We evaluated heterogeneity and used random-effects models to perform risk ratios with 95% confidence intervals.

RESULTS

We included four RCTs (total of 472 patients), which compared the clinical efficacy of erythromycin versus clarithromycin. No studies comparing monotherapy of erythromycin versus azithromycin were found. Erythromycin use was associated with significantly lower rates of clinical success (RR, 0.79; 95% CI, 0.64 to 0.98; P-value = 0.033; I² = 20.27%), clinical cure (RR,0.67; 95% CI, 0.48 to 0.92; P-value = 0.014; I² = 8.75%), and radiological success (RR, 0.84; 95% CI, 0.71 to 0.996; P-value = 0.045; I² = 20.12%) than clarithromycin.

CONCLUSION

Erythromycin is less effective than clarithromycin as empiric treatment of CAP in adults and adolescents. Because of this and the higher rate of adverse reactions, erythromycin should not be used in the majority of CAP patients when azithromycin and clarithromycin are available.

Drug utilization pattern and cost-effectiveness analysis of five most common antibiotics used in Saudi Arabia

Objectives

Inappropriate use of antibiotics is a matter of concern worldwide as that may lead to antimicrobial drug resistance. The objective of current study was to assess drug utilization pattern and cost-effectiveness. Studies are conducted to analyze the pattern of antibiotics prescribing their adherence to standard guidelines and economic impact on the patients in order to promote their rational use.

Methods

The study was designed as a single-centred, cross-sectional retrospective pharmacy database study of prescribing patterns and cost-utility analysis of five most common antibiotics used in Saudi Arabia. Data for the period from 1 January 2019 to 31 December 2019 were used in the study. Demographic characteristics were demonstrated as frequencies and percentages (with Wilson 95% confidence intervals for proportions). The chi-square test (for P-value calculation) was used to compare the adherence of National Antimicrobial Guidelines for prescribing antibiotics in Saudi Arabia.

Key findings

The maximum number of patients was recorded from the age group of 18–35 years (35.97%) and minimum from 72 to 88 years (1.82%). The number of units prescribed was highest for amoxicillin, clavulanic acid (22487) to 42.93% of patients and was lowest for ciprofloxacin (4215) with 8.04%. The longest duration of therapy was for Cefdenir (7.23 days) and lowest for azithromycin (3.58 days). The cost was highest for Cefdenir 38.66SR (10.31USD), and lowest cost was estimated for Cefuroxime 12.43SR (3.31USD).

Conclusions

Our study declared that (amoxicillin with clavulanic acid) was used the most as first-line agents in treating bacterial infections due to their broad coverage against different microbes. Conducting laboratory tests to identify the type of microbe before prescribing could prevent the development of drug resistance and save the antibiotic for future. The cost-to-benefit analysis studies of antibiotics must be conducted for each indication that may promote their rational use.

Pharmacotherapy of Lower Respiratory Tract Infections in Elderly-Focused on Antibiotics

Lower respiratory tract infections (LRTIs) refer to the inflammation of the trachea, bronchi, bronchioles, and lung tissue. Old people have an increased risk of developing LRTIs compared to young adults. The prevalence of LRTIs in the elderly population is not only related to underlying diseases and aging itself, but also to a variety of clinical issues, such as history of hospitalization, previous antibacterial therapy, mechanical ventilation, antibiotic resistance. These factors mentioned above have led to an increase in the prevalence and mortality of LRTIs in the elderly, and new medical strategies targeting LRTIs in this population are urgently needed. After a systematic review of the current randomized controlled trials and related studies, we recommend novel pharmacotherapies that demonstrate advantages for the management of LRTIs in people over the age of 65. We also briefly reviewed current medications for respiratory communicable diseases in the elderly. Various sources of information were used to ensure all relevant studies were included. We searched Pubmed, MEDLINE (OvidSP), EMBASE (OvidSP), and ClinicalTrials.gov. Strengths and limitations of these drugs were evaluated based on whether they have novelty of mechanism, favorable pharmacokinetic/pharmacodynamic profiles, avoidance of interactions and intolerance, simplicity of dosing, and their ability to cope with challenges which was mainly evaluated by the primary and secondary endpoints. The purpose of this review is to recommend the most promising antibiotics for treatment of LRTIs in the elderly (both in hospital and in the outpatient setting) based on the existing results of clinical studies with the novel antibiotics, and to briefly review current medications for respiratory communicable diseases in the elderly, aiming to a better management of LRTIs in clinical practice.

Systematic review and meta-analysis of the safety of erythromycin compared to clarithromycin in adults and adolescents with pneumonia

Macrolides are recommended for the treatment of community-acquired pneumonia (CAP). It is debatable whether erythromycin is associated with more adverse drug reactions (ADRs) compared to clarithromycin, and both are recommended in clinical practice guidelines. This meta-analysis aim is to compare ADRs in CAP patients treated with erythromycin versus clarithromycin. Two investigators independently searched PubMed, EMBASE and Cochrane Library databases through Feb 07, 2019. Randomized-controlled trials (RCTs) comparing ADRs of monotherapy with erythromycin versus with clarithromycin in adults or adolescents with CAP were included. We estimated risk ratios (RRs) with 95% confidence intervals (CIs) using random-effects models and evaluated heterogeneity (I²). Bias risk was assessed using the Cochrane risk of bias tool for RCTs. Five RCTs (total of 693 patients) were included. A significantly higher discontinuation rate due to ADRs was found with erythromycin compared with clarithromycin (RR, 4.347; 95% CI, 2.506-7.539; p < 0.001; I²=0%). Overall, ADRs occurred more significantly with erythromycin compared with clarithromycin (RR, 1.773; 95% CI, 1.423-2.209; p < 0.001; I²=0%). Gastrointestinal (GI) ADRs were higher with erythromycin (RR, 2.678; 95% CI, 1.791-4.006; p < 0.001; I²=5.835%). Restriction of analyses to double-blind RCTs did not change our findings. Based on meta-analysis of RCTs in adults and adolescents with CAP, erythromycin results in more overall ADRs and GI ADRs, as well as a higher rate of discontinuation due to ADRs. Therefore, given that erythromycin is not more effective than clarithromycin, erythromycin should not be selected unless other macrolides cannot be used.

