Community-acquired pneumonia

From virus to inflammation, how influenza promotes lung damage

Despite seasonal vaccines, influenza-related hospitalization and death rates have remained unchanged over the past 5 years. Influenza pathogenesis has 2 crucial clinical components; first, influenza causes acute lung injury that may require hospitalization. Second, acute injury promotes secondary bacterial pneumonia, a leading cause of hospitalization and disease burden in the United States and globally. Therefore, developing an effective therapeutic regimen against influenza requires a comprehensive understanding of the damage-associated immune-mechanisms to identify therapeutic targets for interventions to mitigate inflammation/tissue-damage, improve antiviral immunity, and prevent influenza-associated secondary bacterial diseases. In this review, the pathogenic immune mechanisms implicated in acute lung injury and the possibility of using lung inflammation and barrier crosstalk for developing therapeutics against influenza are highlighted.

Pneumococcal epidemiology among us adults hospitalized for community-acquired pneumonia

BACKGROUND

Few studies have measured the burden of adult pneumococcal disease after the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the US infant vaccination schedule. Further, most data regarding pneumococcal serotypes are derived from invasive pneumococcal disease (IPD), which represents only a fraction of all adult pneumococcal disease burden. Understanding which pneumococcal serotypes cause pneumonia in adults is critical for informing current immunization policy. The objective of this study was to measure the proportion of radiographically-confirmed (CXR+) community-acquired pneumonia (CAP) caused by PCV13 serotypes in hospitalized US adults.

METHODS

This observational, prospective surveillance study recruited hospitalized adults aged ≥18 years from 21 acute care hospitals across 10 geographically-dispersed cities in the United States between October 2013 and September 2016. Clinical and demographic data were collected during hospitalization. Vital status was ascertained 30 days after enrollment. Pneumococcal serotypes were detected via culture from the respiratory tract and normally-sterile sites (including blood and pleural fluid). Additionally, a novel, Luminex-based serotype-specific urinary antigen detection (UAD) assay was used to detect serotypes included in PCV13.

RESULTS

Of 15,572 enrolled participants, 12,055 eligible patients with CXR+CAP were included in the final analysis population. Mean age was 64.1 years and 52.7% were aged ≥65 years. Common comorbidities included chronic obstructive pulmonary disease (43.0%) and diabetes mellitus (28.6%). PCV13 serotypes were detected in 552/12,055 (4.6%) of all patients and 265/6347 (4.2%) of those aged ≥65 years. Among patients aged 18-64 years PCV13 serotypes were detected in 3.8-5.3% of patients depending on their risk status.

CONCLUSIONS

After implementation of a pneumococcal conjugate vaccination program in US children, and despite the herd protection observed in US adults, a persistent burden of PCV13-type CAP remains in this population.

Body mass index and risk of pneumonia: a systematic review and meta-analysis

The aims of our meta-analysis were to examine the pattern and gender's influence on body mass index (BMI) - pneumonia relationship. Published studies were searched from PubMed, Web of Science, Cochrane Library databases using keywords of pneumonia, BMI and epidemiologic studies. Random-effects analysis was applied to estimate pooled effect sizes from individual studies. The Cochrane Q-test and index of heterogeneity (I(2) ) were used to evaluate heterogeneity, and Egger's test was used to evaluate publication bias. Random-effects meta-regression was applied to examine the pattern and gender's influence on BMI-pneumonia relationship. A total of 1,531 studies were initially identified, and 25 studies finally were included. The pooled relative risk (RR) and meta-regression model revealed a J-shaped relationship between BMI and risk of community-acquired pneumonia (underweight, RR 1.8, 95% confidence interval [CI], 1.4-2.2, P < 0.01; overweight, 0.89, 95%CI, 0.8-1.03, P, 0.1; obesity, 1.03, 95% CI, 0.8-1.3, p. 8) and U-shaped relationship between BMI and risk of influenza-related pneumonia (underweight, RR 1.9, 95% CI, 1.2-3, P < 0.01; overweight, 0.89, 95% CI, 0.79-0.99, P, 0.03; obesity, 1.3, 95% CI, 1.05-1.63, p. 2; morbidity obesity, 4.6, 95% CI, 2.2-9.8, P < 0.01); whereas, no difference in risk of nosocomial pneumonia was found across the BMI groups. Gender difference did not make significant contribution in modifying BMI-pneumonia risk relationship.

