New and emerging etiologies for community-acquired pneumonia with implications for therapy. A prospective multicenter study of 359 cases

Inflammatory parameters predict etiologic patterns but do not allow for individual prediction of etiology in patients with CAP: results from the German competence network CAPNETZ

Background

Aim of this study was to evaluate the correlation of inflammatory markers procalcitonin (PCT), C-reactive protein (CRP) and leukocyte count (WBC) with microbiological etiology of CAP.

Methods

We enrolled 1337 patients (62 ± 18 y, 45% f) with proven CAP. Extensive microbiological workup was performed. In all patients PCT, CRP, WBC and CRB-65 score were determined. Patients were classified according to microbial diagnosis and CRB-65 score.

Results

In patients with typical bacterial CAP, levels of PCT, CRP and WBC were significantly higher compared to CAP of atypical or viral etiology. There were no significant differences in PCT, CRP and WBC in patients with atypical or viral etiology of CAP. In contrast to CRP and WBC, PCT markedly increased with severity of CAP as measured by CRB-65 score (p < 0.0001). In ROC analysis for discrimination of patients with CRB-65 scores > 1, AUC for PCT was 0.69 (95% CI 0.66 to 0.71), which was higher compared to CRP and WBC (p < 0.0001). CRB-65, PCT, CRP and WBC were higher (p < 0.0001) in hospitalised patients in comparison to outpatients.

Conclusion

PCT, CRP and WBC are highest in typical bacterial etiology in CAP but do not allow individual prediction of etiology. In contrast to CRP and WBC, PCT is useful in severity assessment of CAP.

Community-acquired pneumonia in older patients: does age influence systemic cytokine levels in community-acquired pneumonia?

BACKGROUND AND OBJECTIVE

Community-acquired pneumonia (CAP) is a major cause of death in the elderly. The age-related increase in comorbid illnesses plays a part but the effect of aging on the immune response may be equally important. We aimed to evaluate patients with CAP for evidence of a muted response to infection in elderly patients admitted to hospital compared with a younger patient group.

METHODS

Patients with CAP admitted through the Emergency Department were recruited for this prospective observational study. Clinical data were collected at presentation. Severity of pneumonia was assessed using the British Thoracic Society confusion, urea nitrogen, respiratory rate, blood pressure (CURB) score, the Pneumonia Severity Index (PSI) and the systemic inflammatory response syndrome (SIRS) definition. IL-6 and IL-10 levels were measured within 24 h of admission.

RESULTS

Eighty patients were included in the study, of whom 38 (48%) were female. The median age was 74 years (range 18-95). Patients greater than 65 years of age had a lower incidence of chest pain and a higher incidence of altered mental status on presentation. CURB score and PSI were higher in the older patients. SIRS showed similar frequencies in both groups. IL-6 and IL-10 levels were similar in young (< 65 years), older (> 65 years) and very elderly (> 80 years) patients. This finding was not altered by severity of pneumonia.

CONCLUSIONS

Age does not diminish the severity of illness scores in patients with CAP. There was no blunting of the systemic cytokine response with advanced age in this study.

Increasing incidence of legionellosis in the United States, 1990-2005: changing epidemiologic trends

BACKGROUND

An abrupt increase in the incidence of legionellosis in the United States has been noted since 2003. Whether the recent increase is associated with shifting epidemiologic trends has not been well characterized.

METHODS

We analyzed all cases of legionellosis reported to the Centers for Disease Control and Prevention through the National Notifiable Disease Surveillance System from 1990 through 2005.

RESULTS

A total of 23,076 cases of legionellosis were reported to the Centers for Disease Control and Prevention from 1990 through 2005. The number of reported cases increased by 70% from 1310 cases in 2002 to 2223 cases in 2003, with a sustained increase to >2000 cases per year from 2003 through 2005. The eastern United States showed most of the increases in age-adjusted incidence rates after 2002, with the mean rate in the Middle Atlantic states during 2003-2005 exceeding that during 1990-2002 by 96%. During 2000-2005, legionellosis cases were most commonly reported in persons aged 45-64 years. Persons aged <65 years comprised 63% of total cases in 2000-2005. Age-adjusted incidence rates in males exceeded those in females for all age groups and years. Legionellosis incidence showed marked seasonality in eastern states, with most cases reported in the summer or fall.

CONCLUSIONS

Reported legionellosis cases have increased substantially in recent years, particularly in the eastern United States and among middle-aged adults. Legionella infection should be considered in the differential diagnosis of any patient with pneumonia. Public health professionals should focus increased attention on detection and prevention of this important and increasing public health problem.

A prospective study of the diagnostic utility of sputum Gram stain in pneumonia

INTRODUCTION

Sputum Gram stain and culture have been said to be unreliable indicators of the microbiological diagnosis of bacterial pneumonia. The etiological diagnosis of pneumonia is surrounded by great degree of uncertainty. This uncertainty should be and can be calculated and incorporated in the diagnosis and treatment.

STUDY OBJECTIVES

To determine the diagnostic accuracy and diagnostic value of sputum Gram stain in etiological diagnosis and initial selection of antimicrobial therapy of bacterial community acquired pneumonia (CAP). DESIGN-METHOD: Prospective study of 1390 patients with CAP admitted January 2002-June 2008, to our institutions. Of the 1390 patients, 178 (12.8%) fulfilled the criteria for inclusion into this study (good-quality sputa and presence of the same microorganism in blood and sputum cultures which was used as gold standard for assessing the diagnostic accuracy and diagnostic value of sputum Gram stain).

RESULTS

The sensitivity of sputum Gram stain was 0.82 for Pneumococcal pneumonia, 0.76 for Staphylococcal pneumonia, 0.79 for Haemophilus influenzae pneumonia and 0.78 for Gram-negative bacilli pneumonia. The specificity of sputum Gram stain was 0.93 for Pneumococcal pneumonia, 0.96 for Staphylococcal pneumonia, 0.96 for H. influenzae pneumonia and 0.95 for Gram-negative bacilli pneumonia. The positive likelihood ratio (LR+) was 11.58 for Pneumococcal pneumonia, 19.38 for Staphylococcal pneumonia, 16.84 for H. influenzae pneumonia, 14.26 for Gram-negative bacilli pneumonia. The negative likelihood ratio (LR-) was 0.20 for Pneumococcal pneumonia, 0.25 for Staphylococcal pneumonia, 0.22 for H. influenzae pneumonia, and 0.23 for Gram-negative bacilli pneumonia.

CONCLUSIONS

Sputum Gram stain is a dependable diagnostic test for the early etiological diagnosis of bacterial CAP that helps in choosing orthological and appropriate initial antimicrobial therapy.

Risk factors and outcome of community-acquired pneumonia due to Gram-negative bacilli

BACKGROUND AND OBJECTIVE

Several sets of guidelines have advocated initial antibiotic treatment for community-acquired pneumonia due to Gram-negative bacilli in patients with specific risk factors. However, evidence to support this recommendation is scarce. We sought to identify risk factors for community-acquired pneumonia due to Gram-negative bacilli, including Pseudomonas aeruginosa, and to assess outcomes.

