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

Macrolides for better resolution of community-acquired pneumonia: A global meta-analysis of clinical outcomes with focus on microbial aetiology

OBJECTIVES

This meta-analysis examined the effect of macrolides on resolution of community-acquired pneumonia (CAP) and interpretation of clinical benefit according to microbiology; emphasis is given to data under-reported countries (URCs).

METHODS

This meta-analysis included 47 publications published between 1994 and 2022. Publications were analysed for 30-d mortality (58 759 patients) and resolution of CAP (6465 patients). A separate meta-analysis was done for the prevalence of respiratory pathogens in URCs.

RESULTS

Mortality after 30 d was reduced by the addition of macrolides (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.51-0.82). The OR for CAP resolution when macrolides were added to the treatment regimen was 1.23 (95% CI 1.00-1.52). In the CAP resolution analysis, the most prevalent pathogen was Streptococcus pneumoniae (12.68%; 95% CI 9.36-16.95%). Analysis of the pathogen epidemiology from the URCs included 12 publications. The most prevalent pathogens were S. pneumoniae (24.91%) and Klebsiella pneumoniae (12.90%).

CONCLUSION

The addition of macrolides to the treatment regimen led to 35% relative decrease of 30-d mortality and to 23% relative increase in resolution of CAP.

Incidence of Respiratory Syncytial Virus Infection in Older Adults: Limitations of Current Data

INTRODUCTION

Respiratory syncytial virus (RSV) is an important cause of severe respiratory illness in older adults and adults with respiratory or cardiovascular comorbidities. Published estimates of its incidence and prevalence in adult groups vary widely. This article reviews the potential limitations affecting RSV epidemiology studies and suggests points to consider when evaluating or designing them.

METHODS

Studies reporting the incidence or prevalence of RSV infection in adults in high-income Western countries from 2000 onwards were identified via a rapid literature review. Author-reported limitations were recorded, together with presence of other potential limitations. Data were synthesized narratively, with a focus on factors affecting incidence estimates for symptomatic infection in older adults.

RESULTS

A total of 71 studies met the inclusion criteria, most in populations with medically attended acute respiratory illness (ARI). Only a minority used case definitions and sampling periods tailored specifically to RSV; many used influenza-based or other criteria that are likely to result in RSV cases being missed. The great majority relied solely on polymerase chain reaction (PCR) testing of upper respiratory tract samples, which is likely to miss RSV cases compared with dual site sampling and/or addition of serology. Other common limitations were studying a single season, which has potential for bias due to seasonal variability; failure to stratify results by age, which underestimates the burden of severe disease in older adults; limited generalizability beyond a limited study setting; and absence of measures of uncertainty in the reporting of results.

CONCLUSIONS

A significant proportion of studies are likely to underestimate the incidence of RSV infection in older adults, although the effect size is unclear and there is also potential for overestimation. Well-designed studies, together with increased testing for RSV in patients with ARI in clinical practice, are required to accurately capture both the burden of RSV and the potential public health impact of vaccines.

Identification of priority pathogens for aetiological diagnosis in adults with community-acquired pneumonia in China: a multicentre prospective study

BACKGROUND

Community-acquired pneumonia (CAP) is a major public health challenge worldwide. However, the aetiological and disease severity-related pathogens associated with CAP in adults in China are not well established based on the detection of both viral and bacterial agents.

METHODS

A multicentre, prospective study was conducted involving 10 hospitals located in nine geographical regions in China from 2014 to 2019. Sputum or bronchoalveolar lavage fluid (BALF) samples were collected from each recruited CAP patient. Multiplex real-time PCR and bacteria culture methods were used to detect respiratory pathogens. The association between detected pathogens and CAP severity was evaluated.

RESULTS

Among the 3,403 recruited eligible patients, 462 (13.58%) had severe CAP, and the in-hospital mortality rate was 1.94% (66/3,403). At least one pathogen was detected in 2,054 (60.36%) patients, with two or more pathogens were co-detected in 725 patients. The ten major pathogens detected were Mycoplasma pneumoniae (11.05%), Haemophilus influenzae (10.67%), Klebsiella pneumoniae (10.43%), influenza A virus (9.49%), human rhinovirus (9.02%), Streptococcus pneumoniae (7.43%), Staphylococcus aureus (4.50%), adenovirus (2.94%), respiratory syncytial viruses (2.35%), and Legionella pneumophila (1.03%), which accounted for 76.06-92.52% of all positive detection results across sampling sites. Klebsiella pneumoniae (p < 0.001) and influenza viruses (p = 0.005) were more frequently detected in older patients, whereas Mycoplasma pneumoniae was more frequently detected in younger patients (p < 0.001). Infections with Klebsiella pneumoniae, Staphylococcus aureus, influenza viruses and respiratory syncytial viruses were risk factors for severe CAP.

CONCLUSIONS

The major respiratory pathogens causing CAP in adults in China were different from those in USA and European countries, which were consistent across different geographical regions over study years. Given the detection rate of pathogens and their association with severe CAP, we propose to include the ten major pathogens as priorities for clinical pathogen screening in China.

Adults with symptoms of pneumonia: a prospective comparison of patients with and without infiltrates on chest radiography

OBJECTIVE

Most studies on patients hospitalized with community-acquired pneumonia (CAP) require confirmation of an infiltrate by chest radiography, but in practice admissions are common among patients with symptoms of pneumonia without an infiltrate (SPWI). The aim of this research was to compare clinical characteristics, microbial etiology, and outcomes among patients with CAP and SPWI.

METHODS

Adults suspected of CAP were prospectively recruited at Landspitali University Hospital over a 1-year period, 2018 to 2019. The study was population based. Those admitted with two or more of the following symptoms were invited to participate: temperature ≥38°C or ≤36°C, sweating, shaking/chills, chest pain, a new cough, or new onset of dyspnea. Primary outcome was mortality at 30 days and one year.

RESULTS

Six hundred twenty-five cases were included, 409 with CAP and 216 with SPWI; median age was 75 (interquartile range [IQR] 64-84) and 315 (50.4%) were females. Patients with CAP were more likely to have fever (≥38.0°C) (66.9% [273/408]) vs. 49.3% (106/215), p < 0.001), a higher CRP (median 103 [IQR 34-205] vs. 55 (IQR 17-103), p < 0.001), identification of Streptococcus pneumoniae (18.0% [64/355]) vs. 6.3% (10/159) of tested, p = 0.002) and to receive antibacterial treatment (99.5% [407/409]) vs. 87.5% (189/216), p < 0.001) but less likely to have a respiratory virus detected (25.4% [33/130]) vs. 51.2% (43/84) of tested, p < 0.001). The adjusted odds ratios for 30-day and 1 year mortality of SPWI compared to CAP were 0.86 (95% CI 0.40-1.86) and 1.46 (95% CI 0.92-2.32), respectively.

DISCUSSION

SPWI is a common cause of hospitalization and despite having fever less frequently, lower inflammatory markers, and lower detection rate of pneumococci than patients with CAP, mortality is not significantly different.

