The etiology of community-acquired pneumonia in Australia: why penicillin plus doxycycline or a macrolide is the most appropriate therapy

Regional differences in antibiotic-resistant pathogens in patients with pneumonia: Implications for clinicians

Antibiotic resistance is of great concern for both infection control and the treatment of infectious diseases. Previous studies reported that the occurrence of drug-resistant pathogens (DRPs)-for instance, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae-were associated with inappropriate antibiotic treatment that resulted in adverse outcomes. In addition, unnecessary use of broad-spectrum antibiotics for patients with non-DRPs increased mortality. Therefore, the assessment of risk for DRPs at diagnosis is critical to avoid patients' adverse events. In the present review, we discuss regional differences in the prevalence of DRPs, which ranged from 6% to 45%, in patients with community-onset pneumonia, including both community-acquired and healthcare-associated pneumonia. We then introduce the reported risk factors for DRPs in those patients, and present proposed prediction models for identifying patients with DRPs at diagnosis. Physicians should be aware that some of the risk factors for DRPs (e.g. prior antibiotic use and prior hospitalization) were common between regions; however, others may be different or the weighting of the risks may vary, even for the same risk factors. Therefore, a specific evaluation of risk factors for DRPs is recommended for each region and institution. Furthermore, we present a possible strategy for initial antibiotic selection in patients with community-onset pneumonia, considering DRPs risk. We also discuss future directions for the study of DRPs in community-onset, hospital-acquired and ventilator-associated pneumonia to improve the management of patients with pneumonia.

A survey of clinicians regarding respiratory physiotherapy intervention for intubated and mechanically ventilated patients with community-acquired pneumonia. What is current practice in Australian ICUs?

RATIONALE, AIMS, AND OBJECTIVES

Community-acquired pneumonia (CAP) is a common cause for intensive care unit (ICU) admission resulting in high morbidity and mortality. There is a paucity of evidence regarding respiratory physiotherapy for intubated and mechanically ventilated patients with CAP, and anecdotally clinical practice is variable in this cohort. The aims of this study were to identify the degree of variability in physiotherapy practice for intubated adult patients with CAP and to explore ICU physiotherapist perceptions of current practice for this cohort and factors that influence physiotherapy treatment mode, duration, and frequency.

METHOD

A survey was developed based on common aspects of assessment, clinical rationale, and intervention for intubated and mechanically ventilated patients. Senior ICU physiotherapists across 88 Australian public and private hospitals were recruited.

RESULTS

The response rate was 72%. Respondents (n = 75) stated their main rationale for providing a respiratory intervention were improved airway clearance (98%, n = 60/61), alveolar recruitment (74%, n = 45/61), and gas exchange (33%, n = 20/61). Respondents estimated that average intervention lasted between 16 and 30 minutes (70% of respondents, n = 41/59) and would be delivered once (44%) or twice (44%) daily. Results indicated large variability in reported practice; however, trends existed regarding positioning in alternate side-lying (81%, n = 52/64) or affected lung uppermost (83%, n = 53/64) and use of hyperinflation techniques (81%, 52/64). Decisions regarding duration were reported to be based on sputum volume (95%), viscosity (93%) and purulence (88%), cough effectiveness (95%), chest X-ray (87%), and auscultation (84%). Sixty percent reported that workload and staffing affected intervention duration and frequency. Intervention time was more likely increased when there was greater staffing (P = .03).

CONCLUSION

Respiratory physiotherapy treatment varies for intubated patients with CAP. Further research is required to determine what is considered best practice for this patient population.

Cost-effectiveness of 13-valent pneumococcal conjugate vaccine (PCV13) in older Australians

BACKGROUND

The 23-valent pneumococcal polysaccharide vaccine (PPV23) has been funded under the Australia National Immunisation Program (NIP) since January 2005 for those aged >65years and other risk groups. In 2016, PCV13 was accepted by the Pharmaceutical Benefits Advisory Committee (PBAC) as a replacement for a single dose of PPV23 in older Australian adults.

METHODS

A single-cohort deterministic multi-compartment (Markov) model was developed describing the transition of the population between different invasive and non-invasive pneumococcal disease related health states. We applied a healthcare system perspective with costs (Australian dollars, A$) and health effects (measured in quality adjusted life-years, QALYs) attached to model states and discounted at 5% annually. We explored replacement of PPV23 with PCV13 at 65years as well as other age based vaccination strategies. Parameter uncertainty was explored using deterministic and probabilistic sensitivity analysis.

RESULTS

In a single cohort, we estimated PCV13 vaccination at the age of 65years to cost ∼A$11,120,000 and prevent 39 hospitalisations and 6 deaths from invasive pneumococcal disease and 180 hospitalisations and 10 deaths from community acquired pneumonia. The PCV13 program had an incremental cost-effectiveness ratio of ∼A$88,100 per QALY gained when compared to a no-vaccination, whereas PPV23 was ∼A$297,200 per QALY gained. To fall under a cost-effectiveness threshold of A$60,000 per QALY, PCV13 would have to be priced below ∼A$46 per dose. The cost-effectiveness of PCV13 in comparison to PPV23 was ∼A$35,300 per QALY gained.

CONCLUSION

In comparison to no-vaccination, we found PCV13 use in those aged 65years was unlikely to be cost-effective unless the vaccine price was below A$46 or a longer duration of protection can be established. However, we found that in comparison to the PPV23, vaccination with PCV13 was cost-effective. This partly reflects the poor value for money estimated for PPV23 use in Australia.

Pneumonia in the developing world: Characteristic features and approach to management

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality in adults worldwide, but its epidemiology varies markedly by region. Whilst in high-income countries, the predominant burden of CAP is in the elderly and those with chronic cardiovascular and pulmonary co-morbidity, CAP patients in low-income settings are often of working age and, in sub-Saharan Africa, frequently HIV-positive. Although region-specific aetiological data are limited, they are sufficient to highlight major trends: in high-burden settings, tuberculosis (TB) is a common cause of acute CAP; Gram-negative pathogens such as Klebsiella pneumoniae are regionally important; and HIV-associated opportunistic infections are common but difficult to diagnose. These differences in epidemiology and aetiological profile suggest that modified approaches to diagnosis, severity assessment and empirical antimicrobial therapy of CAP are necessary, but tailored individualized management approaches are constrained by limitations in the availability of radiological and laboratory diagnostic services, as well as medical expertise. The widespread introduction of the Xpert MTB/RIF platform represents a major advance for TB diagnosis, but innovations in rapid diagnostics for other opportunistic pathogens are urgently needed. Severity assessment tools (e.g. CURB65) that are used to guide early management decisions in CAP have not been widely validated in low-income settings and locally adapted tools are required. The optimal approach to initial antimicrobial therapy choices such as the need to provide early empirical cover for atypical bacteria and TB remain poorly defined. Improvements in supportive care such as correcting hypoxaemia and intravenous fluid management represent opportunities for substantial reductions in mortality.