METHODS

An observational analysis was carried out on prospectively collected data for immunocompetent adults hospitalized for community-acquired pneumonia in two acute-care hospitals. Cases of pneumonia due to Gram-negative bacilli were compared with those of non-Gram-negative bacilli causes.

RESULTS

Sixty-one (2%) of 3272 episodes of community-acquired pneumonia were due to Gram-negative bacilli. COPD (odds ratio (OR) 2.4, 95% confidence interval (CI): 1.2-5.1), current use of corticosteroids (OR 2.8, 95% CI: 1.2-6.3), prior antibiotic therapy (OR 2.6, 95% CI: 1.4-4.8), tachypnoea >or=30 cycles/min (OR 2.1, 95% CI: 1.1-4.2) and septic shock at presentation (OR 6.1, 95% CI: 2.5-14.6) were independently associated with Gram-negative bacilli pneumonia. Initial antibiotic therapy in patients with pneumonia due to Gram-negative bacilli was often inappropriate. These patients were also more likely to require admission to the intensive care unit, had longer hospital stays, and higher early (<48 h) (21% vs 2%; P < 0.001) and overall mortality (36% vs 7%; P < 0.001).

CONCLUSIONS

These results suggest that community-acquired pneumonia due to Gram-negative bacilli is uncommon, but is associated with a poor outcome. The risk factors identified in this study should be considered when selecting initial antibiotic therapy for patients with community-acquired pneumonia.

Community-acquired pneumonia in patients with and without chronic obstructive pulmonary disease

PURPOSE

The purpose of this study was to analyse the possible differences, especially those regarding mortality, between patients hospitalized for community-acquired pneumonia (CAP) with and without chronic obstructive pulmonary disease (COPD), and the risk factors related to mortality in the COPD group.

METHODS

710 patients with CAP were included in a prospective multicenter observational study. 244 of the patients had COPD confirmed by spirometry.

RESULTS

COPD was associated with mortality in patients with CAP (OR=2.62 CI: 1.08-6.39). Patients with COPD and CAP had a significantly higher 30-day mortality rate as compared to patients without COPD. Multivariate analysis showed that PaO(2)< or =60 mmHg (OR=7.95; 95% CI: 3.40-27.5), PaCO(2)> or =45 mmHg (OR=4.6; CI: 2.3-15.1); respiratory rate > or =30/min (OR=12.25; CI: 3.45-35.57), pleural effusion (OR=8.6; 95% CI: 2.01-24.7), septic shock (OR=12.6; 95% CI: 3.4-45.66) and renal failure (OR=13.4; 95% CI: 3.2-37.8) were significantly related to mortality. Purulent sputum and fever were considered as protective factors.

CONCLUSIONS

COPD was an independent risk factor for mortality in patients with CAP. Hypoxemia and hypercapnia are associated with mortality in patients with CAP with and without COPD. Chronic obstructive pulmonary disease and PaCO(2) value could be useful prognostic factors and should be incorporated in risk stratification in patients with CAP.

Clinical predictors for Legionella in patients presenting with community-acquired pneumonia to the emergency department

Background

Legionella species cause severe forms of pneumonia with high mortality and complication rates. Accurate clinical predictors to assess the likelihood of Legionella community-acquired pneumonia (CAP) in patients presenting to the emergency department are lacking.

Methods

We retrospectively compared clinical and laboratory data of 82 consecutive patients with Legionella CAP with 368 consecutive patients with non-Legionella CAP included in two studies at the same institution.

Results

In multivariate logistic regression analysis we identified six parameters, namely high body temperature (OR 1.67, p < 0.0001), absence of sputum production (OR 3.67, p < 0.0001), low serum sodium concentrations (OR 0.89, p = 0.011), high levels of lactate dehydrogenase (OR 1.003, p = 0.007) and C-reactive protein (OR 1.006, p < 0.0001) and low platelet counts (OR 0.991, p < 0.0001), as independent predictors of Legionella CAP. Using optimal cut off values of these six parameters, we calculated a diagnostic score for Legionella CAP. The median score was significantly higher in Legionella CAP as compared to patients without Legionella (4 (IQR 3–4) vs 2 (IQR 1–2), p < 0.0001) with a respective odds ratio of 3.34 (95%CI 2.57–4.33, p < 0.0001). Receiver operating characteristics showed a high diagnostic accuracy of this diagnostic score (AUC 0.86 (95%CI 0.81–0.90), which was better as compared to each parameter alone. Of the 191 patients (42%) with a score of 0 or 1 point, only 3% had Legionella pneumonia. Conversely, of the 73 patients (16%) with ≥4 points, 66% of patients had Legionella CAP.

Conclusion

Six clinical and laboratory parameters embedded in a simple diagnostic score accurately identified patients with Legionella CAP. If validated in future studies, this score might aid in the management of suspected Legionella CAP.

Paradoxically high resistance of natural killer T (NKT) cell-deficient mice to Legionella pneumophila: another aspect of NKT cells for modulation of host responses

In the present study, we examined the roles of natural killer T (NKT) cells in host defence against Legionella pneumophila in a mouse model. The survival rate of NKT cell-deficient Jalpha281 knock-out (KO) mice was significantly higher than that of wild-type mice. There was no bacterial overgrowth in the lungs, but Jalpha281 KO mice showed enhanced pulmonary clearance at a later stage of infection, compared with their wild-type counterparts. The severity of lung injury in L. pneumophila-infected Jalpha281 KO mice was less, as indicated by lung permeability measurements, such as lung weight and bronchoalveolar lavage fluid albumin concentration. Recruitment of inflammatory cells in the lungs was approximately twofold greater in Jalpha281 KO mice on day 3. Interestingly, higher values of interleukin (IL)-1beta and IL-18, and increased caspase-1 activity were noted in the lungs of Jalpha281 KO mice from an early time point (6 h). Exogenous alpha-galactosylceramide, a ligand of NKT cells, induced IL-12 and gamma interferon at 6 h, but suppressed IL-1beta at later time points in wild-type, whereas no effects were evident in Jalpha281 KO mice, as expected. Systemic administration of heat-killed L. pneumophila, but not Escherichia coli LPS, reproduced exaggerated production of IL-1beta in the lungs of Jalpha281 KO mice. These results demonstrate that NKT cells play a role in host defence against L. pneumophila, which is characterized by enhanced lung injury and decreased accumulation of inflammatory cells in the lungs. The regulation of IL-1beta, IL-18 and caspase-1 may be associated with the modulating effect of host responses by NKT cells.

