Etiology of community-acquired pneumonia: impact of age, comorbidity, and severity

Guideline-Concordant Therapy for Community-Acquired Pneumonia in the Hospitalized Population: A Systematic Review and Meta-analysis

Background

A commonly used guideline for community-acquired pneumonia (CAP) is the joint American Thoracic Society and Infectious Diseases Society of America practice guideline. We aimed to investigate the effect of guideline-concordant therapy in the treatment of CAP.

Methods

We systematically searched MEDLINE, Embase, CENTRAL, Web of Science, and Scopus from 2007 to December 2023. We screened citations, extracted data, and assessed risk of bias in duplicate. Primary outcomes were mortality rates, intensive care unit (ICU) admission, and length of stay. Secondary outcomes were guideline adherence, readmission, clinical cure rate, and adverse complications. We performed random-effect meta-analysis to estimate the overall effect size and assessed heterogeneity using the I2 statistics.

Results

We included 17 observational studies and 82 240 patients, of which 10 studies were comparative and pooled in meta-analysis. Overall guideline adherence rate was 65.2%. Guideline-concordant therapy was associated with a statistically significant reduction in 30-day mortality rate (crude odds ratio [OR], 0.49 [95% confidence interval .34-.70; I2 = 60%]; adjusted OR, 0.49 [.37-.65; I2 = 52%]) and in-hospital mortality rate (crude OR, 0.63 [.43-.92]; I2 = 61%). Due to significant heterogeneity, we could not assess the effect of guideline-concordant therapy on length of stay, ICU admission, readmission, clinical cure rate, and adverse complications.

Conclusions

In hospitalized patients with CAP, guideline-concordant therapy was associated with a significant reduction in mortality rate compared with nonconcordant therapy; however, there was limited evidence to support guideline-concordant therapy for other clinical outcomes. Future studies are needed to assess the clinical efficacy and safety of current guideline recommendations.

Population pharmacokinetics and dose optimization of levofloxacin in elderly patients with pneumonia

AIMS

Levofloxacin is a quinolone antibiotic with a broad antibacterial spectrum. It is frequently used in elderly patients with pneumonia. The pharmacokinetic profile of elderly patients changes with age, but data on the pharmacokinetics of levofloxacin in these patients are limited. The aim of this study was to establish a population pharmacokinetic model of levofloxacin in elderly patients with pneumonia and to optimize individualized dosing regimens based on this newly developed model.

METHODS

This is a prospective, open-label pharmacokinetic study in elderly patients with pneumonia. Blood samples were collected using an opportunistic approach. The plasma concentrations of levofloxacin were determined by high-performance liquid chromatography. A population pharmacokinetic model was established using nonlinear mixed-effect model software. Monte Carlo simulations were used for dose simulation and dose optimization.

RESULTS

Data from 51 elderly patients with pneumonia were used for the population pharmacokinetic analysis. A one-compartment model with first-order elimination was most suitable for describing the data, and the estimated glomerular filtration rate was the only covariate that had a significant impact on the model. The final model estimated that the mean clearance of levofloxacin in elderly patients with pneumonia was 5.26 L/h. Monte Carlo simulation results showed that the optimal dosing regimen for levofloxacin was 750 mg once a day in elderly patients with pneumonia, with a minimum inhibitory concentration of 2 mg/L.

CONCLUSIONS

The population pharmacokinetic model of levofloxacin in elderly patients with pneumonia was established, and the dose optimization of levofloxacin was completed through Monte Carlo simulation.

Definition, Epidemiology, and Pathogenesis of Severe Community-Acquired Pneumonia

The clinical presentation of community-acquired pneumonia (CAP) can vary widely among patients. While many individuals with mild symptoms can be managed as outpatients with excellent outcomes, there is a distinct subgroup of patients who present with severe CAP. In these cases, the mortality rate can reach approximately 25% within 30 days and even up to 50% within a year. It is crucial to focus attention on these patients who are at higher risk. Among the various definitions of severe CAP found in the literature, one commonly used criterion is the requirement for admission to intensive care unit. Notable epidemiological characteristics of these patients include the impact of acute cardiovascular diseases on clinical outcomes and the enduring, independent effect of pneumonia on long-term outcomes. Factors such as pathogen virulence, the presence of comorbidities, and the host response are important contributors to the pathogenesis of severe CAP. In these patients, the host response may be dysregulated and compartmentalized. Gaining a better understanding of the epidemiology and pathogenesis of severe CAP will provide a foundation for the development of new therapies for this condition. This manuscript aims to review the definition, epidemiology, and pathogenesis of severe CAP, shedding light on important aspects that can aid in the improvement of patient care and outcomes.

Clinical Characteristics and Microorganisms Isolated in Community-Acquired Pneumonia in the COVID-19 Period

Introduction

Community-acquired pneumonia is a leading cause of mortality and hospital admissions. The aetiology remains unknown in 30-65% of the cases. Molecular tests are available for multiple pathogen detection and are under research to improve the causal diagnosis.

Methods

We carried out a prospective study to describe the clinical characteristics and aetiology of community-acquired pneumonia during the COVID-19 pandemic and to assess the diagnostic effectivity of the microbiological tests, including a molecular test of respiratory pathogens (FilmArray™ bioMérieux).

Results

From the 1st of February 2021 until the 31st of March 2022, 225 patients were included. Failure in microorganism identification occurred in approximately 70% of patients. Streptococcus pneumoniae was the most common isolate. There were 5 cases of viral pneumonia. The tested FilmArray exhibited a low positivity rate of 7% and mainly aided in the diagnosis of viral coinfections.

Conclusions

Despite our extensive diagnostic protocol, there is still a low rate of microorganism identification. We have observed a reduction in influenza and other viral pneumoniae during the COVID-19 pandemic. Having a high NEWS2 score on arrival at the emergency department, an active oncohematological disease or chronic neurological conditions and a positive microbiological test result were related to worse outcomes. Further research is needed to determine the role of molecular tests in the microbiological diagnosis of pneumonia.

Impact of influenza, herpes zoster, and pneumococcal vaccinations on the incidence of cardiovascular events in subjects aged over 65 years: a systematic review

This systematic review aims to summarize the impact of vaccination against influenza, shingles, and pneumococcus on the incidence on the risk of cardiovascular events in the elderly. This protocol was developed in accordance with PRISMA guidelines. We conducted a literature search and identified all relevant articles published regarding the matter up to September 2022. We retrieved 38 studies (influenza vaccine = 33, pneumococcal vaccine = 5, and zoster vaccine = 2). A total of 28 and 2 studies have shown that influenza and pneumococcal vaccines significantly lower the risk of cardiovascular disease in the elderly. Also, repeated influenza vaccination shows a consistent and dose-dependent protective effect against acute coronary syndromes and stroke. Moreover, dual influenza and pneumococcal vaccination was associated with lower risks of some cardiovascular events (stroke, congestive heart failure, ischemic heart disease, and myocardial infarction). However, the impact of PCV13 on cardiovascular events has not been studied, nor has the currently recommended vaccination schedule (PCV13 + PPV23). As for herpes zoster vaccination, only the protective effect against stroke has been studied with the live attenuated herpes zoster vaccine, but no studies have been conducted with the recombinant subunit herpes zoster vaccine. This review outlines the benefits of the vaccines mentioned above beyond their preventive action on infectious diseases. It is intended for health professionals who wish to inform and advise their elderly patients.

Prevalence of atypical pathogens in patients with severe pneumonia: a systematic review and meta-analysis

OBJECTIVES

We aimed to summarise the prevalence of atypical pathogens in patients with severe pneumonia to understand the prevalence of severe pneumonia caused by atypical pathogens, improve clinical decision-making and guide antibiotic use.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Web of Science and Cochrane Library were searched through November 2022.

ELIGIBILITY CRITERIA

English language studies enrolled consecutive cases of patients diagnosed with severe pneumonia, with complete aetiological analysis.