Elderly patients with community-acquired pneumonia: optimal treatment strategies

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

Heterogeneity of the efficacy of the 23-valent pneumococcal polysaccharide vaccine caused by various underlying conditions of chronic pulmonary disease in older patients: prospective cohort study

OBJECTIVE

To determine the ideal conditions for use of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in older outpatients with chronic pulmonary diseases.

DESIGN

Prospective cohort study.

PARTICIPANTS

1378 outpatients with chronic pulmonary diseases ≥ 60 years of age.

INTERVENTION

Participants were educated about PPV23, and those who responded affirmatively were vaccinated between August and November 2002. The participants who chose no intervention served as controls. The prevaccine period was defined as August 2001 to August 2002. Participants were followed for 2 years from December 2002 or until death.

MAIN OUTCOME MEASURES

Events of interest included the first episode of bacterial (including pneumococcal) pulmonary infection (primary endpoint) and death of any cause (secondary endpoint).

RESULTS

Frequent episodes of pulmonary infection during the prevaccine period significantly decreased event-free survival during the 2-year observation period (p<0.001). Chronic respiratory failure was associated with a decreased event-free survival only when the pulmonary infection episode did not occur in the prevaccine period (p<0.001). No significant differences in event-free survival were observed between the vaccinated and unvaccinated group during analysis of the entire cohort. In the Cox proportional hazards regression model, event-free survival decreased significantly when pulmonary infection occurred in the prevaccine period. In the subgroup analysis, the first episode of bacterial pulmonary infection (but not death of any cause) was reduced significantly by PPV23 only in patients with chronic respiratory failure who had no episodes of pulmonary infection during the prevaccine period (p=0.019).

CONCLUSION

The efficacy of PPV23 against pulmonary infection and death of any cause might be unachievable if pulmonary infection occurs during the prevaccine period. PPV23 needs to be given to older patients with chronic pulmonary disease at an earlier time in which infectious complications in the lung have not yet occurred.

Asthma and pneumonia

Chest pain remains a common complaint among children seeking care in the United States. Asthma and lower respiratory tract infections such as pneumonia can be significant causes of chest pain. Children with chest pain caused by either of these pulmonary etiologies generally present with associated respiratory symptoms, including cough, wheezing, tachypnea, respiratory distress, and/or fever. Although analgesic medications can improve chest pain associated with pulmonary pathologies, the mainstay of therapy is to treat the underlying etiology; this includes bronchodilator and/or steroid medications in children with asthma and appropriate antibacterial administration in children with suspicions of bacterial pneumonia. The chest pain generally resolves along with the resolution of other respiratory symptoms.

Utility of brain natriuritic peptide as a diagnostic tool for congestive heart failure in the elderly

We studied the performance characteristics of B-type natriuretic peptide (BNP) as a diagnostic test for congestive heart failure in the elderly dyspneic population. In a retrospective chart review study, dyspneic patients who had a BNP level drawn were included. To diagnose congestive heart failure (CHF), the Framingham Criteria were used. To diagnose pneumonia or a lower respiratory tract infection, the consensus development conference Criteria for Pneumonia/Lower Respiratory Tract Infection were used. Based on the criteria satisfied, the patients were categorized into one of 4 groups: group 1, pneumonia/lower respiratory tract infection; group 2, CHF; group 3, both; group 4, neither. Sensitivity, specificity, and positive and negative likelihood ratios were calculated for various BNP reference limits from 100 pg/ml upwards in increments of 100. A total of 70 patients (mean age 76.5) presenting with dyspnea were included in the study. Forty-six were females. The mean (+/-SD) BNP level for group 1 (n = 13) was 273 (+/-360) pg/ml, for group 2 (n = 30) it was 1394 (+/-934) pg/ml, for group 3 (n = 17) it was 1138 (+/-842) pg/ml, and for group 4 (n = 10) it was 403 (+/-362) pg/ml. Forty-seven patients (groups 2 and 3) met the Framingham criteria (CHF+). The other 23 (groups 1 and 4) did not (CHF-). The sensitivity and specificity of BNP for CHF at a cutoff of 100 pg/ml was 96% and 26%, respectively. The sensitivity (87%) and specificity (74%) were optimal at a cutoff of 400 pg/ml. Our study indicates that the specificity of a BNP level of > or = 100 pg/ml for diagnosing CHF in the elderly is poor. Our data suggest an optimal BNP value of > or = 400 pg/ml. Elderly patients frequently have multiple etiologies contributing to dyspnea. In our study, one-fourth of the patients satisfied the criteria for a dual diagnosis of CHF and pneumonia.

