Aetiology and Clinical Presentation of Mild Community-Acquired Bacterial Pneumonia

Early Detection of Aspergillus Species in Lower Respiratory Tract is Associated with Higher Mortality in Viral Community-Acquired Pneumonia: A Multicenter Prospective Cohort Study in China

PURPOSE

Community-acquired pneumonia (CAP) is a leading cause of adult mortality worldwide and poses a significant global burden. Previous studies have indicated a tendency for viral pneumonia, particularly severe influenza virus pneumonia, to be complicated by Aspergillus superinfection. However, the clinical features and prognostic implications of Aspergillus detection in early-onset viral CAP remain unclear.

METHODS

We conducted a prospective multicenter observational cohort study in China involving CAP patients. Adult patients with CAP from six hospitals were enrolled between January 2017 and October 2018. Within 72 h of admission, lower respiratory tract specimens, including sputum and alveolar lavage fluid, were collected. Comprehensive pathogenic testing, utilizing molecular biology techniques, was performed on the collected specimens, encompassing bacteria, atypical pathogens, viruses, and fungi. Patient clinical data were collected through a unified electronic medical record website system.

RESULTS

A total of 382 adult CAP patients were included in the study. The viral detection rate was 38% (145/382), with Aspergillus identified in 11.0% (16/145) of viral CAP cases. Mortality among Aspergillus-positive patients was significantly higher (25%, 4/16) compared to Aspergillus-negative patients (5.4%, 7/129) in viral CAP (P = 0.021). Multivariable logistic regression models demonstrated that the presence of Aspergillus at admission might increase the mortality risk in viral CAP [OR (95%CI) = 7.34 (0.92-58.65), P = 0.06]. Furthermore, Aspergillus-positive patients exhibited a significantly lower lymphocyte count than Aspergillus-negative patients (P = 0.047).

CONCLUSION

Positive detection of Aspergillus in lower respiratory tract specimens might be associated with higher mortality in early-onset viral CAP.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03093220. Registered retrospectively on 28 March 2017.

Using Probability Estimates to Evaluate a Patient With Weakness

In this case report, we review how probabilistic reasoning can be implemented in retrospect to refine the diagnostic process. A 67-year-old female with a history of polymyalgia rheumatica (PMR) and a recent dental procedure presented with weakness, falls, and chills ongoing for two weeks. She reported pain in her shoulders and lower back. On presentation, she was febrile, and labs were notable for leukocytosis with neutrophilic predominance and an elevated erythrocyte sedimentation rate (ESR). Chest radiograph revealed a left lower lung opacity, which was not seen on a repeat film. She was treated with antibiotics for community-acquired pneumonia and steroids for an exacerbation of PMR. After eight days of hospitalization, she was transferred to a subacute rehabilitation facility. A month later, she was readmitted with worsening lower back pain and right lower extremity weakness. Imaging revealed discitis and osteomyelitis at L1-L2. A spinal epidural abscess was present, leading to severe compression of the cauda equina nerve roots. Aspirate was positive for group B streptococcus. With antibiotic treatment alone, she recovered with resolution of her weakness.

In reviewing the literature, it becomes evident where improvements could have been made in the diagnostic process. Fever, leukocytosis, and neurological weakness are not commonly associated with PMR exacerbations. Lack of cough or shortness of breath, a persistently elevated erythrocyte sedimentation rate and C-reactive protein despite antibiotic treatment, and a repeat chest radiograph without an opacity suggest an alternative diagnosis to pneumonia. Persistent back pain with an insidious onset is a feature of untreated spinal epidural abscess. Steroid use and dental procedures are possible risk factors for spinal epidural abscess. By shedding light on how probabilities should be estimated, we hope to encourage probabilistic thinking to improve diagnostic accuracy. As with the best political forecasters, making precise probability estimates and frequently updating them may improve diagnostic accuracy for clinicians.

Where is Chlamydophila pneumoniae pneumonia?

BACKGROUND

Molecular diagnostic methods have recently gained widespread use, and consequently, the importance of viral pathogens in community-acquired pneumonia (CAP) has undergone re-evaluation. Under these circumstances, the role of Chlamydophila pneumoniae as a pathogen that causes CAP also needs to be reviewed.