DATA EXTRACTION AND SYNTHESIS

We conducted literature retrieval on PubMed, Embase, Web of Science and The Cochrane Library to estimate the prevalence of Chlamydia, Mycoplasma and Legionella in patients with severe pneumonia. After double arcsine transformation of the data, a random-effects model was used for meta-analyses to calculate the pooled prevalence of each pathogen. Meta-regression analysis was also used to explore whether the region, different diagnostic method, study population, pneumonia categories or sample size were potential sources of heterogeneity.

RESULTS

We included 75 eligible studies with 18 379 cases of severe pneumonia. The overall prevalence of atypical pneumonia is 8.1% (95% CI 6.3% to 10.1%) In patients with severe pneumonia, the pooled estimated prevalence of Chlamydia, Mycoplasma and Legionella was 1.8% (95% CI 1.0% to 2.9%), 2.8% (95% CI 1.7% to 4.3%) and 4.0% (95% CI 2.8% to 5.3%), respectively. We noted significant heterogeneity in all pooled assessments. Meta-regression showed that the pneumonia category potentially influenced the prevalence rate of Chlamydia. The mean age and the diagnostic method of pathogens were likely moderators for the prevalence of Mycoplasma and Legionella, and contribute to the heterogeneity of their prevalence.

CONCLUSIONS

In severe pneumonia, atypical pathogens are notable causes, especially Legionella. The diagnostic method, regional difference, sample size and other factors contribute to the heterogeneity of prevalence. The estimated prevalence and relative heterogeneity factors can help with microbiological screening, clinical treatment and future research planning.

PROSPERO REGISTRATION NUMBER

CRD42022373950.

Effectiveness of Pneumococcal Conjugate Vaccination Against Virus-Associated Lower Respiratory Tract Infection Among Adults: A Case-Control Study

BACKGROUND

Interactions of Streptococcus pneumoniae with viruses feature in the pathogenesis of numerous respiratory illnesses.

METHODS

We undertook a case-control study among adults at Kaiser Permanente Southern California between 2015 and 2019. Case patients had diagnoses of lower respiratory tract infection (LRTI; including pneumonia or nonpneumonia LRTI diagnoses), with viral infections detected by multiplex polymerase chain reaction testing. Controls without LRTI diagnoses were matched to case patients by demographic and clinical attributes. We measured vaccine effectiveness (VE) for 13-valent (PCV13) against virus-associated LRTI by determining the adjusted odds ratio for PCV13 receipt, comparing case patients and controls.

RESULTS

Primary analyses included 13 856 case patients with virus-associated LRTI and 227 887 matched controls. Receipt of PCV13 was associated with a VE of 24.9% (95% confidence interval, 18.4%-30.9%) against virus-associated pneumonia and 21.5% (10.9%-30.9%) against other (nonpneumonia) virus-associated LRTIs. We estimated VEs of 26.8% (95% confidence interval, 19.9%-33.1%) and 18.6% (9.3%-27.0%) against all virus-associated LRTI episodes diagnosed in inpatient and outpatient settings, respectively. We identified statistically significant protection against LRTI episodes associated with influenza A and B viruses, endemic human coronaviruses, parainfluenza viruses, human metapneumovirus, and enteroviruses but not respiratory syncytial virus or adenoviruses.

CONCLUSIONS

Among adults, PCV13 conferred moderate protection against virus-associated LRTI. The impacts of pneumococcal conjugate vaccines may be mediated, in part, by effects on polymicrobial interactions between pneumococci and respiratory viruses.

Young Healthy Patient With Severe COVID-19 and Fulminant Community-Acquired Pseudomonas aeruginosa Pneumonia: A Case Report

Community-acquired pneumonia (CAP) caused by Pseudomonas aeruginosa in healthy adults can rapidly lead to severe outcomes. We treated a case of P. aeruginosa-induced CAP and concurrent severe coronavirus disease (COVID-19) in a healthy 39-year-old man without other serious risk factors for severe illness except smoking. Immediately after admission, the patient developed sepsis and received intensive broad-spectrum antibacterial therapy with meropenem and vancomycin, veno-arterial extracorporeal membrane oxygenation (VAECMO), and catecholamine supplementation. Despite receiving multidisciplinary treatment, the patient died within 24 hours. P. aeruginosa with normal antimicrobial susceptibility was identified in blood and sputum cultures of samples taken at admission. Gram staining of the bacteria detected in blood cultures was suspicious for non-glucose-fermenting Gram-negative rods, including P. aeruginosa, and the antimicrobial regimen that was initiated following admission was considered effective. The patient was a plumber and a smoker, which are risk factors for P. aeruginosa-induced CAP, and the clinical course matched those in previous reports of P. aeruginosa-induced CAP, including necrotizing pneumonia with cavities and rapid progression of sepsis. Although COVID-19 can be the sole cause of septic shock, the combination of P. aeruginosa bacteremia and COVID-19 was possibly the cause of septic shock in this case. Even during an infectious disease pandemic, reviewing the patient's occupational history and comorbidities and performing blood and sputum culture tests, including Gram staining, are important for the provision of appropriate treatment.

Clinical risk factors for admission with Pseudomonas and multidrug-resistant Pseudomonas community-acquired pneumonia

Background

Microbial etiology for community-acquired pneumonia (CAP) is evolving with pathogens known for high CAP mortality e.g., Pseudomonas species. Chronic obstructive pulmonary disease (COPD) patients are at risk for hospitalization for CAP. Understanding regional patterns and risk factors for multidrug-resistant (MDR) Pseudomonas acquisition has implications for antimicrobial stewardship.

Objectives

To evaluate the regional epidemiology of MDR Pseudomonas CAP and its association with COPD.

Methods

We queried the electronic medical records of the University of Alabama at Birmingham Healthcare System to identify patients hospitalized for CAP with Pseudomonas positive respiratory samples between 01/01/2013–12/31/2019. Log binomial regression models were used to examine associations between COPD diagnosis and risk of Pseudomonas/MDR Pseudomonas CAP.

Results

Cohort consisted of 913 culture positive CAP cases aged 59-year (IQR:48–68), 61% (560) male, 60% (547) white, 65% (580) current/past smokers, and 42% (384) COPD. Prevalence of Pseudomonas CAP in culture positive CAP was 18% (167), MDR Pseudomonas CAP in Pseudomonas CAP was 22% (36), and yearly incidence of MDR Pseudomonas CAP was stable (p = 0.169). COPD was associated with Pseudomonas CAP (RR 1.39; 95% CI 1.01, 1.91; p = 0.041) but not with MDR Pseudomonas CAP (0.71; 95% CI 0.35, 1.45; p = 0.349). Stroke (RR 2.64; 95% CI 1.51, 4.61; p = 0.0006) and use of supplemental oxygen (RR 2.31; 95% CI 1.30, 4.12; p = 0.005) were associated with MDR Pseudomonas CAP.

Conclusion

Incidence of MDR Pseudomonas CAP was stable over time. COPD was associated with Pseudomonas CAP but not with MDR Pseudomonas CAP. Larger cohort studies are needed to confirm findings.

Q Fever as a Cause of Community-Acquired Pneumonia in French Guiana

In French Guiana, community-acquired pneumonia (CAP) represents over 90% of Coxiella burnetii acute infections. Between 2004 and 2007, we reported that C. burnetii was responsible for 24.4% of the 131 CAP hospitalized in Cayenne. The main objective of the present study was to determine whether the prevalence of Q fever pneumonia remained at such high levels. The secondary objectives were to identify new clinical characteristics and risk factors for C. burnetii pneumonia. A retrospective case-control study was conducted on patients admitted in Cayenne Hospital, between 2009 and 2012. All patients with CAP were included. The diagnosis of acute Q fever relied on titers of phase II IgG ≥ 200 and/or IgM ≥ 50 or seroconversion between two serum samples. Patients with Q fever were compared with patients with non-C. burnetii CAP in bivariate and multivariate analyses. During the 5-year study, 275 patients with CAP were included. The etiology of CAP was identified in 54% of the patients. C. burnetii represented 38.5% (106/275; 95% CI: 31.2-45.9%). In multivariate analysis, living in Cayenne area, being aged 30-60 years, C-reactive protein (CRP) > 185 mg/L, and leukocyte count < 10 G/L were independently associated with Q fever. The prevalence of Q fever among CAP increased to 38.5%. This is the highest prevalence ever reported in the world. This high prevalence justifies the systematic use of doxycycline in addition to antipneumococcal antibiotic regimens.