Infection is an Independent Predictor of Death in Diffuse Large B Cell Lymphoma

To identify risk factors for infection in patients with diffuse large B cell lymphoma (DLBCL) undergoing rituximab, cyclophosphamide, vincristine, adriamycin and prednisolone (R-CHOP) treatment. All patients with DLBCL who received R-CHOP from 2004-2014 in a tertiary Australian hospital were identified and information collected from hospital admission data, laboratory results and medical record review. Infection was defined as hospitalisation with an ICD-10-AM diagnostic code for infection. Risk factors for infection and association between infection and survival were modelled using Cox proportional hazards regression. Over the 10-year period there were 325 patients; 191 (58.8%) males, median age 66 years. 206 (63.4%) patients experienced ≥1 infection. Independent predictors of infection were Charlson comorbidity index score (hazard ratio [HR] 3.60, p = 0.002), Eastern Cooperative Oncology Group (ECOG) performance status (HR 2.09 p = <0.001) and neutropenia (HR 2.46, p = <0.001). 99 (31%) patients died. Infection was an independent predictor of survival (HR 3.27, p = <0.001, as were age (HR 2.49, p = 0.001), Charlson comorbidity index (HR 4.34, p = <0.001), ECOG performance status (HR 4.33, p = 0.045) and neutropenia (HR 1.95, p = 0.047). Infections are common and infection itself is an independent predictor of survival. Patients at highest risk of infection and death are those with multiple comorbidities, poor performance status and neutropenia.

Efficacy of a respiratory physiotherapy intervention for intubated and mechanically ventilated adults with community acquired pneumonia: a systematic review protocol

REVIEW OBJECTIVES

The objective of the review is to map evidence on the efficacy of a respiratory physiotherapy intervention for intubated and mechanically ventilated adults with community acquired pneumonia (CAP). Specifically, the review seeks to investigate if respiratory physiotherapy interventions can achieve the following for intubated and mechanically ventilated adults with CAP.

The Diagnostic Utility of Induced Sputum Microscopy and Culture in Childhood Pneumonia

BACKGROUND.

Sputum microscopy and culture are commonly used for diagnosing the cause of pneumonia in adults but are rarely performed in children due to difficulties in obtaining specimens. Induced sputum is occasionally used to investigate lower respiratory infections in children but has not been widely used in pneumonia etiology studies.

METHODS.

We evaluated the diagnostic utility of induced sputum microscopy and culture in patients enrolled in the Pneumonia Etiology Research for Child Health (PERCH) study, a large study of community-acquired pneumonia in children aged 1-59 months. Comparisons were made between induced sputum samples from hospitalized children with radiographically confirmed pneumonia and children categorized as nonpneumonia (due to the absence of prespecified clinical and laboratory signs and absence of infiltrate on chest radiograph).

RESULTS.

One induced sputum sample was available for analysis from 3772 (89.1%) of 4232 suspected pneumonia cases enrolled in PERCH. Of these, sputum from 2608 (69.1%) met the quality criterion of <10 squamous epithelial cells per low-power field, and 1162 (44.6%) had radiographic pneumonia. Induced sputum microscopy and culture results were not associated with radiographic pneumonia, regardless of prior antibiotic use, stratification by specific bacteria, or interpretative criteria used.

CONCLUSIONS.

The findings of this study do not support the culture of induced sputum specimens as a diagnostic tool for pneumonia in young children as part of routine clinical practice.

Controversies in diagnosis and management of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a common condition; however, it appears to be overdiagnosed. Diagnosing CAP too frequently may be adding to the problems of overuse of antibiotics, such as bacterial resistance in the community and greater costs and complications in individuals. Data support that most patients with non-severe CAP can be treated for 3-5 days; however, most patients with CAP are receiving much longer courses of therapy. Macrolides such as azithromycin have the potential to prolong the QT interval, although large population studies show that this does not appear to result in excess cardiac mortality. CAP is associated with an increase in a variety of cardiac complications, most notably infarctions and worsening cardiac failure, so clinicians should be vigilant for signs and symptoms of these complications, particularly in patients with a history of ischaemic cardiac disease or the presence of cardiac risk factors. Cardiac risk factors should be assessed and managed in patients with CAP over 40 years of age, although there are yet to be data to show that this approach reduces deaths. Corticosteroids may have a slight effect on reducing deaths in patients with severe CAP, but this must be balanced against the significant potential for side effects.

Viral infection in community-acquired pneumonia: a systematic review and meta-analysis

The advent of PCR has improved the identification of viruses in patients with community-acquired pneumonia (CAP). Several studies have used PCR to establish the importance of viruses in the aetiology of CAP.We performed a systematic review and meta-analysis of the studies that reported the proportion of viral infection detected via PCR in patients with CAP. We excluded studies with paediatric populations. The primary outcome was the proportion of patients with viral infection. The secondary outcome was short-term mortality.Our review included 31 studies. Most obtained PCR via nasopharyngeal or oropharyngeal swab. The pooled proportion of patients with viral infection was 24.5% (95% CI 21.5-27.5%). In studies that obtained lower respiratory samples in >50% of patients, the proportion was 44.2% (95% CI 35.1-53.3%). The odds of death were higher in patients with dual bacterial and viral infection (OR 2.1, 95% CI 1.32-3.31).Viral infection is present in a high proportion of patients with CAP. The true proportion of viral infection is probably underestimated because of negative test results from nasopharyngeal or oropharyngeal swab PCR. There is increased mortality in patients with dual bacterial and viral infection.

Utility of oropharyngeal real-time PCR for S. pneumoniae and H. influenzae for diagnosis of pneumonia in adults

A lack of sensitive tests and difficulties obtaining representative samples contribute to the challenge in identifying etiology in pneumonia. Upper respiratory tract swabs can be easily collected and analyzed with real-time PCR (rtPCR). Common pathogens such as S. pneumoniae and H. influenzae can both colonize and infect the respiratory tract, complicating the interpretation of positive results. Oropharyngeal swabs were collected (n = 239) prospectively from adults admitted to hospital with pneumonia. Analysis with rtPCR targeting S. pneumoniae and H. influenzae was performed and results compared with sputum cultures, blood cultures, and urine antigen testing for S. pneumoniae. Different Ct cutoff values were applied to positive tests to discern colonization from infection. Comparing rtPCR with conventional testing for S. pneumoniae in patients with all tests available (n = 57) resulted in: sensitivity 87 %, specificity 79 %, PPV 59 % and NPV 94 %, and for H. influenzae (n = 67): sensitivity 75 %, specificity 80 %, PPV 45 % and NPV 94 %. When patients with prior antimicrobial exposure were excluded sensitivity improved: 92 % for S. pneumoniae and 80 % for H. influenzae. Receiver operating characteristic curve analysis demonstrated for S. pneumoniae: AUC = 0.65 (95 % CI 0.51-0.80) and for H. influenzae: AUC = 0.86 (95 % CI 0.72-1.00). Analysis of oropharyngeal swabs using rtPCR proved both reasonably sensitive and specific for diagnosing pneumonia caused by S. pneumoniae and H. influenzae. This method may be a useful diagnostic adjunct to other methods and of special value in patients unable to provide representative lower airway samples.