Clinical diagnosis and etiology of patients with Chlamydia psittaci pneumonia based on metagenomic next-generation sequencing

The incidence of severe Chlamydia psittaci (C. psittaci) pneumonia and coinfections is increasing. Early detection of this condition is needed to prevent negative outcomes, along with detailed descriptions of its associated clinical characteristics. Our study contributes by undertaking etiological analysis of patients with C. psittaci pneumonia based on metagenomic next-generation sequencing (mNGS). A retrospective analysis of 30 patients with C. psittaci pneumonia was undertaken and confirmed by mNGS or polymerase chain reaction (PCR). Clinical manifestations of the severe and non-severe C. psittaci pneumonia groups were compared for clinical reference. Etiological analyses were also performed to comprehensively understand pathogeny and coinfection with other respiratory pathogens in C. psittaci patients. The absolute value of lymphocytes (LYM) in the severe group was lower than in the non-severe group. At the same time, neutrophil-to-lymphocyte ratio (NLR), procalcitonin (PCT), alanine aminotransferase (ALT), D-II polymer, brain natriuretic peptide (BNP), myoglobin (MYO), and cardiac troponin I (cTnI) were significantly higher (P < 0.05) in the severe group. mNGS has a broader pathogen spectrum and can more sensitively detect C. psittaci and other low-abundance pathogens with a higher positive detection rate (100%, 13/13 vs. 46%, 6/13, P <0.05) than conventional culture methods. mNGS detected the following dominant species associated with C. psittaci in patients: bacteria (53.2%, 39% gram-positive, 61% gram-negative), fungi (12.9%), and viruses (33.9%). A total of 73.3% (11/15) of patients had suspected coinfections, with a coinfection rate of 91.7% (11/12) in the severe group. No coinfection or death occurred in the non-severe group. Prognosis in the severe group was poor, with a mortality rate of 27.3% (3/11) for patients with coinfection. Eight of 11 patients with coinfections (72.7%) recovered. In conclusion, the clinical symptoms of severe C. psittaci pneumonia manifested as abnormal inflammatory indicators, impaired liver function, myocardial injury, coagulation, and relatively low immune responses. The higher proportion of patients with coinfections in our study supports the use of mNGS for comprehensive early detection of respiratory infections in patients with C. psittaci pneumonia. Simultaneous early identification of coinfections would further improve the clinical treatment of these patients.

Appropriate prescribing of azithromycin for community-acquired pneumonia

Azithromycin is prescribed for atypical antimicrobial cover in severe community‐acquired pneumonia. Inappropriate azithromycin administration incurs unnecessary financial costs, exacerbates antimicrobial resistance and risks QTc interval prolongation leading to cardiac arrhythmias. The present study demonstrated that a majority of patients were prescribed azithromycin without having electrocardiograms to assess the QTc interval and without meeting criteria for severe community‐acquired pneumonia based on CURB‐65 score.

Potential impact of national recommendations to use short course antibiotic therapy on antibiotic use in the emergency department of a UK hospital: retrospective observational study

BACKGROUND AND IMPORTANCE

The National Institute for Health and Care Excellence (NICE) antimicrobial prescribing guidelines for common infections recommend short course antimicrobial therapy in order to reduce antibiotic associated harm.

OBJECTIVE

To quantify the opportunity to reduce antibiotic use in an emergency department (ED) through adoption of these short antibiotic course recommendations.

DESIGN, SETTINGS AND PARTICIPANTS

A retrospective observational study in an ED in the UK with 95 000 attendances a year. Patients managed in the ED between 1 December and 31 December 2019 with the following infections were identified: acute otitis media, human and animal bites, pyelonephritis, lower urinary tract infections, cellulitis, cough, infective exacerbation of chronic obstructive pulmonary disease, pneumonia, sore throat, sinusitis, and diverticulitis.

OUTCOME MEASURE

Excess antibiotic use due to either a protracted course length, or not meeting criteria for antibiotics.

RESULTS

395 patients (260 adults and 135 children) were identified. Of the 1215 days of antibiotic therapy, 198 (16%) were excess because of protracted course lengths. In terms of antibiotic defined daily doses (DDD), there were 1201.5 antibiotic DDD prescribed, of which 232 (19%) DDD were excess because of protracted course lengths. If both protracted courses and unnecessary antibiotic use were included, then 321 (27%) DDD were excess. Excess antibiotic use and total antibiotic use by infection group were: 123/546 (23%) DDD in lower respiratory tract infection, 46/59 (79%) in upper respiratory tract infection, 44/231 (19%) in upper and lower urinary tract infection, 0/113 (0%) cellulitis, 77/180 (43%) bites, and 30/40 (75%) diverticulitis. Excess antibiotic use, as a proportion of all antibiotic use in the ED, was 321/4291 (7.5%) DDD, and of whole hospital antibiotic use, the ED's excess use was 321/33 566 (0.96%).

CONCLUSION

Adoption of NICE antibiotic prescribing guidelines for common infections has the potential to reduce total antibiotic use in the ED by 7.5% and contribute to the hospital-wide antibiotic stewardship programme.

Pseudomonas aeruginosa Pneumonia: Evolution of Antimicrobial Resistance and Implications for Therapy

Pseudomonas aeruginosa (PA), a non-lactose-fermenting gram-negative bacillus, is a common cause of nosocomial infections in critically ill or debilitated patients, particularly ventilator-associated pneumonia (VAP), and infections of urinary tract, intra-abdominal, wounds, skin/soft tissue, and bloodstream. PA rarely affects healthy individuals, but may cause serious infections in patients with chronic structural lung disease, comorbidities, advanced age, impaired immune defenses, or with medical devices (e.g., urinary or intravascular catheters, foreign bodies). Treatment of pseudomonal infections is difficult, as PA is intrinsically resistant to multiple antimicrobials, and may acquire new resistance determinants even while on antimicrobial therapy. Mortality associated with pseudomonal VAP or bacteremias is high (> 35%) and optimal therapy is controversial. Over the past three decades, antimicrobial resistance (AMR) among PA has escalated globally, via dissemination of several international multidrug resistant "epidemic" clones. We discuss the importance of PA as a cause of pneumonia including health care-associated pneumonia, hospital-acquired pneumonia, VAP, the emergence of AMR to this pathogen, and approaches to therapy (both empirical and definitive).

Antimicrobial prescribing and outcomes of community-acquired pneumonia in Australian hospitalized patients: a cross-sectional study

Objective

We aimed to assess prescribing practices, compliance with guidelines, and outcomes for patients who were admitted to the authors’ institution with community-acquired pneumonia (CAP).

Methods

We performed a single-center retrospective cross-sectional study of adults with CAP presenting during the 2019 influenza season. CAP severity was assessed using the CURB-65 risk score. The effect of CURB-65 risk score use on the rate of appropriate antimicrobial prescribing was assessed using the chi-square test and reported as odds ratio (OR). Fisher’s exact test was used to assess the relationship between prescribing appropriateness and patient outcomes.

Results

Patients with low-risk CAP were most likely to be inappropriately prescribed antimicrobials (OR: 4.77; 95% confidence interval: 2.44–10.47). In low-risk CAP, the most common prescribing error was overuse of ceftriaxone. In high-risk CAP, the most common errors were ceftriaxone underdosing and missed atypical coverage with azithromycin. Overall, 80% of patients were considered to have been inappropriately prescribed antimicrobials. No effect on mortality was observed.

Conclusions

In this study, we found low use of CAP risk scores and low adherence to antimicrobial prescribing guidelines for CAP at the authors’ institution.

Effectiveness of Beta-Lactam plus Doxycycline for Patients Hospitalized with Community-Acquired Pneumonia

BACKGROUND

Despite clinical practice guideline recommendations to use doxycycline as part of combination therapy for some patients hospitalized with pneumonia, there is minimal evidence supporting this recommendation. Our aim was to examine the association between beta-lactam plus doxycycline and mortality for patients hospitalized with community-acquired pneumonia.

