Epidemiologie und Erreger bei ambulant erworbener Pneumonie (CAP)

[Community-acquired pneumonia]

Community-acquired pneumonia (CAP) is a frequent and potentially fatal disorder. Due to the notably high mortality within the first days, the immediate initiation of rational diagnostic pathways and treatment is of tremendous prognostic impact. In this review article, the current German guideline on the diagnosis and therapy of CAP is presented. Special focus is put on structured patient management based on the individual risk for early identification of critically ill patients. In particular, risk assessment directly influences rational diagnostics and adequate therapy. New recommendations concerning preventive strategies are also discussed in this article.

Pneumonia in the Noninstitutionalized Older Population

BACKGROUND

Pneumonia is a common and potentially serious disease, with an incidence of ca. 300 per 100 000 persons per year. Until now, there have been only a few population-based studies of risk factors for pneumonia.

METHODS

From 2000 to 2002, nearly 10 000 persons aged 50 to 75 were recruited into the prospective ESTHER cohort study while visiting their family physician for a check-up. The mean duration of follow-up was 10.6 years. Data on newly diagnosed pneumonia were acquired from the participants and their physicians by means of standardized questionnaires. Potential associations with various predictors were studied in survival-time regression models.

RESULTS

435 participants had pneumonia at least once during follow-up. The cumulative 10-year-incidence was 4.5% (95% confidence interval [4.0; 4.9]). Multiple regression revealed that age (relative risk [RR]: 1.43 [1.22; 1.67] per 10 years), current cigarette smoking (RR: 1.56 [1.19; 2.05], compared with never having smoked), and known congestive heart failure (RR: 1.65 [1.24; 2.20]) were independently associated with an elevated risk of pneumonia. The risk was insignificantly elevated in persons with diabetes mellitus (RR: 1.29 [0.98; 1.68]). Alcohol consumption, obesity, stroke, and cancer were not associated with an elevated risk of pneumonia in age- and sex-adjusted analyses.

CONCLUSION

Pneumonia plays an important role in the medical care of non-institutionalized older people. With the aid of the predictors identified in this study, primary care physicians can identify patients at risk, smokers can gain additional motivation to quit, treatment compliance can be increased, and patients may become more willing to be vaccinated as recommended in the current guidelines.

Community-Acquired Pneumonia in Adults

BACKGROUND

The clinical spectrum of community-acquired pneumonia ranges from infections that can be treated on an outpatient basis, with 1% mortality, to those that present as medical emergencies, with a mortality above 40%.

METHODS

This article is based on pertinent publications and current guidelines retrieved by a selective search of the literature.

RESULTS

The radiological demonstration of an infiltrate is required for the differentiation of pneumonia from acute bronchitis regardless of whether the patient is seen in the outpatient setting or in the emergency room. For risk prediction, it is recommended that the CRB-65 criteria, unstable comorbidities, and oxygenation should be taken into account. Amoxicillin is the drug of choice for mild pneumonia; it should be given in combination with clavulanic acid if there are any comorbid illnesses. The main clinical concerns in the emergency room are the identification of acute organ dysfunction and the management of sepsis. Intravenous beta-lactam antibiotics should be given initially, in combination with a macrolide if acute organ dysfunction is present. The treatment should be continued for 5-7 days. Cardiovascular complications worsen the patient's prognosis and should be meticulously watched for. Structured followup care includes the follow-up of comorbid conditions and the initiation of recommended preventive measures such as antipneumococcal and anti-influenza vaccination, the avoidance of drugs that increase the risk, smoking cessation, and treatment of dysphagia, if present.

CONCLUSION

Major considerations include appropriate risk stratification and the implementation of a management strategy adapted to the degree of severity of the disease, along with the establishment of structured follow-up care and secondary prevention, especially for patients with comorbidities.

Spectrum of pathogen- and model-specific histopathologies in mouse models of acute pneumonia

Pneumonia may be caused by a wide range of pathogens and is considered the most common infectious cause of death in humans. Murine acute lung infection models mirror human pathologies in many aspects and contribute to our understanding of the disease and the development of novel treatment strategies. Despite progress in other fields of tissue imaging, histopathology remains the most conclusive and practical read out tool for the descriptive and semiquantitative evaluation of mouse pneumonia and therapeutic interventions. Here, we systematically describe and compare the distinctive histopathological features of established models of acute pneumonia in mice induced by Streptococcus (S.) pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Legionella pneumophila, Escherichia coli, Middle East respiratory syndrome (MERS) coronavirus, influenza A virus (IAV) and superinfection of IAV-incuced pneumonia with S. pneumoniae. Systematic comparisons of the models revealed striking differences in the distribution of lesions, the characteristics of pneumonia induced, principal inflammatory cell types, lesions in adjacent tissues, and the detectability of the pathogens in histological sections. We therefore identified core criteria for each model suitable for practical semiquantitative scoring systems that take into account the pathogen- and model-specific patterns of pneumonia. Other critical factors that affect experimental pathologies are discussed, including infectious dose, time kinetics, and the genetic background of the mouse strain. The substantial differences between the model-specific pathologies underscore the necessity of pathogen- and model-adapted criteria for the comparative quantification of experimental outcomes. These criteria also allow for the standardized validation and comparison of treatment strategies in preclinical models.