Application of real-time quantitative polymerase chain reaction assay to detect Legionella pneumophila in patients of community-acquired pneumonia in a tertiary care hospital

Legionella pneumophila is one of the important pathogen responsible for community -acquired pneumonia attributing for 1-5% of cases. Since early and accurate therapy reduces mortality, rapid and reliable diagnostic methods are needed. A total of 134 samples of blood, urine and respiratory tract fluids were collected. Blood was tested for IgG, IgM and IgA antibodies using commercially available kits. A total of 8 (6%) samples were found to be positive for L. pneumophila by quantitative reverse transcription polymerase chain reaction (qRT-PCR), compared to conventional PCR where 6 (4.4%) samples were positive. Serology was positive in a total of 32 (23%) cases though only 3 (2.2%) of the PCR-positive cases were positive by serology as well. These results suggest that real-time PCR can detect Legionella infection early in the course of the disease before serological response develops.

Copeptin for risk stratification in non-traumatic headache in the emergency setting: a prospective multicenter observational cohort study

BACKGROUND

In the emergency setting, non-traumatic headache is a benign symptom in 80% of cases, but serious underlying conditions need to be ruled out. Copeptin improves risk stratification in several acute diseases. Herein, we investigated the value of copeptin to discriminate between serious secondary headache and benign headache forms in the emergency setting.

METHODS

Patients presenting with acute non-traumatic headache were prospectively enrolled into an observational cohort study. Copeptin was measured upon presentation to the emergency department. Primary endpoint was serious secondary headache defined by a neurologic cause requiring immediate treatment of the underlying disease. Secondary endpoint was the combination of mortality and hospitalization within 3 months. Two board-certified neurologist blinded to copeptin levels verified the endpoints after a structured 3-month-telephone interview.

RESULTS

Of the 391 patients included, 75 (19%) had a serious secondary headache. Copeptin was associated with serious secondary headache (OR 2.03, 95%CI 1.52-2.70, p < 0.0001). Area under the curve (AUC) for copeptin to identify the primary endpoint was 0.70 (0.63-0.76). After adjusting for age > 50, focal-neurological abnormalities, and thunderclap onset of symptoms, copeptin remained an independent predictive factor for serious secondary headache (OR 1.74, 95%CI 1.26-2.39, p = 0.001). Moreover, copeptin improved the AUC of the multivariate logistic clinical model (p-LR-test < 0.001). Even though copeptin values were higher in patients reaching the secondary endpoint, this association was not significant in multivariate logistic regression.

CONCLUSIONS

Copeptin was independently associated with serious secondary headache as compared to benign headaches forms. Copeptin may be a promising novel blood biomarker that should be further validated to rule out serious secondary headache in the emergency department.

TRIAL REGISTRATION

Study Registration on 08/02/2010 as NCT01174901 at clinicaltrials.gov.

Community-Acquired Pneumonia in the Asia-Pacific Region

Community-acquired pneumonia (CAP) is an important cause of mortality and morbidity worldwide. Aging population, dense urbanization, and poor access to health care make the Asia-Pacific region vulnerable to CAP. The high incidence of CAP poses a significant health and economic burden in this region. Common etiologic agents in other global regions including Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, Staphylococcus aureus, and respiratory viruses are also the most prevalent pathogens in the Asia-Pacific region. But the higher incidence of Klebsiella pneumoniae and the presence of Burkholderia pseudomallei are unique to the region. The high prevalence of antimicrobial resistance in S. pneumoniae and M. pneumoniae has been raising the need for more prudent use of antibiotics. Emergence and spread of community-acquired methicillin-resistant S. aureus deserve attention, while the risk has not reached significant level yet in cases of CAP. Given a clinical and socioeconomic importance of CAP, further effort to better understand the epidemiology and impact of CAP is warranted in the Asia-Pacific region.

Fluoroquinolones or macrolides in combination with β-lactams in adult patients hospitalized with community acquired pneumonia: a systematic review and meta-analysis

OBJECTIVE

The best treatment option for hospitalized patients with community-acquired pneumonia (CAP) has not been defined. The effectiveness of β-lactam/fluoroquinolone (BLFQ) versus β-lactam/macrolide (BLM) combinations for the treatment of patients with CAP was evaluated.

METHODS

PubMed, Scopus and the Cochrane Library were searched for observational cohort studies, non-randomized and randomized controlled trials providing data for patients with CAP receiving BLM or BLFQ. Mortality was the primary outcome. A meta-analysis was performed. MINORS and GRADE were used for data quality assessment.

RESULTS

Seventeen studies (16 684 patients) were included. Randomized trials were not identified. A variety of β-lactams, fluoroquinolones and macrolides were used within and between the studies. Mortality was reported at different time points. The available body of evidence had very low quality. In the analysis of unadjusted data, mortality with BLFQ was higher than with BLM (risk ratio 1.33, 95% CI 1.15-1.54, I² 28%). BLFQ was associated with higher mortality regardless of the study design, mortality recording time, study period and study BLM group mortality. BLFQ was associated with higher mortality in American but not European studies. No difference was observed in patients with bacteraemia and septic shock. In the meta-analysis of adjusted mortality data, a non-significant difference between the two regimens was observed (eight studies, adjusted risk ratio 1.26, 95% CI 0.95-1.67, I² 43%).

CONCLUSION

In the absence of data from randomized controlled trials recommendations cannot be made for or against either of the studied regimens in this group of hospitalized patients with CAP. Well designed randomized controlled trials comparing the two regimens are warranted.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Neumonía aguda extrahospitalaria

La neumonía aguda extrahospitalaria sigue estando asociada a una elevada morbimortalidad. Durante estos últimos años, y gracias al desarrollo de técnicas de biología molecular, se han realizado importantes progresos en los métodos diagnósticos. Estas técnicas permiten mejorar la detección de bacterias atípicas y de virus respiratorios estacionales. Han permitido asimismo subrayar el lugar de los virus respiratorios en su aparición. El protocolo terapéutico se basa siempre en la instauración precoz de una antibioticoterapia que casi siempre es empírica. Las recomendaciones europeas para el tratamiento de las neumonías extrahospitalarias han sido puestas al día en 2011, como también lo han sido recientemente las pautas vacunales frente al neumococo. En este artículo, se resumen las etiologías de las neumonías, su diagnóstico, las escalas que permiten evaluar su gravedad y orientar el tratamiento del paciente, los datos sobre la sensibilidad a los antibióticos y las recomendaciones terapéuticas resultantes, así como las estrategias de prevención.

Burden of pneumococcal disease in adults aged 65 years and older: an Australian perspective

BACKGROUND

The burden of pneumococcal disease in adults aged 65 years and older in Australia is not well defined. This retrospective cross-sectional study calculated rates for pneumococcal pneumonia using data from the Australian Institute of Health and Welfare and from the Bettering Evaluation and Care of Health program.

METHODS

Invasive pneumococcal disease (IPD) incidence was calculated using National Notifiable Diseases Surveillance System data. Population estimates and pneumonia mortality data were from the Australian Bureau of Statistics. Medical costs were derived from Australian Refined Diagnosis Related Groups and the literature. Clinical and economic burden of pneumococcal pneumonia hospitalisations and general practitioner (GP) visits were described and compared with IPD.