METHODS

We identified patients > 65 years of age admitted to any United States Department of Veterans Affairs hospital in fiscal years 2002-2012 with a discharge diagnosis of pneumonia. We excluded those patients who did not receive antibiotic therapy concordant with the 2019 ATS/IDSA clinical practice guidelines. Using propensity score matching, we examined the association of doxycycline with 30- and 90-day mortality.

RESULTS

Our overall cohort was comprised of 70,533 patients and 5,282 (7.49%) received doxycycline. Unadjusted 30-day mortality was 6.4% for those who received a beta-lactam plus doxycycline vs. 9.1% in those who did not (p<0.0001), and 90-day mortality was 13.8% for those who received a beta-lactam + doxycycline vs. 16.8% for those who did not (p<0.0001). In the propensity score matched models, both 30- (odds ratio 0.72, 95% confidence interval, 0.63-0.84) and 90-day (0.83, 0.74-0.92) mortality were significantly lower for those who received doxycycline.

CONCLUSIONS

In this retrospective observational cohort study, we found that doxycycline use, as part of guideline-concordant antibiotic therapy, was associated with lower 30- and 90-day mortality than regimens without doxycycline. While this supports the safety and effectiveness of antibiotic regimes that include doxycycline, additional studies, especially randomized clinical trials, are needed to confirm this.

Clinical metagenomic sequencing for rapid diagnosis of pneumonia and meningitis caused by Chlamydia psittaci

BACKGROUND

Chlamydia psittaci (C. psittaci) is a gram-negative intracellular parasitic pathogenic bacterium that can infect avian and mammalian hosts, including humans. The detection of C. psittaci infections typically relies on traditional antigen-based immunoassays or serological testing that often lack sensitivity and/or specificity. Metagenomic next generation sequencing (mNGS) is an emerging tool for diagnosis.

AIM

To demonstrate that mNGS represents a valuable tool for rapid, sensitive, and accurate pathogen detection including C. psittaci infections.

METHODS

Four cases of psittacosis pneumonia and one case of pediatric psittacosis meningitis were diagnosed between December 2019 and May 2020 using mNGS at Changzhou Second People’s Hospital affiliated to Nanjing Medical University. Patients’ clinical characteristics, manifestations, and treatment histories were retrospectively evaluated.

RESULTS

All five patients had a history of exposure to wild (psittacine or other birds) or domesticated birds (chickens). All patients had a high fever (> 39℃) and three of them (60%) experienced organ insufficiency during the disease. The laboratory data showed normal to slightly increased leucocyte and neutrophil counts, and elevated procalcitonin levels in all five cases, and very high C-reactive protein levels in psittacosis pneumonia patients. mNGS identified a potential pathogen, C. psittaci, in patients’ bronchoalveolar lavage fluid or cerebrospinal fluid. Computed tomography revealed lung air-space consolidation, pleural thickening, and effusion fluid buildup in psittacosis pneumonia cases, and an arachnoid cyst in the right temporal lobe of the pediatric psittacosis meningitis patient. All patients experienced complete recovery following the administration of targeted anti-chlamydia therapy.

CONCLUSION

This study not only demonstrated that mNGS represents a valuable tool for rapid, sensitive, and accurate pathogen detection, but also raised public health concerns over C. psittaci infections.

Metagenomics next-generation sequencing tests take the stage in the diagnosis of lower respiratory tract infections

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The applications of mNGS for LRIs span a wide range of areas including LRI diagnosis, airway microbiome analyses, human host response analyses, and prediction of drug resistance.

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The workflow of mNGS used in clinical practice involves the wet-lab pipeline and dry-lab pipeline, the complex workflow poses challenges for its extensive use.

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mNGS will become an important tool in the field of infectious disease diagnosis in the next decade.

Metagenomic next-generation sequencing (mNGS) has changed the diagnosis landscape of lower respiratory tract infections (LRIs). With the development of newer sequencing assays, it is now possible to assess all microorganisms in a sample using a single mNGS analysis. The applications of mNGS for LRIs span a wide range of areas including LRI diagnosis, airway microbiome analyses, human host response analyses, and prediction of drug resistance. mNGS is currently in an exciting transitional period; however, before implementation in a clinical setting, there are several barriers to overcome, such as the depletion of human nucleic acid, discrimination between colonization and infection, high costs, and so on.

Aim of Review: In this review, we summarize the potential applications and challenges of mNGS in the diagnosis of LRIs to promote the integration of mNGS into the management of patients with respiratory tract infections in a clinical setting.

Key Scientific Concepts of Review: Once its analytical validation, clinical validation and clinical utility been demonstrated, mNGS will become an important tool in the field of infectious disease diagnosis.

A secondary approach with conventional medicines and supplements to recuperate current COVID-19 status

Novel coronavirus 2019 (COVID-19) is a zoonosis that revised the global economic and societal progress since early 2020. The SARS-CoV-2 has been recognized as the responsible pathogen for COVID-19 with high infection and mortality rate potential. It has spread in 192 countries and infected about 1.5% of the world population, and still, a proper therapeutic approach is not unveiled. COVID-19 indication starts with fever to shortness of breathing, leading to ICU admission with the ventilation support in severe conditions. Besides the symptomatic mainstay clinical therapeutic approach, only Remdesivir has been approved by the FDA. Several pharmaceutical companies claimed different vaccines with exceptionally high efficacy (90–95%) against COVID-19; how long these vaccines can protect and long-term safety with the new variants are unpredictable. After the worldwide spread of the COVID-19 pandemic, numerous clinical trials with different phases are being performed to find the most appropriate solution to this condition. Some of these trials with old FDA-approved drugs showed promising results. In this review, we have precisely compiled the efforts to curb the disease and discussed the clinical findings of Ivermectin, Doxycycline, Vitamin-D, Vitamin-C, Zinc, and cannabidiol and their combinations. Additionally, the correlation of these molecules on the prophylactic and diseased ministration against COVID-19 has been explored.

The impact of infectious diseases consultation on the management and outcomes of Pseudomonas aeruginosa bacteraemia in adults: a retrospective cohort study

BACKGROUND

Pseudomonas aeruginosa bacteraemia (PAB) is associated with high mortality. The benefits of infectious diseases consultation (IDC) has been demonstrated in Staphylococcal aureus bacteraemia and other complex infections. Impact of IDC in PAB is unclear. This study aimed to evaluate the impact of IDC on the management and outcomes in patients with PAB.

METHODS

This is a retrospective cohort single-centre study from 1 November 2006 to 29 May 2019, in all adult patients admitted with first episode of PAB. Data collected included demographics, clinical management and outcomes for PAB and whether IDC occurred. In addition, 29 Pseudomonas aeruginosa (PA) stored isolates were available for Illumina whole genome sequencing to investigate if pathogen factors contributed to the mortality.

RESULTS

A total of 128 cases of PAB were identified, 71% received IDC. Patients who received IDC were less likely to receive inappropriate duration of antibiotic therapy (4.4%; vs 67.6%; p < 0.01), more likely to be de-escalated to oral antibiotic in a timely manner (87.9% vs 40.5%; p < 0.01), undergo removal of infected catheter (27.5% vs 13.5%; p = 0.049) and undergo surgical intervention (20.9% vs 5.4%, p = 0.023) for source control. The overall 30-day all-cause mortality rate was 24.2% and was significantly higher in the no IDC group in both unadjusted (56.8% vs 11.0%, odds ratio [OR] = 10.63, p < 0.001) and adjusted analysis (adjusted OR = 7.84; 95% confidence interval, 2.95-20.86). The genotypic analysis did not reveal any PA genetic features associated with increased mortality between IDC versus no IDC groups.

CONCLUSION

Patients who received IDC for PAB had lower 30-day mortality, better source control and management was more compliant with guidelines. Further prospective studies are necessary to determine if these results can be validated in other settings.