Simkania negevensis, an insight into the biology and clinical importance of a novel member of the Chlamydiales order

Simkania negevensis is a Chlamydia-related bacterium discovered in 1993 and represents the founding member of the Simkaniaceae family within the Chlamydiales order. As other Chlamydiales, it is an obligate intracellular bacterium characterized by a biphasic developmental cycle. Its similarities with the pathogenic Chlamydia trachomatis and Chlamydia pneumoniae make it an interesting bacterium. So far, little is known about its biology, but S. negevensis harbors various microbiological characteristics of interest, including a strong association of the Simkania-containing vacuole with the ER and the presence of an intron in the 23S rRNA encoding gene. Evidence of human exposition has been reported worldwide. However, there is a lack of robust clinical studies evaluating its implication in human diseases; current data suggest an association with pneumonia and bronchiolitis making S. negevensis a potential emerging pathogen. Owing to its fastidious growth requirements, the clinical relevance of S. negevensis is probably underestimated. In this review, we summarize the current knowledge on S. negevensis and explore future research challenges.

Characteristics and management of patients with influenza in a German hospital during the 2014/2015 influenza season

The objective of this study was to review the management of patients with influenza during the influenza season 2014/2015 (n = 197). Our study revealed a high rate of healthcare-associated influenza infection (35.5 %) and a correlation between the total number of patients with HA influenza and the number of nurses on sick leave. The results of the study underline the importance of strict hygiene management. Furthermore, widespread influenza vaccination for both high-risk patients and health care workers is recommended.

Community-acquired pneumonia related to intracellular pathogens

Community-acquired pneumonia (CAP) is associated with high rates of morbidity and mortality worldwide; the annual incidence of CAP among adults in Europe has ranged from 1.5 to 1.7 per 1000 population. Intracellular bacteria are common causes of CAP. However, there is considerable variation in the reported incidence between countries and change over time. The intracellular pathogens that are well established as causes of pneumonia are Legionella pneumophila, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Chlamydophila psittaci, and Coxiella burnetii. Since it is known that antibiotic treatment for severe CAP is empiric and includes coverage of typical and atypical pathogens, microbiological diagnosis bears an important relationship to prognosis of pneumonia. Factors such as adequacy of initial antibiotic or early de-escalation of therapy are important variables associated with outcomes, especially in severe cases. Intracellular pathogens sometimes appear to cause more severe disease with respiratory failure and multisystem dysfunction associated with fatal outcomes. The clinical relevance of intracellular pathogens in severe CAP has not been specifically investigated. We review the prevalence, general characteristics, and outcomes of severe CAP cases caused by intracellular pathogens.

Mycoplasma pneumoniae and Chlamydia spp. infection in community-acquired pneumonia, Germany, 2011-2012

Mycoplasma pneumoniae and Chlamydia spp., which are associated with community-acquired pneumonia (CAP), are difficult to propagate, and can cause clinically indistinguishable disease patterns. During 2011-2012, we used molecular methods to test adult patients in Germany with confirmed CAP for infection with these 2 pathogens. Overall, 12.3% (96/783) of samples were positive for M. pneumoniae and 3.9% (31/794) were positive for Chlamydia spp.; C. psittaci (2.1%) was detected more frequently than C. pneumoniae (1.4%). M. pneumoniae P1 type 1 predominated, and levels of macrolide resistance were low (3.1%). Quarterly rates of M. pneumoniae-positive samples ranged from 1.5% to 27.3%, showing a strong epidemic peak for these infections, but of Chlamydia spp. detection was consistent throughout the year. M. pneumoniae-positive patients were younger and more frequently female, had fewer co-occurring conditions, and experienced milder disease than did patients who tested negative. Clinicians should be aware of the epidemiology of these pathogens in CAP.

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.

Absence of Streptococcus pneumoniae in pharyngeal swabs of geriatric inpatients

Colonization of the pharynx by Streptococcus pneumoniae was studied in 185 in-hospital geriatric patients (median age 81 years) from 29 March 2011 to 22 June 2011. Swabs were plated on blood agar plates. Colonies with a morphology suggesting S. pneumoniae were further analyzed. Surprisingly, pneumococci were not found in any of the samples. Pneumococci chronically colonizing the pharynx of elderly people may be much rarer than previously thought and probably are not the source of pneumococcal pneumonia in old age.

Detection of pneumonia associated pathogens using a prototype multiplexed pneumonia test in hospitalized patients with severe pneumonia

Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods – particularly in patients with prior antibiotic treatment – and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time.