Pneumonia in the elderly: a review of the epidemiology, pathogenesis, microbiology, and clinical features

Pneumonia is a common and important disease in the elderly. The incidence is expected to rise as the population ages, and, therefore, it will become an increasingly significant problem in hospitals and the community. A comprehensive literature review was performed in order to look at the characteristics of pneumonia in the elderly population. In particular, the epidemiology, etiology and pathogenesis--including risk factors, microbiology, and clinical features--were evaluated. While aging causes physiological changes which make elderly patients more susceptible to pneumonia, it was found that comorbidities, rather than age, are also an important risk factor. The most common micro-organism responsible for pneumonia is Streptococcus pneumoniae, but other organisms need to be considered, depending on the environment of presentation. Elderly patients are more likely than younger adults to present with an absence of fever and an altered mental state. Nursing home residents tend to present with more atypical and less characteristic symptoms.

Pneumonia in the elderly: a review of severity assessment, prognosis, mortality, prevention, and treatment

Pneumonia is an increasingly common disease in the elderly due to an aging population. This is a comprehensive literature review outlining the severity assessment, morbidity, mortality, prevention and treatment options. Several models have been postulated to predict severity assessment and prognosis in older patients. Mortality increases with age and functional status is also an independent predictor for short- and long-term mortality. The effectiveness of the pneumococcal vaccine is controversial, whereas the influenza vaccine is universally recommended. Treatment involves antibiotics with the type and method depending on the severity of the pneumonia. However, treatment of nursing home patients is challenging and there are no validated guidelines at present to determine when transfer to the hospital is necessary.

Community-acquired pneumonia in elderly patients

Community-acquired pneumonia continues to have a significant impact on elderly individuals, who are affected more frequently and with more severe consequences than younger populations. As the population ages it is expected that the medical and economic impact of this disease will increase. Despite these concerns, little progress has been made in research specifically focusing on community-acquired pneumonia in the elderly. Data continue to show that a high index of suspicion, early antimicrobial therapy and appropriate medications to cover typical pathogens are extremely important in treating community-acquired pneumonia in older individuals. This review is designed to serve as an update to our previous work published in Aging Health in 2006, with specific emphasis on the most recent evidence published since that time.

Economic Impact of Implementing Pneumonia Treatment Guidelines for Intravenous to Oral Conversion

Background

Inpatient treatment of pneumonia produces significant costs to the health care system. In an effort to improve quality of care, decrease length of stay, and decrease drug costs associated with treating pneumonia, on October 1, 2006, the Veterans Affairs New York Harbor Healthcare System (VANYHHS) implemented guidelines for treating hospitalized patients with pneumonia. These guidelines included specific criteria for initial selection of an antimicrobial agent based on patient risk factors, conversion from intravenous (IV) to oral antibiotics, and selection of an appropriate oral agent for conversion. The primary objective of this study was assessment of the economic impact of implementing pneumonia treatment guidelines at the VANYHHS.

Methods

Retrospective analysis of 100 patients admitted to the VANYHHS for treatment of pneumonia was completed before implementation of the guidelines, and then those data were compared with similar data from a group of 100 patients admitted to the hospital for treatment of pneumonia after implementation of the guidelines. Electronic medical records were reviewed for (1) initial antibiotic therapy administered, (2) time needed for conversion from IV to oral antibiotics after becoming eligible for the switch based on implemented guidelines, and (3) length of hospital stay.