Bacterial co-infections in community-acquired pneumonia caused by SARS-CoV-2, influenza virus and respiratory syncytial virus

Background

A mismatch between a widespread use of broad-spectrum antibiotic agents and a low prevalence of reported bacterial co-infections in patients with SARS-CoV-2 infections has been observed. Herein, we sought to characterize and compare bacterial co-infections at admission in hospitalized patients with SARS-CoV-2, influenza or respiratory syncytial virus (RSV) positive community-acquired pneumonia (CAP).

Methods

A retrospective cohort study of bacterial co-infections at admission in SARS-CoV-2, influenza or RSV-positive adult patients with CAP admitted to Karolinska University Hospital in Stockholm, Sweden, from year 2011 to 2020. The prevalence of bacterial co-infections was investigated and compared between the three virus groups. In each virus group, length of stay, ICU-admission and 30-day mortality was compared in patients with and without bacterial co-infection, adjusting for age, sex and co-morbidities. In the SARS-CoV-2 group, risk factors for bacterial co-infection, were assessed using logistic regression models and creation of two scoring systems based on disease severity, age, co-morbidities and inflammatory markers with assessment of concordance statistics.

Results

Compared to influenza and RSV, the bacterial co-infection testing frequency in SARS-CoV-2 was lower for all included test modalities. Four percent [46/1243 (95% CI 3–5)] of all SARS-CoV-2 patients had a bacterial co-infection at admission, whereas the proportion was 27% [209/775 (95% CI 24–30)] and 29% [69/242 (95% CI 23–35)] in influenza and RSV, respectively. S. pneumoniae and S. aureus constituted the most common bacterial findings for all three virus groups. Comparing SARS-CoV-2 positive patients with and without bacterial co-infection at admission, a relevant association could not be demonstrated nor excluded with regards to risk of ICU-admission (aHR 1.53, 95% CI 0.87–2.69) or 30-day mortality (aHR 1.28, 95% CI 0.66–2.46) in adjusted analyses. Bacterial co-infection was associated with increased inflammatory markers, but the diagnostic accuracy was not substantially different in a scoring system based on disease severity, age, co-morbidities and inflammatory parameters [C statistic 0.66 (95% CI 0.59–0.74)], compared to using disease severity, age and co-morbidities only [C statistic 0.63 (95% CI 0.56–0.70)].

Conclusions

The prevalence of bacterial co-infections was significantly lower in patients with community-acquired SARS-CoV-2 positive pneumonia as compared to influenza and RSV positive pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07089-9.

Active disease-related compound identification based on capsule network

Pneumonia, especially corona virus disease 2019 (COVID-19), can lead to serious acute lung injury, acute respiratory distress syndrome, multiple organ failure and even death. Thus it is an urgent task for developing high-efficiency, low-toxicity and targeted drugs according to pathogenesis of coronavirus. In this paper, a novel disease-related compound identification model-based capsule network (CapsNet) is proposed. According to pneumonia-related keywords, the prescriptions and active components related to the pharmacological mechanism of disease are collected and extracted in order to construct training set. The features of each component are extracted as the input layer of capsule network. CapsNet is trained and utilized to identify the pneumonia-related compounds in Qingre Jiedu injection. The experiment results show that CapsNet can identify disease-related compounds more accurately than SVM, RF, gcForest and forgeNet.

Body composition, physical capacity, and immuno-metabolic profile in community-acquired pneumonia caused by COVID-19, influenza, and bacteria: a prospective cohort study

BACKGROUND

Different pathogens can cause community-acquired pneumonia (CAP); however, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) has re-emphasized the vital role of respiratory viruses as a cause of CAP. The aim was to explore differences in metabolic profile, body composition, physical capacity, and inflammation between patients hospitalized with CAP caused by different etiology.

METHODS

A prospective study of Danish patients hospitalized with CAP caused by SARS-CoV-2, influenza, or bacteria. Fat (FM) and fat-free mass (FFM) were assessed with bioelectrical impedance analysis. Physical activity and capacity were assessed using questionnaires and handgrip strength. Plasma (p)-glucose, p-lipids, hemoglobin A1c (HbA1c), p-adiponectin, and cytokines were measured.

RESULTS

Among 164 patients with CAP, etiology did not affect admission levels of glucose, HbA1c, adiponectin, or lipids. Overall, 15.2% had known diabetes, 6.1% had undiagnosed diabetes, 51.3% had pre-diabetes, 81% had hyperglycemia, and 60% had low HDL-cholesterol, with no difference between groups. Body mass index, FM, and FFM were similar between groups, with 73% of the patients being characterized with abdominal obesity, although waist circumference was lower in patients with COVID-19. Physical capacity was similar between groups. More than 80% had low handgrip strength and low physical activity levels. Compared to patients with influenza, patients with COVID-19 had increased levels of interferon (IFN)-γ (mean difference (MD) 4.14; 95% CI 1.36-12.58; p = 0.008), interleukin (IL)-4 (MD 1.82; 95% CI 1.12-2.97; p = 0.012), IL-5 (MD 2.22; 95% CI 1.09-4.52; p = 0.024), and IL-6 (MD 2.41; 95% CI 1.02-5.68; p = 0.044) and increased IFN-γ (MD 6.10; 95% CI 2.53-14.71; p < 0.001) and IL-10 (MD 2.68; 95% CI 1.53-4.69; p < 0.001) compared to patients with bacterial CAP, but no difference in IL-1β, tumor necrosis factor-α, IL-8, IL-18, IL-12p70, C-reactive protein, and adiponectin.

CONCLUSION

Despite higher inflammatory response in patients with COVID-19, metabolic profile, body composition, and physical capacity were similar to patients with influenza and bacterial CAP.

Detection of Viruses by Multiplex Real-Time Polymerase Chain Reaction in Bronchoalveolar Lavage Fluid of Patients with Nonresponding Community-Acquired Pneumonia

Background

Nonresponding pneumonia is responsible for the most mortality of community-acquired pneumonia (CAP). However, thus far, it is not clear whether viral infection plays an important role in the etiology of nonresponding CAP and whether there is a significant difference in the clinical characteristics between viral and nonviral nonresponding CAP.

Methods

From 2016 to 2019, nonresponding CAP patients were retrospectively enrolled in our study. All patients received bronchoalveolar lavage (BAL) and virus detection in BAL fluid by multiplex real-time polymerase chain reaction (PCR), and clinical, laboratory, and radiographic data were collected.

Results

A total of 43 patients were included. The median age was 62 years, and 65.1% of patients were male. Overall, 20 patients (46.5%) were identified with viral infection. Of these viruses, influenza virus (n = 8) and adenovirus (n = 7) were more frequently detected, and others included herpes simplex virus, human enterovirus, cytomegalovirus, human coronavirus 229E, rhinovirus, and parainfluenza virus. Compared with nonviral nonresponding CAP, only ground-glass opacity combined with consolidation was a more common imaging manifestation in viral nonresponding CAP. However, no obvious differences were found in clinical and laboratory findings between the presence and the absence of viral infections.

Conclusions

Viral infections were particularly frequent in adults with nonresponding CAP. The ground-glass opacity combined with consolidation was a specific imaging manifestation for viral nonresponding CAP, while the clinical and laboratory data showed no obvious differences between viral and nonviral nonresponding CAP.

The increasing importance of Haemophilus influenzae in community-acquired pneumonia: results from a Danish cohort study

BACKGROUND

Numerous studies have shown that the aetiology of community-acquired pneumonia (CAP) varies considerably among different healthcare settings. Because empiric therapies for CAP should cover the major pathogens, reports examining CAP aetiology are considered crucial, particularly in Nordic countries that still rely on penicillin G or V treatments for most patients with CAP. The primary objective of our study was to report CAP aetiology. Secondary objectives included the estimation of positivity rates for different tests and the odds of a positive test for various subgroups.