Clinical characteristics and outcomes of community-acquired pneumonia in western Saudi Arabia: A four-year retrospective analysis of medical records

BACKGROUND

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality, especially for the elderly and people who suffer from chronic conditions. This study was conducted to assess the clinical and microbiological characteristics and disease outcomes associated with the occurrence of CAP.

METHODS

This retrospective chart review was conducted at King Abdulaziz Medical City, Jeddah, Saudi Arabia. Cases with documented clinical diagnosis of CAP during the period from 2016 to 2019 were included. Data were collected on demographic, clinical, and microbiological characteristics, used antimicrobials and patients' outcomes, including length of hospital stay, intensive care unit admission, and mortality. Multivariate regression analysis was performed to identify risk factors for increased length of hospital stay.

RESULTS

A total of two hundred and eighteen CAP episodes were identified. Patients had a median age of 64.5 years, and 54.1% were males. Microbiological diagnosis was established in 33 patients (15.1%). Admission to ICU and diagnosis of a neurological disease were significantly associated with longer hospital stay (>7 days). An average of 2.7 antimicrobials were used per patient, and the most common antibiotics used were Piperacillin/Tazobactam (46.3%), Doxycycline (44%), then Ceftriaxone (42.7%). Four patients (1.8%) died during hospital stay.

CONCLUSIONS

This retrospective analysis of CAP cases identified a lack of microbiological diagnosis and increased burden associated with disease severity and the need for hospitalization. The ability to identify CAP at an earlier stage will be a cornerstone to mitigate its impact on the healthcare system and ICU units.

Efficacy of Respiratory Physiotherapy Interventions for Intubated and Mechanically Ventilated Adults with Pneumonia: A Systematic Review and Meta-Analysis

Purpose: A systematic review was conducted to investigate the effect of respiratory physiotherapy on mortality, quality of life, functional recovery, intensive care length of stay, duration of ventilation, oxygenation, secretion clearance, and pulmonary mechanics for invasively ventilated adults with pneumonia. Method: Five databases were searched for randomized trials published between January 1995 and November 2018. Study quality was assessed using a standardized Joanna Briggs Institute critical appraisal tool, and Review Manager software was used to pool the studies. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to evaluate the level of certainty of the evidence. Results: A total of 14 studies of moderate quality included 251 subjects with pneumonia. Eight studies were pooled for meta-analysis. Interventions that increased inspiratory volume appeared to benefit secretion clearance by nearly 2 grams (mean difference [MD] 1.97; 95% CI: 0.80, 3.14; very low GRADE evidence) and increase static lung compliance immediately after treatment by more than 5 millilitres/centimetre H20 (MD 5.40 mL/cm H2O; 95% CI: 2.37, 8.43; very low GRADE evidence) or by more than 6 millilitres/centimetre H2O after a 20- to 30-minute delay (MD 6.86 mL/cm H2O; 95% CI: 2.86, 10.86; very low GRADE evidence). No adverse events were found. Conclusions: Respiratory physiotherapy that increases tidal volume may benefit secretion clearance and lung compliance in invasively ventilated adults with pneumonia, but its impact on other outcomes, including mortality, length of stay, and other patient-centred outcomes, is unclear, and further research is required.

Where is Chlamydophila pneumoniae pneumonia?

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Chlamydia pneumoniae infection in patients hospitalised for community-acquired pneumonia in Southern Jordan

Purpose

Chlamydia pneumoniae is associated with human respiratory diseases. Few reports examined the involvement of this bacterium in community-acquired pneumonia (CAP) in Jordan. This study investigates for the first time the role of C. pneumoniae in the establishment of CAP among nationals residing the southern part of Jordan.

Materials and Methods

Nasopharyngeal and sera samples were collected from 70 hospitalised CAP patients and 63 healthy controls from Al-Karak Governorate and examined using the microimmunofluorescence and polymerase chain reaction techniques. The overall prevalence of C. pneumoniae infection was estimated by detecting the chlamydial immunoglobulin G (IgG) antibodies at a titre of 1:16. Rate of acute infection was estimated by detecting chlamydial DNA in nasopharyngeal samples and IgG and IgM at titres of 1:512 and 1:16, respectively.

Results

A higher overall seroprevalence of C. pneumoniae IgG was detected in CAP patients than controls (44.3% vs. 30.2%). The rate of acute infection in the entire CAP patients, based on IgG titre of 1:512, was 7.14% compared to 1.58% in the controls. Approximately, three-fold increase in the rate of acute infection was observed in CAP cases, seropositive at IgG titre of 1:16, compared to seropositive controls (16.1% vs. 5.3%). Interestingly, chlamydial IgM antibodies were detectable in 27.1% compared to only 3.2% of the controls. The presence of chlamydial nucleic acids was confirmed in 40% of CAP patients and in 7.9% of controls.

Conclusions

The present findings clearly suggest a role of C. pneumoniae in the aetiology of CAP in Southern Jordan. However, coinfections with other respiratory pathogens should not be excluded.

Antibodies against atypical pathogens and respiratory viruses detected by Pneumoslide IgM test in adults with community-acquired pneumonia in Guangzhou City

Background

To detect the serum antibodies against respiratory viruses and atypical pathogens in adults with community‐acquired pneumonia (CAP) in Guangzhou City (Guangdong province, China).

Methods

A retrospective study was carried out with samples from 685 adults who were admitted with CAP and 108 non‐CAP control patients. Atypical pathogens and respiratory viruses in serum were detected using the Pneumoslide IgM test from Vircell, Spain. All patients were divided into 6 groups according to age: 18‐24, 25‐44, 45‐59, 60‐74, 75‐89, and >90.

Results

The total positive rate of CAP was 35.4%, which was highest in the 18‐24 age group (P < .05). The highest positive rate, 17.11%, was observed for Mycoplasma pneumoniae (MP). The mean age of MP‐infected patients was higher than that of the controls (P < .05). The positive rates for influenza B (INFB), Legionella pneumophila (LP1), Coxiella burnetii (COX), influenza A (INFA), parainfluenza virus (PIV), respiratory syncytial virus (RSV), Chlamydophila pneumoniae (CP), and adenovirus (ADV) were 5.56%, 3.07%, 2.63%, 2.34%, 1.90%, 1.61, 0.88%, and 0.29%, respectively. There were 4.37% of patients with CAP having multiple infections. The main symptoms observed in the 685 CAP patients were cough and sputum production, in 78.4% and 67.4%. Fever was followed by 54% of CAP patients. Dyspnea (39.1%), anorexia (36.8%), increased thirst (26.7%), chills (18.7), headache (14.6%), and nausea (13.1%) were also frequently observed in the CAP patients.

Conclusions

MP infection was the most common in adult CAP patients in Guangzhou City with the highest positive rate in the 18‐24 age groups.

Clinical validation of expert consensus statements for respiratory physiotherapy management of invasively ventilated adults with community-acquired pneumonia: A qualitative study

OBJECTIVES

To conduct multidisciplinary peer-review of expert consensus statements for respiratory physiotherapy for invasively ventilated adults with community-acquired pneumonia, to determine clinical acceptability for development into a clinical practice guideline.

RESEARCH METHODOLOGY

A qualitative study was undertaken using focus groups (n = 3) conducted with clinician representatives from five Australian states. Participants were senior intensive care physiotherapists, nurses and consultants. Thematic analysis was used, with a deductive approach to confirm clinical validity, and inductive analysis to identify new themes relevant to the application of the 38 statements into practice.

SETTING

Adult intensive care.