METHODS

We reviewed articles that contained data on the frequency of identification of C. pneumoniae pneumonia as a causative pathogen for CAP. The articles were identified by performing a search in PubMed with the keywords "community-acquired pneumonia" and "pathogen".

RESULTS

Sixty-three articles were identified. The reviewed articles demonstrated that the rates of identification of C. pneumoniae as the causative pathogen for CAP were significantly lower in assessments based on polymerase chain reaction (PCR) methods than in those based on serological methods. In some studies, it was possible to compare both serological and PCR methods directly using the same set of samples.

CONCLUSIONS

The use of PCR methods, including multiplex PCR assays, has revealed that C. pneumoniae may play a limited role as a pathogen for CAP.

Community-acquired Pneumonia and Hospital-acquired Pneumonia

Pneumonia is among the leading causes of morbidity and mortality worldwide. Although Streptococcus pneumoniae is the most likely cause in most cases, the variety of potential pathogens can make choosing a management strategy a complex endeavor. The setting in which pneumonia is acquired heavily influences diagnostic and therapeutic choices. Because the causative organism is typically unknown early on, timely administration of empiric antibiotics is a cornerstone of pneumonia management. Disease severity and rates of antibiotic resistance should be carefully considered when choosing an empiric regimen. When complications arise, further work-up and consultation with a pulmonary specialist may be necessary.

Community-acquired Pneumonia Secondary to Legionella pneumophila and Streptococcus pneumoniae: A Rare Co-infection

Community-acquired pneumonia (CAP) is a frequent cause of hospitalization in adults. Streptococcus pneumoniae is the most commonly identified pathogen in CAP whereas Legionella pneumophilia is infrequently identified in CAP. Although co-infections have been previously described, the presence of both pneumococcus and legionella together is rare. We present a patient with positive urinary antigens for both Streptococcus pneumoniae and Legionella pneumophilia serogroup 1, indicating an unusual co-infection.

Chlamydia psittaci (psittacosis) as a cause of community-acquired pneumonia: a systematic review and meta-analysis

Psittacosis is a zoonotic infectious disease caused by the transmission of the bacterium Chlamydia psittaci from birds to humans. Infections in humans mainly present as community-acquired pneumonia (CAP). However, most cases of CAP are treated without diagnostic testing, and the importance of C. psittaci infection as a cause of CAP is therefore unclear. In this meta-analysis of published CAP-aetiological studies, we estimate the proportion of CAP caused by C. psittaci infection. The databases MEDLINE and Embase were systematically searched for relevant studies published from 1986 onwards. Only studies that consisted of 100 patients or more were included. In total, 57 studies were selected for the meta-analysis. C. psittaci was the causative pathogen in 1·03% (95% CI 0·79-1·30) of all CAP cases from the included studies combined, with a range between studies from 0 to 6·7%. For burden of disease estimates, it is a reasonable assumption that 1% of incident cases of CAP are caused by psittacosis.

Dipstick proteinuria level is significantly associated with pre-morbid and in-hospital functional status among hospitalized older adults: a preliminary study

Although chronic kidney disease (CKD) is associated with functional decline, whether proteinuria alone is associated with functional statuses over the course of acute illnesses independent of CKD is unclear. During 2014, we prospectively enrolled non-dialysis patients aged ≥65 years, and all participants underwent spot dipstick urinalysis on admission, divided into 3 groups according to the results (none, trace to 1 + , and 2 + or higher); functional status was evaluated using the pre-morbid and in-hospital Barthel index (BI) scores. Of 136 community-dwelling elderly patients enrolled (age 80.7 ± 8.2 years, with 19% having CKD), 17%, 57%, and 26% had no, trace to 1 + , or 2 + or higher proteinuria. Overall pre-morbid, on-admission, and on-discharge BI scores were 50.4 ± 41.9, 38.6 ± 31.8, and 38.7 ± 35.3, respectively with significant negative correlations with proteinuric severity on admission. Finally, multivariate linear stepwise regression analysis with backward variable selection found that dipstick proteinuric severity was significantly associated with pre-morbid, on-admission, and on-dischrage BI scores (p = 0.048, <0.01, and <0.01, respectively), independent of diabetes and CKD. This relationship between dipstick proteinuric levels and functional status of hospitalized elderly suggests an under-recognized association. Prospective evaluation of long-term outcome is needed.