Treatment and outcomes for patients with bacteremic pneumococcal pneumonia

Delayed time to antibiotic administration has been linked with higher mortality for patients with community-acquired pneumonia, but the impact of antibiotic resistance on clinical outcomes has been controversial. In the current study we assess the combined impact of antibiotic resistance and antibiotic timing on outcomes, including inhospital mortality, complications, length of stay, and time to stability, for patients hospitalized with community-acquired bacteremic pneumococcal pneumonia. We conducted a retrospective cohort study in 43 hospitals in the Southeastern Pennsylvania region from 2001 to 2004. Eligible adult patients had pneumococcal bacteremia and radiographic evidence of pneumonia. Outcomes were assessed based on medical record review. Multivariable regression was used to adjust for severity of illness and sequentially assess the impact of antibiotic resistance and time to active antibiotic therapy. The overall inhospital mortality was 10%. Overall, levels of macrolide, cephalosporin, and fluoroquinolone resistance were low and did not adversely impact the time to administration of active antibiotic therapy. Receipt of at least 1 active antibiotic within 4 hours was associated with reduced mortality (odds ratio [OR], 0.47; 95% confidence interval [CI], 0.2-1.0) and shortened length of stay (OR, 0.77; CI, 0.6-1.0) but did not reduce the risk of other adverse outcomes. We conclude that early antibiotic administration reduces the risks of mortality in patients with bacteremic pneumococcal pneumonia. Current patterns of drug resistance did not lead to delays in administration of active antimicrobial therapy.

Healthcare-associated pneumonia: principles and emerging concepts on management

Healthcare-associated pneumonia (HCAP) is a relatively new entity that includes pneumonia occurring in healthcare settings other than acute-care hospitals. Many patients with HCAP are at greater risk for colonization and infection with multi-drug resistant (MDR) bacteria such as Pseudomonas aeruginosa, Gram-negative bacilli-producing extended-spectrum beta-lactamases and methicillin-resistant Staphylococcus aureus. Infections with these MDR pathogens require different empiric antibiotic therapy. To avoid initiation of inappropriate antibiotic therapy that may result in poorer patient outcomes, new principles for HCAP management were outlined in the 2005 American Thoracic Society and Infectious Diseases Society of America guidelines. These guidelines were suggested for patients assessed in acute-care hospitals and clinics, and may not be applicable for all patients with suspected HCAP in nursing homes and other long-term care settings. This review article addresses HCAP management strategies in both clinical settings.

Medical microbiology: laboratory diagnosis of invasive pneumococcal disease

The laboratory diagnosis of invasive pneumococcal disease (IPD) continues to rely on culture-based methods that have been used for many decades. The most significant recent developments have occurred with antigen detection assays, whereas the role of nucleic acid amplification tests has yet to be fully clarified. Despite developments in laboratory diagnostics, a microbiological diagnosis is still not made in most cases of IPD, particularly for pneumococcal pneumonia. The limitations of existing diagnostic tests impact the ability to obtain accurate IPD burden data and to assess the effectiveness of control measures, such as vaccination, in addition to the ability to diagnose IPD in individual patients. There is an urgent need for improved diagnostic tests for pneumococcal disease--especially tests that are suitable for use in underresourced countries.

Diagnosis and management of pneumonia in the emergency department

Pneumonia is a condition that is often treated by emergency physicians. This article reviews the diagnosis and management of pneumonia in the emergency department and highlights dilemmas in diagnostic testing, use of blood and sputum cultures, hospital admission decisions, infection control, quality measures for pneumonia care, and empiric antimicrobial therapy.

Azithromycin for acute lower respiratory tract infections

BACKGROUND

Acute lower respiratory tract infections (LRTI) range from acute bronchitis and acute exacerbations of chronic bronchitis to pneumonia. Approximately five million people die of acute respiratory tract infections annually. Among these, pneumonia represents the most frequent cause of mortality, hospitalization and medical consultation. Azithromycin is a new macrolide antibiotic, structurally modified from erythromycin and noted for its activity against some gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae (H. influenzae).

OBJECTIVES

To compare the effectiveness of azithromycin to amoxycillin or amoxycillin/clavulanic acid (amoxyclav) in the treatment of LRTI, in terms of clinical failure, incidence of adverse events and microbial eradication.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007 Issue 2), MEDLINE (January 1966 to July 2007), and EMBASE (January 1974 to July 2007).

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials, comparing azithromycin to amoxycillin or amoxycillin/clavulanic acid in participants with clinical evidence of acute LRTI: acute bronchitis, pneumonia, and acute exacerbation of chronic bronchitis were studied.

DATA COLLECTION AND ANALYSIS

The criteria for assessing study quality were generation of allocation sequence, concealment of treatment allocation, blinding, and completeness of the trial. All types of acute LRTI were initially pooled in the meta-analyses. The heterogeneity of results was investigated by the forest plot and Chi-square test. Index of I-square (I(2)) was also used to measure inconsistent results among trials. Subgroup and sensitivity analyses were conducted.

MAIN RESULTS

Fifteen trials were analysed. The pooled analysis of all trials showed that there was no significant difference in the incidence of clinical failure on about day 10 to 14 between the two groups (relative risk (RR), random-effects 1.09; 95% confidence interval (CI) 0.64 to 1.85). Sensitivity analysis showed a reduction of clinical failure in azithromycin-treated participants (RR 0.55; 95% CI 0.25 to 1.21) in three adequately concealed studies, compared to RR 1.32; 95% CI 0.70 to 2.49 in 12 studies with inadequate concealment. Twelve trials reported the incidence of microbial eradication and there was no significant difference between the two groups (RR 0.95; 95% CI 0.87 to 1.03). The reduction of adverse events in the azithromycin group was RR 0.76 (95% CI 0.57 to 1.00).

AUTHORS' CONCLUSIONS

There is unclear evidence that azithromycin is superior to amoxicillin or amoxyclav in treating acute LRTI. In patients with acute bronchitis of a suspected bacterial cause, azithromycin tends to be more effective in terms of lower incidence of treatment failure and adverse events than amoxicillin or amoxyclav. Future trials of high methodological quality are needed.

Bacterial Infections

In Osier’s time, bacterial pneumonia was a dreaded event, so important that he borrowed John Bunyan’s characterization of tuberculosis and anointed the pneumococcus, as the prime pathogen, “Captain of the men of death.”1 One hundred years later much has changed, but much remains the same. Pneumonia is now the sixth most common cause of death and the most common lethal infection in the United States. Hospital-acquired pneumonia is now the second most common nosocomial infection.2 It was documented as a complication in 0.6% of patients in a national surveillance study,3 and has been reported in as many as 20% of patients in critical care units.4 Furthermore, it is the leading cause of death among nosocomial infections.5 Leu and colleagues6 were able to associate one third of the mortality in patients with nosocomial pneumonia to the infection itself. The increase in hospital stay, which averaged 7 days, was statistically significant. It has been estimated that nosocomial pneumonia produces costs in excess of $500 million each year in the United States, largely related to the increased length of hospital stay.