FINDINGS

Senior intensive care clinicians from physiotherapy (n = 16), medicine (n = 6) and nursing (n = 4) participated. All concurred that the consensus statements added valuable guidance to practice; twenty-nine (76%) were deemed relevant and applicable for the intensive care setting without amendment, with modifications suggested for remaining nine statements to enhance utility. Overarching themes of patient safety, teamwork and communication and culture were identified as factors influencing clinical application. Cultural differences in practice, particularly related to patient positioning, was evident between jurisdictions. Participants raised practicality and safety concerns for two statements related to the use of head-down patient positioning.

CONCLUSION

Multidisciplinary peer-review established clinical validity of expert consensus statements for implementation with invasively ventilated adults with community-acquired pneumonia.

Assessment of polymyxin B-doxycycline in combination against Pseudomonas aeruginosa in vitro and in a mouse model of acute pneumonia

The increasing prevalence of antibiotic resistance in Pseudomonas aeruginosa has created an urgent need for suitable therapy. This study explored the pairing of doxycycline with other antipseudomonal antibiotics, and found that polymyxin B in combination with doxycycline had a synergistic effect against clinical strains of P. aeruginosa. This synergistic combination was studied by checkerboard assays and time-kill curve analysis. Further, in-vitro biofilm disruption, pyoverdine inhibition assays were performed. The efficacy of polymyxin B-doxycycline in combination, administered by inhalation, was evaluated using a mouse model of acute pneumonia. The combination was found to have a synergistic effect in both in-vitro and in-vivo studies. The combination decreased biofilms of P. aeruginosa and reduced the level of pyoverdine, an important siderophore of P. aeruginosa. In addition, the combination decreased the P. aeruginosa population by 3 log₁₀ (P<0.01) in the mouse model of acute pneumonia, and showed an improvement in lung function by inhalation. To the best of the authors' knowledge, this is the first in-vivo study to evaluate the efficacy of polymyxin B in combination with doxycycline against P. aeruginosa, showing a possible promising option for acute pneumonia due to multi-drug-resistant P. aeruginosa.

Adherence to Treatment Guideline Improves Patient Outcomes in a Prospective Cohort of Adults Hospitalized for Community-Acquired Pneumonia

Background

Understanding local epidemiology and etiologies of community-acquired pneumonia in hospitalized patients is crucial for determining the appropriateness of treatment guidelines. We aim to determine the etiologies, severity, and outcomes in adults hospitalized for community-acquired pneumonia and to study the impact of empirical antibiotic therapy on patient outcomes.

Methods

We performed a prospective observational cohort study involving adults hospitalized for community-acquired pneumonia in Hong Kong. Sputum, nasopharyngeal aspirate, blood, and urine were collected for bacterial culture, molecular tests for detection of viruses and atypical pathogens, and antigen tests. Multivariable logistic regression model and Cox proportional hazard models were performed to determine independent factors associated with prolonged hospitalization and mortality.

Results

From February 2017 to July 2018, 258 patients were enrolled. The median age was 73 (interquartile range, 61-80) years, 66% were male, 57% had underlying chronic illnesses, 13% had CURB-65 score ≥3, and 10% had higher 1-year mortality. Pathogens were identified in 45% of patients; 20% had viral, 15% had bacterial, and 9% had polymicrobial pneumonia. Streptococcus pneumoniae (12%), influenza virus (12%), and Mycoplasma pneumoniae (1.2%) were the most common bacterial, viral, and atypical pathogens, respectively. Nonadherence to local empirical antibiotic treatment guidelines (primarily recommending beta-lactam and doxycycline) was observed in 25% and was independently associated with prolonged hospitalization (≥7 days) and higher mortality, after adjustment for age, underlying chronic illness, and disease severity.

Conclusions

Adherence to treatment guidelines was associated with shorter hospitalization and improved survival. We provided evidence for the use of doxycycline for coverage of atypical pathogens in nonsevere pneumonia.

Metagenomic next-generation sequencing in the diagnosis of severe pneumonias caused by Chlamydia psittaci

PURPOSE

Chlamydia psittaci infection in humans can lead to serious clinical manifestations, including severe pneumonia, adult respiratory distress syndrome, and, rarely, death. Implementation of metagenomic next-generation sequencing (mNGS) gives a promising new tool for diagnosis. The clinical spectrum of severe psittacosis pneumonia is described to provide physicians with a better understanding and to highlight the rarity and severity of severe psittacosis pneumonia.

METHODS

Nine cases of severe psittacosis pneumonia were diagnosed using mNGS. Retrospective analysis of the data on disease progression, new diagnosis tool, treatments, and outcomes, and the findings were summarised.

RESULTS

Frequent symptoms included chills and remittent fever (100%), cough and hypodynamia (100%), and headache and myalgia (77.8%). All patients were severe psittacosis pneumonia developed respiratory failure, accompanied by sepsis in 6/9 patients. mNGS takes 48-72 h to provide the results, and help to identify diagnosis of psittacosis. Laboratory data showed normal or slightly increased leucocytes, neutrophils, and procalcitonin but high C-reactive protein levels. Computed tomography revealed air-space consolidation and ground-glass opacity, which began in the upper lobe of one lung, and spread to both lungs, along with miliary, nodular, or consolidated shadows. One patient died because of secondary infection with Klebsiella pneumoniae, while the other eight patients experienced complete recoveries.

CONCLUSIONS

The use of mNGS can improve accuracy and reduce the delay in diagnosis of psittacosis. Severe psittacosis pneumonia responds well to the timely use of appropriate antibiotics.

Chlamydiae from Down Under: The Curious Cases of Chlamydial Infections in Australia

In Australia, the most researched and perhaps the most successful chlamydial species are the human pathogen Chlamydia trachomatis, animal pathogens Chlamydia pecorum and Chlamydia psittaci. C. trachomatis remains the leading cause of sexually transmitted infections in Australians and trachoma in Australian Indigenous populations. C. pecorum is globally recognised as the infamous koala and widespread livestock pathogen, whilst the avian C. psittaci is emerging as a horse pathogen posing zoonotic risks to humans. Certainly not innocuous, the human infections with Chlamydia pneumoniae seem to be less prevalent that other human chlamydial pathogens (namely C. trachomatis). Interestingly, the complete host range for C. pecorum and C. psittaci remains unknown, and infections by other chlamydial organisms in Australian domesticated and wildlife animals are understudied. Considering that chlamydial organisms can be encountered by either host at the human/animal interface, I review the most recent findings of chlamydial organisms infecting Australians, domesticated animals and native wildlife. Furthermore, I also provide commentary from leading Australian Chlamydia experts on challenges and future directions in the Chlamydia research field.

Factors Associated With 30-Day Mortality Rate in Respiratory Infections Caused by Streptococcus pneumoniae

In multivariable analysis of associations between initial antibiotic therapy and clinical outcomes in 5005 patients with microbiologically confirmed Streptococcus pneumoniae infections, "discordant" empiric antibiotic therapy was not associated with 30-day mortality rate (hazard ratio, 0.94; 95% confidence interval, .67-1.32).