Prevalence of Atypical Pathogens in Patients With Cough and Community-Acquired Pneumonia: A Meta-Analysis

PURPOSE

Community-acquired pneumonia (CAP), acute cough, bronchitis, and lower respiratory tract infections (LRTI) are often caused by infections with viruses or Streptococcus pneumoniae. The prevalence of atypical pathogens Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, and Bordetella pertussis among patients with these illnesses in the ambulatory setting has not been previously summarized. We set out to derive prevalence information from the existing literature.

METHODS

We performed a systematic review of MEDLINE for prospective, consecutive-series studies reporting the prevalence of M pneumoniae, C pneumoniae, L pneumophila and/or B pertussis in outpatients with cough, acute bronchitis, LRTI, or CAP. Articles were independently reviewed by 2 authors for inclusion and abstraction of data; discrepancies were resolved by consensus discussion. A meta-analysis was performed on each pathogen to calculate the pooled prevalence estimates using a random effects model of raw proportions.

RESULTS

Fifty studies met our inclusion criteria. While calculated heterogeneity was high, most studies reported prevalence for each pathogen within a fairly narrow range. In patients with CAP, the overall prevalences of M pneumoniae and C pneumoniae were 10.1% (95% CI, 7.1%-13.1%) and 3.5% (95% CI, 2.2%-4.9%), respectively. Consistent with previous reports, M pneumoniae prevalence peaked in roughly 6-year intervals. Overall prevalence of L pneumophila was 2.7% (95% CI, 2.0%-3.4%), but the organism was rare in children, with only 1 case in 1,765. In patients with prolonged cough in primary care, the prevalence of B pertussis was 12.4% (95% CI, 4.9%-19.8%), although it was higher in studies that included only children (17.6%; 95% CI, 3.4%-31.8%).

CONCLUSIONS

Atypical bacterial pathogens are relatively common causes of lower respiratory diseases, including cough, bronchitis, and CAP. Where surveillance data were available, we found higher prevalences in studies where all patients are tested for these pathogens. It is likely that these conditions are underreported, underdiagnosed, and undertreated in current clinical practice.

Prevalence, genotyping and macrolide resistance of Mycoplasma pneumoniae among isolates of patients with respiratory tract infections, Central Slovenia, 2006 to 2014

In this retrospective study we employed real-time polymerase chain reaction (PCR) to analyse the occurrence of Mycoplasma pneumoniae among upper and lower respiratory tract infections (RTI) in the Central Region of Slovenia between January 2006 and December 2014. We also used a culture and pyrosequencing approach to genotype strains and infer their potential macrolide resistance. Of a total 9,431 tested samples from in- and out-patient with RTI, 1,255 (13%) were found to be positive by M. pneumoniae PCR. The proportion of positive samples was 19% (947/5,092)among children (≤16 years-old) and 7% (308/4,339) among adults (>16 years-old). Overall, among those PCR tested, the highest proportions of M. pneumonia infections during the study period were observed in 2010 and 2014. In these two years, 18% (218/1,237) and 25% (721/2,844) of samples were positive respectively,indicating epidemic periods. From the 1,255 M. pneumoniae PCR-positive samples, 783 (614 from paediatric and 169 from adult patients) were successfully cultured. Of these, 40% (312/783) were constituted of strains belonging to the P1 type II genomic group, while 60% (469/783) contained strains of the P1 type I group. Two isolates comprised both P1 type Iand II strains. Results of a genotype analysis by year,showed that the dominant M. pneumoniae P1 type during the 2010 epidemic was P1 type II (82% of isolates;81/99), which was replaced by P1 type I in the 2014 epidemic (75%; 384/510). This observation could indicate that the two epidemics may have been driven by a type shift phenomenon, although both types remained present in the studied population during the assessed period of time. Only 1% of strains (7/783) were found to harbour an A2063G mutation in the 23S rRNA gene,which confers macrolide resistance, suggesting that the occurrence of M. pneumoniae macrolide resistance still seems to be sporadic in our geographic area.