Epidemiology and clinical outcomes of community-acquired pneumonia in adult patients in Asian countries: a prospective study by the Asian network for surveillance of resistant pathogens

Appropriate antimicrobial treatment of community-acquired pneumonia (CAP) should be based on the distribution of aetiological pathogens, antimicrobial resistance of major pathogens, clinical characteristics and outcomes. We performed a prospective observational study of 955 cases of adult CAP in 14 hospitals in eight Asian countries. Microbiological evaluation to determine etiological pathogens as well as clinical evaluation was performed. Bronchopulmonary disease (29.9%) was the most frequent underlying disease, followed by cardiovascular diseases (19.9%), malignancy (11.7%) and neurological disorder (8.2%). Streptococcus pneumoniae (29.2%) was the most common isolate, followed by Klebsiella pneumoniae (15.4%) and Haemophilus influenzae (15.1%). Serological tests were positive for Mycoplasma pneumoniae (11.0%) and Chlamydia pneumoniae (13.4%). Only 1.1% was positive for Legionella pneumophila by urinary antigen test. Of the pneumococcal isolates, 56.1% were resistant to erythromycin and 52.6% were not susceptible to penicillin. Seventeen percent of CAP had mixed infection, especially S. pneumoniae with C. pneumoniae. The overall mortality rate was 7.3%, and nursing home residence, mechanical ventilation, malignancy, cardiovascular diseases, respiratory rate > 30/min and hyponatraemia were significant independent risk factors for mortality by multivariate analysis (P < 0.05). The current data provide relevant information about pathogen distribution and antimicrobial resistance of major pathogens of CAP as well as clinical outcomes of illness in Asian countries.

Acute Chlamydia pneumoniae infections in asthmatic and non-asthmatic military conscripts during a non-epidemic period

Chlamydia pneumoniae respiratory tract infections were studied in 512 male military conscripts (123 asthmatic and 389 non-asthmatic) taking part in 180-day service between July 2004 and July 2005 in Kajaani, Finland. Respiratory tract infections requiring a medical consultation were analysed prospectively. At baseline, at end of service, and during each episode of respiratory infection, blood samples were obtained for measurement of C. pneumoniae antibodies. Data concerning the clinical features of each infection episode were collected. Serological evidence of acute C. pneumoniae infection was found in 34 of the 512 conscripts with antibody data available, including 9.8% of the asthmatic subjects and 5.7% of the non-asthmatic subjects (p 0.111). A serological diagnosis could be made for 25 clinical episodes in 24 conscripts. The spectrum of respiratory tract infections included 13 episodes of mild upper respiratory tract infection and seven episodes of sinusitis, with five episodes involving asthma exacerbation. Two of three pneumonias were primary infections. Primary infections were diagnosed in five subjects, and re-infection/reactivation in 19 subjects, with the latter comprising 12 non-asthmatic subjects and seven asthmatic subjects (p 0.180). Prolonged infections were present in six asthmatic subjects and one non-asthmatic subject (p 0.001). A wide variety of respiratory tract infections, ranging from common cold to pneumonia, were associated with serologically confirmed C. pneumoniae infections. Infections were often mild, with common cold and sinusitis being the most common manifestations. Acute, rapidly resolved C. pneumoniae infections were equally common among asthmatic subjects and non-asthmatic subjects, whereas prolonged infections were more common among subjects with asthma.

Antimicrobial susceptibility and genetic characteristics of Streptococcus pneumoniae isolates indicating possible nosocomial transmission routes in a community hospital in Japan

A clinical study was designed to study Streptococcus pneumoniae isolates recovered from a community hospital in Japan from April 2001 to November 2002. A total of 73 isolates were defined as derived from inpatient, outpatient, and hospital staff groups. The MIC results showed that 20 strains (27.4%) were susceptible to penicillin G, 39 strains (53.4%) had intermediate resistance, and 14 strains (19.2%) had full resistance. Low susceptibility to macrolides was also detected: 32.9%, 32.9%, and 34.2% of all strains were resistant to erythromycin, clarithromycin, and azithromycin, respectively. Thirty strains (41%) were resistant to at least two different kinds of antibiotics. Nineteen disparate serotypes were detected besides two nontypeable strains, and the predominant serotypes were 19F and 23F. Pulsed-field gel electrophoresis (PFGE) pattern A was dominant in the serotype 19F group; this pattern was similar to that of the international clone Taiwan 19F. A total of 10 different patterns were detected in the 23F group and were distinguishable from those of the international clones Spain 23F and Taiwan 23F. Pattern b strains were identified in the same ward, and pattern d strains were found both in patients with nosocomial pneumococcal infections (NPI) and in outpatients. In conclusion, drug-resistant S. pneumoniae was spreading rapidly, especially isolates of the serotype 19F and 23F groups. PFGE data revealed interpatient transmission and suggested that there might be some association between NPI patient strains and outpatient strains.

Community-acquired viral pneumonia

Advanced age often is associated with functional and immunologic decline and chronic cardiopulmonary diseases that predispose to pneumonia when viral infection occurs. Influenza virus remains the primary viral pathogen in the elderly, although the impact of the other respiratory viruses remains to be defined. The clinical syndromes associated with respiratory viruses frequently are indistinguishable from one another or bacterial pathogens; often, viral illness in older adults exacerbates underlying conditions, complicating diagnosis. Antiviral therapy is available for influenza A and B; specific viral diagnosis, particularly with the use of rapid antigen detection, may be useful for clinical management. Treatment for other viruses primarily is supportive.

Epidemiology of sepsis: race, sex, and chronic alcohol abuse

The annual incidences of severe sepsis in several industrialized nations have recently been reported to be 50-100 cases per 100,000 persons. These numbers exceed the estimated rates for other diseases that hold a heightened public awareness, including breast cancer and acquired immune deficiency syndrome. There are also sex and race differences in the incidence of sepsis. Men are more likely than women to develop sepsis, with a mean annual relative risk of 1.28. Nonwhites are nearly twice as likely to develop sepsis as whites. These race and sex disparities in the incidence of sepsis are likely explained by differences in a variety of factors, including the presence of comorbid conditions. For example, chronic alcohol abuse is associated with a persistent fever, delayed resolution of symptoms, increased rates of bacteremia, increased use of intensive care, prolonged duration of hospital stay, and increased cost of hospitalization for infected patients.

Valeur pronostique du dosage de la protéine C réactive (CRP) dans les pneumopathies aiguës infectieuses du sujet âgé: corrélation avec le score de Fine 97

The Fine's score, a predictive score of infectious pneumonia gravity, does not integrate inflammatory parameters, which are routinely used in the management of infectious pneumonia. The aim of our study was to establish a correlation between the Fine's score and C reactive protein.

PATIENTS AND METHODS

One hundred patients hospitalized for infectious pneumonia, 57 men and 43 female, with an average age of 85 years were retrospectively recorded.

RESULTS

The median level of C reactive protein was 157 mg/L. Global mortality rate was 26% and respectively 5, 16 and 45% in the grades III, IV, V of the Fine's score. Beyond 75,5 mg/L C reactive protein concentration, the mortality rate was contained between 28 and 32%. The comparison of the ROC curves of the Fine's score and C reactive protein did not showed any difference.