Ceftaroline fosamil as a potential treatment option for Staphylococcus aureus community-acquired pneumonia in adults

Staphylococcus aureus (S. aureus), including methicillin-resistant S. aureus (MRSA), is an important aetiological cause of community-acquired pneumonia (CAP) and associated with significant morbidity and mortality. Empiric therapy for CAP frequently consists of β-lactam monotherapy or β-lactam/macrolide combination therapy. However, such agents are often ineffective against S. aureus and do not reflect the emergence and increasing prevalence of MRSA in the community setting. Ceftaroline fosamil is a fifth-generation parenteral cephalosporin with broad-spectrum activity against Gram-positive pathogens - such as S. aureus (including MRSA), Streptococcus pneumoniae and Streptococcus pyogenes - and typical Gram-negative pathogens, including Haemophilus influenzae and Moraxella catarrhalis. The approval of ceftaroline fosamil in the United States and Europe for the treatment of adults with moderate-to-severe CAP was based on two phase 3 trials (FOCUS 1 and 2), which demonstrated that ceftaroline fosamil was non-inferior to ceftriaxone, a standard empiric treatment for CAP, while exhibiting a comparable safety profile. Although head-to-head trials of ceftaroline fosamil versus comparators against MRSA CAP are lacking, the effectiveness of ceftaroline fosamil in subpopulations of patients not covered by phase 3 trials (e.g. those with MRSA CAP or severe renal impairment) has been demonstrated in the Clinical Assessment Program and Teflaro Utilization Registry (CAPTURE) study. As ineffective empiric therapy is associated with adverse outcomes, including mortality and increased costs, ceftaroline fosamil, with its extended spectrum of activity, is an attractive alternative to standard antibiotic CAP regimens.

Antimicrobial prescription in patients dying from chronic obstructive pulmonary disease

BACKGROUND

Despite rising antimicrobial resistance, treatment guidelines for chronic obstructive pulmonary disease (COPD) exacerbations are frequently ignored. Patients with terminal conditions are often prescribed antimicrobials despite the goal of care to reduce burdensome treatments. The appropriate use of antimicrobials in patients who die from an exacerbation of COPD is unknown.

AIM

To review antimicrobial prescription during the final admission in patients who died from an acute exacerbation of COPD.

METHODS

A retrospective medical record audit was performed for 475 patients who died over 12 years (2004-2015). Patients were analysed within three groups: Group 1 - pneumonia on chest radiograph, Group 2 - infective exacerbation of COPD +/- raised inflammatory markers (white cell count, C-reactive protein) and Group 3 - non-infective exacerbation of COPD.

RESULTS

A total of 221 patients died from COPD. The median age was 80 years, and 136 (60%) were male. Median respiratory function: forced expiratory volume in 1 s 0.8 L (41.0%), forced vital capacity 2.0 L (74.0%) and diffusing capacity for carbon monoxide 8 (40.5%). A total of 109 (49.3%) patients used home oxygen and 156 (70.6%) were ex-smokers. Of the cohort, 90.5% received antimicrobials. In Groups 1, 2 and 3, 68 (94.4%), 108 (92.3%) and 24 (75.0%) patients received antimicrobials respectively. Guideline-concordant therapy was administered to 31.7% of patients (Group 1: 79.2%, Group 2: 4.3%, Group 3: 25.0%), 60.2% of patients received ceftriaxone and 44.8% received azithromycin. The median duration of therapy was 4 days and 27.1% received antimicrobials at the time of death.

CONCLUSION

Antimicrobials are overprescribed, and non-guideline antimicrobials are overused in patients who die from COPD. Further education of medical staff, regular medication reviews and the use of disease severity scores or clinical pathways may improve antimicrobial stewardship.

Respiratory viruses in adults hospitalised with Community-Acquired Pneumonia during the non-winter months in Melbourne: Routine diagnostic practice may miss large numbers of influenza and respiratory syncytial virus infections

Background Community-Acquired Pneumonia (CAP) is one of the highest health burden conditions in Australia. Disease notifications and other data from routine diagnosis suffers from selection bias that may misrepresent the true contribution of various aetiological agents. However existing Australian prospective studies of CAP aetiology have either under-represented elderly patients, not utilised Polymerase Chain Reaction (PCR) diagnostics or been limited to winter months. We therefore sought to re-evaluate CAP aetiology by systematically applying multiplex PCR in a representative cohort of mostly elderly patients hospitalised in Melbourne during non-winter months and compare diagnostic results with those obtained under usual conditions of care. Methods Seventy two CAP inpatients were prospectively enrolled over 2 ten-week blocks during non-winter months in Melbourne in 2016-17. Nasopharyngeal and oropharyngeal swabs were obtained at admission and analysed by multiplex-PCR for 7 respiratory viruses and 5 atypical bacteria. Results Median age was 74 (interquartile range 67-80) years, with 38 (52.8%) males and 34 (47.2%) females. PCR was positive in 24 (33.3%), including 12 Picornavirus (50.5% of those with a virus), 4 RSV (16.7%) and 4 influenza A (16.7%). CAP-Sym questionnaire responses were similar in those with and without viral infections. Most (80%) pathogens detected by the study, including all 8 cases of influenza and RSV, were not otherwise detected by treating clinicians during hospital admission. Conclusion One third of patients admitted with CAP during non-winter months had PCR-detectable respiratory viral infections, including many cases of influenza and RSV that were missed by existing routine clinical diagnostic processes. Keywords: Lower Respiratory Tract Infection (LRTI), Community-Acquired Pneumonia (CAP) Polymerase Chain Reaction (PCR), Influenza, Respiratory Syncytial Virus

Optimal antimicrobial duration for common bacterial infections

Most antibiotic use in Australia arises from prescriptions in the community

The risk of antibiotic-related adverse events including resistance increases with longer treatment courses

When antibiotics are indicated for treatment short courses are as effective as standard ones for most common infections

Therapeutic Guidelines Antibiotic is a key reference for antimicrobial prescribing in Australia

General practitioners play a key role in reducing antibiotic use

Microbiological testing of adults hospitalised with community-acquired pneumonia: an international study

This study aimed to describe real-life microbiological testing of adults hospitalised with community-acquired pneumonia (CAP) and to assess concordance with the 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) and 2011 European Respiratory Society (ERS) CAP guidelines.

This was a cohort study based on the Global Initiative for Methicillin-resistant Staphylococcus aureus Pneumonia (GLIMP) database, which contains point-prevalence data on adults hospitalised with CAP across 54 countries during 2015.

In total, 3702 patients were included. Testing was performed in 3217 patients, and included blood culture (71.1%), sputum culture (61.8%), Legionella urinary antigen test (30.1%), pneumococcal urinary antigen test (30.0%), viral testing (14.9%), acute-phase serology (8.8%), bronchoalveolar lavage culture (8.4%) and pleural fluid culture (3.2%). A pathogen was detected in 1173 (36.5%) patients. Testing attitudes varied significantly according to geography and disease severity. Testing was concordant with IDSA/ATS and ERS guidelines in 16.7% and 23.9% of patients, respectively. IDSA/ATS concordance was higher in Europe than in North America (21.5% versus 9.8%; p<0.01), while ERS concordance was higher in North America than in Europe (33.5% versus 19.5%; p<0.01).

Testing practices of adults hospitalised with CAP varied significantly by geography and disease severity. There was a wide discordance between real-life testing practices and IDSA/ATS/ERS guideline recommendations.

Testing practices vary based on geography and disease severity, and IDSA/ATS/ERS testing recommendations are rarely followedhttp://ow.ly/80Iy30lxo1c

Review article: Sepsis in the emergency department - Part 3: Treatment

Although comprehensive guidelines for treatment of sepsis exist, current research continues to refine and revise several aspects of management. Imperatives for rapid administration of broad-spectrum antibiotics for all patients with sepsis may not be supported by contemporary data. Many patients may be better served by a more judicious approach allowing consideration of investigation results and evidence-based guidelines. Conventional fluid therapy has been challenged with early evidence supporting balanced, restricted fluid and early vasopressor use. Albumin, vasopressin and hydrocortisone have each been shown to support blood pressure and reduce catecholamine requirements but without effect on mortality, and as such should be considered for ED patients with septic shock on a case-by-case basis. Measurement of quality care in sepsis should incorporate quality of blood cultures and guideline-appropriateness of antibiotics, as well as timeliness of therapy. Local audit is an essential and effective means to improve practice. Multicentre consolidation of data through agreed minimum sepsis data sets would provide baseline quality data, required for the design and evaluation of interventions.