Results

Data from the preguideline group demonstrated that it took an additional 2.31 days to convert patients from IV to oral antibiotics after they were eligible for the switch to oral therapy. The mean length of stay was 9.2 days. Data from the postguideline group illustrated that the time needed to convert patients from IV to oral therapy was decreased to 1.09 days ( P = 0.002) and the mean length of stay was decreased to 8.76 days ( P = 0.677) when compared with the preguideline group data. The estimated annual cost savings from implementing pneumonia treatment guidelines based on the decrease in mean length of stay was $290,482.20 annually.

Conclusion

Implementing pneumonia treatment guidelines was associated with decreased length of stay and, thus, a decrease in the costs associated with treating pneumonia in an institutional setting. It is estimated that the VANYHHS could save nearly $300,000 annually as a result of the implementation of the treatment guidelines for pneumonia.

Comparative study of levofloxacin in the treatment of children with community-acquired pneumonia

BACKGROUND

Levofloxacin has established efficacy and safety in the treatment of community-acquired pneumonia (CAP) in adults, and its use as an alternative therapy for children with CAP has been proposed.

OBJECTIVE

Assess the clinical efficacy and safety of levofloxacin compared with standard of care antibiotic therapy in the treatment of CAP in children aged 6 months to 16 years.

METHODS

In an open-label, multicenter, noninferiority trial, children with CAP were randomized 3:1 to receive levofloxacin or comparator antimicrobial therapy (0.5 to <5 years: amoxicillin/clavulanate or ceftriaxone; > or =5 years: clarithromycin or ceftriaxone with clarithromycin or erythromycin lactobinate) for 10 days. The primary outcome was cure rates at the test-of-cure visit (10-17 days after completing treatment) as determined by symptoms, physical examination, and chest radiography.

RESULTS

Seven hundred and thirty-eight children were enrolled and 539 (405 levofloxacin-treated, 134 comparator-treated) were clinically evaluable at test-of-cure visit. Clinical cure rates were 94.3% (382 of 405) in levofloxacin-treated and 94.0% (126 of 134) in comparator-treated children. Cure rates were also similar for levofloxacin and comparator for each age group (<5 years, 92.2% versus 90.8%; > or =5 years, 96.5% versus 97.1%; respectively) and for children categorized as being at higher risk for severe disease. Mycoplasma pneumoniae was the most frequently identified cause of pneumonia (230 children). Levofloxacin was as well tolerated as comparators, with similar type and incidence of adverse events.

CONCLUSIONS

Levofloxacin was as well tolerated and effective as standard-of-care antibiotics for the treatment of CAP in infants and 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).

Hospitalized community-acquired pneumonia due to Streptococcus pneumoniae: Has resistance to antibiotics decreased?

STUDY OBJECTIVES

To determine the incidence and trends of pneumococcal community-acquired pneumonia (CAP) resistant to antibiotics, to describe clinical and microbiological features of pneumococcal CAP, and to ascertain prognostic risk factors in a third-level hospital.

DESIGN AND SETTING

We performed a prospective study of all well-defined pneumococcal CAP hospitalizations in the Hospital Clínic de Barcelona (Spain) over 2 years of follow-up, and results were compared with a previous study.

MEASUREMENTS AND RESULTS

One hundred twenty-five patients were included (mean age, 59.6 years; 71.2% male and 28.8% female). Mortality was 7% (n = 9). Twenty-four percent were HIV-1 seropositive (n = 30), and 53% had at least one comorbidity (n = 65). Nonsusceptibility to penicillin, ceftriaxone, and erythromycin accounted for 34%, 9%, and 33%, respectively. A decrease in penicillin (p = 0.01) and cephalosporin (p < 0.001) resistance was observed on comparison with a previous study, while macrolide resistance remained unchanged. Serotype 1 infection was overrepresented (8%, n = 10). A bad outcome was related to female gender (relative risk [RR], 9.1; confidence interval [CI], 1.3 to 61.3), pleural effusion (RR, 13.35; CI, 1.9 to 93.1), and prior oral corticoid intake (RR, 10.59; CI, 1.2 to 91.2), whereas drug-resistant strains were not.