Hypervirulent Klebsiella pneumoniae

Hypervirulent K. pneumoniae (hvKp) is an evolving pathotype that is more virulent than classical K. pneumoniae (cKp). hvKp usually infects individuals from the community, who are often healthy. Infections are more common in the Asian Pacific Rim but are occurring globally. hvKp infection frequently presents at multiple sites or subsequently metastatically spreads, often requiring source control. hvKp has an increased ability to cause central nervous system infection and endophthalmitis, which require rapid recognition and site-specific treatment. The genetic factors that confer hvKp's hypervirulent phenotype are present on a large virulence plasmid and perhaps integrative conjugal elements. Increased capsule production and aerobactin production are established hvKp-specific virulence factors. Similar to cKp, hvKp strains are becoming increasingly resistant to antimicrobials via acquisition of mobile elements carrying resistance determinants, and new hvKp strains emerge when extensively drug-resistant cKp strains acquire hvKp-specific virulence determinants, resulting in nosocomial infection. Presently, clinical laboratories are unable to differentiate cKp from hvKp, but recently, several biomarkers and quantitative siderophore production have been shown to accurately predict hvKp strains, which could lead to the development of a diagnostic test for use by clinical laboratories for optimal patient care and for use in epidemiologic surveillance and research studies.

Medication Use for Childhood Pneumonia at a Children's Hospital in Shanghai, China: Analysis of Pattern Mining Algorithms

BACKGROUND

Pattern mining utilizes multiple algorithms to explore objective and sometimes unexpected patterns in real-world data. This technique could be applied to electronic medical record data mining; however, it first requires a careful clinical assessment and validation.

OBJECTIVE

The aim of this study was to examine the use of pattern mining techniques on a large clinical dataset to detect treatment and medication use patterns for childhood pneumonia.

METHODS

We applied 3 pattern mining algorithms to 680,138 medication administration records from 30,512 childhood inpatients with diagnosis of pneumonia during a 6-year period at a children's hospital in China. Patients' ages ranged from 0 to 17 years, where 37.53% (11,453/30,512) were 0 to 3 months old, 86.55% (26,408/30,512) were under 5 years, 60.37% (18,419/30,512) were male, and 60.10% (18,338/30,512) had a hospital stay of 9 to 15 days. We used the FP-Growth, PrefixSpan, and USpan pattern mining algorithms. The first 2 are more traditional methods of pattern mining and mine a complete set of frequent medication use patterns. PrefixSpan also incorporates an administration sequence. The newer USpan method considers medication utility, defined by the dose, frequency, and timing of use of the 652 individual medications in the dataset. Together, these 3 methods identified the top 10 patterns from 6 age groups, forming a total of 180 distinct medication combinations. These medications encompassed the top 40 (73.66%, 500,982/680,138) most frequently used medications. These patterns were then evaluated by subject matter experts to summarize 5 medication use and 2 treatment patterns.

RESULTS

We identified 5 medication use patterns: (1) antiasthmatics and expectorants and corticosteroids, (2) antibiotics and (antiasthmatics or expectorants or corticosteroids), (3) third-generation cephalosporin antibiotics with (or followed by) traditional antibiotics, (4) antibiotics and (medications for enteritis or skin diseases), and (5) (antiasthmatics or expectorants or corticosteroids) and (medications for enteritis or skin diseases). We also identified 2 frequent treatment patterns: (1) 42.89% (291,701/680,138) of specific medication administration records were of intravenous therapy with antibiotics, diluents, and nutritional supplements and (2) 11.53% (78,390/680,138) were of various combinations of inhalation of antiasthmatics, expectorants, or corticosteroids. Fleiss kappa for the subject experts' evaluation was 0.693, indicating moderate agreement.

CONCLUSIONS

Utilizing a pattern mining approach, we summarized 5 medication use patterns and 2 treatment patterns. These warrant further investigation.

Recommendations and guidelines for the treatment of pneumonia in Taiwan

Pneumonia is a leading cause of death worldwide, ranking third both globally and in Taiwan. This guideline was prepared by the 2017 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group, formed under the auspices of the Infectious Diseases Society of Taiwan (IDST). A consensus meeting was held jointly by the IDST, Taiwan Society of Pulmonary and Critical Care Medicine (TSPCCM), the Medical Foundation in Memory of Dr. Deh-Lin Cheng, the Foundation of Professor Wei-Chuan Hsieh for Infectious Diseases Research and Education and CY Lee's Research Foundation for Pediatric Infectious Diseases and Vaccines. The final guideline was endorsed by the IDST and TSPCCM. The major differences between this guideline and the 2007 version include the following: the use of GRADE methodology for the evaluation of available evidence whenever applicable, the specific inclusion of healthcare-associated pneumonia as a category due to the unique medical system in Taiwan and inclusion of recommendations for treatment of pediatric pneumonia. This guideline includes the epidemiology and recommendations of antimicrobial treatment of community-acquired pneumonia, hospital-acquired pneumonia, ventilator-associated pneumonia, healthcare-associated pneumonia in adults and pediatric pneumonia.

Atypical pathogens in hospitalized patients with community-acquired pneumonia: a worldwide perspective

BACKGROUND

Empirical antibiotic coverage for atypical pathogens in community-acquired pneumonia (CAP) has long been debated, mainly because of a lack of epidemiological data. We aimed to assess both testing for atypical pathogens and their prevalence in hospitalized patients with CAP worldwide, especially in relation with disease severity.

METHODS

A secondary analysis of the GLIMP database, an international, multicentre, point-prevalence study of adult patients admitted for CAP in 222 hospitals across 6 continents in 2015, was performed. The study evaluated frequency of testing for atypical pathogens, including L. pneumophila, M. pneumoniae, C. pneumoniae, and their prevalence. Risk factors for testing and prevalence for atypical pathogens were assessed through univariate analysis.

RESULTS

Among 3702 CAP patients 1250 (33.8%) underwent at least one test for atypical pathogens. Testing varies greatly among countries and its frequency was higher in Europe than elsewhere (46.0% vs. 12.7%, respectively, p < 0.0001). Detection of L. pneumophila urinary antigen was the most common test performed worldwide (32.0%). Patients with severe CAP were less likely to be tested for both atypical pathogens considered together (30.5% vs. 35.0%, p = 0.009) and specifically for legionellosis (28.3% vs. 33.5%, p = 0.003) than the rest of the population. Similarly, L. pneumophila testing was lower in ICU patients. At least one atypical pathogen was isolated in 62 patients (4.7%), including M. pneumoniae (26/251 patients, 10.3%), L. pneumophila (30/1186 patients, 2.5%), and C. pneumoniae (8/228 patients, 3.5%). Patients with CAP due to atypical pathogens were significantly younger, showed less cardiovascular, renal, and metabolic comorbidities in comparison to adult patients hospitalized due to non-atypical pathogen CAP.

CONCLUSIONS

Testing for atypical pathogens in patients admitted for CAP in poorly standardized in real life and does not mirror atypical prevalence in different settings. Further evidence on the impact of atypical pathogens, expecially in the low-income countries, is needed to guidelines implementation.

The dilemma of monotherapy or combination therapy in community-acquired pneumonia

SCOPE

To study the factors associated with mortality in hospitalized patients with community-acquired pneumonia treated with monotherapy or combination therapy.

METHODS

PubMed and Scopus were searched. Patients receiving macrolides, β-lactams and fluoroquinolones, as monotherapy or in combination, were included. Meta-analyses and meta-regressions were performed.