Pneumonia in patients with systemic lupus erythematosus: Epidemiology, microbiology and outcomes

Background and objective Pneumonia remains the main cause of mortality in patients with systemic lupus erythematosus (SLE). The aim of the study was to establish the clinical characteristics, microbiology and risk factors for poor prognosis in patients with SLE and pneumonia. Methods We reviewed medical records of patients with SLE (American College of Rheumatology criteria) and pneumonia who attended the emergency room in a single tertiary care center (January 2010-March 2015). We collected demographics, treatment and disease activity (SLEDAI-2K) data. Severity scales of pneumonia (CURB-65 (acronym for risk factors measured: confusion, urea nitrogen, respiratory rate, blood pressure, 65 years of age and older) and Pneumonia Severity Index (PSI)) were obtained. A negative composite outcome was defined as need for mechanical ventilation, septic shock or death secondary to pneumonia up to 30 days after discharge. We conducted a univariate and multivariable analysis. Results We studied 158 patients (76% women) with 187 episodes of pneumonia. There were no differences in age, SLE duration, SLE activity, treatment or comorbidities between patients with negative composite outcome vs the other group. In 53 episodes, patients presented with a negative composite outcome. Of these, 46 (24.6%) required intubation, 13 (7%) developed shock and 12 (6.4%) died. The most common bacteria isolated was S. aureus, and we observed a high percentage of nonhabitual microorganisms. Fifteen percent of patients who presented with a negative outcome had low values on CURB-65 and PSI scales. Conclusion Patients with SLE and pneumonia have a high risk of complications and present with a high percentage of nonhabitual microorganisms. Severity scales for pneumonia can misclassify as low risk SLE patients with poor prognosis.

Is gentamicin safe and effective for severe community-acquired pneumonia? An 8-year retrospective cohort study

Gram-negative bacilli are the causative organisms in a significant proportion of patients with severe community-acquired pneumonia (CAP) admitted to the intensive care unit (ICU). Clinical guidelines recommend broad-spectrum antimicrobials for empirical treatment despite alarming global trends in antimicrobial resistance. In this study, we aimed to assess the safety and efficacy of gentamicin, an aminoglycoside with potent bactericidal activity, for empirical Gram-negative coverage of severe CAP in patients admitted to the ICU. A retrospective cohort study was performed at a university teaching hospital where the severe CAP guideline recommends penicillin, azithromycin and gentamicin as empirical cover. Ceftriaxone plus azithromycin is used as an alternative. Adults with radiologically-confirmed severe CAP were included, comparing those who received gentamicin in the first 72 h of admission with those who did not. Participants were identified using ICD-10 codes for bacterial pneumonia and data manually extracted from electronic medical records. Of 148 patients admitted with severe pneumonia, 117 were given at least one dose of gentamicin whereas the remaining 31 were not. The two groups were well matched in terms of demographics, co-morbidities and disease severity. There were no significant differences between the gentamicin and no-gentamicin groups in the incidence of acute kidney injury [60/117 (51%) vs. 16/31 (52%), respectively], hospital mortality [20/117 (17%) vs. 7/31 (23%)] and secondary outcomes including relapse and length of hospital stay. In conclusion, gentamicin is safe and has similar outcomes to alternative Gram-negative antimicrobial regimens for empirical coverage in severe CAP patients admitted to the ICU.

Procalcitonin as a Marker of Etiology in Adults Hospitalized With Community-Acquired Pneumonia

Background

Recent trials suggest procalcitonin-based guidelines can reduce antibiotic use for respiratory infections. However, the accuracy of procalcitonin to discriminate between viral and bacterial pneumonia requires further dissection.

Methods

We evaluated the association between serum procalcitonin concentration at hospital admission with pathogens detected in a multicenter prospective surveillance study of adults hospitalized with community-acquired pneumonia. Systematic pathogen testing included cultures, serology, urine antigen tests, and molecular detection. Accuracy of procalcitonin to discriminate between viral and bacterial pathogens was calculated.

Results

Among 1735 patients, pathogens were identified in 645 (37%), including 169 (10%) with typical bacteria, 67 (4%) with atypical bacteria, and 409 (24%) with viruses only. Median procalcitonin concentration was lower with viral pathogens (0.09 ng/mL; interquartile range [IQR], <0.05-0.54 ng/mL) than atypical bacteria (0.20 ng/mL; IQR, <0.05-0.87 ng/mL; P = .05), and typical bacteria (2.5 ng/mL; IQR, 0.29-12.2 ng/mL; P < .01). Procalcitonin discriminated bacterial pathogens, including typical and atypical bacteria, from viral pathogens with an area under the receiver operating characteristic (ROC) curve of 0.73 (95% confidence interval [CI], .69-.77). A procalcitonin threshold of 0.1 ng/mL resulted in 80.9% (95% CI, 75.3%-85.7%) sensitivity and 51.6% (95% CI, 46.6%-56.5%) specificity for identification of any bacterial pathogen. Procalcitonin discriminated between typical bacteria and the combined group of viruses and atypical bacteria with an area under the ROC curve of 0.79 (95% CI, .75-.82).

Conclusions

No procalcitonin threshold perfectly discriminated between viral and bacterial pathogens, but higher procalcitonin strongly correlated with increased probability of bacterial pathogens, particularly typical bacteria.

Impact of an antimicrobial stewardship intervention on appropriateness of prescribing for community-acquired pneumonia in an Australian regional hospital

Community-acquired pneumonia (CAP) is the second commonest indication for antibiotic use in Australian hospitals and is therefore a frequent target for antimicrobial stewardship. A single-centre prospective study was conducted in a regional referral hospital comparing management of adult patients with CAP before and after an educational intervention. We demonstrated a reduction in duration of therapy and reduced inappropriate use of ceftriaxone-based regimens for non-severe CAP.

The role of timeliness in the cost-effectiveness of older adult vaccination: A case study of pneumococcal conjugate vaccine in Australia

While the impact of the timeliness of vaccine administration has been well-studied for childhood vaccinations, there has been little detailed quantitative analysis on the potential impact of the timeliness of vaccinations in older adults. The aim of this study was to explore the impact of implementing more realistic observed uptake distributions, taking into the account reduced vaccine efficacy but higher pneumococcal disease burden with increasing age beyond 65 years. A multi-cohort Markov model was constructed to evaluate the cost-effectiveness of a pneumococcal (PCV13) immunisation program in Australia, assuming two different uptake modelling approaches. The approach using an estimate of observed uptake was compared with a scenario in which the total cumulative uptake was delivered at the recommended age of vaccination. We found these two approaches produced different results both in terms of cases prevented and cost-effectiveness. The impact of the non-timely uptake in adult programs may sometimes have positive and other times negative effects, depending on several factors including the age-specific disease rates and the duration of vaccine protection. Our study highlights the importance of using realistic assumptions around uptake (including non-timely vaccination) when estimating the impact of vaccination in adults.

Incidence, Etiology, and Outcomes of Community-Acquired Pneumonia: A Population-Based Study

Background

The microbial etiology of community-acquired pneumonia (CAP) is often unclear in clinical practice, and previous studies have produced variable results. Population-based studies examining etiology and incidence are lacking. This study examined the incidence and etiology of CAP requiring hospitalization in a population-based cohort as well as risk factors and outcomes for specific etiologies.