CONCLUSION

C-Reactive protein is less precise than the Fine's score to assess infectious pneumonia gravity but seems to be an indicator of the potential gravity of the pneumonia.

Etiology of Community-Acquired Pneumonia in Hospitalized Patients in Chile

BACKGROUND AND STUDY OBJECTIVES

The range and relative impact of microbial pathogens, particularly viral pathogens, as a cause of community-acquired pneumonia (CAP) in hospitalized adults has not received much attention. The aim of this study was to determine the microbial etiology of CAP in adults and to identify the risk factors for various specific pathogens.

METHODS

We prospectively studied 176 patients (mean [+/- SD] age, 65.8 +/- 18.5 years) who had hospitalized for CAP to identify the microbial etiology. For each patient, sputum and blood cultures were obtained as well as serology testing for Mycoplasma pneumoniae and Chlamydophila pneumoniae, urinary antigen testing for Legionella pneumophila and Streptococcus pneumoniae, and a nasopharyngeal swab for seven respiratory viruses.

RESULTS

Microbial etiology was determined in 98 patients (55%). S pneumoniae (49 of 98 patients; 50%) and respiratory viruses (32%) were the most frequently isolated pathogen groups. Pneumococcal pneumonia was associated with tobacco smoking of > 10 pack-years (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.2 to 5.4; p = 0.01). Respiratory viruses were isolated more often in fall or winter (28%; p = 0.011), and as an exclusive etiology tended to be isolated in patients >/= 65 years of age (20%; p = 0.07). Viral CAP was associated with antimicrobial therapy prior to hospital admission (OR, 4.5; 95% CI, 1.4 to 14.6).

CONCLUSIONS

S pneumoniae remains the most frequent pathogen in adults with CAP and should be covered with empirical antimicrobial treatment. Viruses were the second most common etiologic agent and should be tested for, especially in fall or winter, both in young and elderly patients who are hospitalized with CAP.

Pulmonary tuberculosis presenting as community-acquired pneumonia

OBJECTIVE AND BACKGROUND

The aims of this study were to investigate the frequency of Mycobacterium tuberculosis as a cause of community-acquired pneumonia (CAP) requiring hospitalization in Malaysia, and to define the clinical features of pulmonary tuberculosis (PTB) that distinguish it from non-TB CAP.

METHODS

A prospective study was performed on consecutive non-immunocompromised patients aged 12 years and older, who were hospitalized for CAP.

RESULTS

Of a total of 346 patients hospitalized for CAP, the aetiological agent was identified in 163 patients (47.1%). M. tuberculosis was isolated in 17 patients (4.9%). Multivariate analysis revealed that the following features were significantly associated with culture-positive PTB: duration of symptoms of more than 2 weeks before hospital admission (odds ratio (OR) 25.10; 95% confidence interval (CI) 4.63-136.05; P<0.001), history of night sweats (OR 5.43; 95% CI 1.10-26.79; P=0.038), chest radiograph showing upper lobe involvement (OR 8.23; 95% CI 1.59-42.53; P=0.012) or cavitary infiltrates (OR 19.41; 95% CI 2.94-128.19; P=0.002), total white blood cell count on admission of 12x10(9)/L or less (OR 6.28; 95% CI 1.21-32.52; P=0.029) and lymphopenia (OR 4.73; 95% CI 1.08-20.85; P=0.040).

CONCLUSION

Mycobacterium tuberculosis was not an uncommon cause of CAP requiring hospitalization in Malaysia. A longer duration of symptoms, history of night sweats, upper lobe involvement, cavitary infiltrates, lower total white blood cell count and lymphopenia were predictive of PTB.

Capture-recapture estimation of underreporting of legionellosis cases to the National Legionellosis Register: Italy 2002

The objective of this study was to evaluate the degree of underreporting to the Italian National Legionellosis Register (NLR). For the year 2002, all cases of Legionellosis notified to the NLR were compared with cases recorded in the hospital discharge record (HDR) database. The number of unreported cases and the total number of cases in the population were estimated using the capture-recapture method with two independent data sources. Seventeen out of 21 Italian regions participated in the study. Overall, underreporting was estimated to be 21.4% and was found to be significantly greater in the Centre-South (28.2%) than in the North (20.0%). However, even after taking into account the higher degree of underreporting, a significantly lower incidence of the disease is registered in central-southern Italy. The hypothesis, which needs to be verified, is that, in addition to underreporting, under-diagnosis of legionellosis is more widespread in this geographical area.

Comparison of plain chest radiography and high-resolution CT in human immunodeficiency virus infected patients with community-acquired pneumonia: a sub-Saharan Africa study

The objective of the study was to determine the proportion of patients with missed lesions on plain chest radiographs compared with high-resolution computed tomography (HRCT) in 49 human immunodeficiency virus (HIV) infected patients with community-acquired pneumonia (CAP). Patients underwent plain chest radiography and HRCT scans of the chest at admission. Microbiological investigations for CAP were performed. An experienced radiologist, without knowledge of clinical or pathological data, reported the chest radiographs and HRCT scans. The study group included 26 females and 23 males, aged 18-53 years (mean age 36 years). Organisms were isolated from 26 patients (53%). In 40 patients (82%), the HRCT scans demonstrated lesions not visualized on the plain chest radiographs. There was 100% correlation between plain radiographic and HRCT scan findings in nine cases (18%). Lesions that were not visualized on the plain radiographs but elucidated on HRCT included: pleural effusion (n = 14), ground-glass opacification (n = 20), pericardial effusion (n = 8), cavitation (n = 4), cysts (n = 4), bullae (n = 4), abscess (n = 1) and pneumothorax (n = 1). In 20 of 23 cases, hilar lymphadenopathy, identified on HRCT, was not recognized on plain chest radiographs. In patients in whom an organism was isolated, a correct HRCT diagnosis of pulmonary tuberculosis, bacterial pneumonia and Pneumocystis carinii pneumonia (PCP) was made in 80%, 84% and 100% of cases, respectively. The proportion of patients with missed lesions on plain chest radiographs in HIV infected patients with CAP was high. This has important implications for management and prognosis. HRCT scans correlate well with the microbiological diagnosis when reported by an experienced radiologist.

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

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

Serum vascular endothelial growth factor in pediatric patients with community-acquired pneumonia and pleural effusion

This study investigated the serum vascular endothelial growth factor (VEGF) levels in children with community-acquired pneumonia. Serum VEGF levels were measured in patients with pneumonia (n=29) and in control subjects (n=27) by a sandwich enzyme-linked immunosorbent assay. The pneumonia group was classified into bronchopneumonia with pleural effusion (n=1), bronchopneumonia without pleural effusion (n=15), lobar pneumonia with pleural effusion (n=4), and lobar pneumonia without pleural effusion (n=9) groups based on the findings of chest radiographs. We also measured serum IL-6 levels and the other acute inflammatory parameters. Serum levels of VEGF in children with pneumonia were significantly higher than those in control subjects (p<0.01). Children with lobar pneumonia with or without effusion showed significantly higher levels of serum VEGF than children with bronchopneumonia. For lobar pneumonia, children with pleural effusion showed higher levels of VEGF than those without pleural effusion. Children with a positive urinary S. pneumonia antigen test also showed higher levels of VEGF than those with a negative result. Serum IL-6 levels did not show significant differences between children with pneumonia and control subjects. Serum levels of VEGF showed a positive correlation with the erythrocyte sedimentation rate in the children with pneumonia. In conclusion, VEGF may be one of the key mediators that lead to lobar pneumonia and parapneumonic effusion.