RESULTS

Fifty studies were included. Overall, monotherapy was not associated with higher mortality than combination (RR 1.14, 95% CI 0.99-1.32, I² 84%). Monotherapy was associated with higher mortality than combination in North American and retrospective studies. β-lactam monotherapy was associated with higher mortality than β-lactam/macrolide combination in the primary (1.32, 1.12-1.56, I² 85%) and most sensitivity analyses. There was no difference in mortality between fluoroquinolone monotherapy and β-lactam/macrolide combination (0.98, 0.78-1.23, I² 73%). In meta-regressions, the moderators that could partially explain the observed statistical heterogeneity were the frequency of cancer patients (P = .03) and Pneumonia Severity Index score IV (P = .008).

CONCLUSION

Due to the considerable heterogeneity and inclusion of unadjusted data, it is difficult to recommend a specific antibiotic regimen over another. Specific antibiotic regimens, study design and the characteristics of the population under study seem to influence the reported outcomes.

Azithromycin and Doxycycline Attenuation of Acanthamoeba Virulence in a Human Corneal Tissue Model

Background

Amoebic keratitis is a potentially blinding eye infection caused by ubiquitous, free-living, environmental acanthamoebae, which are known to harbor bacterial endosymbionts. A Chlamydia-like endosymbiont has previously enhanced Acanthamoeba virulence in vitro. We investigated the potential effect of Acanthamoeba-endosymbiont coinfection in a human corneal tissue model representing clinical amoebic keratitis infection.

Methods

Environmental and corneal Acanthamoeba isolates from the American Type Culture Collection were screened for endosymbionts by amplifying and sequencing bacterial 16S as well as Chlamydiales-specific DNA. Each Acanthamoeba isolate was used to infect EpiCorneal cells, a 3-dimensional human corneal tissue model. EpiCorneal cells were then treated with azithromycin, doxycycline, or control medium to determine whether antibiotics targeting common classes of bacterial endosymbionts attenuated Acanthamoeba virulence, as indicated by decreased observed cytopathic effect and inflammatory biomarker production.

Results

A novel endosymbiont closely related to Mycobacterium spp. was identified in Acanthamoeba polyphaga 50495. Infection of EpiCorneal cells with Acanthamoeba castellanii 50493 and A. polyphaga 50372 led to increased production of inflammatory cytokines and cytopathic effects visible under microscopy. These increases were attenuated by azithromycin and doxycycline.

Conclusions

Our findings suggest that azithromycin and doxycycline may be effective adjuvants to standard antiacanthamoebal chemotherapy by potentially abrogating virulence-enhancing properties of bacterial endosymbionts.

Atypical pathogen infection in community-acquired pneumonia

Community-acquired pneumonia (CAP) is a world wide cause of morbidity and mortality. The etiology of CAP is different between countries and changes over time. With the increasing incidence, atypical pathogens are attracting more and more attention all over the world. In many countries, atypical pathogens are one of the main pathogens of CAP, and even could be the most prevalent etiology in China. Atypical pathogen infections can cause multi-system complications, which leads to a worse prognosis. Although still controversial, empirical antibiotic coverage of atypical pathogens in CAP may improve outcomes, shorten length of hospitalization, reduce mortality and lower total hospitalization costs. The macrolide resistance rate of atypical pathogens, especially Mycoplasma Pneumoniae (M. Pneumoniae) is high, so fluoroquinolones or tetracyclines should be considered as alternative therapy.

Fluoroquinolones or macrolides alone versus combined with β-lactams for adults with community-acquired pneumonia: Systematic review and meta-analysis

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality. This review compared two of the main treatment alternatives: quinolone or macrolide monotherapy versus their combination with β-lactams. A systematic review and meta-analysis of randomised controlled trials (RCTs) including adult inpatients and outpatients with CAP that compared treatment with any respiratory fluoroquinolone or macrolide administered as single agent with combination therapy of a β-lactam plus either a fluoroquinolone or a macrolide (four separate comparisons) were conducted. The primary outcome was all-cause 30-day mortality. Secondary outcomes included clinical and microbiological failure, treatment discontinuation and adverse events. A comprehensive search was conducted with no date, language or publication status restrictions. Pooled risk ratios (RRs) with 95% confidence intervals are reported. Sixteen RCTs randomising 4809 patients were included. All but one included hospitalised patients. Mortality was low, and no differences between groups were observed in all comparisons. Quinolone monotherapy resulted in significantly less clinical failures [RR=0.72 (0.57-0.91)], treatment discontinuations [RR=0.65 (0.54-0.78)] and diarrhoea [RR=0.13 (0.05-0.34)] compared with β-lactam/macrolide combinations (nine trials). Addition of a β-lactam to quinolones did not improve outcomes (three trials). In all comparisons, treatment discontinuation and diarrhoea were more frequent in patients receiving combination therapy with a β-lactam. Overall, there is no evidence for a benefit of β-lactam/macrolide or β-lactam/quinolone combination therapies over monotherapy with a respiratory fluoroquinolone. The ecological implications of selecting fluoroquinolone or β-lactam monotherapy as the preferred regimen for hospitalised CAP among adults should be further investigated.

Treatment of Chlamydial infections: 2014 update

INTRODUCTION

Chlamydiae are obligate intracellular bacterial pathogens whose entry into mucosal epithelial cells is required for intracellular survival and subsequent growth. The life cycle of Chlamydia spp. and the ability to cause persistent, often subclinical infection, has major ramifications for diagnosis and treatment of Chlamydia trachomatis and C. pneumoniae infections in humans.

AREAS COVERED

This paper reviews the current literature on the antimicrobial susceptibilities and treatment of genital infections due to C. trachomatis and respiratory infections due to C. pneumoniae published since 2011.

EXPERT OPINION

Chlamydiae are susceptible to antibiotics that interfere with DNA and protein synthesis, including tetracyclines, macrolides and quinolones, which are the compounds that have been most extensively studied and used for treatment of human infection. Since our original review was published in 2011, there have been some major advances in diagnostic tests for C. trachomatis and the introduction of the first FDA-approved test for the detection of C. pneumoniae in respiratory samples. However, the options for treating chlamydial infections have largely remained the same. There are a small number of new drugs currently in preclinical development and early clinical trials that may have a role in the treatment of chlamydial infections.