Methods

Consecutive admissions due to CAP in Reykjavik, Iceland were studied. Etiologic testing was performed with cultures, urine-antigen detection, and polymerase chain reaction analysis of airway samples. Outcomes were length of stay, intensive care unit admission, assisted ventilation, and mortality.

Results

The inclusion rate was 95%. The incidence of CAP requiring hospitalization was 20.6 cases per 10000 adults/year. A potential pathogen was detected in 52% (164 of 310) of admissions and in 74% (43 of 58) with complete sample sets. Streptococcuspneumoniae was the most common pathogen (61 of 310, 20%; incidence: 4.1/10000). Viruses were identified in 15% (47 of 310; incidence: 3.1/10000), Mycoplasmapneumoniae were identified in 12% (36 of 310; incidence: 2.4/10000), and multiple pathogens were identified in 10% (30 of 310; incidence: 2.0/10000). Recent antimicrobial therapy was associated with increased detection of M pneumoniae (P < .001), whereas a lack of recent antimicrobial therapy was associated with increased detection of S pneumoniae (P = .02). Symptoms and outcomes were similar irrespective of microbial etiology.

Conclusions

Pneumococci, M pneumoniae, and viruses are the most common pathogens associated with CAP requiring hospital admission, and they all have a similar incidence that increases with age. Symptoms do not correlate with specific agents, and outcomes are similar irrespective of pathogens identified.

The IMPROVE-GAP Trial aiming to improve evidence-based management of community-acquired pneumonia: study protocol for a stepped-wedge randomised controlled trial

Background

Community-acquired pneumonia is a leading worldwide cause of hospital admissions and healthcare resource consumption. The largest proportion of hospitalisations now occurs in older patients, with high rates of multimorbidity and complex care needs. In Australia, this population is usually managed by hospital inpatient general internal medicine units. Adherence to consensus best-practice guidelines is poor. Ensuring evidence-based care and reducing length of stay may improve patient outcomes and reduce organisational costs. This study aims to evaluate an alternative model of care designed to improve adherence to four Level 1 or 2 evidence-supported interventions (routine corticosteroids, early switch to oral antibiotics, early mobilisation and routine malnutrition screening).

Methods/Design

The IMPROVing Evidence-based treatment Gaps and outcomes in community-Acquired Pneumonia (IMPROVE-GAP) trial is a pragmatic, investigator-initiated, stepped-wedge randomised trial. Patients hospitalised under a general internal medicine unit who meet a standard case definition for community-acquired pneumonia will be included. Eight general internal medicine units at two Australian hospitals in a single health service will be randomised using concealed allocation to: (i) usual medical, nursing and allied health care delivered according to existing organisational practice or (ii) care supported by a dedicated “community-acquired pneumonia service”: a multidisciplinary team deploying algorithm-based implementation of a bundle of the four evidence-based interventions. The primary outcome measure will be length of hospital stay. Secondary outcome measures include inpatient mortality, 30 and 90 day readmission rates and mortality and health-service utilisation costs. Protocol adherence will be measured and reported, and serious adverse events (rates of hyperglycaemia requiring new insulin; falls during mobilisation) will be collected and reported.

Discussion

IMPROVE-GAP represents an important and unique precedent for testing a new service-delivery model for improving compliance with a number of evidence-based interventions. Its stepped-wedge randomised controlled trial design provides a means to address some significant ethical, organisational and other methodological challenges to evaluating the effectiveness of health-service interventions in complex hospital populations. The new service-delivery model will effectively be fully implemented by trial completion, facilitating rapid, seamless translation into practice should care outcomes be superior. This trial is currently recruiting.

Trial registration

ClinicalTrials.gov, NCT02835040. Prospectively registered on 22 May 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2407-4) contains supplementary material, which is available to authorized users.

Development of an Extended-Specificity Multiplex Immunoassay for Detection of Streptococcus pneumoniae Serotype-Specific Antigen in Urine by Use of Human Monoclonal Antibodies

Current pneumococcal vaccines cover the 10 to 23 most common serotypes of the 92 presently described. However, with the increased usage of pneumococcal-serotype-based vaccines, the risk of serotype replacement and an increase in disease caused by nonvaccine serotypes remains. Serotype surveillance of pneumococcal infections relies heavily on culture techniques, which are known to be insensitive, particularly in cases of noninvasive disease. Pneumococcal-serotype-specific urine assays offer an alternative method of serotyping for both invasive and noninvasive disease. However, the assays described previously cover mainly conjugate vaccine serotypes, give little information about circulating nonvaccine serotypes, and are currently available only in one or two specialist laboratories. Our laboratory has developed a Luminex-based extended-range antigen capture assay to detect pneumococcal-serotype-specific antigens in urine samples. The assay targets 24 distinct serotypes/serogroups plus the cell wall polysaccharide (CWP) and some cross-reactive serotypes. We report that the assay is capable of detecting all the targeted serotypes and the CWP at 0.1 ng/ml, while some serotypes are detected at concentrations as low as 0.3 pg/ml. The analytical serotype specificity was determined to be 98.4% using a panel of polysaccharide-negative urine specimens spiked with nonpneumococcal bacterial antigens. We also report clinical sensitivities of 96.2% and specificities of 89.9% established using a panel of urine specimens from patients diagnosed with community-acquired pneumonia or pneumococcal disease. This assay can be extended for testing other clinical samples and has the potential to greatly improve serotype-specific surveillance in the many cases of pneumococcal disease in which a culture is never obtained.

The dilemma of monotherapy or combination therapy in community-acquired pneumonia

SCOPE

To study the factors associated with mortality in hospitalized patients with community-acquired pneumonia treated with monotherapy or combination therapy.

METHODS

PubMed and Scopus were searched. Patients receiving macrolides, β-lactams and fluoroquinolones, as monotherapy or in combination, were included. Meta-analyses and meta-regressions were performed.

RESULTS

Fifty studies were included. Overall, monotherapy was not associated with higher mortality than combination (RR 1.14, 95% CI 0.99-1.32, I² 84%). Monotherapy was associated with higher mortality than combination in North American and retrospective studies. β-lactam monotherapy was associated with higher mortality than β-lactam/macrolide combination in the primary (1.32, 1.12-1.56, I² 85%) and most sensitivity analyses. There was no difference in mortality between fluoroquinolone monotherapy and β-lactam/macrolide combination (0.98, 0.78-1.23, I² 73%). In meta-regressions, the moderators that could partially explain the observed statistical heterogeneity were the frequency of cancer patients (P = .03) and Pneumonia Severity Index score IV (P = .008).

CONCLUSION

Due to the considerable heterogeneity and inclusion of unadjusted data, it is difficult to recommend a specific antibiotic regimen over another. Specific antibiotic regimens, study design and the characteristics of the population under study seem to influence the reported outcomes.

Underdiagnosis of Chlamydia trachomatis and Chlamydia psittaci revealed by introduction of respiratory multiplex PCR assay with Chlamydiaceae family primers

We describe unanticipated detection of respiratory infection with Chlamydia trachomatis and Chlamydia psittaci after introduction of respiratory multiplex polymerase chain reaction assay that includes Chlamydiaceae family primers. We detected cases of pediatric C. trachomatis and of adult C. psittaci infection in patients with previously unrecognized risk factors. Directed testing for C. trachomatis and C. psittaci based on clinical features and risk factors alone is likely to miss the majority of infected cases.

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

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

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.