METHODS

In this cohort study, microbiological data were analysed for an overall cohort (variable degree of microbiological testing) and for a subgroup that was tested for both, bacteria, viruses and fungi, using routine methods (defined as extensive testing).

RESULTS

The overall cohort comprised 2,264 patients, including 315 who were extensively tested. Bacterial and viral monoinfections were the most commonly identified infections. The dominant pathogen identified among extensively tested patients was Haemophilus influenzae (23.7%), followed by Streptococcus pneumoniae (20.6%). The tests with the highest positivity rates were sputum cultures (34.7%) and viral polymerase chain reaction (PCR, 24.4%). The odds of achieving a microbiological diagnosis increased significantly when extensive testing was performed compared with selective testing (OR 2.86, 95% CI 2.24-3.64).

CONCLUSION

Our study indicated that H. influenzae is the dominant responsible pathogen for bacterial CAP in Denmark. Thus, we believe that the current treatment recommendations that encourage the use of penicillin G or V for the majority of patients with CAP need to be revised.

Prevalence of gram negative bacteria causing community acquired pneumonia among adults in Mwanza City, Tanzania

BACKGROUND

Community acquired pneumonia (CAP) in adults is still a common and serious illness in the sub-Saharan Africa. Identification of the pathogens is crucial in the management of CAP. This study was done to determine the common bacterial pathogens, treatment outcomes and associated factors for microbiological confirmed CAP among adults attending the Bugando Medical Centre and Sekou Toure hospital in the city of Mwanza, Tanzania.

METHODS

This was a hospital based cross sectional study involving patients with community acquired pneumonia attending Bugando Medical Centre and Sekou Toure regional Hospital. Demographic and other data were collected using standardized data collection tool. Sputum culture was done followed by identification of the isolates and antibiotics susceptibility testing.

RESULTS

A total of 353 patients were enrolled in the study. Out of 353 sputum samples, 265(75%) were of good quality. Of 353 non-repetitive sputum cultures, 72/353 (20.4, 95% CI: 16.2-24.6) were positive for the bacterial pathogens with five patients having more than one pathogen. Good quality sputa had significantly higher yield of pathogenic bacteria than poor quality sputa (26.1% vs.3.4%, P = 0.001). The majority 64 (83.1%) of the isolates were gram negative bacteria. Common bacteria isolated were Klebsiella pneumoniae 23/77(29.9%), Streptococcus pyogenes 10/77 (13.0%), Pseudomonas aeruginosa 9/77 (11.7%) and Escherichia coli 7/77 (9.1%). Of 23 K. pneumoniae isolates, 20/23 (87.0%) were resistant to ceftriaxone. Resistance to ceftriaxone was found to be associated with prolongation of CAP symptoms (p = 0.009).

CONCLUSION

Gram negative bacteria resistant to ampicillin, amoxicillin/clavulanic acid and ceftriaxone were most frequently isolated bacteria among adults' patients with CAP attending BMC and Sekou Toure hospital. Routine sputum culture should be performed to guide appropriate treatment of CAP among adults in developing countries.

A 72-Year-Old Woman With Respiratory Failure and Bilateral Ground-Glass Opacities

A 72-year-old woman with diabetes mellitus was admitted to our hospital because of dyspnea on exertion. Sputum cytologic evaluation revealed intranuclear inclusion bodies in the cells; we therefore considered viral pneumonia and performed a bronchoscopy. The bronchial washing fluid was positive for immunoperoxidase staining of herpes simplex virus type 1 (HSV1) and HSV1 polymerase chain reaction. The patient was diagnosed as having pneumonia due to HSV1 and was successfully treated with acyclovir.

Short-Chain Alcohols Upregulate GILZ Gene Expression and Attenuate LPS-Induced Septic Immune Response

Alcohol differentially affects human health, depending on the pattern of exposure. Moderate intake provides beneficial mood modulation and an anti-inflammatory effect, while excessive consumption leads to immunosuppression and various alcohol use disorders. The mechanism underlying this bi-phasic action mode of alcohol has not been clearly defined. Our previous publication demonstrated that ethanol, in the absence of glucocorticoids (GCs), induces expression of Glucocorticoid-Induced Leucine Zipper (GILZ), a key molecule that transduces GC anti-inflammatory effect through a non-canonical activation of glucocorticoid receptor (1). Here we report that similar short-chain alcohols, such as ethanol, propanol and isopropanol, share the same property of upregulating GILZ gene expression, and blunt cell inflammatory response in vitro. When mice were exposed to these alcohols, GILZ gene expression in immune cells was augmented in a dose-dependent manner. Monocytes and neutrophils were most affected. The short-chain alcohols suppressed host inflammatory response to lipopolysaccharide (LPS) and significantly reduced LPS-induced mortality. Intriguingly, propanol and isopropanol displayed more potent protection than ethanol at the same dose. Inhibition of ethanol metabolism enhanced the ethanol protective effect, suggesting that it is ethanol, not its derivatives or metabolites, that induces immune suppression. Taken together, short-chain alcohols per se upregulate GILZ gene expression and provide immune protection against LPS toxicity, suggesting a potential measure to counter LPS septic shock in a resource limited situation.

Disease correlation network: a computational package for identifying temporal correlations between disease states from Large-Scale longitudinal medical records

Objective

To provide an open-source software package for determining temporal correlations between disease states using longitudinal electronic medical records (EMR).

Materials and Methods

We have developed an R-based package, Disease Correlation Network (DCN), which builds retrospective matched cohorts from longitudinal medical records to assess for significant temporal correlations between diseases using two independent methodologies: Cox proportional hazards regression and random forest survival analysis. This optimizable package has the potential to control for relevant confounding factors such as age, gender, and other demographic and medical characteristics. Output is presented as a DCN which may be analyzed using a JavaScript-based interactive visualization tool for users to explore statistically significant correlations between disease states of interest using graph-theory-based network topology.

Results

We have applied this package to a longitudinal dataset at Loyola University Chicago Medical Center with 654 084 distinct initial diagnoses of 51 conditions in 175 539 patients. Over 90% of disease correlations identified are supported by literature review. DCN is available for download at https://github.com/qunfengdong/DCN.

Conclusions

DCN allows screening of EMR data to identify potential relationships between chronic disease states. This data may then be used to formulate novel research hypotheses for further characterization of these relationships.

[Etiology of severe community - acquired pneumonia in adults: results of the first Russian multicenter study]

AIM

to study the etiology of severe community - acquired pneumonia (SCAP) in adults in Russian Federation. SCAP is distinguished by high mortality and socio - economic burden. Both etiology and antimicrobial resistance are essential for appropriate antibiotic choice.

MATERIALS AND METHODS

A prospective cohort study recruited adults with confirmed diagnosis of SCAP admitted to multi - word hospitals of six Russian cities in 2014-2018. Etiology was confirmed by routine culture of blood, respiratory (sputum, endotracheal aspirate or bronchoalveolar lavage) and when appropriate, autopsy samples, urinary antigen tests (L. pneumophila serogroup 1, S. pneumoniae); real - time PCR for identification of "atypical" bacterial pathogens (M. pneumoniae, C. pneumoniae, L. pneumophila) and respiratory viruses (influenza viruses A and B, parainfluenza, human metapneumovirus, etc.) was applied.

RESULTS

Altogether 109 patients (60.6% male; mean age 50.8±18.0 years old) with SCAP were enrolled. Etiological agent was identified in 65.1% of patients, S. pneumoniae, rhinovirus, S. aureus and K. pneumoniae were the most commonly isolated pathogens (found in 43.7, 15.5, 14.1 and 11.3% of patients with positive results of microbiological investigations, respectively). Bacteriemia was seen in 14.6% of patients and most commonly associated with S. pneumoniae. Co - infection with 2 or more causative agents was revealed in 36.6% of cases. Combination of bacterial pathogens (mainly S. pneumoniae with S. aureus or/and Enterobacterales) prevailed - 57.7% of cases; associations of bacteria and viruses were identified in 38.5% of patients, different viruses - in one case.