Clinical Efficacy and Safety of a Short Regimen of Azithromycin Sequential Therapy vs Standard Cefuroxime Sequential Therapy in the Treatment of Community-Acquired Pneumonia: An International, Randomized, Open-Label Study

An international, randomized, open-label, comparative study was undertaken in order to assess the efficacy and safety of azithromycin and cefuroxime, short sequential vs standard sequential therapy, respectively, in the treatment of patients with community-acquired pneumonia (CAP). 180 adult patients were included in the study. 89 patients received azithromycin 500 mg intravenously (i.v.) once daily for 1-4 days followed by azithromycin 500 mg orally once daily for 3 days. 91 patients received cefuroxime 1.5 g i.v. three times daily for 1-4 days followed by cefuroxime axetil 500 mg orally twice daily for 7 days. Clinical efficacy was achieved in 67/82 (81.7%) patients treated with azithromycin, and in 73/89 (82.0%) patients treated with cefuroxime. The mean duration of total (i.v. and oral) therapy was significantly shorter for the azithromycin group than for the cefuroxime group (6.2 days vs 10.1 days). Adverse events were recorded in 38.2% of patients treated with azithromycin, and in 29.7% of patients treated with cefuroxime (p = 0.20). Shorter sequential i.v.-to-oral azithromycin therapy of patients with CAP was as effective as standard sequential i.v.-to-oral cefuroxime therapy.

Community-acquired Legionella pneumophila pneumonia: a single-center experience with 214 hospitalized sporadic cases over 15 years

Legionella pneumophila has been increasingly recognized as a cause of community-acquired pneumonia (CAP) and an important public health problem worldwide. We conducted the present study to assess trends in epidemiology, diagnosis, clinical features, treatment, and outcomes of sporadic community-acquired L. pneumophila pneumonia requiring hospitalization at a university hospital over a 15-year period (1995-2010). Among 3934 nonimmunosuppressed hospitalized patients with CAP, 214 (5.4%) had L. pneumophila pneumonia (16 cases were categorized as travel-associated pneumonia, and 21 were part of small clusters). Since the introduction of the urinary antigen test, the diagnosis of L. pneumophila using this method remained stable over the years (p = 0.42); however, diagnosis by means of seroconversion and culture decreased (p < 0.001 and p = 0.001, respectively). The median age of patients with L. pneumophila pneumonia was 58.2 years (SD 13.8), and 76.4% were male. At least 1 comorbid condition was present in 119 (55.6%) patients with L. pneumophila pneumonia, mainly chronic heart disease, diabetes mellitus, and chronic pulmonary disease. The frequency of older patients (aged >65 yr) and comorbidities among patients with L. pneumophila pneumonia increased over the years (p = 0.06 and p = 0.02, respectively). In addition, 100 (46.9%) patients were classified into high-risk classes according to the Pneumonia Severity Index (groups IV-V). Twenty-four (11.2%) patients with L. pneumophila pneumonia received inappropriate empirical antibiotic therapy at hospital admission. Compared with patients who received appropriate empirical antibiotic, patients who received inappropriate therapy more frequently had acute onset of illness (p = 0.004), pleuritic chest pain (p = 0.03), and pleural effusion (p = 0.05). The number of patients who received macrolides decreased over the study period (p < 0.001), whereas the number of patients who received levofloxacin increased (p < 0.001). No significant difference was found in the outcomes between patients who received erythromycin and clarithromycin. However, compared with macrolide use during hospital admission, levofloxacin therapy was associated with a trend toward a shorter time to reach clinical stability (median, 3 vs. 5 d; p = 0.09) and a shorter length of hospital stay (median, 7 vs. 10 d; p < 0.001). Regarding outcomes, 38 (17.8%) patients required intensive care unit (ICU) admission, and the inhospital case-fatality rate was 6.1% (13 of 214 patients). The frequency of ICU admission (p = 0.34) and the need for mechanical ventilation (p = 0.57) remained stable over the study period, but the inhospital case-fatality rate decreased (p = 0.04). In the logistic regression analysis, independent factors associated with severe disease (ICU admission and death) were current/former smoker (odds ratio [OR], 2.96; 95% confidence interval [CI], 1.01-8.62), macrolide use (OR, 2.40; 95% CI, 1.03-5.56), initial inappropriate therapy (OR, 2.97; 95% CI, 1.01-8.74), and high-risk Pneumonia Severity Index classes (OR, 9.1; 95% CI, 3.52-23.4). In conclusion, L. pneumophila is a relatively frequent causative pathogen among hospitalized patients with CAP and is associated with high morbidity. The annual number of L. pneumophila cases remained stable over the study period. In recent years, there have been significant changes in diagnosis and treatment, and the inhospital case-fatality rate of L. pneumophila pneumonia has decreased.

Chronic Lyme Disease and Co-infections: Differential Diagnosis

In Lyme disease concurrent infections frequently occur. The clinical and pathological impact of co-infections was first recognized in the 1990th, i.e. approximately ten years after the discovery of Lyme disease. Their pathological synergism can exacerbate Lyme disease or induce similar disease manifestations. Co-infecting agents can be transmitted together with Borrelia burgdorferi by tick bite resulting in multiple infections but a fraction of co-infections occur independently of tick bite. Clinically relevant co-infections are caused by Bartonella species, Yersinia enterocolitica, Chlamydophila pneumoniae, Chlamydia trachomatis, and Mycoplasma pneumoniae. In contrast to the USA, human granulocytic anaplasmosis (HGA) and babesiosis are not of major importance in Europe. Infections caused by these pathogens in patients not infected by Borrelia burgdorferi can result in clinical symptoms similar to those occurring in Lyme disease. This applies particularly to infections caused by Bartonella henselae, Yersinia enterocolitica, and Mycoplasma pneumoniae. Chlamydia trachomatis primarily causes polyarthritis. Chlamydophila pneumoniae not only causes arthritis but also affects the nervous system and the heart, which renders the differential diagnosis difficult. The diagnosis is even more complex when co-infections occur in association with Lyme disease. Treatment recommendations are based on individual expert opinions. In antibiotic therapy, the use of third generation cephalosporins should only be considered in cases of Lyme disease. The same applies to carbapenems, which however are used occasionally in infections caused by Yersinia enterocolitica. For the remaining infections predominantly tetracyclines and macrolides are used. Quinolones are for alternative treatment, particularly gemifloxacin. For Bartonella henselae, Chlamydia trachomatis, and Chlamydophila pneumoniae the combination with rifampicin is recommended. Erythromycin is the drug of choice for Campylobacter jejuni.

Legionnaires’ Disease

Infection with Legionella spp. is an important cause of serious community- and hospital-acquired pneumonia, occurring sporadically and in outbreaks. Outbreaks of Legionnaires' disease have recently received considerable media attention, and some factors indicate that the problem will increase in future. Infection with Legionella spp. ranks among the three most common causes of severe pneumonia in the community setting, and is isolated in 1-40% of cases of hospital-acquired pneumonia. Underdiagnosis and underreporting are high. Only 2-10% of estimated cases are reported. Detection of a single case should not be considered an isolated sporadic event, but rather indicative of unrecognized cases. There are no clinical features unique to Legionnaires' disease; however, suspicion should be raised by epidemiologic information commensurate with the diagnosis and the presence of headache, confusion, hyponatremia, elevated creatine kinase and/or severe pneumonia. An arterial oxygen partial pressure <60mm Hg on presentation and progression of pulmonary infiltrates despite appropriate antibacterial therapy should always alert clinicians to this cause.Macrolides, fluoroquinolones and rifampin (rifampicin) are the most widely used drugs in treatment. Fluoroquinolones or azithromycin are the treatment of choice in immunosuppressed patients and those with severe pneumonia. Incorporation of the legionella urinary antigen test in emergency departments in hospitals and progressive improvement in this test will, in the near future, permit appropriate diagnosis and treatment of this frequent, sometimes severe, illness.