Multimarker Prognostication for Hospitalized Patients with Community-acquired Pneumonia

OBJECTIVE

The optimal prognostic model for community-acquired pneumonia (CAP) remains unclear. In this study, we sought to identify independent predictors of 30-day mortality in patients with CAP and to determine whether adding specific prognostic factors to each of the two clinical prediction scores could improve the prognostic yield.

METHODS

This retrospective study involved 797 CAP patients who had been hospitalized at a tertiary referral center. The patients were categorized into two groups: those who survived and those who had died on or before 30 days after admission. Select clinical parameters were then compared between the two groups.

RESULTS

During the 30-day period, there were 72 deaths (9%). We constructed two models for a multivariate analysis: one was based on a high CURB-65 score (3-5) and the other on a high pneumonia severity index (PSI) class (V). In both models, a high CURB-65 score or a high PSI class, along with the presence of dyspnea, high Eastern Cooperative Oncology Group (ECOG) performance status (3-4), and a low serum albumin level, were independent predictors of 30-day mortality. In both the CURB-65-based and PSI-based models, the addition of dyspnea, high ECOG performance status, and hypoalbuminemia (<3 g/dL) enhanced the prognostic assessment, and subsequently, the c-statistics calculated with the use of three- or four- predictor combinations exceeded 0.8.

CONCLUSION

In addition to the CURB-65 or PSI, the clinical factors of dyspnea, the ECOG performance status, and serum albumin level may be independent predictors of 30-day mortality in CAP patients. When combined with the CURB-65 or PSI, these parameters provide additional evidence for predicting poor prognoses.

Estimating the burden of pneumococcal pneumonia among adults: a systematic review and meta-analysis of diagnostic techniques

Background

Pneumococcal pneumonia causes significant morbidity and mortality among adults. Given limitations of diagnostic tests for non-bacteremic pneumococcal pneumonia, most studies report the incidence of bacteremic or invasive pneumococcal disease (IPD), and thus, grossly underestimate the pneumococcal pneumonia burden. We aimed to develop a conceptual and quantitative strategy to estimate the non-bacteremic disease burden among adults with community-acquired pneumonia (CAP) using systematic study methods and the availability of a urine antigen assay.

Methods and Findings

We performed a systematic literature review of studies providing information on the relative yield of various diagnostic assays (BinaxNOW® S. pneumoniae urine antigen test (UAT) with blood and/or sputum culture) in diagnosing pneumococcal pneumonia. We estimated the proportion of pneumococcal pneumonia that is bacteremic, the proportion of CAP attributable to pneumococcus, and the additional contribution of the Binax UAT beyond conventional diagnostic techniques, using random effects meta-analytic methods and bootstrapping. We included 35 studies in the analysis, predominantly from developed countries. The estimated proportion of pneumococcal pneumonia that is bacteremic was 24.8% (95% CI: 21.3%, 28.9%). The estimated proportion of CAP attributable to pneumococcus was 27.3% (95% CI: 23.9%, 31.1%). The Binax UAT diagnosed an additional 11.4% (95% CI: 9.6, 13.6%) of CAP beyond conventional techniques. We were limited by the fact that not all patients underwent all diagnostic tests and by the sensitivity and specificity of the diagnostic tests themselves. We address these resulting biases and provide a range of plausible values in order to estimate the burden of pneumococcal pneumonia among adults.

Conclusions

Estimating the adult burden of pneumococcal disease from bacteremic pneumococcal pneumonia data alone significantly underestimates the true burden of disease in adults. For every case of bacteremic pneumococcal pneumonia, we estimate that there are at least 3 additional cases of non-bacteremic pneumococcal pneumonia.

Prevalence of methicillin-resistant staphylococcus aureus as an etiology of community-acquired pneumonia

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of skin infections. Recent case series describe severe community-acquired pneumonia (CAP) caused by MRSA, but the prevalence and risk factors are unknown.

METHODS

We prospectively enrolled adults hospitalized with CAP from 12 university-affiliated emergency departments during the winter-spring of 2006 and 2007. Clinical information and culture results were collected, and factors associated with MRSA were assessed.