CONCLUSION

S. pneumoniae was the most common pathogen in adults with SCAP. A high rate of respiratory viruses (mainly rhinovirus and influenza viruses) identification both as mixt infection with bacteria and mono - infection should be taken into account.

Urinary antigen testing for pneumococcal pneumonia: is there evidence to make its use uncommon in clinical practice?

Microbiological confirmation of pneumonia caused by Streptococcus pneumoniae remains challenging as culture from blood or pleural fluid is positive in only 15–30% cases. It was hoped that a commercially available urine antigen test would improve diagnosis and consequently patient care, with improved antimicrobial stewardship. Urine antigen testing for pneumococcal pneumonia is recommended in current British Thoracic Society guidelines, whilst the National Institute for Health and Care Excellence and The American Thoracic Society and the Infectious Diseases Society of America guidelines consider its usage. Urine antigen testing is therefore widely used in hospital medicine. The assay is noninvasive, simple and culture-independent, producing a result within 15 min. Whilst initial evidence suggested urine antigen testing had a high sensitivity, recently data have suggested the actual sensitivity is lower than expected, at approximately 60–65%. Evidence has also emerged indicating that clinicians infrequently rationalise antibiotics following positive urine antigen testing, with multiple publications evaluating the role of urine antigen testing in clinical care. Furthermore, urine antigen testing does not appear to lead to any cost saving or reduction in length of hospital stay. We therefore conclude that the pneumococcal urinary antigen test does not alter patient management and leads to no cost saving, and has a lower than expected accuracy. Therefore, it may be time to make its use uncommon in clinical practice.

This article reviews the pneumococcal urine antigen test (Pn UAT), recommended in BTS, NICE and ATS/IDSA guidelines. Pn UAT is less accurate than expected, and has not been shown to improve patient care or antimicrobial stewardship or lead to cost saving.http://bit.ly/2MJpjWL

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.

Plasma cytokine profile on admission related to aetiology in community-acquired pneumonia

BACKGROUND

Potentially unnecessary antibiotic use for community-acquired pneumonia (CAP) contributes to selection of antibiotic-resistant pathogens. Cytokine expression at the time that treatment is started may assist in identifying patients not requiring antibiotics. We determined plasma cytokine patterns in patients retrospectively categorized as strict viral, pneumococcal or combined viral-bacterial CAP.

OBJECTIVE

To investigate whether cytokine-based prediction models can be used to differentiate strict viral CAP from other aetiologies at admission.

METHODS

From 344 hospitalized CAP patients, 104 patients were categorized as viral CAP (n = 17), pneumococcal CAP (n = 48) and combined bacterial-viral CAP (n = 39). IL-6, IL-10, IL-27, IFN-γ and C-reactive protein (CRP) were determined on admission in plasma. Prediction of strict viral aetiology was explored with two multivariate regression models and ROC curves.

RESULTS

Viral pneumonia was predicted by logistic regression using multiple cytokine levels (IL-6, IL-27 and CRP) with an AUC of 0.911 (95% CI: 0.852-0.971, P < .001). For the same patients the AUC of CRP was 0.813 (95% CI: 0.728-0.898, P < .001).

CONCLUSIONS

This study demonstrated differences in cytokine expression in selected CAP patients between viral and bacterial aetiology. Prospective validation studies are warranted.

Streptococcus pneumoniae as a Cause of Community-Acquired Pneumonia in Indian Adolescents and Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Streptococcus pneumoniae is one of the primary cause of community-acquired pneumonia (CAP) worldwide. However, scant data are available on the prevalence of etiological organisms for CAP in adolescent and adult Indian population.

OBJECTIVE

We performed a systematic review and meta-analysis to determine the contribution of S. pneumoniae in the causation of CAP in Indian patients aged 12 years or above.

METHODOLOGY

We performed a systematic search of both indexed and non-indexed publications using PubMed, databases of National Institute of Science Communication and Information Resources (NISCAIR), Annotated Bibliography of Indian Medicine (ABIM), Google Scholar, and hand search including cross-references using key terms 'community acquired pneumonia AND India'. All studies, published between January 1990 and January 2017, that evaluated Indian patients aged above 12 years with a confirmed diagnosis of CAP were eligible for inclusion. Our search retrieved a total of 182 studies, of which only 17 and 12 qualified for inclusion in the systematic review of all etiological organisms, and meta-analysis of S. pneumonia, respectively.

RESULTS

A total of 1435 patients met the inclusion criteria. The pooled proportion of patients with S. pneumoniae infection was 19% (95% confidence interval [CI]: 12%-26%; I2 = 94.5% where I2 represents heterogeneity, P < .01). Other major etiological agents are Mycoplasma pneumoniae (15.5% [1.1%-35.5%]), Klebsiella pneumoniae (10.5% [1.6%-24.0%]), and Legionella pneumophila (7.3% [2.5%-23.8%]).

CONCLUSIONS

Analysis found approximately a one-fifth proportion of adult Indian patients of CAP with S. pneumoniae infection, suggesting it as a leading organism for causing CAP compared with other etiological organisms.

[Lung abscess: Diagnosis and management]

Lung abscesses are necrotic cavitary lesions of the lung parenchyma. They are usually caused by anaerobic bacteria or mixed flora and typically occur after aspiration. Primary lung abscesses occur in previously healthy patients with no underlying medical disorders and are usually solitary. Secondary lung abscesses occur in patients with underlying or predisposing conditions and may be multiple. The initial diagnosis is usually made by chest radiography showing a lung cavity with an air-fluid level. Typically, the cavity wall is thick and irregular, and a surrounding pulmonary infiltrate is often present. The differential diagnosis of pulmonary cavitation is wide, including different types of possible infections, neoplasia and malformations of the bronchial tree. Management is usually based on prolonged antibiotic treatment. Failure of conservative management, manifested by the persistence of sepsis and/or other abscess complications, may necessitate drainage with invasive techniques (percutaneous, endoscopic or surgical) or open surgical removal of the lung lesion in patients with good performance status and sufficient respiratory reserve.

Validation of a diagnostic score model for the prediction of Legionella pneumophila pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) due to Legionella has a high mortality rate in patients who do not receive adequate antibiotic therapy. In a previous study, we developed a simple Legionella Score to distinguish patients with Legionella and non-Legionella pneumonia based on clinical information at diagnosis. In the present study, we validated this Legionella Score for the presumptive diagnosis of Legionella CAP.

METHODS

This validation cohort included 109 patients with Legionella CAP and 683 patients with non-Legionella CAP. The Legionella Score includes six parameters by assigning one point for each of the following items: being male, absence of cough, dyspnea, C-reactive protein (CRP) ≥ 18 mg/dL, lactate dehydrogenase (LDH) ≥ 260 U/L, and sodium < 134 mmol/L.

RESULTS

When the Legionella CAP and non-Legionella CAP were compared by univariate analysis, most of the evaluated symptoms and laboratory test results differed substantially. The six parameters that were used for the Legionella Score also indicated clear differences between the Legionella and non-Legionella CAP. All Legionella patients had a score of 2 points or higher. The median Legionella Scores were 4 in the Legionella CAP cases and 2 in the non-Legionella CAP cases. A receiver operating characteristics curve showed that the area under the curve was 0.93. The proposed best cutoff, total score ≥3, had sensitivity of 93% and specificity of 75%.

CONCLUSION

Our Legionella Score was shown to have good diagnostic ability with a positive likelihood of 3.7 and a negative likelihood of 0.10.

The role of Endocan as a Prognostic Biomarker in community-acquired pneumonia

Objective:

The aim of this study was to determine the importance of using endocan as a biomarker in deciding the setting of treatment and predicting prognosis in patients with community-acquired pneumonia (CAP).

Methods:

This prospective, case-control study was conducted at Okmeydani Training and Research Hospital between November 20, 2016 to March 20^th 2017. Blood samples were obtained from 63 patients who were admitted to internal medicine clinic due to CAP and 25 volunteers without active infection. Serum samples were centrifuged at 1000G for 15 minutes and stored at -20ºC. Samples were analyzed using human ESM1 (endocan) (Lot No: AK0017MAR0830) (Elabscience, Texas, USA) kit with Robonik (Mumbai, India) ELISA Plate Reader and Washer. Demographic and clinical data of the patients were recorded. CURB-65, qSOFA and Pneumonia Severity Index (PSI) scores were calculated. Primary endpoint of the study was 30-days mortality.