Community-acquired Legionella Pneumonia in the intensive care unit: Impact on survival of combined antibiotic therapy

OBJECTIVES

To compare intensive care unit (ICU) mortality in patients with severe community-acquired pneumonia (SCAP) caused by Legionella pneumophila receiving combined therapy or monotherapy.

METHODS

A prospective multicenter study was made, including all patients with sporadic, community-acquired Legionnaires' disease (LD) admitted to the ICU. Admission data and information on the course of the disease were recorded. Antibiotic prescriptions were left to the discretion of the attending physician and were not standardized.

RESULTS

Twenty-five cases of SCAP due to L. pneumophila were included, and 7 patients (28%) out of 25 died after a median of 7 days of mechanical ventilation. Fifteen patients (60%) presented shock. Levofloxacin and clarithromycin were the antibiotics most commonly used in monotherapy, while the most frequent combination was rifampicin plus clarithromycin. Patients subjected to combination therapy presented a lower mortality rate versus patients subjected to monotherapy (odds ratio for death [OR] 0.15; 95%CI 0.02-1.04; p=0.08). In patients with shock, this association was stronger and proved statistically significant (OR for death 0.06; 95%CI 0.004-0.86; p=0.04).

CONCLUSIONS

Combined antibiotic therapy decreases mortality in patients with SCAP and shock caused by L. pneumophila.

[Cytomegalovirus. Pathological-anatomical manifestations and detection methods]

Human cytomegalovirus, a double-stranded DNA virus, is a member of the Herpesviridae family with high rates of transmission. Primary infection is often asymptomatic and leads to life-long latency. Reactivation may induce different organ manifestations, particularly in the setting of immunosuppression. Histopathologically, the virus can be detected by light microscopy. Different cell populations in different organs are transformed into"owl's eye" cells, which are pathognomonic. Immunohistochemistry and electron microscopy can be applied as complementary methods. Various PCR approaches in molecular pathology including nested PCR, capture probe ELISA-PCR and real time PCR confer HCMV tests high sensitivity and specificity. The present article discusses the methods of pathological diagnostic approaches and describes organ manifestations of HCMV.

Treatment of chlamydial infections

INTRODUCTION

Chlamydiae are obligate intracellular bacterial pathogens whose entry into mucosal epithelial cells is required for intracellular survival and subsequent growth. The life cycle of Chlamydia spp. and the ability to cause persistent, often subclinical infection, has major ramifications for diagnosis and treatment of C. trachomatis and C. pneumoniae infections in humans.

AREAS COVERED

This up-to-date review describes the current state of knowledge of antimicrobial susceptibilities and treatment of genital infections due to C. trachomatis and respiratory infections due to C. pneumoniae.

EXPERT OPINION

Chlamydiae are susceptible to antibiotics that interfere with DNA and protein synthesis, including tetracyclines, macrolides and quinolones, which are the compounds that have been most extensively studied and used for treatment of human infection. Treatment of individuals with C. trachomatis genital infection prevents sexual transmission and complications, including pelvic inflammatory disease. Treatment of pregnant women will prevent the transmission of infection to infants during delivery. The benefits of treatment of respiratory infections due to C. pneumoniae are more difficult to assess, primarily because of the lack of FDA-approved, specific diagnostic tests for detection of the organism in clinical samples. The majority of published studies have relied on serology for diagnosis, making it difficult to assess microbiologic efficacy.

Elderly patients with community-acquired pneumonia: optimal treatment strategies

Community-acquired pneumonia (CAP) is a common infectious disease that still causes substantial morbidity and mortality. Elderly people are frequently affected, and several issues related to care of this condition in the elderly have to be considered. This article reviews current recommendations of guidelines with a special focus on aspects of the care of elderly patients with CAP. The most common pathogen in CAP is still Streptococcus pneumoniae, followed by other pathogens such as Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella species. Antimicrobial resistance is an increasing problem, especially with regard to macrolide-resistant S. pneumoniae and fluoroquinolone-resistant strains. With regard to β-lactam antibacterials, resistance by H. influenzae and Moraxella catarrhalis is important, as is the emergence of multidrug-resistant Staphylococcus aureus. The main management decisions should be guided by the severity of disease, which can be assessed by validated clinical risk scores such as CURB-65, a tool for measuring the severity of pneumonia based on assessment of confusion, serum urea, respiratory rate and blood pressure in patients aged ≥65 years. For the treatment of low-risk pneumonia, an aminopenicillin such as amoxicillin with or without a β-lactamase inhibitor is frequently recommended. Monotherapy with macrolides is also possible, although macrolide resistance is of concern. When predisposing factors for special pathogens are present, a β-lactam antibacterial combined with a β-lactamase inhibitor, or the combination of a β-lactam antibacterial, a β-lactamase inhibitor and a macrolide, may be warranted. If possible, patients who have undergone previous antibacterial therapy should receive drug classes not previously used. For hospitalized patients with non-severe pneumonia, a common recommendation is empirical antibacterial therapy with an aminopenicillin in combination with a β-lactamase inhibitor, or with fluoroquinolone monotherapy. With proven Legionella pneumonia, a combination of β-lactams with a fluoroquinolone or a macrolide is beneficial. In severe pneumonia, ureidopenicillins with β-lactamase inhibitors, broad-spectrum cephalosporins, macrolides and fluoroquinolones are used. A combination of a broad-spectrum β-lactam antibacterial (e.g. cefotaxime or ceftriaxone), piperacillin/tazobactam and a macrolide is mostly recommended. In patients with a predisposition for Pseudomonas aeruginosa, a combination of piperacillin/tazobactam, cefepime, imipenem or meropenem and levofloxacin or ciprofloxacin is frequently used. Treatment duration of more than 7 days is not generally recommended, except for proven infections with P. aeruginosa, for which 15 days of treatment appears to be appropriate. Further care issues in all hospitalized patients are timely administration of antibacterials, oxygen supply in case of hypoxaemia, and fluid management and dose adjustments according to kidney function. The management of elderly patients with CAP is a challenge. Shifts in antimicrobial resistance and the availability of new antibacterials will change future clinical practice. Studies investigating new methods to detect pathogens, determine the optimal antimicrobial regimen and clarify the duration of treatment may assist in further optimizing the management of elderly patients with CAP.