RESULTS

For adults aged ≥65 years, pneumococcal pneumonia hospitalisation incidence was 274 per 100,000 population in 2011-2012. From 2004 to 2012, a mean of 2235 pneumonia hospitalisation deaths were recorded, corresponding to a case fatality rate of 6.1 %. GP visits accounted for the largest portion of healthcare encounters, with an annual average of 455 pneumococcal pneumonia GP visits per 100,000 population from 2008 to 2013. In 2012, IPD incidence was 19 per 100,000 population. The estimated annual costs of treating pneumococcal pneumonia hospitalisations and GP visits were A$55,722,136 and A$1,604,189, respectively. Estimated costs for IPD were A$1,172,986.

CONCLUSIONS

The healthcare and economic burden of pneumococcal disease in adults aged ≥65 years in Australia is substantial, with the incidence of pneumococcal pneumonia hospitalisation nearly 15-fold higher than for IPD. Despite this, it remains less recognised than other infectious diseases such as influenza.

Identification of pathogens by comprehensive real-time PCR versus conventional methods in community-acquired pneumonia in Japanese adults

BACKGROUND

Community-acquired pneumonia (CAP) has high morbidity and mortality. Unfortunately, the pathogen detection rate using conventional culture methods is relatively low. We compared comprehensive real-time polymerase chain reaction (real-time PCR) analysis of nasopharyngeal swab specimens (NPS) and sputum samples against conventional methods for ability to detect causative pathogens of CAP.

METHODS

We prospectively enrolled adult CAP patients, including those with prior antibiotic use, from December 2012 to May 2014. For each patient, causative pathogens were investigated conventionally and by real-time PCR that can identify 6 bacterial and 11 viral pathogens.

RESULTS

Patients numbered 92 (mean age, 63 years; 59 male), including 30 (33%) with prior antibiotic use. Considering all patients, identification of causative pathogens by real-time PCR was significantly more frequent than by conventional methods in all patients (72% vs. 57%, p = 0.018). In patients with prior antibiotic use, identification rates also differed significantly (PCR, 77%; conventional, 50%; p = 0.027). Mixed infections were more frequent according to real-time PCR than conventional methods (26% vs. 4%, p < 0.001). By the real-time PCR, Streptococcus pneumoniae was most frequently identified (38%) as a causative pathogen, followed by Haemophilus influenzae (37%) and Mycoplasma pneumoniae (5%). PCR also identified viral pathogens (21%), with sensitivity enhanced by simultaneous examination of both NPS and sputum samples rather than only NPS samples.

CONCLUSIONS

Real-time PCR of NPS and sputum samples could better identify bacterial and viral pathogens in CAP than conventional methods, both overall and in patients with prior antibiotic treatment.

Comprehensive Molecular Testing for Respiratory Pathogens in Community-Acquired Pneumonia

Background. The frequent lack of a microbiological diagnosis in community-acquired pneumonia (CAP) impairs pathogen-directed antimicrobial therapy. This study assessed the use of comprehensive multibacterial, multiviral molecular testing, including quantification, in adults hospitalized with CAP.

Methods. Clinical and laboratory data were collected for 323 adults with radiologically-confirmed CAP admitted to 2 UK tertiary care hospitals. Sputum (96%) or endotracheal aspirate (4%) specimens were cultured as per routine practice and also tested with fast multiplex real-time polymerase-chain reaction (PCR) assays for 26 respiratory bacteria and viruses. Bacterial loads were also calculated for 8 bacterial pathogens. Appropriate pathogen-directed therapy was retrospectively assessed using national guidelines adapted for local antimicrobial susceptibility patterns.

Results. Comprehensive molecular testing of single lower respiratory tract (LRT) specimens achieved pathogen detection in 87% of CAP patients compared with 39% with culture-based methods. Haemophilus influenzae and Streptococcus pneumoniae were the main agents detected, along with a wide variety of typical and atypical pathogens. Viruses were present in 30% of cases; 82% of these were codetections with bacteria. Most (85%) patients had received antimicrobials in the 72 hours before admission. Of these, 78% had a bacterial pathogen detected by PCR but only 32% were culture-positive (P < .0001). Molecular testing had the potential to enable de-escalation in number and/or spectrum of antimicrobials in 77% of patients.

Conclusions. Comprehensive molecular testing significantly improves pathogen detection in CAP, particularly in antimicrobial-exposed patients, and requires only a single LRT specimen. It also has the potential to enable early de-escalation from broad-spectrum empirical antimicrobials to pathogen-directed therapy.

Management of community-acquired pneumonia in an Australian regional hospital

OBJECTIVE

Current management of hospitalised patients with community-acquired pneumonia (CAP) in an Australian regional hospital in accordance with the recommended guidelines is unknown. The prescription rate of inappropriate antibiotic therapy was measured and analysed.

DESIGN

A retrospective audit, December 2012 to November 2013.

SETTING

Regional Australian hospital in North East Victoria.

INTERVENTIONS

Interventions were the average of inpatient and intensive care unit length of stay, time to first antibiotic and to first chest X-ray, days of intravenous antibiotics, and extra intravenous therapy; proportion of intensive care unit admissions, average time to first antibiotic administration, patients with failed outpatient management of CAP, initial microbiological investigations, positive investigations, predominant microbiology, antibiotic choice, and concordance with guidelines; proportion of justifiable deviation from guidelines, ratio of patients switched to oral therapy appropriately, complications during therapy, clinical failure, inpatient mortality, mortality at 30 days, mortality at 6 months, and readmission with CAP in 30 days and in 3 months.

MAIN OUTCOME MEASURES

To improve the rates of concordance with guidelines by following a specified method to rate severity of CAP, to clearly document reasons for non-concordance with guidelines, and to rationalise investigations.

RESULTS

To improve antibiotic stewardship in the management of CAP.

CONCLUSION

In an Australian regional hospital, ceftriaxone and azithromycin were the predominant combination used at 56%, demonstrating that mild CAP was frequently overtreated. Mild CAP was eight times more likely to be treated as severe CAP (odds ratio = 8.2 (95% confidence interval, 1.7-40.3) P < 0.009). There is a need for a simple yet effective strategy to be introduced to rationalise treatment and investigation of CAP in this setting.

Viruses and Gram-negative bacilli dominate the etiology of community-acquired pneumonia in Indonesia, a cohort study

Objective

Knowledge about the etiology of community-acquired pneumonia (CAP) is essential for adequate management. Presently, few studies about CAP are available from Southeast Asia. This study aimed to investigate the etiology, severity, and outcome of CAP in the most populous Southeast Asia country, Indonesia.

Methods

From October 2007 to April 2009, adult patients admitted with CAP to two hospitals in Semarang, Indonesia, were included to detect the etiology of CAP using a full range of diagnostic methods. The severity of disease was classified according to the Pneumonia Severity Index (PSI). The outcome was assessed as 30-day mortality.

Results

In total, 148 consecutive patients with CAP were included. Influenza virus (18%), Klebsiella pneumoniae (14%), and Streptococcus pneumoniae (13%) were the most common agents identified. Other Gram-negative bacilli, Mycobacterium tuberculosis, Chlamydia pneumoniae each accounted for 5%. The bacteria presented wild type antibiotic susceptibility profiles. Forty-four percent of subjects were high-risk patients (PSI class IV-V). The mortality rate (30%) was significantly associated with disease severity score (P<0.001), and with failure to establish an etiological diagnosis (P=0.027). No associations were found between etiology and underlying diseases, PSI class, nor mortality.