CONCLUSIONS

We found a decrease in drug resistance compared with a previous report and a relatively high incidence of serotype 1 pneumococcal CAP. We also observed a high prevalence of HIV-1 infection among individuals with pneumococcal pneumonia. We confirm the lack of association of drug resistance with mortality and length of hospitalization. Mortality was associated with female gender, pleural effusion, and previous oral corticoid treatment. These results should be better ascertained in further studies.

Pharmacokinetics and intrapulmonary diffusion of levofloxacin in critically ill patients with severe community-acquired pneumonia

OBJECTIVE

To determine the steady-state plasma and epithelial lining fluid concentrations of intravenous levofloxacin, 500 mg, administered once or twice daily in critically ill patients with severe community-acquired pneumonia.

DESIGN

Prospective, open-label study.

SETTING

An intensive care unit and a clinical pharmacokinetic laboratory in two university hospitals.

PATIENTS

Twenty-four adult patients with severe community-acquired pneumonia and receiving mechanical ventilation were enrolled.

INTERVENTIONS

All subjects received 1-hr intravenous infusions of 500 mg levofloxacin once or twice daily. The plasma and epithelial lining fluid levofloxacin concentrations were determined at steady-state after 2 days of therapy with high-performance liquid chromatography.

MEASUREMENTS AND MAIN RESULTS

The median (interquartile range [IQR]) plasma and epithelial lining fluid peak levofloxacin concentrations were 12.6 (IQR, 12.0-14.1) and 11.9 (IQR, 8.7-13.7) mg/L, respectively, in the once-daily group and 19.7 (IQR, 19.0-22.0) and 17.8 (IQR, 16.2-23.5) mg/L in the twice-daily group, showing a pulmonary percentage penetration of >100% in both groups. The median (IQR) total body exposures were 151 (IQR, 137-174) and 416 (IQR, 406-472) mg.hr/L, respectively, in the once-daily and twice-daily groups.

CONCLUSIONS

Our results suggest that in critically ill patients who are receiving mechanical ventilation and have severe community-acquired pneumonia and creatinine clearance of >40 mL/min, the administration of 500 mg of intravenous levofloxacin once and twice daily allows for the exceeding of pharmacodynamic thresholds predictive of outcome (i.e., peak concentration to minimum inhibitory concentration ratio of >10 or area under concentration-time curve to minimal inhibitory concentration ratio of >125 hrs) both in serum and epithelial lining fluid for pathogens with minimum inhibitory concentration values of < or =1 mg/L and >1 mg/L, respectively.

Office pediatrics: current issues in lower respiratory infections in children

PURPOSE OF REVIEW

Recent estimates indicate that 1.9 million children worldwide die each year from acute respiratory illnesses, many of which are lower respiratory infections (LRIs). Global threats from indoor and outdoor air pollution, urban crowding, biologic weapons, and worldwide rapid transportation complicate our efforts to reduce the impact of LRI disease in children. As new strategies are developed to limit the spread of LRI disease in children, existing pathogens become more complex to treat and newer pathogens emerge as causes of clinical disease. Most LRI disease is managed in outpatient settings and remains a challenge to those who care for children.

RECENT FINDINGS

Atypical pathogens (notably mycoplasma pneumoniae) are now known to cause a wide spectrum of disease, and with more extensive complications than previously recognized. Available data suggest a rapid increase in S. pneumoniae resistance to penicillin and macrolides in many cases of community acquired pneumonia, which has resulted in shifts in outpatient (and inpatient) antibiotic treatment regimens. Human metapneumovirus (HMPV) is now recognized to cause LRI illness similar to respiratory syncytial virus (RSV) in infants and children. General strategies for the prevention of influenza infection are expanded to include many infants and young children, and are projected to significantly reduce morbidity and mortality from this key LRI pathogen.

SUMMARY

The spectrum of LRI pathogens--and the clinical illnesses caused by them--continues to change. Innovations in immunotherapy and vaccines will be instrumental to reducing the burden of LRI morbidity in infants and children worldwide in the future.

Adult community-acquired pneumonia in Malaysia: prediction of mortality from severity assessment on admission

OBJECTIVES

Prediction of mortality in patients with community-acquired pneumonia (CAP) can be assessed using clinical severity scores on admission to hospital. The clinical benefit of such tools is untested in Asian countries. The aim of this study was to determine the early adverse prognostic factors in patients hospitalized with CAP in Malaysia and to assess the usefulness of the British Thoracic Society (BTS) severity criteria.