RESULTS

Of 627 patients, 595 (95%) had respiratory (50%) and/or blood cultures (92%) performed. A pathogen was identified in 102 (17%); MRSA was identified in 14 (2.4%; range by site, 0%-5%) patients and in 5% of patients admitted to the intensive care unit. Two (14%) MRSA pneumonia patients died. All 9 MRSA isolates tested were pulsed-field type USA300. Features significantly associated with isolation of MRSA (as compared with any other or no pathogen) included patient history of MRSA; nursing home admission in the previous year; close contact in the previous month with someone with a skin infection; multiple infiltrates or cavities on chest radiograph; and comatose state, intubation, receipt of pressors, or death in the emergency department.

CONCLUSIONS

Methicillin-resistant Staphylococcus aureus remains an uncommon cause of CAP. Detection of MRSA was associated with more severe clinical presentation.

[Community-acquired Legionella pneumonia : data from the CAPNETZ study]

Legionella are present in the environment as well as in biofilms of water installation systems. Most Legionella live in amoebae. More than 51 different species of Legionella have been identified; however, most pneumonias are caused by Legionella pneumophila serogroup 1. Legionnaire's disease has an incidence of about 4% in Germany. Most cases of Legionnaire's disease are sporadic. Microbiological identification of Legionella can be achieved by cultivation of Legionella spp. on specific media, performing of Legionella-specific PCR from respiratory samples, or Legionella urinary antigen testing. Patients with severe underlying diseases, patients receiving immunosuppression, and patients who are heavy smokers have a predisposition to Legionnaire's disease. Men are significantly more often affected. Whereas outpatients show a mild clinical course, mortality for hospitalized patients is 11.2%. It can be assumed that only a minority of cases of Legionnaire's disease is recognized and reported in Germany.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Mixed community-acquired lower respiratory tract infections

Although mixed infections are known to be clinically relevant in conditions such as nosocomial pneumonia and ventilator-related pneumonia, it is increasingly recognized that a substantial number of community-acquired lower respiratory tract infections may also be attributed to more than one pathogenic organism. A better definition of the true incidence of mixed infections in community-acquired lower respiratory tract infections is partly derived from recent advances in available diagnostic methods (eg, molecular biology). Two points still must be determined: whether the presence of a mixed infection is associated with altered outcomes and whether empirical antibiotic selection should be modified to account for potential polymicrobial infections.

Diagnosis of community-acquired pneumonia in adults

Community-acquired pneumonia (CAP) is a common presentation to both primary and secondary care, representing approximately 5% of the acute medical intake in the UK. Treatment is often based on an empirical approach, using broad-spectrum antibiotic regimens, with which the majority of patients will achieve clinical cure. However, in cases of severe CAP, initial treatment failure or severe comorbidity, a more rigorous diagnostic approach is required. This review assesses the evidence base behind the common diagnostic methods for CAP, and presents the case for a rapid and accurate microbiological and radiological diagnosis in improving management and outcomes of this common condition.

Macrolide-resistant Mycoplasma pneumoniae: characteristics of isolates and clinical aspects of community-acquired pneumonia

Mycoplasma pneumoniae is one of the main pathogens causing community-acquired respiratory tract infections in children and adults. Macrolide (ML) antibiotics are recognized generally as first-choice agents for M. pneumoniae infections, and these antibiotics were thought to have excellent effectiveness against M. pneumoniae for many years. In 2000, however, M. pneumoniae showing resistance to macrolides was isolated from clinical samples obtained from Japanese pediatric patients with community-acquired pneumonia (CAP). Since then, prevalence of ML-resistant M. pneumoniae isolates in pediatric patients has increased rapidly. In 2007, ML-resistant M. pneumoniae isolates were obtained from Japanese adults with CAP; numbers of such isolates also have gradually increased in Japan. Recently, similar antimicrobial resistance in M. pneumoniae has begun to emerge worldwide. In this review, we focus on changes of ML-resistant M. pneumoniae from year to year and consider resistance mechanisms as well as clinical features of patients with resistant M. pneumoniae infection.