Results:

Mean serum endocan levels of the study group and the control group were 30.99±3.3 pg/ml and 246.5±49.95pg/ml, respectively. The difference between groups was statistically significant (p<0.005). 30-days mortality rate was 12.7% with eight patients, three of which died subsequently in the ICU. When patients were classified according to PSI and CURB-65 scores, endocan levels of PSI class ≥4 and CURB-65 ≥2 individuals were found to be significantly different than the control group. ROC analysis showed that serum endocan levels less than 64.96pg/ml has 85.2% sensitivity and 83.3% specificity for PSI class ≥4 and 82.4% sensitivity and 55.6% specificity for CURB-65 score ≥2.

Conclusion:

Serum endocan levels are significantly lower in patients with community-acquired pneumonia than the control group.

Circulating Extracellular Vesicles and Their miR "Barcode" Differentiate Alcohol Drinkers With Liver Injury and Those Without Liver Injury in Severe Trauma Patients

Short Summary: Extracellular vesicles (EVs), released during tissue/cell injury, contain a “barcode” indicating specific microRNAs (miRs) that can uncover their origin. We examined whether systemic EVs possessing hepatic miR-signatures would indicate ongoing liver injury and clinical complications in trauma patients (TP). We grouped the patients of alcoholic drinkers into “alcohol-drinkers with liver injury (LI)” (EtOH with LI) or “alcohol-drinkers without LI” (EtOH w/o LI) and we compared these groups to “non-drinkers” (no EtOH). When we examined patient blood from the EtOH with LI group we found the total number of EVs to be increased, along with an increase in miR-122 and let7f—two EV-associated miRNAs—and several inflammation-associating cytokines, such as interleukin (IL)-6 and IL-33. In contrast, all of the aforementioned readouts were found to be decreased in the EtOH w/o LI group. These novel data demonstrate that hepatocyte damage in alcohol-intoxicated trauma patients presenting with liver injury can be reflected by an increase in circulating serum EVs, their specific miR-“barcode” and the concomitant increase of systemic inflammatory markers IL-6 and IL-33. Anti-inflammatory effect of alcohol-drinking in EtOH w/o LI can be presented by a reduced number of hepato-derived EVs, no upregulation of IL-6 and IL-33, and a miR “barcode” different from patients presenting with liver injury.

Background: Alcohol abuse is associated with (neuro)protective effects related to (head) injuries, and with negative effects regarding infection rates and survival in severely injured trauma patients (TP). Extracellular vesicles (EVs), which are released during tissue and/or cell injury, can contain a “barcode” including specific microRNAs (miRs) that uncover their origin. We examined whether EVs with a hepatic miR signature can be systemically measured, and whether they can indicate ongoing liver injury in alcohol-intoxicated TP and foretell clinical complications.

Patients/Methods: We enrolled 35 TP and measured blood EVs, IL-6, TNF-alpha, IL-1beta, IL-10 and IL-33, alcohol (ethanol, EtOH) concentration (BAC), GLDH, GGT, AST, ALT, leukocytes, platelets, and bilirubin. Within circulating EVs we measured the expression levels of miR-122, let7f, miR21, miR29a, miR-155, and miR-146a. Patients of alcohol-drinkers were grouped into “alcohol drinkers with liver injury (LI)” (EtOH with LI) or “alcohol drinkers without LI” (EtOH w/o LI) and compared to “non-drinkers” (no EtOH). We assessed systemic injury characteristics and the outcome of hospitalization with regard to sepsis, septic shock, pneumonia, or mortality.

Results: EtOH with LI patients had significantly increased rates of pneumonia vs. the EtOH w/o LI group. EVs, IL-6, and IL-33 levels were significantly increased in EtOH with LI vs. EtOH w/o LI group (p < 0.05). EV number correlated positively with ALT and IL-6 (p < 0.0001). Two miRs, miR-122 and let7f, were increased only in the blood EVs from the EtOH with LI group (p < 0.05). Five miRs, miR-122, let7f, miR-21, miR-29a, and miR-146a, were reduced in the blood EVs from the EtOH w/o LI group, vs. no EtOH (p < 0.05). Notably miR-122 correlated significantly with increased bilirubin levels in the EtOH with LI group (p < 0.05).

Conclusions: Liver injury in alcohol-intoxicated TP is reflected by increased EV numbers, their specific miR barcode, and the correlated increase of systemic inflammatory markers IL-6 and IL-33. Interestingly, severely injured TP without liver injury were found to have a reduced number of liver-derived EVs, no observed inflammatory infiltration and reduced specific miR “barcode.”

Pneumonia-Associated Hospitalizations, New York City, 2001-2014

OBJECTIVES

Death certificate data indicate that the age-adjusted death rate for pneumonia and influenza is higher in New York City than in the United States. Most pneumonia and influenza deaths are attributed to pneumonia rather than influenza. Because most pneumonia deaths occur in hospitals, we analyzed hospital discharge data to provide insight into the burden of pneumonia in New York City.

METHODS

We analyzed data for New York City residents discharged from New York State hospitals with a principal diagnosis of pneumonia, or a secondary diagnosis of pneumonia if the principal diagnosis was respiratory failure or sepsis, during 2001-2014. We calculated mean annual age-adjusted pneumonia-associated hospitalization rates per 100 000 population and 95% confidence intervals (CIs). We examined data on pneumonia-associated hospitalizations by sociodemographic characteristics and colisted conditions.

RESULTS

During 2001-2014, a total of 495 225 patients residing in New York City were hospitalized for pneumonia, corresponding to a mean annual age-adjusted pneumonia-associated hospitalization rate of 433.8 per 100 000 population (95% CI, 429.3-438.3). The proportion of pneumonia-associated hospitalizations with in-hospital death was 12.0%. The mean annual age-adjusted pneumonia-associated hospitalization rate per 100 000 population increased as area-based poverty level increased, whereas the percentage of pneumonia-associated hospitalizations with in-hospital deaths decreased with increasing area-based poverty level. The proportion of pneumonia-associated hospitalizations that colisted an immunocompromising condition increased from 18.7% in 2001 to 33.1% in 2014.

CONCLUSION

Sociodemographic factors and immune status appear to play a role in the epidemiology of pneumonia-associated hospitalizations in New York City. Further study of pneumonia-associated hospitalizations in at-risk populations may lead to targeted interventions.

Imaging of Community-acquired Pneumonia

Community-acquired pneumonia refers to an acute infection of the lung in patients who did not meet any of the criteria for health care-acquired pneumonia, and is associated with at least some symptoms of acute infection, accompanied by the presence of an acute infiltrate on a chest radiograph. Chest radiography remains an important component of the evaluation of a patient with a suspicion of pneumonia, and is usually the first examination to be obtained. The diagnosis of community-acquired pneumonia is based on the presence of select clinical features and is supported by imaging of the lung, usually by chest radiography. Infection of the lower respiratory tract typically presents radiologically as one of 3 patterns: (a) focal nonsegmental or lobar pneumonia, (b) multifocal bronchopneumonia or lobular pneumonia, and (c) focal or diffuse "interstitial" pneumonia. High-resolution computed tomography allows a better depiction of the pattern and distribution of pneumonia than the radiograph but is seldom required in the evaluation of patients with suspected or proven bacterial pneumonia. However, high-resolution computed tomography is a useful adjunct to conventional radiography in selected cases.

Etiology and epidemiology of community-acquired pneumonia in adults requiring hospital admission: A prospective study in rural Central Philippines

BACKGROUND

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality among adults worldwide. However, the distribution of the etiology of CAP varies from one country to another, with limited data from rural areas.

METHODS

A prospective hospital-based study on adult CAP was conducted in Leyte, Central Philippines from May 2010 to May 2012. Blood, sputum, and nasopharyngeal samples obtained from patients were used to identify pathogens using standard microbiological culture methods and PCR.