Macrolides: A Canadian Infectious Disease Society position paper

Since the introduction of erythromycin in 1965, no new compounds from the macrolide antimicrobial class were licensed in Canada until the 1990s. Clarithromycin and azithromycin, since their introduction, have become important agents for treating a number of common and uncommon infectious diseases. They have become prime agents in the treatment of respiratory tract infections, and have revolutionized the management of both genital chlamydial infections, by the use of single-dose therapy with azithromycin, and nontuberculous mycobacterial infections, by the use of clarithromycin. The improvement of clarithromycin and azithromycin over the gastrointestinal intolerability of erythromycin has led to supplanting the use of the latter for many primary care physicians. Unfortunately, the use of these agents has also increased the likelihood for misuse and has raised concerns about a resultant increase in the rates of macrolide resistance in many important pathogens, such as Streptococcus pneumoniae. This paper reviews the pharmacology and evidence for the current indications for use of these newer agents, and provides recommendations for appropriate use.

Review of macrolides (azithromycin, clarithromycin), ketolids (telithromycin) and glycylcyclines (tigecycline)

The advanced macrolides, azithromycin and clarithromycin, and the ketolide, telithromycin, are structural analogs of erythromycin. They have several distinct advantages when compared with erythromycin, including enhanced spectrum of activity, more favorable pharmacokinetics and pharmacodynamics, once-daily administration, and improved tolerability. Clarithromycin and azithromycin are used extensively for the treatment of respiratory tract infections, sexually transmitted diseases, and Helicobacter pylori-associated peptic ulcer disease. Telithromycin is approved for the treatment of community-acquired pneumonia. Severe hepatotoxicity has been reported with the use of telithromycin.

Isolation, identification of Streptococcus pneumoniae from infected rhesus monkeys and control efficacy

BACKGROUND

Streptococcus pneumoniae can cause a wide variety of illnesses. Primate animals can be infected by the pneumococcus. A disease occurred among rhesus monkeys in winter 2006.

METHODS

Routine clinical observation, necropsies, bacteriological examinations were conducted, and PCR, pathogenicity to BALB/c mice and antibiotic susceptibility test were examined additionally.

RESULTS

We conclude that the agent is S. pneumoniae. Based on the antibiotic susceptibility test, a dose of 20 mg/kg body weight daily of Erythromycin was given intramuscular injection for 5 days, resulting in the disappearance of clinical signs, and no newly case reappear be observed till today.

CONCLUSIONS

Therefore, it is suggested that the outbreak of respiratory disease in the rhesus monkeys was because of transmission of S. pneumoniae among rhesus monkeys. The antibiotic therapy finding underscores the utility of Erythromycin to cure the infected rhesus monkeys without causing side effects and without contributing to the further development of antibiotic resistance.

Respiratory infections due to drug-resistant bacteria

Pneumonia is the most common infection that is the leading cause of death. The increasing antimicrobial resistance in major respiratory pathogens such as Streptococcus pneumoniae, Staphylococcus aureus and gram-negative bacteria has severely restricted the treatment options. Respiratory infections caused by multidrug-resistant bacteria are associated with a greater likelihood of inappropriate antimicrobial therapy and poor clinical outcome. Especially, treatment of infections caused by pandrug-resistant gram-negative bacteria is a major challenge. Continuous efforts to control the global spread of drug-resistant bacteria are essential.

Clinical features and predictors of mortality in admitted patients with community- and hospital-acquired legionellosis: a Danish historical cohort study

Background

Legionella is a common cause of bacterial pneumonia. Community-acquired [CAL] and hospital-acquired legionellosis [HAL] may have different presentations and outcome. We aimed to compare clinical characteristics and examine predictors of mortality for CAL and HAL.

Methods

We identified hospitalized cases of legionellosis in 4 Danish counties from January 1995 to December 2005 using the Danish national surveillance system and databases at departments of clinical microbiology. Clinical and laboratory data were retrieved from medical records; vital status was obtained from the Danish Civil Registration System. We calculated 30- and 90-day case fatality rates and identified independent predictors of mortality using logistic regression analyses.

Results

We included 272 cases of CAL and 60 cases of HAL. Signs and symptoms of HAL were less pronounced than for CAL and time from in-hospital symptoms to legionellosis diagnosis was shorter for CAL than for HAL (5.5 days vs. 12 days p < 0.001). Thirty-day case fatality was 12.9% for CAL and 33.3% for HAL; similarly 90-day case fatalities in the two groups were 15.8% and 55.0%, respectively. In a logistic regression analysis (excluding symptoms and laboratory tests) age >65 years (OR = 2.6, 95% CI: 1.1-5.9) and Charlson comorbidty index ≥2 (OR = 2.7, 95% CI: 1.1-6.5) were associated with an increased risk of death in CAL. We identified no statistically significant predictors of 30-day mortality in HAL.

Conclusions

Signs and symptoms were less pronounced in HAL compared to CAL. Conversely, 30-day case fatality was almost 3 times higher. Clinical awareness is important for the timely diagnosis and treatment especially of HAL. There is a need for further studies of prognostic factors in order to improve the therapeutic approach to legionellosis and potentially reduce mortality.

Brazilian guidelines for community-acquired pneumonia in immunocompetent adults - 2009

Community-acquired pneumonia continues to be the acute infectious disease that has the greatest medical and social impact regarding morbidity and treatment costs. Children and the elderly are more susceptible to severe complications, thereby justifying the fact that the prevention measures adopted have focused on these age brackets. Despite the advances in the knowledge of etiology and physiopathology, as well as the improvement in preliminary clinical and therapeutic methods, various questions merit further investigation. This is due to the clinical, social, demographical and structural diversity, which cannot be fully predicted. Consequently, guidelines are published in order to compile the most recent knowledge in a systematic way and to promote the rational use of that knowledge in medical practice. Therefore, guidelines are not a rigid set of rules that must be followed, but first and foremost a tool to be used in a critical way, bearing in mind the variability of biological and human responses within their individual and social contexts. This document represents the conclusion of a detailed discussion among the members of the Scientific Board and Respiratory Infection Committee of the Brazilian Thoracic Association. The objective of the work group was to present relevant topics in order to update the previous guidelines. We attempted to avoid the repetition of consensual concepts. The principal objective of creating this document was to present a compilation of the recent advances published in the literature and, consequently, to contribute to improving the quality of the medical care provided to immunocompetent adult patients with community-acquired pneumonia.

Macrolides, ketolides, and glycylcyclines: azithromycin, clarithromycin, telithromycin, tigecycline

The advanced macrolides, azithromycin and clarithromycin, and the ketolide, telithromycin, are structural analogs of erythromycin. They have several distinct advantages when compared with erythromycin, including enhanced spectrum of activity, more favorable pharmacokinetics and pharmacodynamics, once-daily administration, and improved tolerability. Clarithromycin and azithromycin are used extensively for the treatment of respiratory tract infections, sexually transmitted diseases, and Helicobacter pylori-associated peptic ulcer disease. Telithromycin is approved for the treatment of community-acquired pneumonia. Severe hepatotoxicity has been reported with the use of telithromycin.