Conclusions

Viruses and Gram-negative bacilli are dominant causes of CAP in this region, more so than S. pneumoniae. Most of the bacteria have wild type susceptibility to antimicrobial agents. Patients with severe disease and those with unknown etiology have a higher mortality risk.

Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults

BACKGROUND

Community-acquired pneumonia is a leading infectious cause of hospitalization and death among U.S. adults. Incidence estimates of pneumonia confirmed radiographically and with the use of current laboratory diagnostic tests are needed.

METHODS

We conducted active population-based surveillance for community-acquired pneumonia requiring hospitalization among adults 18 years of age or older in five hospitals in Chicago and Nashville. Patients with recent hospitalization or severe immunosuppression were excluded. Blood, urine, and respiratory specimens were systematically collected for culture, serologic testing, antigen detection, and molecular diagnostic testing. Study radiologists independently reviewed chest radiographs. We calculated population-based incidence rates of community-acquired pneumonia requiring hospitalization according to age and pathogen.

RESULTS

From January 2010 through June 2012, we enrolled 2488 of 3634 eligible adults (68%). Among 2320 adults with radiographic evidence of pneumonia (93%), the median age of the patients was 57 years (interquartile range, 46 to 71); 498 patients (21%) required intensive care, and 52 (2%) died. Among 2259 patients who had radiographic evidence of pneumonia and specimens available for both bacterial and viral testing, a pathogen was detected in 853 (38%): one or more viruses in 530 (23%), bacteria in 247 (11%), bacterial and viral pathogens in 59 (3%), and a fungal or mycobacterial pathogen in 17 (1%). The most common pathogens were human rhinovirus (in 9% of patients), influenza virus (in 6%), and Streptococcus pneumoniae (in 5%). The annual incidence of pneumonia was 24.8 cases (95% confidence interval, 23.5 to 26.1) per 10,000 adults, with the highest rates among adults 65 to 79 years of age (63.0 cases per 10,000 adults) and those 80 years of age or older (164.3 cases per 10,000 adults). For each pathogen, the incidence increased with age.

CONCLUSIONS

The incidence of community-acquired pneumonia requiring hospitalization was highest among the oldest adults. Despite current diagnostic tests, no pathogen was detected in the majority of patients. Respiratory viruses were detected more frequently than bacteria. (Funded by the Influenza Division of the National Center for Immunizations and Respiratory Diseases.).

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Incidence of respiratory viral infections detected by PCR and real-time PCR in adult patients with community-acquired pneumonia: a meta-analysis

Background

With the development of more rapid and sensitive detection methods based on PCR techniques, the contributions of respiratory viral infections to community-acquired pneumonia (CAP) in adult patients are being more and more recognized. Yet, up to now, there has been a lack of synthetic data that clearly demonstrates the incidence of respiratory viral infections in adult patients with CAP.

Objectives

We intended to demonstrate the incidence of respiratory viral infections detected by PCR and real-time PCR in adult patients with CAP.

Methods

We searched PubMed and Embase for studies providing the incidence of respiratory viral infections in adult patients with CAP. We investigated potential sources of heterogeneity by a univariant metaregression analysis and calculated the combined incidence of viral infections, viral infections mixed with other pathogens and individual respiratory virus species.

Results

We eventually identified 23 eligible reports with a total number of 6,404 patients. Incidences ranged from 8.6 to 56.2% for overall respiratory viral infections. We noted significant heterogeneity in incidence estimates for the incidence of viral infections (Cochran's χ² = 269.9, p < 0.0001, I² = 91.8%). The combined incidence of viral infections was 22.4% (95% CI = 19.0-25.7). Incidences of viral coinfections with other pathogens ranged from 3 to 28%. A high level of heterogeneity was identified as well during the estimates for incidences of coinfections (χ² = 200.9, p < 0.0001, I² = 91.5%). The combined incidence of viral coinfections with other pathogens was 12.4% (95% CI = 9.7-15.0). Our heterogeneity analyses suggested that a lower respiratory tract sample was associated with higher overall viral incidence. Moreover, the influenza virus, rhinovirus and coronavirus were the 3 most frequently detected viral pathogens in adult patients with CAP according to our study.

Conclusions

Respiratory viruses are probably crucial pathogens of adult patients with CAP, with the influenza virus being the most frequent viral pathogen identified. More than half of the viral infections are characterized as mixed infections with other pathogens.

Mortality in healthcare-associated pneumonia in a low resistance setting: a prospective observational study

BACKGROUND

The classification of pneumonia as community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP) has implications for selection of initial antimicrobial therapy. HCAP has been associated with an increased prevalence of multidrug-resistant (MDR) pathogens and with high mortality leading to recommendations for broad empiric therapy.

METHODS

We performed a prospective, population-based study on consecutive adults (≥ 18 years) admitted for pneumonia over 1 calendar year. Patients were classified by pneumonia type and severity. Microbial etiologic testing was performed on all patients. Treatment, length of stay, and mortality rates were compared.

RESULTS

A total of 373 admissions were included, 94% of all eligible patients. They were classified as CAP (n = 236, 63%) or HCAP (n = 137, 37%). Chronic underlying disease was more commonly found among patients with HCAP compared with CAP (74% vs 51%, p < 0.001). Mycoplasma pneumoniae was more common among CAP patients (p < 0.01), while gram-negative bacteria were more often found among HCAP patients (p = 0.02). No MDR pathogens were detected, and rates of Staphylococcus aureus were similar in the two groups. HCAP patients were not more likely to receive ineffective initial antimicrobial therapy. HCAP patients had worse prognostic scores on admission and higher in-house mortality than CAP patients (10% vs 1%, respectively, p < 0.01).

CONCLUSIONS

Even in a low resistance setting, patients with HCAP have increased mortality compared with patients with CAP. This is most likely explained by a higher prevalence of co-morbidities. Our data do not support broad-spectrum empiric antibiotic therapy for HCAP.

Etiology of community-acquired pneumonia and diagnostic yields of microbiological methods: a 3-year prospective study in Norway

Background

Despite recent advances in microbiological techniques, the etiology of community-acquired pneumonia (CAP) is still not well described. We applied polymerase chain reaction (PCR) and conventional methods to describe etiology of CAP in hospitalized adults and evaluated their respective diagnostic yields.

Methods

267 CAP patients were enrolled consecutively over our 3-year prospective study. Conventional methods (i.e., bacterial cultures, urinary antigen assays, serology) were combined with nasopharyngeal (NP) and oropharyngeal (OP) swab samples analyzed by real-time quantitative PCR (qPCR) for Streptococcus pneumoniae, and by real-time PCR for Mycoplasma pneumoniae, Chlamydophila pneumoniae, Bordetella pertussis and 12 types of respiratory viruses.