Trial Registration

Deutsches Register Klinischer Studien (DRKS) DRKS00005684

Impact of age and comorbidity on cause and outcome in community-acquired pneumonia

BACKGROUND

Prolonged life expectancy has currently increased the proportion of the very elderly among patients with community-acquired pneumonia (CAP). The aim of this study was to determine the influence of age and comorbidity on microbial patterns in patients over 65 years of age with CAP.

METHODS

This study was a prospective observational study of adult patients with CAP (excluding those in nursing homes) over a 12-year period. We compared patients aged 65 to 74 years, 75 to 84 years, and > 85 years for potential differences in clinical presentation, comorbidities, severity on admission, microbial investigations, causes, antimicrobial treatment, and outcomes.

RESULTS

We studied a total of 2,149 patients: 759 patients (35.3%) aged 65 to 74 years, 941 patients (43.7%) aged 75 to 84 years, and 449 patients (20.8%) aged > 85 years. At least one comorbidity was present in 1,710 patients (79.6%). Streptococcus pneumoniae was the most frequent pathogen in all age groups, regardless of comorbidity. Staphylococcus aureus, Enterobacteriaceae, and Pseudomonas aeruginosa accounted for 9.1% of isolates, and Haemophilus influenzae, 6.4%. All these pathogens were isolated only in patients with at least one comorbidity. Mortality increased with age (65-74 years, 6.9%; 75-84 years, 8.9%; > 85 years, 17.1%; P < .001) and was associated with increased comorbidities (neurologic; OR, 2.1; 95% CI, 1.5-2.1), Pneumonia Severity Index IV or V (OR, 3.2; 95% CI, 1.8-6.0), bacteremia (OR, 1.7; 95% CI, 1.1-2.7), the presence of a potential multidrug-resistant (MDR) pathogen (S. aureus, P. aeruginosa, Enterobacteriaceae; OR, 2.4; 95% CI, 1.3-4.3), and ICU admission (OR, 4.2; 95% CI, 2.9-6.1) on multivariate analysis.

CONCLUSIONS

Age does not influence microbial cause itself, whereas comorbidities are associated with specific causes such as H. influenzae and potential MDR pathogens. Mortality in the elderly is mainly driven by the presence of comorbidities and potential MDR pathogens.

Microbiological diagnosis and antibiotic therapy in patients with community-acquired pneumonia and acute COPD exacerbation in daily clinical practice: comparison to current guidelines

BACKGROUND

The aim of this secondary analysis was to evaluate current microbiological approaches, microbiology, and antibiotic therapy in patients with community-acquired pneumonia (CAP) and acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in clinical practice and to compare them with current international guidelines.

METHODS

A total of 362 patients with suspected CAP were enrolled in 14 European centers in a prospective multicenter study.

RESULTS

A total of 279 inpatients (CAP, n = 222; AECOPD, n = 57) were evaluated. A total of 83 (37 %) CAP patients and 25 (44 %) AECOPD patients did not undergo any microbiological tests. In patients with CAP/AECOPD, blood culture was performed in 109 (49 %)/16 (28.1 %), urinary antigen tests for Legionella pneumophila in 67 (30 %)/9 (16 %), and sputum investigation in 55 (25 %)/17 (30 %), respectively. The most frequent pathogens in CAP were Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, L. pneumophila, Staphylococcus aureus, and Enterobacter cloacae; in AECOPD they were Escherichia coli, Haemophilus haemolyticus, Haemophilus influenzae, and Moraxella catarrhalis. All CAP patients (mean = 11.1 days) and 35 (61.4 %) of AECOPD patients (mean = 8.9 days) received antibiotics. CAP patients were given mostly aminopenicillin with β-lactamase inhibitors and AECOPD patients were given mostly cephalosporins.

CONCLUSIONS

Pathogens isolated in CAP and AECOPD and the antibiotic therapy used are in good accordance with the guidelines. Blood culture, recommended for all CAP patients, was performed in only 50 % of the cases and antibiotic therapy lasted longer than the suggested 5-7 days. Therefore, international guidelines regarding performance of blood culture and duration of antibiotic therapy should be adopted more often. This duration was independent of the number of isolated pathogens and number of symptoms on admission. Therefore, the question arises as to whether microbiological data are necessary only for patients who are resistant to initial therapy.

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.

[Influenza : clinical symptoms, diagnostics and therapy]

Influenza infections have important socio-economic consequences. Risk groups identified so far include small children and elderly adults with comorbidities. In recent years in addition to seasonal influenza an outbreak of avian influenza occurred in 2005 and the new H1N1 pandemic occurred in 2009. For the latter other at risk groups were affected and a different clinical course has been documented. The focus of this article is to give an overview on the epidemiology, clinical characteristics, diagnosis and therapy of influenza infections.