METHODOLOGY

A prospective study was undertaken of all adult patients admitted between August 2002 and March 2003 in an urban-based university teaching hospital.

RESULTS

One hundred and eight patients (mean +/- SD age 55 +/- 20 years; 58% men) were eligible for the study. Thirteen patients (12%) died in hospital and 95 (88%) survived to hospital discharge. Older age, the presence of chronic illness, severity of comorbidity, reduced oxygen saturation and higher blood urea were associated with mortality during admission. Multivariate logistic regression of these variables identified reduced oxygen saturation as the only independently associated variable. BTS criteria fared poorly in predicting mortality compared with clinical assessment by attending clinicians (36-fold increased risk of death by 'clinical assessment' vs two-threefold by 'BTS criteria').

CONCLUSIONS

In hospitalized patients with CAP, certain factors are adversely associated with mortality during admission. Severity criteria validated in specific countries might not be universally applicable.

Pneumococcal conjugate vaccines for preventing vaccine-type invasive pneumococcal disease and pneumonia with consolidation on x-ray in children under two years of age

BACKGROUND

Pneumonia, most commonly caused by Streptococcus pneumoniae (Pnc), is a major cause of morbidity and mortality among young children especially in developing countries. Recently, the prevalence of antibiotic-resistant Pnc has increased worldwide such that the effectiveness of preventive strategies, like the new pneumococcal conjugate vaccines (PCV) on rates of invasive pneumococcal disease (IPD) and pneumonia, needs to be evaluated.

OBJECTIVES

To determine the efficacy of PCV in reducing the incidence of IPD due to vaccine serotypes (VT) and x-ray confirmed pneumonia with consolidation of unspecified etiology in children who received PCV before 12 months of age.

SEARCH STRATEGY

We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1 2004), MEDLINE (1990 to March 2004) and EMBASE (1990 to December 2003). Reference list of articles, and books of abstracts of relevant symposia, were hand searched. Researchers in the field were also contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing PCV with placebo, or another vaccine, among children below two years with IPD and clinical/radiographic pneumonia as outcomes.

DATA COLLECTION AND ANALYSIS

Two reviewers independently identified eligible studies, assessed trial quality, and extracted data. Differences were resolved by discussion. The inverse variance method was used to pool effect sizes.

MAIN RESULTS

We identified four trials assessing the efficacy of PCV in reducing the incidence of IPD, two on x-ray confirmed pneumonia as outcome, and one on clinical pneumonia, with or without x-ray confirmation. Results from pooling HIV-1 negative children from the South African study with the other studies were as follows: the pooled vaccine efficacy (VE) for vaccine-type IPD was 88% (95% confidence interval (CI) 73% to 94%; fixed effect and random effects models), the effect measure was statistically significant (p <0.00001) and there was no heterogeneity (p = 0.77I2 0%); the pooled VE for all-serotype IPD was 66% (95% CI 46% to 79%; fixed effect model), the effect measure was statistically significant (p <0.00001) and there was no statistical heterogeneity (p = 0.09, I2 51%); the pooled VE for x-ray confirmed pneumonia was 22% (95% CI 11% to 31%; both fixed effect and random effects models) and there was no statistical heterogeneity (p = 0.80, I2 0%). Analyses that included all the children in the South African study (HIV-1 negative and HIV-1 positive children) and pooled with data from the other studies gave very similar results.

REVIEWERS' CONCLUSIONS

PCV is effective in reducing the incidence of IPD from all serotypes but exerts a greater effect in reducing VT IPD. Although PCV is also effective in reducing the incidence of x-ray confirmed pneumonia, there are still uncertainties about the definition of this outcome. Additional randomised controlled trials are currently in progress.