Results

Etiology was established in 167 (63%) patients with 69 (26%) patients having ≥1 copathogen. There were 75 (28%) pure bacterial and 41 (15%) pure viral infections, and 51 (19%) viral–bacterial coinfections, resulting in 126 (47%) patients with bacterial and 92 (34%) patients with viral etiology. S. pneumoniae (30%), influenza (15%) and rhinovirus (12%) were most commonly identified, typically with ≥1 copathogen. During winter and spring, viruses were detected more frequently (45%, P=.01) and usually in combination with bacteria (39%). PCR improved diagnostic yield by 8% in 64 cases with complete sampling (and by 15% in all patients); 5% for detection of bacteria; 19% for viruses (P=.04); and 16% for detection of ≥1 copathogen. Etiology was established in 79% of 43 antibiotic-naive patients with complete sampling. S. pneumoniae qPCR positive rate was significantly higher for OP swab compared to NP swab (P<.001). Positive rates for serology were significantly higher than for real-time PCR in detecting B. pertussis (P=.001) and influenza viruses (P<.001).

Conclusions

Etiology could be established in 4 out of 5 CAP patients with the aid of PCR, particularly in diagnosing viral infections. S. pneumoniae and viruses were most frequently identified, usually with copathogens. Viral–bacterial coinfections were more common than pure infections during winter and spring; a finding we consider important in the proper management of CAP. When swabbing for qPCR detection of S. pneumoniae in adult CAP, OP appeared superior to NP, but this finding needs further confirmation.

Trial registration

ClinicalTrials.gov Identifier: NCT01563315.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-0803-5) contains supplementary material, which is available to authorized users.

Procalcitonin, a valuable biomarker assisting clinical decision-making in the management of community-acquired pneumonia

BACKGROUND AND AIM

Community-acquired pneumonia (CAP) is a leading cause of mortality, morbidity and hospital admission, which places strain on our healthcare system. Procalcitonin (PCT) is a biomarker of bacterial infection which may help gauge the severity and prognosis of patients with CAP. In addition to clinical predictors, PCT may assist in decisions pertaining to timing of discharge from hospital and the discontinuation of antibiotics. This study aimed to determine the predictive role of PCT measurement in reducing hospital admissions, length of stay (LOS) and antibiotic (AB) usage in patients with CAP.

METHODS

A prospective, single-blinded, externally controlled study of consenting adult patients admitted with CAP. PCT levels were obtained on day 1 and day 3 (when indicated). Investigator-evaluated clinical parameters, together with results of PCT levels, determined the timing of oral AB switch and discharge from hospital. This process was compared against standard practice, but was not actually implemented, for the purpose of this study.

RESULTS

Sixty patients were included in the study. The mean age was 66.5 ± 21.2 years (56.3% male). The average Pneumonia Severity Index was 93 ± 39 (class IV) and the median CURB-65 was 2. The mean LOS for the standard practice cohort was 5.3 ± 4.6 days versus calculated LOS using the PCT guidance pathway of 3.7 ± 2.8 days. (P = 0.00006).

CONCLUSIONS

Our study supports the hypothesis that by incorporation of PCT levels, hospital admission and LOS in patients with CAP can be reduced. A randomised prospective clinical trial is planned in an attempt to help confirm these findings.

Community-acquired pneumonia: why aren't national antibiotic guidelines followed?

AIMS

Adherence to guidelines for the management of community-acquired pneumonia (CAP) has been shown to improve patients' clinical outcomes. This study aimed to assess adherence to the Australian Therapeutic Guidelines (TG14) for the empirical management of CAP, and explore the potential barriers affecting adherence to these guidelines.

METHODS

Medical records were reviewed for all patients who were diagnosed with CAP within 24 h of presentation at the Royal Hobart Hospital, the main teaching hospital in Tasmania, Australia, between July 2010 and March 2011. A survey of emergency department and medical team prescribers was also undertaken to identify potential barriers to adhere with the guidelines. χ(2) and Fisher's exact tests were used to test the significance between categorical data. To compare categorical and scale data, the Mann-Whitney U-test was used.

RESULTS

A total of 193 patient records were assessed. The overall adherence to TG14 for the empirical antibiotic management of CAP was 16.1% (3.1%, 20.7% and 25.4% for patients with mild, moderate and severe CAP, respectively). Ceftriaxone was prescribed to 34.4%, 26.8% and 57.4% of patients with mild, moderate and severe CAP, respectively. The response rate to the barrier survey was 43.1%; of those who responded, 46.4% thought the influence of senior doctors on junior doctors could be a factor affecting adherence to the guidelines. Other barriers noted were a lack of guideline awareness (39.3%), the requirement to calculate the severity of CAP (35.7%), and the existence of other guidelines that conflict with TG14 (28.6%).

CONCLUSIONS

Adherence to CAP treatment guidelines was poor, especially in patients with mild disease. Prescribing was mainly influenced by senior doctors. Efforts to improve compliance with CAP treatment guidelines should consider the potential barriers that hinder adherence.

[Two Cases of Rapidly Progressive Community-acquired Pneumonia Due to Pseudomonas aeruginosa]

Pseudomonas aeruginosa is a significant causative bacterium in hospital-acquired pneumonia and nursing and healthcare-associated pneumonia, but it seems to be rare in community-acquired pneumonia (CAP). We report two cases of severe CAP due to P. aeruginosa. Case 1: A 52-year-old man was referred to our hospital for chest and back pain. He was being treated for diabetes mellitus and had a long history of smoking. Chest images showed consolidation in the right upper lobe. Soon after hospitalization, he developed sepsis shock and died seven hours later. Case 2: A 73-year-old man with a history of heavy smoking was referred to our hospital for right chest pain. Chest images showed right upper lobe pneumonia. Although wide-spectrum antimicrobial agents were administrated, he died ten hours after admission. In both cases, there was a rapid progression to death, despite administration of a broad spectrum of antibiotics and treatment for sepsis. In cases of CAP involving the right upper lobe, the possibility of bacteremia and rapid progress should be considered.

Viral pneumonia in adults and older children in sub-Saharan Africa - epidemiology, aetiology, diagnosis and management

Community-acquired pneumonia causes substantial morbidity and mortality in sub-Saharan Africa with an estimated 131 million new cases each year. Viruses - such as influenza virus, respiratory syncytial virus and parainfluenza virus - are now recognised as important causes of respiratory disease in older children and adults in the developed world following the emergence of sensitive molecular diagnostic tests, recent severe viral epidemics, and the discovery of novel viruses. Few studies have comprehensively evaluated the viral aetiology of adult pneumonia in Africa, but it is likely to differ from Western settings due to varying seasonality and the high proportion of patients with immunosuppression and co-morbidities. Emerging data suggest a high prevalence of viral pathogens, as well as multiple viral and viral/bacterial infections in African adults with pneumonia. However, the interpretation of positive results from highly sensitive polymerase chain reaction tests can be challenging. Therapeutic and preventative options against viral respiratory infections are currently limited in the African setting. This review summarises the current state of the epidemiology, aetiology, diagnosis and management of viral pneumonia in sub-Saharan Africa.

Factors influencing ceftriaxone use in community-acquired pneumonia: Emergency doctors' perspectives

OBJECTIVE

To explore the perceptions of ED doctors regarding the use of ceftriaxone in patients with community-acquired pneumonia (CAP).

METHODS

Face-to-face interviews were conducted with ED doctors in an Australian tertiary public hospital. A semi-structured interview method was used for collecting data and a framework analysis approach utilised to identify emerging themes regarding the influences on ED prescribers when using ceftriaxone for CAP.