Clinical policy: critical issues in the management of adult patients presenting to the emergency department with community-acquired pneumonia

This clinical policy from the American College of Emergency Physicians focuses on critical issues concerning the management of adult patients presenting to the emergency department (ED)with community-acquired pneumonia. It is an update of the 2001 clinical policy for the management and risk stratification of adult patients presenting to the ED with community-acquired pneumonia. A subcommittee reviewed the current literature to derive evidence-based recommendations to help answer the following questions: (1) Are routine blood cultures indicated in patients admitted with community-acquired pneumonia? (2) In adult patients with community-acquired pneumonia without severe sepsis, is there a benefit in mortality or morbidity from the administration of antibiotics within aspecific time course? The evidence was graded and recommendations were given based on the strength of evidence.

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.

[Managing lower respiratory tract infections in immunocompetent patients. Definitions, epidemiology, and diagnostic features]

Les infections respiratoires basses sont une des principales cause de mortalité dans le monde et les pneumopathies représentent en France la première cause de décès d'origine infectieuse. Trois entités nosologiques distinctes sont habituellement isolées en fonction de la localisation infectieuse : la bronchite aiguë, la pneumopathie et la bronchopneumopathie (atteignant les bronches et le parenchyme pulmonaire). En cas d'infections de l'arbre bronchique dans le cadre d'une bronchopathie chronique on parle de décompensation infectieuse de la maladie bronchique. Les deux principales difficultés diagnostiques de ces infections sont de déterminer la présence d'une participation alvéolaire au processus infectieux et de définir l'agent (ou les agents) pathogènes. Ces deux éléments vont conditionner la prise en charge thérapeutique. En dehors de l'examen physique, indispensable dans ce contexte, seule la radiographie thoracique pourra, en cas de persistance d'un doute, permettre de confirmer la présence d'une participation alvéolaire. Le diagnostic microbiologique pose la question de sa nécessité systématique et celui de sa valeur. Il n'est pas indispensable de réaliser un diagnostic microbiologique de certitude dans tous les cas. La décision de documentation doit répondre à deux impératifs : faisabilité et valeur diagnostique. La valeur d'un prélèvement dépend de son aptitude à mettre en évidence l'agent pathogène et dans certains cas de la possibilité d'en déterminer le profil de sensibilité (qui reste une indication majeure à la réalisation de ces prélèvements).

Atypical pathogens as etiologic agents in hospitalized patients with community-acquired pneumonia in Korea: a prospective multi-center study

Local epidemiologic data on the etiologies of patients hospitalized with community-acquired pneumonia (CAP) is needed to develop guidelines for clinical practice. This study was conducted prospectively to determine the proportion of atypical bacterial pathogens in adults patients hospitalized with CAP in Korea between October 2001 and December 2002. Microbiological diagnosis was determined by serology for antibodies to Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. Nucleic acid of M. pneumoniae and C. pneumoniae in respiratory samples and Legionella antigen in urine samples were detected. The study population consisted of 126 patients (71 males, 55 females), averaging 54.6 yr (SD+/-17.8), whose paired sera were available. An etiologic diagnosis for atypical pathogens was made in 18 patients (14.3%): C. pneumoniae 9 (7.1%), M. pneumoniae 8 (6.3%), and L. pneumophila 3 patients (2.4%). Streptococcus preumoniae and other typical pathogens were isolated from 36 patients (28.6%). Of 126 patients, 16 (12.7%) were admitted to intensive care unit and atypical pathogens were identified in 5 patients (31.3%). Initial clinical features of patients with pneumonia due to atypical, typical or undetermined pathogens were indistinguishable. We conclude that atypical pathogens should be seriously considered in hospitalized patients with CAP, when initiating empiric treatment in Korea.