Severe community-acquired pneumonia

PURPOSE OF REVIEW

Community-acquired pneumonia remains a prevalent and potentially life-threatening infection. In general, the disease is considered severe when inpatient care including ICU admission is required, and this often suggests a poorer prognosis. Severe community-acquired pneumonia continues to be an important subject of research from different perspectives, including assessment of illness severity, etiology, diagnostic tests, and treatment options. The aim of this descriptive review is to comment on the results of the relevant original articles in this area published since April 1, 2003.

RECENT FINDINGS

The main themes in the literature covered by the review include the time course of serum concentrations of different markers of the inflammatory response, validation of severity scores to optimize hospital and ICU admission, outcome improvement (duration of therapy and optimal dosing, time to antibiotic administration, adequate initial treatment, and the impact of positive microbiological diagnosis on management and prognosis), and the efficacy of new antimicrobials.

SUMMARY

The usefulness of inflammatory markers to assess the outcome of the disease is unclear. Data on severity scores are conclusive and different validated and simple predictive rules are available for the classification of patients into risk classes. Therapeutic strategies that have been investigated confirm the impact of adequate empiric antibiotic treatment on clinical outcome and the equivalence between short and long courses in the duration of therapy. A definitive beneficial effect of early administration of antimicrobials or the knowledge of the etiology of pneumonia on the clinical course of the disease has not been demonstrated.

Community-acquired pneumonia in casualty

PURPOSE OF REVIEW

Community-acquired pneumonia, because of its substantial treatment costs, incidence, and mortality, is an aggressively researched diagnosis. In this review, we highlight new developments in the diagnosis, etiology, pathophysiology, treatment, and prevention of community-acquired pneumonia published since April 2002.

RECENT FINDINGS

The combined end points of improved patient care and conservation of health care resources have prompted several studies examining current professional society community-acquired pneumonia guidelines. In general, patients treated with the recommended third-generation cephalosporin and macrolide or an antipneumococcal fluoroquinolone when indicated have fared better, including reduced overall costs, inpatient days, and mortality, than those receiving alternative treatments. Etiologic identification efforts by traditional methods, blood and sputum cultures, are being questioned owing to poor success rates and, even when positive, are being underused or ignored in antibiotic selection and patient management. Newer diagnostic tests are becoming commercially available, along with tests for biologic markers that have been only recently identified as contributors to, or prognosticators of, community-acquired pneumonia. Because antibiotic resistance remains a major obstacle to successful patient treatment, prevention or mitigation of community-acquired pneumonia is gaining increasing popularity through more aggressive pneumococcal and influenza vaccination of at risk groups, even before hospital discharge from a community-acquired pneumonia admission.

SUMMARY

Although prevention is our best defense, current community-acquired pneumonia treatment guidelines are effective for treatment and cost containment. However, they should be scrutinized in light of clinical utilization data now entering the literature regarding their testing recommendations. Providers should consider encouraging focused culturing of sicker patients and those with significant comorbidities.

Current challenges in lower respiratory infections in children

PURPOSE OF REVIEW

Lower respiratory infections threaten the health of children worldwide. Streptococcus pneumoniae remains the most common bacterial cause of lower respiratory infection in children, whereas viral pathogens dominate as a more common cause of lower respiratory infection illness in infants and children overall. The diagnosis and clinical management of lower respiratory infections pose challenges to pediatric health providers as new technology is developed and new pathogens emerge in the spectrum of clinical disease.

RECENT FINDINGS

Human metapneumovirus is now recognized as a cause of lower respiratory infection disease in children, and coronavirus has been linked to epidemics of severe acute respiratory syndrome. Respiratory syncytial virus continues to be a major source of viral lower respiratory infection illness in children and can lead to childhood asthma. Treatment for respiratory syncytial virus bronchiolitis depends largely on the severity of disease and the course of clinical symptoms. The diagnosis of bacterial lower respiratory infection disease remains a clinical challenge, but new methods to detect S. pneumoniae, or Chlamydia pneumoniae and Mycoplasma pneumoniae may facilitate the clinical management of these illnesses. As immunization against S. pneumoniae becomes more widely used, the complications of bacterial lower respiratory infections will diminish markedly.

SUMMARY

Future progress in the clinical management of lower respiratory infection diseases will entail improved methods of early diagnosis, broader options for treatment, and better defined clinical parameters for triage and follow-up of children with lower respiratory infections.