RESULTS

Eight interviews were performed (two consultants, four registrars and two residents). Five main themes emerged as influencing decisions regarding the selection of ceftriaxone for patients with CAP: (i) clinical intuition versus structured evaluation of severity; (ii) clinical uncertainty; (iii) prior experience; (iv) source of guidance; and (v) prescribing etiquette.

CONCLUSION

As most cases of CAP are initially diagnosed and treated empirically in the ED, any interventions that aim to decrease inappropriate use of ceftriaxone for CAP should address the factors identified here that influence ED doctors' prescribing decisions.

Bacterial etiologies of five core syndromes: laboratory-based syndromic surveillance conducted in Guangxi, China

BACKGROUND

Under the existing national surveillance system in China for selected infectious diseases, bacterial cultures are performed for only a small percentage of reported cases. We set up a laboratory-based syndromic surveillance system to elucidate bacterial etiologic spectrum and detect infection by rare etiologies (or serogroups) for five core syndromes in the given study area.

METHODS

Patients presenting with one of five core syndromes at nine sentinel hospitals in Guagnxi, China were evaluated using laboratory-based syndrome surveillance to elucidate bacterial etiologies. We collected respiratory and stool specimens, as well as CSF, blood and other related samples for bacterial cultures and pulse field gel electrophoresis (PFGE) assays.

RESULTS

From February 2009 to December 2011, 2,964 patients were enrolled in the study. Etiologies were identified in 320 (10.08%) patients. Streptococcus pneumonia (37 strains, 24.18%), Klebsiella pneumonia (34, 22.22%), Pseudomonas aeruginosa (19, 12.42%) and Haemophilus influenza (18, 11.76%) were the most frequent pathogens for fever and respiratory syndrome, while Salmonella (77, 81.05%) was most often seen in diarrhea syndrome cases. Salmonella paratyphi A (38, 86.36%) occurred in fever and rash syndrome, with Cryptococcus neoformans (20, 35.09%), Streptococcus pneumonia (5, 8.77%), Klebsiella pneumonia (5, 8.77%),streptococcus suis (3, 5.26%) and Neisseria meningitides group B (2, 3.51%) being the most frequently detected in encephalitis-meningitis syndrome. To date no pathogen was isolated from the specimens from fever and hemorrhage patients.

CONCLUSIONS

In addition to common bacterial pathogens, opportunistic pathogens and fungal infections require more attention. Our study contributes to the strengthening of the existing national surveillance system and provides references for other regions that are similar to the study area.

Respiratory virus is a real pathogen in immunocompetent community-acquired pneumonia: comparing to influenza like illness and volunteer controls

BACKGROUND

Viral pathogens were more commonly reported than previously estimated in community-acquired pneumonia (CAP) patients. However, the real role of virus was still controversial.

METHODS

Consecutive adult patients with CAP between April and December, 2009 were prospectively enrolled. A four-fold or greater increase of IgG-titres against respiratory viruses in pair sera was tested by means of hemagglutination inhibition assay or indirect immunofluorescence. Swab samples were tested by cell culture and/or nucleic amplification tests. Viral etiology was considered definitive if at least one of the above tests was positive.

RESULTS

Viral etiology was established in fifty-two (34.9%) of 149 CAP patients, twenty-two (81.5%) of 27 influenza like illness patients, and none of 75 volunteer controls. Forty-seven CAP patients were infected by a single virus (24 influenza A virus, 5 influenza B, 10 parainfluenza virus type 3 [PIV-3], 2 PIV-1, 2 adenovirus, 2 human rhinovirus and 2 coronavirus OC43), five cases by two or three viruses co-infection. Fever ≥ 39 °C (66.7%), fatigue (64.6%), and purulent sputum (52.1%) was the most common symptoms in viral pneumonia patients. On multivariate analysis, myalgia was included in the model for pneumonia associated with influenza infection. In the CURB-65 model only influenza infection was found independently associated with severe disease (CURB-65 score ≥ 3) out of variables, including age(years), sex, current smoking status, sick contact with febrile patients, numbers of comorbidity, presence of influenza infection, presence of PIV infection, with P = 0.021, OR 7.86 (95% CI 1.37-45.04).

CONCLUSION

Respiratory virus was not a bystander, but pathogenic in pneumonia and was a common cause of CAP.

Lower respiratory tract virus findings in mechanically ventilated patients with severe community-acquired pneumonia

BACKGROUND

The role of viral infections in the etiology of severe community-acquired pneumonia (SCAP) was prospectively evaluated from 2008 to 2012 at a university-level intensive care unit.

METHODS

Clinical data and microbiological tests were assessed: blood cultures, urine pneumococcal and legionella antigens, Mycoplasma pneumoniae and Chlamydia pneumoniae antibodies from paired serums, and respiratory virus detection by multiplex, real-time polymerase chain reaction (PCR) from nasopharyngeal swabs and lower tracheal specimens via intubation tube.

RESULTS

Of 49 mechanically ventilated SCAP patients (21 men and 28 women; median age, 54 years), the etiology was identified in 45 cases (92%). There were 21 pure bacterial infections (43%), 5 probably pure viral infections (10%), and 19 mixed bacterial-viral infections (39%), resulting in viral etiology in 24 patients (49%). Of 26 viruses, 21 (81%) were detected from bronchial specimens and 5 (19%) from nasopharyngeal swabs. Rhinovirus (15 cases, 58%) and adenovirus (4 cases, 15%) were the most common viral findings. The bacterial-viral etiology group had the highest peak C-reactive protein levels (median, 356 [25th-75th percentiles, 294-416], P = .05), whereas patients with probably viral etiology had the lowest peak procalcitonin levels (1.7 [25th-75th percentiles, 1.6-1.7]). The clinical characteristics of pure bacterial and mixed bacterial-viral etiologies were comparable. Hospital stay was longest among the bacterial group (17 vs 14 days; P = .02).

CONCLUSIONS

Viral findings were demonstrated in almost half of the SCAP patients. Clinical characteristics were similar between the pure bacterial and mixed bacterial-viral infections groups. The frequency of viral detection depends on the availability of PCR techniques and lower respiratory specimens.

Macrolides and mortality in critically ill patients with community-acquired pneumonia: a systematic review and meta-analysis

OBJECTIVE

Some studies suggest better outcomes with macrolide therapy for critically ill patients with community-acquired pneumonia. To further explore this, we performed a systematic review of studies with mortality endpoints that compared macrolide therapy with other regimens in critically ill patients with community-acquired pneumonia.

DATA SOURCES

Studies were identified via electronic databases, grey literature, and conference proceedings through May 2013.

STUDY SELECTION

Using prespecified criteria, two reviewers selected studies; studies of outpatients and hospitalized noncritically ill patients were excluded.

DATA EXTRACTION

Two reviewers extracted data and evaluated bias using the Newcastle-Ottawa Scale. Random effects models were used to generate pooled risk ratios and evaluate heterogeneity (I).