RESULTS

Of the 535 patients enrolled, 38% were younger than 50 years old. More than half of the patients had an underlying disease, including pulmonary tuberculosis (22%). The detection rate was higher for bacteria (40%) than viruses (13%). Haemophilus influenzae (12%) was the most commonly detected bacterium and influenza virus (5%) was the most commonly detected virus. The proportion of CAP patients with Mycobacterium tuberculosis infection was higher in the younger age group than in the older age group. Among CAP patients, 14% died during hospitalization, and drowsiness on admission and SpO₂ <90% were independent risk factors for mortality.

CONCLUSIONS

Bacterial infections contribute substantially to the number of hospitalizations among CAP patients in rural Philippines. This study also highlights the importance of treatment of tuberculosis in reducing the burden of adult CAP in the country.

Distribution of 13-Valent pneumococcal conjugate vaccine serotype streptococcus pneumoniae in adults 50 Years and Older presenting with community-acquired pneumonia in Israel

BACKGROUND

Community acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide, and is a leading cause of hospitalization in previously healthy individuals without predisposing risk factors or comorbidities. In this study we determined PCV13 serotype distribution in adults aged ≥50 years with radiographically confirmed CAP in Israel.

METHODS

Subjects aged ≥50 years were enrolled from one of three hospitals (Emek Medical Center, Meir Medical Center and Sheba Medical Center) from March 2014 to July 2015. Information was collected on subject demographics, comorbidities, risk factors, and pneumococcal vaccine immunization status. Subjects presented with suspected CAP supported by radiographic evidence, and provided a urine sample and informed consent. Subjects without radiographic confirmation of CAP or who received PPSV23 within 30 days of study enrollment were excluded from the final analysis. Serotype distribution was performed using the urinary antigen detection (UAD) assay and/or microbiological culture.

RESULTS

Overall, 498 subjects with radiographically confirmed CAP were enrolled in the study. Eighty subjects (16.1%) were positive for any S. pneumoniae serotype by ≥1 assay, and 38 (7.6%) were positive for PCV13 serotypes via the UAD. The overall 30-day mortality rate was 1.2%, though S. pneumoniae was not isolated from any case leading to death.

CONCLUSION

Despite six years of high pneumococcal immunization coverage in children in Israel, we have shown that 7.6% of CAP cases among adults in Israel remain related to PCV13 serotypes; and that the burden of PCV13 may be as high as 47% of observed pneumococcal CAP.

Pneumonia in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a frequent comorbid condition associated with increased morbidity and mortality. Pneumonia is the most common infectious disease condition. The purpose of this review is to evaluate the impact of pneumonia in patients with COPD. We will evaluate the epidemiology and factors associated with pneumonia. We are discussing the clinical characteristics of COPD that may favor the development of infections conditions such as pneumonia. Over the last 10 years, there is an increased evidence that COPD patients treated with inhaled corticosteroids are at increased risk to develp pneumonia. We will review the avaialbe information as well as the possible mechanism for this events. We also discuss the impact of influenza and pneumococcal vaccination in the prevention of pneumonia in COPD patients.

Testing Pneumonia Vaccines in the Elderly: Determining a Case Definition for Pneumococcal Pneumonia in the Absence of a Gold Standard

Clinical assessments of vaccines to prevent pneumococcal community-acquired pneumonia (CAP) require sensitive and specific case definitions, but there is no gold standard diagnostic test. To develop a new case definition suitable for vaccine efficacy studies, we applied latent class analysis (LCA) to the results from 7 diagnostic tests for pneumococcal etiology on clinical specimens from 323 elderly persons with radiologically confirmed pneumonia enrolled in the Finnish Community-Acquired Pneumonia Epidemiology study during 2005-2007. Compared with the conventional use of LCA, which is mainly to determine sensitivities and specificities of different tests, we instead used LCA as an appropriate instrument to predict the probability of pneumococcal etiology for each CAP case based on individual test profiles, and we used the predictions to minimize the sample size that would be needed for a vaccine efficacy trial. When compared with the conventional laboratory criteria of encapsulated pneumococci in culture, in blood culture or high-quality sputum culture, or urine antigen positivity, our optimized case definition for pneumococcal CAP resulted in a trial sample size that was almost 20,000 subjects smaller. We believe that the novel application of LCA detailed here to determine a case definition for pneumococcal CAP could also be similarly applied to other diseases without a gold standard.

Evaluation of monoclonal antibodies that detect conserved proteins from Respiratory Syncytial Virus, Metapneumovirus and Adenovirus in human samples

Human Respiratory Syncytial Virus (hRSV), human Metapneumovirus (hMPV) and Adenovirus (ADV), are three of the most prevalent viruses responsible for pneumonia and bronchiolitis in children and elderly worldwide, accounting for a high number of hospitalizations annually. Diagnosis of these viruses is required to take clinical actions that allow an appropriate patient management. Thereby, new strategies to design fast diagnostic methods are highly required. In the present work, six monoclonal antibodies (mAbs, two for each virus) specific for conserved proteins from hRSV, hMPV and ADV were generated and evaluated through different immunological techniques, based on detection of purified protein, viral particles and human samples. In vitro evaluation of these antibodies showed higher specificity and sensitivity than commercial antibodies tested in this study. These antibodies were used to design a sandwich ELISA tests that allowed the detection of hRSV, hMPV, and ADV in human nasopharyngeal swabs. We observed that hRSV and ADV were detected with sensitivity and specificity equivalent to a current Direct Fluorescence Assay (DFA) methodology. However, hMPV was detected with more sensitivity than DFA. Our data suggest that these new mAbs can efficiently identify infected samples and discriminate from patients infected with other respiratory pathogens.

Pharmacokinetics and Safety of Omadacycline in Subjects with Impaired Renal Function

Many antibiotics require dose adjustments in patients with renal impairment and/or in those undergoing hemodialysis. Omadacycline, the first aminomethylcycline antibiotic in late-stage clinical development, displays activity against a broad spectrum of bacterial pathogens, including drug-resistant strains. Data from completed phase 3 studies of omadacycline for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP) showed intravenous (i.v.) to once-daily oral omadacycline to be clinically effective and well tolerated. To determine if the dosing of omadacycline should be adjusted in patients with impaired renal function, a phase 1 study examining the pharmacokinetics (PK) and safety of i.v. omadacycline (100 mg) was conducted in subjects with end-stage renal disease (ESRD) on stable hemodialysis (n = 8) and in matched healthy subjects (n = 8). i.v. administration of omadacycline produced similar plasma concentration-time profiles in subjects with ESRD and healthy subjects. Further, in subjects with ESRD, similar values of the PK parameters were observed when omadacycline was administered i.v. after or before dialysis. The mean area under the concentration-time curve from time zero extrapolated to infinity in plasma was 10.30 μg · h/ml when omadacycline was administered to ESRD subjects after dialysis, 10.20 μg · h/ml when omadacycline was administered to ESRD subjects before dialysis, and 9.76 μg · h/ml when omadacycline was administered to healthy subjects. The mean maximum observed concentration of omadacycline in plasma in ESRD subjects was 1.88 μg/ml when it was administered after dialysis and 2.33 μg/ml when it was administered before dialysis, and in healthy subjects it was 1.92 μg/ml. The 100-mg i.v. dose of omadacycline was generally safe and well tolerated in both ESRD and healthy subjects. This study demonstrates that no dose adjustment is necessary for omadacycline in patients with impaired renal function or on days when patients are receiving hemodialysis.

Assessment of Mediastinal Lymph Node Size in Pneumococcal Pneumonia with Bacteremia

INTRODUCTION

The significance of mediastinal lymphadenopathy in bacterial pneumonia is unclear.

METHODS

We performed a retrospective analysis of mediastinal lymph node size determined by chest CT in patients with bacteremic pneumococcal pneumonia. All patients who had positive blood cultures for streptococcus pneumonia over an 11-year period and had a chest CT scan (index CT) within 2 weeks of the positive blood culture were included in the study. Two thoracic radiologists and one pulmonologist independently examined the index CT plus any chest CT scans performed prior (pre-CT) or after (post-CT) the bacteremic episode.