Development of conventional and real-time NASBA for the detection of Legionella species in respiratory specimens

Isothermal nucleic acid sequence-based amplification (NASBA) was applied to detect Legionella 16S rRNA. The assay was originally developed as a Legionella pneumophila conventional NASBA assay with electrochemiluminescence (ECL) detection and was subsequently adapted to a L. pneumophila real-time NASBA format and a Legionella spp. real-time NASBA using molecular beacons. L. pneumophila RNA prepared from a plasmid construct was used to assess the analytical sensitivity of the assay. The sensitivity of the NASBA assay was 10 molecules of in vitro wild type L. pneumophila RNA and 0.1-1 colony-forming units (CFU) of L. pneumophila. In spiked respiratory specimens, the sensitivity of the NASBA assays was 1-10000 CFU of L. pneumophila serotype 1 depending on the background. After dilution of the nucleic acid extract prior to amplification, 1-10 CFU of L. pneumophila serotype 1 could be detected with both detection methods. Finally, 27 respiratory specimens, well characterized by culture and PCR, collected during a L. pneumophila outbreak, were tested by conventional and real-time NASBAs. All 11 PCR positive samples were positive by conventional NASBA, 9/11 and 10/11 were positive by L. pneumophila real-time NASBA and Legionella spp. real-time NASBA, respectively.

Predictors of mortality for lower respiratory infections in nursing home residents with dementia were validated transnationally

BACKGROUND AND OBJECTIVE

Generalizability of clinical predictors for mortality from lower respiratory infection (LRI) in nursing home residents has not been assessed for residents with dementia.

STUDY DESIGN AND SETTING

In prospective cohort studies of LRI in 61 nursing homes in the Netherlands (n = 541) and 36 nursing homes in Missouri, USA (n = 564), we examined 14-day and 1- and 3-month mortality in residents with dementia who were treated with antibiotics.

RESULTS

A logistic model predicting 14-day mortality derived from Dutch data included eating dependency, elevated pulse, decreased alertness, respiratory difficulty, insufficient fluid intake, high respiratory rate, male gender, and pressure sores. After adjusting coefficients with the heuristic shrinkage factor, the 14-day model showed good discrimination and calibration in both datasets. The apparent c-statistic for the original Dutch model was 0.80 (after correction for optimism, it was 0.75); the c-statistic was 0.74 in the U.S. validation population. The models predicting 1- and 3-month mortality showed moderate performance. A scoring system for estimating 14-day mortality performed equally well as the original model.

CONCLUSION

We identified a set of credible clinical predictors that are easily assessed and demonstrated validity in identifying residents at low risk of dying from LRI across different nursing home populations. This tool should inform decision-making for families and doctors.

Community-acquired pneumonia: a practical approach to management for the hospitalist

Community-acquired pneumonia (CAP) is common, and inpatient physicians should be familiar with the most current evidence about and guidelines for CAP management. Our conclusions and recommendations include: Streptococcus pneumoniae is the most common identified cause of CAP requiring hospitalization, whereas Legionella pneumophila is a common cause of severe CAP. The chest radiograph remains an essential initial test in the diagnosis of CAP and should be supplemented by blood cultures sampled prior to antibiotic therapy and sputum for gram stain and culture if a high-quality specimen can be rapidly processed. Once the diagnosis is made, the Pneumonia Severity Index (PSI) should be used to optimize the location of treatment and to provide prognostic information. Absent other mitigating factors, patients in PSI risk classes I, II, and III can safely be treated as outpatients. Hospitalized patients with CAP should be treated promptly with empiric antibiotics. Nonsevere pneumonia should be treated with a parenteral beta-lactam plus either doxycycline or a macrolide. Patients admitted to the intensive care unit should be treated with a beta-lactam plus either a macrolide or a fluoroquinolone as well as be evaluated for pseudomonal risk factors. Most patients with nonsevere CAP reach clinical stability in 2-3 days and should be considered for a switch to oral therapy and discharge shortly thereafter. Patients should receive pneumococcal vaccination, influenza vaccination, and tobacco cessation counseling prior to discharge if eligible. Multiple quality indicators are measured and publicly reported in the management of CAP, which provides hospitals with an opportunity to improve care processes and patient outcomes.

Clinical and bacteriologic efficacy of telithromycin in patients with bacteremic community-acquired pneumonia

This retrospective analysis was performed to determine the clinical and bacteriologic efficacy of the ketolide antibacterial telithromycin in patients with community-acquired pneumonia (CAP) with pneumococcal bacteremia. Patients 13 years old with radiologically confirmed CAP and a positive blood culture for Streptococcus pneumoniae at screening were analyzed from eight multicenter Phase III/IV clinical trials. In four open-label, non-comparative studies, patients received telithromycin 800 mg once daily for 7-10 days. In four randomized, controlled, double-blind, comparative studies, patients received telithromycin 800 mg once daily for 5-10 days or a comparator antimicrobial (amoxicillin 1000 mg three times daily, clarithromycin 500 mg twice daily, or trovafloxacin 200 mg once daily) for 7-10 days. In total, 118 patients (telithromycin, 94/1061 [8.9%]; comparator, 24/244 [9.8%]) had documented pneumococcal bacteremia. Those who were treated with telithromycin achieved a clinical cure rate of 90.2% (74/82, per-protocol population); S. pneumoniae was eradicated in 77/82 (93.9%) bacteremic patients who received telithromycin and 15/19 (78.9%) comparator-treated patients. Clinical cure was also observed among telithromycin-treated bacteremic patients who were infected with penicillin- or erythromycin-resistant strains of S. pneumoniae (5/7 and 8/10, respectively). In conclusion, telithromycin achieves high clinical and bacteriologic cure rates in CAP patients with pneumococcal bacteremia.

Usefulness of procalcitonin to differentiate typical from atypical community-acquired pneumonia

BACKGROUND

The value of elevated serum procalcitonin concentration for differentiating between typical and atypical community-acquired pneumonia was assessed and compared with other parameters that are usually used in clinical practice.

PATIENTS AND METHODS

Thirty consecutive adult patients with community-acquired bacterial pneumonia admitted to the Department of Infectious Diseases, University Medical Center Ljubljana, Slovenia, were included in this prospective study. Only those patients for whom the etiology of bacterial pneumonia was confirmed participated in the study.