[Low mortality rate in an outbreak of Legionnaires' disease: correlation with the cytopathogenity study]

BACKGROUND

In 2001 an outbreak of Legionnaires' diseases occurred in Murcia, Spain, with one of the lowest known rates of associated mortality. We describe the clinical data of a subgroup of patients, and present the results from molecular and virulence studies to correlate the lower mortality of the overall series with the strain virulence.

PATIENTS AND METHODS

A subgroup of 86 patients from the outbreak of Legionnaires'disease was prospectively included. Demographic, risk factors and clinical evolution data were obtained. Moreover, we performed a pulsed field gel electrophoresis and cytopathogenicity assay of the Murcia outbreak that were compared with other unrelated Legionella isolates.

RESULTS

Sixty-nine (77.9%) patients were males. The mean age of the patients was 58.2 years (range: 32-87). Smoking was the most frequent risk factor in 62 patients (71.7%) and 61 patients (70.2%) had underlying diseases. Clinical, laboratory and radiological manifestations were compatible with the atypical pneumonia syndrome. The mortality rate was 3.2%. All the clinical L. pneumophila isolates analyzed by PFGE showed the same subtype. When analyzing theses strains together with other Legionella strains, they were included in the group with lower virulence in the cytopathogenicity study.

CONCLUSIONS

The most outstanding data in this subgroup of patients were: male-sex, smoking, atypical clinical manifestations and low mortality. The low virulence of this molecular genotype of L. pneumophila may be responsible, in part, for the low mortality observed in the outbreak in Murcia.

Treatment strategies for Legionella infection

Given the nonspecific clinical manifestations of Legionnaires' disease and the high mortality of untreated Legionnaires' disease, we recommend routine use of Legionella testing, especially the Legionella urinary antigen test, for all patients with community-acquired pneumonia. This includes patients with ambulatory pneumonia and hospitalized children. Legionella cultures should be more widely available, especially in hospitals where the drinking water is colonized with Legionella. Azithromycin or levofloxacin can be considered as first-line therapy. Other antibiotics including tetracyclines, tigecycline, other fluoroquinolones and other macrolides (especially clarithromycin) are also effective. The clinical response of quinolones may be somewhat more favorable compared to macrolides, but the outcome is similar. If the Legionnaires' disease is hospital-acquired, culturing of the hospital drinking water for Legionella is indicated.

Pneumonia estafilocócica adquirida na comunidade

OBJETIVO: A pneumonia estafilocócica geralmente apresenta uma elevada taxa de morbidade e mortalidade. Normalmente ocorre em infecções por influenza (via aerógena) ou durante episódios de bacteremia (via hematogênica). MÉTODOS: Um estudo retrospectivo e descritivo foi realizado com os pacientes que foram admitidos em nosso hospital entre janeiro de 1992 e dezembro de 2003 com diagnóstico de pneumonia adquirida na comunidade causada por Staphylococcus aureus. Todos eles eram maiores de 14 anos e não usuários de drogas endovenosas. RESULTADOS: De um total de 332 casos de pneumonia adquirida na comunidade, foram encontrados 24 pacientes (7,3%) com pneumonia estafilocócica. A idade mínima e máxima eram de, respectivamente, 14 anos e 89 anos. Quinze pacientes eram homens e nove eram mulheres. Doze pacientes preenchiam critérios para pneumonia grave. O radiograma de tórax evidenciou consolidação unilateral em 14 casos, bilateral em 10, derrame pleural em 15, rápida progressão radiológica das lesões pulmonares em 14, presença de cavitação em 6 e pneumotórax em 1 paciente. A maioria dos pacientes apresentou co-morbidades e diabetes mellitus foi a mais freqüente. Doze pacientes apresentaram complicações como empiema e choque séptico. Houve quatro óbitos, o que representou 16,6% da amostra. CONCLUSÕES: A apresentação clínica da pneumonia causada por S. aureus é similar à apresentação das pneumonias originadas por outros agentes etiológicos. Os achados radiológicos, os dados epidemiológicos e os fatores de risco fornecem importantes indícios para o diagnóstico. Estes fatores são importantes para uma suspeição clínica, já que o S. aureus normalmente não é incluído nos tratamentos empíricos.

Sequential therapy with cefuroxime and cefuroxime-axetil for community-acquired lower respiratory tract infection in the oldest old

BACKGROUND AND AIMS

Community acquired lower respiratory tract infection (CALRTI) is the most common infection requiring hospitalization in the elderly. Sequential antibiotic therapy offers the potential for earlier functional rehabilitation, shorter length of hospital stay and lower costs. We studied the efficacy and safety of an empiric sequential antibiotic therapy with cefuroxime-cefuroxime axetil in elderly patients hospitalized with a CALRTI.

METHODS

A prospective, randomized, open-label, in-hospital study of cefuroxime IV 750 mg tid for 10 days (IV group) vs cefuroxime 750 mg IV tid for 3 days, followed by cefuroxime-axetil PO 500 mg bid for 7 days (sequence group), when clinical (symptoms improved and fever disappeared) and/or laboratory response [decrease in C-reactive protein (CRP)] occurred.

RESULTS

A total of 142 patients, 71 (mean age: 83.3 (+/-6 SD), M/F ratio: 1.1) in the IV group, and 71 (mean age: 81.5 (+/-7 SD), M/F ratio: 1.5) in the sequence group, were included in the study. Eighty-three (58.4%) presented with radiologically confirmed pneumonia (CAP) and 59 (41.6%) with non-pneumonic LRTI (NPLRTI) (p=ns between study groups). Treatment was considered effective in 84.5% (60/71) of patients in the IV group and 80.3% (57/71) in the sequence group (p=ns). Therapy failed in 15% (21/142) of the study population (p=ns between study groups) and, after day 3 of therapy, 8.45% (6/71) failed in both study groups. By the end of treatment, two patients had died in each study group, and total in-hospital mortality was 8.5% (12/142, p=ns between study groups). The length of hospital stay (LOS) did not differ between the two study groups.

CONCLUSIONS

When a favorable clinical or biochemical response occurs on day 3 of IV cefuroxime therapy, further therapy with oral cefuroxime-axetil is as effective and safe as a full course of cefuroxime IV in elderly patients hospitalized with CALRTI. However, LOS was not reduced after sequential antibiotic therapy in this population.