The atypical pneumonias: clinical diagnosis and importance

The most common atypical pneumonias are caused by three zoonotic pathogens, Chlamydia psittaci (psittacosis), Francisella tularensis (tularemia), and Coxiella burnetii (Q fever), and three nonzoonotic pathogens, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella. These atypical agents, unlike the typical pathogens, often cause extrapulmonary manifestations. Atypical CAPs are systemic infectious diseases with a pulmonary component and may be differentiated clinically from typical CAPs by the pattern of extrapulmonary organ involvement which is characteristic for each atypical CAP. Zoonotic pneumonias may be eliminated from diagnostic consideration with a negative contact history. The commonest clinical problem is to differentiate legionnaire's disease from typical CAP as well as from C. pneumoniae or M. pneumonia infection. Legionella is the most important atypical pathogen in terms of severity. It may be clinically differentiated from typical CAP and other atypical pathogens by the use of a weighted point system of syndromic diagnosis based on the characteristic pattern of extrapulmonary features. Because legionnaire's disease often presents as severe CAP, a presumptive diagnosis of Legionella should prompt specific testing and empirical anti-Legionella therapy such as the Winthrop-University Hospital Infectious Disease Division's weighted point score system. Most atypical pathogens are difficult or dangerous to isolate and a definitive laboratory diagnosis is usually based on indirect, i.e., direct flourescent antibody (DFA), indirect flourescent antibody (IFA). Atypical CAP is virtually always monomicrobial; increased IFA IgG tests indicate past exposure and not concurrent infection. Anti-Legionella antibiotics include macrolides, doxycycline, rifampin, quinolones, and telithromycin. The drugs with the highest level of anti-Legionella activity are quinolones and telithromycin. Therapy is usually continued for 2 weeks if potent anti-Legionella drugs are used. In adults, M. pneumoniae and C. pneumoniae may exacerbate or cause asthma. The importance of the atypical pneumonias is not related to their frequency (approximately 15% of CAPs), but to difficulties in their diagnosis, and their nonresponsiveness to beta-lactam therapy. Because of the potential role of C. pneumoniae in coronary artery disease and multiple sclerosis (MS), and the role of M. pneumoniae and C. pneumoniae in causing or exacerbating asthma, atypical CAPs also have public health importance.

Evaluation of infections in non-small cell lung cancer patients treated with radiotherapy

PURPOSE

We aim to determine infections occurring in patients with non-small cell lung cancer during radiotherapy (RT).

METHODS AND MATERIALS

A total of 181 patients had been treated with thoracic radiotherapy between October 1995 and December 1999. Radiotherapy was given using 1.8-3Gray (Gy) fraction daily, five fractions a week for a total dose of 59.4Gy (30-70.2Gy). A complete history was collected retrospectively for each patient. All microbiological examinations were performed according to the routine procedures of the hospital laboratory. Numeric and categoric variables were employed such as sex, age, performance status, histology, stage, chemotherapy, usage of corticosteroids, neutropenia, surgery, hospitalization, associated diseases, smoking during treatment, package per year of cigarette smoking, dose of radiotherapy, and response rates.

RESULTS

Infections developed in 84 patients (46%, 84/181) during thoracic radiotherapy. A 101 episodes of infections developed in these patients. Most patients suffered from sputum production (65%), cough (59%), auscultation findings (31%) and fever (31%). Gram-negative bacteria were the most frequently isolated pathogens in the cultures of specimens (70%, 16/23 samples). Neoadjuvant chemotherapy (OR=4.81; 95% CI, 1.57-9.12; p=0.003) and neutropenia (OR=4.25; 95% CI, 1.44-6.89; p=0.009) were found as risk factors for influencing infection based on logistic regression analyses. Package per year of cigarette smoking was found statistically significantly higher in patients with infections than patients without infections (p=0.001). A slight increase in infections, which was of borderline statistical significance (p=0.07), was observed in patients age over 70. Ciprofloxacin and clarithromycin were the most frequently used agents in treatment. Median survival was 9 months in the patients with infection and 13 months in the 97 patients without infection. Overall survival seemed to be statistically significantly better in patients without infection than patients with infection (p=0.042) calculated using Kaplan-Meier method. Based on Cox regression analyses; overall survival was not correlated to presence of infection but associated with poor performance status (</=80) (OR=2.35; 95% CI, 0.85-8.93; p=0.03), and usage of corticosteroids (OR=2.68; 95% CI, 0.98-6.72; p=0.01). The dose of radiation therapy >5940 cGy (OR=2.06; 95% CI, 0.72-7.18; p=0.007) and the absence of response to treatment (OR=2.45; 95% CI, 0.89-14.23; p<0.001) were also found to be risk factors for survival.

CONCLUSIONS

Infections are important causes of morbidity and mortality in lung cancer patients. The control of infection in these patients may improve the survival. Predisposing factors and treatment management approaches in non-small cell lung cancer should be defined carefully.