RESULTS

The median serum procalcitonin level in patients with typical pneumonia was 7.64 ng/ml (range 0.26-63.16) and in the group with atypical pneumonia 0.80 ng/ml (range 0.13-34.90). A significant difference between the typical and atypical pneumonia groups was found only for the procalcitonin serum concentration on admission. The standard laboratory markers of bacterial infections, such as C-reactive protein, total leukocyte count and immature polymorphonuclear cells, did not discriminate between typical and atypical etiology. Median procalcitonin levels were significantly higher among patients with bacteremic pneumonia.

CONCLUSIONS

Determination of the procalcitonin level may provide useful additional diagnostic information on the etiology of pneumonia and could have a crucial influence on the initial antimicrobial therapy.

Fulminant community-acquired Acinetobacter baumannii pneumonia as a distinct clinical syndrome

STUDY OBJECTIVES

Acinetobacter baumannii (AB) is an important cause of hospital-acquired pneumonia (HAP), and an uncommon but important cause of community-acquired pneumonia (CAP) with high mortality. To better characterize CAP-AB, we compared its clinical features and outcomes with a control group of HAP-AB patients.

METHODS

This is a retrospective case-control study comparing CAP-AB and HAP-AB patients, which was performed at United Christian Hospital between July 2000 and December 2003.

RESULTS

There were 19 cases of CAP-AB and 74 cases of HAP-AB. When compared with the HAP-AB group, the CAP-AB group had more ever-smokers (84.3% vs 55.4%, respectively; p = 0.031), more COPD patients (63.2% vs 29.7%, respectively; p = 0.014), and fewer median days of hospitalization (HAP-AB group, median, 0 days; CAP-AB group, 0 days [range, 0 to 30 days]; p = 0.049) in the previous year. The CAP-AB group had more patients with positive blood culture findings (31.6% vs 0%, respectively; p < 0.001), a higher frequency of ARDS (84.2% vs 17.6%, respectively; p < 0.001), and disseminated intravascular coagulation (DIC) (57.9% vs 8.1%, respectively; p < 0.001). The median survival time was only 8 days in the CAP-AB group, vs 103 days in the HAP-AB group (p = 0.003). Factors associated with the higher mortality in the CAP-AB group included the presence of AB bacteremia (p = 0.040), platelet count of < 120 x 10(9) cells/L (p = 0.026), pH < 7.35 on presentation (p = 0.047), and the presence of DIC (p = 0.004).

CONCLUSIONS

CAP-AB appears to be a unique clinical entity with a high incidence of bacteremia, ARDS, DIC, and death, when compared to HAP-AB. Further studies are needed to investigate the mechanism of the fulminant nature of CAP-AB.

Swedish guidelines for the management of community-acquired pneumonia in immunocompetent adults

This document presents the evidence-based guidelines of the Swedish Society of Infectious Diseases for the management of adult immunocompetent patients with community-acquired pneumonia (CAP), who are assessed at hospital. The prognostic score 'CURB-65' is recommended for all CAP patients in the emergency room. The score provides an assessment tool for the decision regarding outpatient treatment or level of hospital supervision, the choice of microbiological investigations, and empirical antibiotic treatment. In patients with non-severe CAP (CURB-65 score 0-2) we recommend initial narrow-spectrum antibiotic treatment, orally or intravenously, primarily directed at Streptococcus pneumoniae. In those with CURB-65 score 3, penicillin G or a cephalosporin intravenously is recommended. For CURB-65 score 0-3 atypical pathogens should be covered only when they are suspected on clinical or epidemiological grounds. In patients with CURB-65 score 4-5 intravenous combination therapy with either cephalosporin/macrolide or penicillin G/fluoroquinolone is recommended. Efforts should be made to identify the CAP aetiology in order to support the ongoing antibiotic treatment or to suggest treatment alterations. Recommended measures for prevention of CAP include influenza -- and pneumococcal -- vaccination to risk groups and efforts for smoking cessation.

Neumonías comunitarias graves del adulto

Las neumonías agudas comunitarias son causa frecuente de hospitalización y mortalidad. El reconocimiento inmediato de las formas graves según criterios simples, clínicos, radiológicos y de laboratorio, es una etapa esencial para un tratamiento rápido en el servicio de reanimación con el fin de controlar los fallos orgánicos. La obtención de muestras apropiadas para realizar estudios microbiológicos precede al tratamiento antibiótico, que se debe instaurar con rapidez después de diagnosticar la neumonía. Pese a las técnicas de identificación, sólo la mitad de las neumonías se documentan adecuadamente. El tratamiento antibiótico, en principio empírico, integra los gérmenes patógenos, tanto extracelulares como intracelulares, que producen neumonías con mayor frecuencia; siempre debe ser activo contra el neumococo, la bacteria implicada más a menudo. La asociación de un betalactámico y un macrólido o una fluoroquinolona es la que mejor responde a este objetivo. En las recomendaciones más comunes, las fluoroquinolonas activas contra los neumococos sustituyen a los fármacos precedentes. En el caso excepcional de los pacientes con factores de riesgo especiales, el tratamiento empírico debe tener en cuenta Pseudomonas aeruginosa. La gravedad de parte de las neumonías comunitarias justifica el que se recurra a tratamientos complementarios. Se debe evaluar de nuevo el tratamiento antibiótico en las 72 horas siguientes a su instauración, a fin de valorar su eficacia, adaptar el tratamiento en caso necesario y simplificarlo. El mantenimiento de antibióticos de amplio espectro expone al paciente a efectos secundarios y contribuye a producir resistencias bacterianas. En cuanto a las neumonías neumocócicas, las fluoroquinolonas activas contra el neumococo podrían representar una alternativa en caso de que el neumococo desarrolle resistencia a los betalactámicos. La mortalidad persistente de las neumonías sigue siendo notable. Esto debe fomentar la mejora del tratamiento inicial y la búsqueda de nuevas opciones terapéuticas.

Diarrhea caused by primarily non-gastrointestinal infections

Direct infections of the gastrointestinal tract cause most cases of diarrhea, but diarrhea can also be caused by systemic infections or infections that affect other organ systems. The authors of this Review discuss clinically relevant infectious diseases that do not primarily affect the gastrointestinal tract but commonly cause diarrhea, and note that they should be included in the differential diagnosis and diagnostic approach to diarrhea.

Infectious diseases that do not primarily affect the gastrointestinal tract can cause severe diarrhea. The pathogenesis of this kind of diarrhea includes cytokine action, intestinal inflammation, sequestration of red blood cells, apoptosis and increased permeability of endothelial cells in the gut microvasculature, and direct invasion of gut epithelial cells by various infectious agents. Of the travel-associated systemic infections presenting with fever, diarrhea occurs in patients with malaria, dengue fever and SARS. Diarrhea also occurs in patients with community-acquired pneumonia, when it is suggestive of legionellosis. Diarrhea can also occur in patients with systemic bacterial infections. In addition, although diarrhea is rare in patients with early Lyme borreliosis, the incidence is higher in those with other tick-borne infections, such as ehrlichiosis, tick-borne relapsing fever and Rocky Mountain spotted fever. Unfortunately, it is often not established whether diarrhea is an initial symptom or develops during the course of the disease. The real incidence of diarrhea in some infectious diseases must also be questioned because it could represent an adverse reaction to antibiotics.