Development of real-time multiplex nucleic acid sequence-based amplification for detection of Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella spp. in respiratory specimens

Real-time multiplex isothermal nucleic acid sequence-based amplification (NASBA) was developed to detect Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella spp. in respiratory specimens using the NucliSens Basic Kit (bioMérieux, Boxtel, The Netherlands). Oligonucleotide primers were derived from the M. pneumoniae, C. pneumoniae, and Legionella pneumophila 16S rRNA. For real-time detection, molecular beacons were used. Specificity was established on a panel of bacterial strains. The analytical sensitivity of the assay was determined by testing dilutions of wild-type in vitro-generated RNA in water and dilutions of reference strains in lysis buffer or added to pools of respiratory specimens. Subsequently, a limited number of M. pneumoniae-, C. pneumoniae-, and L. pneumophila-positive and -negative clinical specimens were analyzed. Specific detection of the 16S rRNA of the three organisms was achieved. The analytical sensitivity of the multiplex NASBA on spiked respiratory specimens was slightly diminished compared to the results obtained with the single-target (mono) real-time assays. We conclude that the proposed real-time multiplex NASBA assay, although less sensitive than the real-time mono NASBA assay, is a promising tool for the detection of M. pneumoniae, C. pneumoniae, and Legionella spp. in respiratory specimens, regarding handling, speed, and number of samples that can be analyzed in a single run.

Combination antibiotic therapy improves survival in patients with community-acquired pneumonia and shock*

OBJECTIVE

To assess whether combination antibiotic therapy improves outcome of severe community-acquired pneumonia in the subset of patients with shock.

DESIGN

Secondary analysis of a prospective observational, cohort study.

SETTING

Thirty-three intensive care units (ICUs) in Spain.

PATIENTS

Patients were 529 adults with community-acquired pneumonia requiring ICU admission.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Two hundred and seventy (51%) patients required vasoactive drugs and were categorized as having shock. The effects of combination antibiotic therapy and monotherapy on survival were compared using univariate analysis and a Cox regression model. The adjusted 28-day in-ICU mortality was similar (p = .99) for combination antibiotic therapy and monotherapy in the absence of shock. However, in patients with shock, combination antibiotic therapy was associated with significantly higher adjusted 28-day in-ICU survival (hazard ratio, 1.69; 95% confidence interval, 1.09-2.60; p = .01) in a Cox hazard regression model. Even when monotherapy was appropriate, it achieved a lower 28-day in-ICU survival than an adequate antibiotic combination (hazard ratio, 1.64; 95% confidence interval, 1.01-2.64).

CONCLUSIONS

Combination antibiotic therapy does not seem to increase ICU survival in all patients with severe community-acquired pneumonia. However, in the subset of patients with shock, combination antibiotic therapy improves survival rates.

Clinical and bacteriological outcomes in hospitalised patients with community-acquired pneumonia treated with azithromycin plus ceftriaxone, or ceftriaxone plus clarithromycin or erythromycin: a prospective, randomised, multicentre study

This study compared patients with moderate-to-severe community-acquired pneumonia (CAP) requiring hospitalisation, who received initial therapy with either intravenous ceftriaxone plus intravenous azithromycin, followed by step-down to oral azithromycin (n = 135), with patients who received intravenous ceftriaxone combined with either intravenous clarithromycin or erythromycin, followed by step-down to either oral clarithromycin or erythromycin (n = 143). Clinical and bacteriological outcomes were evaluated at the end of therapy (EOT; day 12-16) or at the end of study (EOS; day 28-35). At baseline, mean APACHE II scores were 13.3 and 12.6, respectively, with >50% of patients classified as Fine Pneumonia Severity Index (PSI) category IV or V. Clinical success rates (cure or improvement) in the modified intent-to-treat (MITT) population at EOT were 84.3% in the ceftriaxone/azithromycin group and 82.7% in the ceftriaxone/clarithromycin or erythromycin group. At EOS, MITT success rates (cure only) were 81.7% and 75.0%, respectively. Equivalent success rates in the clinically evaluable population were 83% and 87%, respectively, at EOT, and 79% and 78%, respectively, at EOS. MITT bacteriological eradication rates were 73.2% and 67.4%, respectively, at EOT, and 68.3% vs. 60.9%, respectively, at EOS. Mean length of hospital stay (LOS) was 10.7 and 12.6 days, and the mean duration of therapy was 9.5 and 10.5 days, respectively. The incidence of infusion-related adverse events was 16.3% and 25.2% (p 0.04), respectively. An intravenous-to-oral regimen of ceftriaxone/azithromycin was at least equivalent in efficacy and safety to the comparator regimen and appeared to be a suitable treatment option for hospitalised patients with CAP.

Antibiotics for Bacteremic Pneumonia

BACKGROUND

The questions of whether the use of antibiotics that are active against atypical organisms is beneficial in the treatment of community-acquired pneumonia and of the potential mechanisms of any beneficial effects remain unresolved. Proposed mechanisms include activity against atypical organisms vs the immunomodulatory effects of these antibiotics. The study of outcomes of a large cohort of patients with bacteremic pneumonia provides a unique opportunity to address these questions by excluding patients with primary atypical infection.

METHODS

We reviewed data from the charts of 2,209 Medicare patients who were admitted to hospitals across the United States from either home or a nursing facility with bacteremic pneumonia between 1998 and 2001. Patients were stratified according to the type of antibiotic treatment. Multivariate modeling was performed to assess the relationship between the class of antibiotic used and several outcome variables.

RESULTS

The initial use of any antibiotic active against atypical organisms was independently associated with a decreased risk of 30-day mortality (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.59 to 0.98; p = 0.03) and hospital admission within 30 days of discharge (OR, 0.67; 95% CI, 0.51 to 0.89; p = 0.02). Further analysis revealed that the benefits of atypical treatment were associated with the use of macrolides, but not the use of fluoroquinolones or tetracyclines, with macrolides conferring lower risks of in-hospital mortality (OR, 0.59; 95% CI, 0.40 to 0.88; p = 0.01), 30-day mortality (OR, 0.61; 95% CI, 0.43 to 0.87; p = 0.007), and hospital readmission within 30 days of discharge (OR, 0.59; 95% CI, 0.42 to 0.85; p = 0.004).

CONCLUSIONS

Initial antibiotic treatment including a macrolide agent is associated with improved outcomes in Medicare patients hospitalized with bacteremic pneumonia. These results have implications regarding the mechanism by which the use of a macrolide for treatment of pneumonia is associated with improved outcomes.

Legionnaires’ Disease

The incidence of legionnaires’ disease (LD) seems to increase with age, particularly in males [36]. It was considered an infrequent cause of pneumonia in the past, but it currently ranks second to pneumococcus in the list of etiologic agents of severe community-acquired pneumonia (CAP) of bacterial origin [2, 24, 60, 89]. Considering less severe cases, in a series of 145 pneumonias in which BCYE culture, serology and the Legionella urinary antigen (LUA) test were systematically applied, Vergis et al. [91] reported a prevalence of LD of 13.7%. In another series of 392 adult patients with CAP treated in a university hospital, Sopena et al. found a prevalence of 12.5%, and LD was the second cause of pneumonia [83].