RESULTS

The study cohort of 49 patients was 57% male, 65% White, with mean age of 53 (SD = 20) years. Mediastinal lymphadenopathy was detected in 25/49 (51%) of the cases. The mean size of the largest mediastinal lymph node in short axis was 0.99 (SD = 0.71), ranging from 0.0 to 2.05 cm. There was no correlation noted between the number of lobes involved with pneumonia, and the size of the largest mediastinal lymph node (p = 0.33) or the number of pathologically enlarged mediastinal lymph nodes (p = 0.08). There was a statistically significant increase in the mean size of the largest lymph node between the pre-CT and index-CT group (p = 0.02), and decrease between the index-CT group and the post-CT (p = 0.03).

CONCLUSION

Pneumococcal pneumonia with bacteremia is associated with mild mediastinal lymph node enlargement. The presence of marked mediastinal lymphadenopathy (short axis LN size > 2 cm) should not be assumed from pneumococcal pneumonia.

Management of community-acquired pneumonia in immunocompetent adults: updated Swedish guidelines 2017

Based on expert group work, Swedish recommendations for the management of community-acquired pneumonia in adults are here updated. The management of sepsis-induced hypotension is addressed in detail, including monitoring and parenteral therapy. The importance of respiratory support in cases of acute respiratory failure is emphasized. Treatment with high-flow oxygen and non-invasive ventilation is recommended. The use of statins or steroids in general therapy is not found to be fully supported by evidence. In the management of pleural infection, new data show favourable effects of tissue plasminogen activator and deoxyribonuclease installation. Detailed recommendations for the vaccination of risk groups are afforded.

Diagnosis and treatment of community-acquired pneumonia in adults: 2016 clinical practice guidelines by the Chinese Thoracic Society, Chinese Medical Association

Community‐acquired pneumonia (CAP) in adults is an infectious disease with high morbidity in China and the rest of the world. With the changing pattern in the etiological profile of CAP and advances in medical techniques in diagnosis and treatment over time, Chinese Thoracic Society of Chinese Medical Association updated its CAP guideline in 2016 to address the standard management of CAP in Chinese adults. Extensive and comprehensive literature search was made to collect the data and evidence for experts to review and evaluate the level of evidence. Corresponding recommendations are provided appropriately based on the level of evidence. This updated guideline covers comprehensive topics on CAP, including aetiology, antimicrobial resistance profile, diagnosis, empirical and targeted treatments, adjunctive and supportive therapies, as well as prophylaxis. The recommendations may help clinicians manage CAP patients more effectively and efficiently. CAP in pediatric patients and immunocompromised adults is beyond the scope of this guideline. This guideline is only applicable for the immunocompetent CAP patients aged 18 years and older. The recommendations on selection of antimicrobial agents and the dosing regimens are not mandatory. The clinicians are recommended to prescribe and adjust antimicrobial therapies primarily based on their local etiological profile and results of susceptibility testing, with reference to this guideline.

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.

Age-Related Vitamin D Deficiency Is Associated with the Immune Response in Children with Community-Acquired Pneumonia

To investigate vitamin D status in children with community-acquired pneumonia (CAP) and explore the association between vitamin D deficiency and the immune response in CAP children, 77 children with CAP were retrospectively analyzed. The baseline characteristics of patients were obtained from medical records. Based on the blood samples collected during diagnosis of CAP, the routine blood examination results and proportions of lymphocyte subsets were assessed. There were 71.4% (55/77) of patients with vitamin D deficiency among CAP children. The serum 25(OH)D level significantly decreased with age. Patients with vitamin D deficiency had a significantly higher neutrophil percentage, but significantly lower lymphocyte percentage and count as well as proportion of CD19 positive lymphocytes (CD19+). Spearman's rho test further confirmed these positive correlations and negative correlations. Moreover, significant associations of vitamin D deficiency with age and the above immune markers were also confirmed by univariate logistic regression analysis. However, only age entered the backward stepwise regression model in multivariate analysis. Vitamin D status in CAP children was negatively associated with age. Age-related vitamin D deficiency may affect the immune response in children with CAP.

Non-canonical Glucocorticoid Receptor Transactivation of gilz by Alcohol Suppresses Cell Inflammatory Response

Acute alcohol exposure suppresses cell inflammatory response. The underlying mechanism has not been fully defined. Here we report that alcohol was able to activate glucocorticoid receptor (GR) signaling in the absence of glucocorticoids (GCs) and upregulated glucocorticoid-induced leucine zipper (gilz), a prominent GC-responsive gene. Such a non-canonical activation of GR was not blocked by mifepristone, a potent GC competitor. The proximal promoter of gilz, encompassing five GC-responsive elements (GREs), was incorporated and tested in a luciferase reporter system. Deletion and/or mutation of the GREs abrogated the promoter responsiveness to alcohol. Thus, the GR–GRE interaction transduced the alcohol action on gilz. Alcohol induced GR nuclear translocation, which was enhanced by the alcohol dehydrogenase inhibitor fomepizole, suggesting that it was alcohol, not its metabolites, that engendered the effect. Gel mobility shift assay showed that unliganded GR was able to bind GREs and such interaction withstood clinically relevant levels of alcohol. GR knockout via CRISPR/Cas9 gene targeting or GILZ depletion via small RNA interference diminished alcohol suppression of cell inflammatory response to LPS. Thus, a previously unrecognized, non-canonical GR activation of gilz is involved in alcohol modulation of cell immune response.

Risk Factors for Drug-Resistant Cap in Immunocompetent Patients

PURPOSE OF REVIEW

The increase in drug-resistant community-acquired pneumonia (CAP) is an important problem all over the world. This article explores the current state of antimicrobial resistance of different bacteria that cause CAP and also assesses risk factors to identify those pathogens.

RECENT FINDINGS

In the last two decades, it has been documented that there is a significant increase in drug-resistant Streptococcus pneumoniae and other bacteria causing CAP. The most important risk factors are overuse of antibiotics, prior hospitalization, and lung comorbidities. The direct consequences can be severe, including prolonged stays in hospital, increased costs, and morbi-mortality. However, drug-resistant CAP declined after the introduction of the pneumococcal conjugate vaccine. This review found an increase in resistance to the antibiotics used in CAP, and the risk factor can be used for identifying patients with drug-resistant CAP and initiate appropriate treatment. Judicious use of antibiotics and the development of effective new vaccines are needed.

A Mouse Model of Post-Stroke Pneumonia Induced by Intra-Tracheal Inoculation with Streptococcus pneumoniae

Background: Stroke-induced immunodeficiency increases the risk of infectious complications, which adversely affects neurological outcome. Among those, pneumonia affects as many as one third of stroke patients and is the main contributor to mortality in the post-acute phase of stroke. Experimental findings on post-stroke susceptibility to spontaneous pneumonia in mice are contradictory. Here, we established a mouse model inducing standardized bacterial pneumonia and characterized the impaired pulmonary cellular and humoral immune responses after experimental stroke. Methods: Bacterial pneumonia was induced by intra-tracheal inoculation with Streptococcus pneumoniae at different time points after transient middle cerebral artery occlusion (MCAO). Bacterial counts in lungs and blood, histological changes, and cytokine production in the lungs were assessed. Furthermore, we investigated the effect of pneumonia on stroke outcome. Results: Intra-tracheal inoculation resulted in reproducible pneumonia and bacteraemia, and demonstrated post-stroke susceptibility to streptococcal pneumonia developing with a delay of at least 24 h after MCAO. Higher bacterial counts in mice infected 3 days after stroke induction correlated with reduced neutrophil and macrophage infiltration in the lungs and lower levels of pro-inflammatory cytokines in the broncho-alveolar lavage compared to sham-operated animals. Pneumonia increased mortality without affecting brain-infiltrating leukocytes. Conclusions: In this standardized mouse model of post-stroke pneumonia, we describe attenuated leukocyte infiltration and cytokine production in response to bacterial infection in the lungs that has a profound effect on outcome.