Enhancing the etiologic diagnosis of community-acquired pneumonia in adults using the urinary antigen assay (Binax NOW)

OBJECTIVES

Approximately 40% of community-acquired pneumonia (CAP) remains of unknown etiology. To improve the rate of detection of the causative microbiologic agent, the Binax NOW Streptococcus pneumoniae urinary antigen test (UAT) was evaluated.

DESIGN

In this prospective study, 67 adults with CAP were compared with 81 healthy patients to determine sensitivity and specificity of the UAT and its role in improving the etiologic diagnosis of CAP.

RESULTS

An etiology could be found for 22 patients (33%) using conventional methods (14 S. pneumoniae, sensitivity 64.3%, 1/81 positive UAT control urine samples, specificity 98.8%). This proportion increased to 33 patients (49%) with the addition of the urinary antigen test (p = 0.039). Pneumococcal infection was diagnosed by the UAT in 24% of our patients without an etiologic identification by conventional methods.

CONCLUSIONS

Given its excellent specificity, this test can be considered an important tool for detecting S. pneumoniae in CAP of unknown etiology, enabling the diagnosis of pneumococcal pneumonia in a quarter of cases.

Epidemiology of community-acquired pneumonia in adult patients at the dawn of the 21st century: a prospective study on the Mediterranean coast of Spain

This study presents data from a prospective study of adult patients with community-acquired pneumonia (CAP). Of 493 patients included in the study, 223 (45.2%) were aged > or = 65 years, and 265 (53.7%) had one or more underlying diseases, mostly chronic obstructive pulmonary disease, diabetes mellitus or dementia. In total, 281 microorganisms were identified in 250 (50.7%) patients, with two or more pathogens detected in 28 (5.7%) cases. Microbial diagnosis varied according to age, severity, co-morbidity and site-of-care, but there was much overlap among groups. Streptococcus pneumoniae was the single most prevalent organism in outpatients, patients admitted to hospital, and patients who died, either as a single pathogen or combined with another organism. Infections caused by 'atypical' pathogens were seen across all groups, including the elderly and patients with co-morbidities. Mortality varied according to the pneumonia severity index (PSI) of the pneumonia patient outcomes research team. Shock (OR 34.48), an age of > 65 years (OR 25) and altered mental status (OR 9.92) were factors associated independently with 30-day mortality. Key findings from this study were the advanced age of the population with CAP, and the high prevalence of dementia as an underlying disease. The study also revealed that microbiological diagnosis of CAP remains problematic. Although certain epidemiological features may help to predict the microbial aetiology, the overlap among groups reduces the usefulness of this information in guiding therapeutic decisions. Greater effort should be made to improve identification methods for microbial pathogens causing CAP.

Comparison between pathogen directed antibiotic treatment and empirical broad spectrum antibiotic treatment in patients with community acquired pneumonia: a prospective randomised study

BACKGROUND

There is much controversy about the ideal approach to the management of community acquired pneumonia (CAP). Recommendations differ from a pathogen directed approach to an empirical strategy with broad spectrum antibiotics.

METHODS

In a prospective randomised open study performed between 1998 and 2000, a pathogen directed treatment (PDT) approach was compared with an empirical broad spectrum antibiotic treatment (EAT) strategy according to the ATS guidelines of 1993 in 262 hospitalised patients with CAP. Clinical efficacy was primarily determined by the length of hospital stay (LOS). Secondary outcome parameters for clinical efficacy were assessment of therapeutic failure on antibiotics, 30 day mortality, duration of antibiotic treatment, resolution of fever, side effects, and quality of life.

RESULTS

Three hundred and three patients were enrolled in the study; 41 were excluded, leaving 262 with results available for analysis. No significant differences were found between the two treatment groups in LOS, 30 day mortality, clinical failure, or resolution of fever. Side effects, although they did not have a significant influence on the outcome parameters, occurred more frequently in patients in the EAT group than in those in the PDT group (60% v 17%, 95% CI -0.5 to -0.3; p<0.001).

CONCLUSIONS

An EAT strategy with broad spectrum antibiotics for the management of hospitalised patients with CAP has comparable clinical efficacy to a PDT approach.

The spectrum of practice in the diagnosis and management of pneumonia in patients requiring mechanical ventilation. Australian and New Zealand practice in intensive care (ANZPIC II)

This study of ventilated patients investigated current clinical practice in 476 episodes of pneumonia (48% community-acquired pneumonia, 24% hospital-acquired pneumonia, 28% ventilator-associated pneumonia) using a prospective survey in 14 intensive care units (ICUs) within Australia and New Zealand. Diagnostic methods and confidence, disease severity, microbiology and antibiotic use were assessed. All pneumonia types had similar mortality (community-acquired pneumonia 33%, hospital-acquired pneumonia 37% and ventilator-associated pneumonia 24%, P=0.15) with no inter-hospital differences (P=0.08-0.91). Bronchoscopy was performed in 26%, its use predicted by admission hospital (one tertiary: OR 9.98, CI 95% 5.11-19.49, P< 0.001; one regional: OR 6.29, CI 95% 3.24-12.20, P<0.001), clinical signs of consolidation (OR 3.72, CI 95% 2.09-6.62, P<0.001) and diagnostic confidence (OR 2.19, CI 95% 1.29-3.72, P=0.004). Bronchoscopy did not predict outcome (P=0.11) or appropriate antibiotic selection (P=0.69). Inappropriate antibiotic prescription was similar for all pneumonia types (11-13%, P=0.12) and hospitals (0-16%, P=0.25). Blood cultures were taken in 51% of cases. For community-acquired pneumonia, 70% received a third generation cephalosporin and 65% a macrolide. Third generation cephalosporins were less frequently used for mild infections (OR 0.38, CI 95% 0.16-0.90, P=0.03), hospital-acquired pneumonia (OR 0.40, CI 95% 0.23-0.72, P<0.01), ventilator-associated pneumonia (OR 0.04, CI 95% 0.02-0.13, P<0.001), suspected aspiration (OR 0.20, CI 95% 0.04-0.92, P=0.04), in one regional (OR 0.26, CI95% 0.07-0.97, P=0.05) and one tertiary hospital (OR 0.14, CI 95% 0.03-0. 73, P=0.02) but were more commonly used in older patients (OR 1.02, CI 95% 1.01-1.03, P=0.01). There is practice variability in bronchoscopy and antibiotic use for pneumonia in Australian and New Zealand ICUs without significant impact on patient outcome, as the prevalence of inappropriate antibiotic prescription is low. There are opportunities for improving microbiological diagnostic work-up for isolation of aetiological pathogens.