DATA SYNTHESIS

Twenty-eight observational studies (no randomized control trials) were included. Average age ranged from 58 to 78 years and 14-49% were women. In our primary analysis of 9,850 patients, macrolide use was associated with statistically significant lower mortality compared with nonmacrolides (21% [846 of 4,036 patients] vs 24% [1,369 of 5,814]; risk ratio, 0.82; 95% CI, 0.70-0.97; p = 0.02; I = 63%). When macrolide monotherapy was excluded, the macrolide mortality benefit was maintained (21% [737 of 3,447 patients] vs 23% [1,245 of 5,425]; risk ratio, 0.84; 95% CI, 0.71-1.00; p = 0.05; I = 60%). When broadly guideline-concordant regimens were compared, there was a trend to improved mortality and heterogeneity was reduced (20% [511 of 2,561 patients] mortality with beta-lactam/macrolide therapy vs 23% [386 of 1,680] with beta-lactam/fluoroquinolone; risk ratio, 0.83; 95% CI, 0.67-1.03; p = 0.09; I = 25%). When adjusted risk estimates were pooled from eight studies, macrolide therapy was still associated with a significant reduction in mortality (risk ratio, 0.75; 95% CI, 0.58-0.96; p = 0.02; I = 57%).

CONCLUSIONS

In observational studies of almost 10,000 critically ill patients with community-acquired pneumonia, macrolide use was associated with a significant 18% relative (3% absolute) reduction in mortality compared with nonmacrolide therapies. After pooling data from studies that provided adjusted risk estimates, an even larger mortality reduction was observed. These results suggest that macrolides be considered first-line combination treatment in critically ill patients with community-acquired pneumonia and support current guidelines.

Evaluation of yield of currently available diagnostics by sample type to optimize detection of respiratory pathogens in patients with a community-acquired pneumonia

BACKGROUND

For the detection of respiratory pathogens, the sampling strategy may influence the diagnostic yield. Ideally, samples from the lower respiratory tract are collected, but they are difficult to obtain.

OBJECTIVES

In this study, we compared the diagnostic yield in sputum and oropharyngeal samples (OPS) for the detection of respiratory pathogens in patients with community-acquired pneumonia (CAP), with the objective to optimize our diagnostic testing algorithm.

METHODS

Matched sputum samples, OPS, blood cultures, serum, and urine samples were taken from patients (>18 years) with CAP and tested for the presence of possible respiratory pathogens using bacterial cultures, PCR for 17 viruses and five bacteria and urinary antigen testing.

RESULTS

When using only conventional methods, that is, blood cultures, sputum culture, urinary antigen tests, a pathogen was detected in 49·6% of patients (n = 57). Adding molecular detection assays increased the yield to 80%. A pathogen was detected in 77 of the 115 patients in OPS or sputum samples by PCR. The sensitivity of the OPS was lower than that of the sputum samples (57% versus 74%). In particular, bacterial pathogens were more often detected in sputum samples. The sensitivity of OPS for the detection of most viruses was higher than in sputum samples (72% versus 66%), except for human rhinovirus and respiratory syncytial virus.

CONCLUSION

Addition of PCR on both OPS and sputum samples significantly increased the diagnostic yield. For molecular detection of bacterial pathogens, a sputum sample is imperative, but for detection of most viral pathogens, an OPS is sufficient.

Incidence and etiology of community-acquired pneumonia in the elderly in a prospective population-based study

BACKGROUND

We conducted a prospective population-based epidemiological study to prepare a setting for documentation of the efficacy of novel vaccines against pneumococcal (Pnc) community-acquired pneumonia (CAP) in the elderly. Specific objectives were to demonstrate setting feasibility, to construct a case definition for Pnc CAP, and to estimate its incidence.

METHODS

We prospectively enrolled patients with clinical and radiological findings compatible with CAP at municipal on-call clinics serving an elderly population (age ≥ 65 y) of approximately 29,500. Sputum, urine, nasopharyngeal swab (NPS), and blood samples were analyzed using diverse methods for the identification of Pnc (culture, PCR, antigen tests, serology) and of other pathogens. The following case definition for Pnc CAP was derived: encapsulated Pnc in blood culture or in high-quality sputum culture or at least 2 of the following: positive urine Pnc antigen; ≥ 2-fold increase in serum anti-PsaA or anti-CbpA antibodies; encapsulated Pnc culture or LytA PCR in either sputum or NPS.

RESULTS

We enrolled 490 clinical CAP patients during the 2-y follow-up, 53% of all clinical CAP patients in the source population; 323 were radiologically confirmed. The incidence of radiologically confirmed CAP was 5.5/1000 person-y (95% confidence interval (CI) 4.9-6.1) and 10.5/1000 person-y when adjusted for non-captured patients. The proportion of radiologically confirmed CAP caused by Pnc was estimated at 17%; i.e. 0.95/1000 person-y (95% CI 0.7-1.2) and 1.8 when adjusted for non-captured patients.

CONCLUSIONS

We developed and documented a feasible methodology for capturing endpoints in a vaccine trial for the prevention of pneumonia. CAP incidence in the elderly population remains considerable and Streptococcus pneumoniae was one of the most commonly detected causative agents.

Clinical features of endemic community-acquired psittacosis

Following a large outbreak of community-acquired psittacosis in 2002 in residents of the Blue Mountains, New South Wales, Australia, we reviewed new cases in this area over a 7-year period from 2003 to 2009. Using the 2010 criteria from the Centers for Disease Control National Notifiable Diseases Surveillance System, 85 patients with possible psittacosis were identified, of which 48 were identified as definite or probable infection. Clinical features of these cases are summarized. In addition to Chlamydia-specific serology, specimens, where available, underwent nucleic acid testing for chlamydial DNA using real-time PCR. Chlamydophila psittaci DNA was detected in samples from 23 patients. Four of 18 specimens were culture positive. This is the first description of endemic psittacosis, and is characterized in this location by community-acquired psittacosis resulting from inadvertent exposure to birds. The disease is likely to be under-diagnosed, and may often be mistaken for gastroenteritis or meningitis given the frequency of non-respiratory symptoms, particularly without a history of contact with birds. Clinical characteristics of endemic and outbreak-associated cases were similar. The nature of exposure, risk factors and reasons for the occurrence of outbreaks of psittacosis require further investigation.

Advances in antibiotic therapy for community-acquired pneumonia

PURPOSE OF REVIEW

Community-acquired pneumonia (CAP) is a major public health problem all over the world. The increasing number of antibiotic-resistant bacteria is a matter of concern for physicians when choosing antibiotic treatment in patients with CAP. This review focuses on the current recommendations of antibiotic treatment, recent information concerning antibiotic resistance of pathogens, and the advances in antibiotic therapy in the field of CAP.

RECENT FINDINGS

A significant increase in the frequency of resistance to the antibiotics commonly used against causative pathogens of CAP, such as β-lactams or macrolides, has been reported in recent years. At present, the prevalence of fluoroquinolone resistance in Streptococcus pneumoniae remains low. Community-acquired methicillin-resistant Staphylococcus aureus and influenza A(H1N1)pdm09 have been reported as causes of severe CAP. Several newly-developed antibiotics, including cepholosporins, ketolides and quinolones, present marked activity in vitro against the main causative pathogens of CAP. Many randomized controlled trials have demonstrated equivalent efficacy of the newer antibiotics compared with conventional antimicrobial therapy in mild-to-moderate CAP.

SUMMARY

An increase of resistance to the antibiotics used in CAP has been documented over the years. Several new antibiotics have been developed for treating CAP, with promising results. However, data regarding their efficacy and safety in patients with severe CAP are lacking.