Should We Quantify Valvular Calcifications on Cardiac CT in Patients with Infective Endocarditis?

Background: Evaluate the impact of valvular calcifications measured on cardiac computed tomography (CCT) in patients with infective endocarditis (IE). Methods: Seventy patients with native IE (36 aortic IE, 31 mitral IE, 3 bivalvular IE) were included and explored with CCT between January 2016 and April 2018. Mitral and aortic valvular calcium score (VCS) were measured on unenhanced calcium scoring images, and correlated with clinical, surgical data, and 1-year death rate. Results: VCS of patients with mitral IE and no peripheral embolism was higher than those with peripheral embolism (868 (25–1725) vs. 6 (0–95), p < 0.05). Patients with high calcified mitral IE (mitral VCS > 100; n = 15) had a lower rate of surgery (40.0% vs.78.9%; p = 0.03) and a higher 1-year-death risk (53.3% vs. 10.5%, p = 0.04; OR = 8.5 (2.75–16.40) than patients with low mitral VCS (n = 19). Patients with aortic IE and high aortic calcifications (aortic VCS > 100; n = 18) present more frequently atypical bacteria on blood cultures (33.3% vs. 4.8%; p = 0.03) than patients with low aortic VCS (n = 21). Conclusion: The amount of valvular calcifications on CT was associated with embolism risk, rate of surgery and 1-year risk of death in patients with mitral IE, and germ’s type in aortic IE raising the question of their systematic quantification in native IE.

Etiology and characteristics and of community-acquired pneumonia among children requiring bronchoalveolar lavage in North China

Objective: To identify the pathogens and compare the clinical characteristics between different type pathogen infection among children with community-acquired pneumonia (CAP) requiring bronchoalveolar lavage. Study design: Children <14 years old hospitalized with CAP requiring bronchoalveolar lavage were enrolled between February 2019 to January 2020. Multiplex reverse transcription polymerase chain reaction (mRT-PCR) and loop-mediated isothermal amplification (LAMP) were used for pathogen detection. The demographic and clinical characteristics were compared between different type pathogen infection groups. Results: Among 1166 children studied, ≥1 pathogen was detected in 1084 (93.0%) children and co-infection was detected in 215 (18.4%) children. Mycoplasma pneumoniae, Streptococcus pneumoniae and adenovirus were the most frequently detected pathogens. Children infected with atypical bacteria alone were older and more likely to display a fever, cough, decreased breath sounds, consolidation, single lobar infiltration, mucosal erosion and/or necrosis and plastic bronchitis. Children with virus-atypical bacteria co-infection were more prone to manifest fatigue, chest pain, tachypnea, chest indrawing, and mucosal erosion and/or necrosis. Those infected with virus alone or co-infected with ≥3 pathogens were liable to display changes in bronchial morphology. Conclusions: Pathogens were detected in 93.0% of enrolled children. M. pneumoniae infection might be the greatest pediatric disease burden due to CAP in North China. Keywords: Children; community-acquired pneumonia; bronchoalveolar lavage fluid; etiology; co-infection.

Efficacy of Empiric Antibiotic Coverage in Community-Acquired Pneumonia Associated with Each Atypical Bacteria: A Meta-Analysis

The benefit of empiric coverage for community-acquired pneumonia (CAP) for atypical bacteria is controversial. This meta-analysis purpose was to compare the clinical failure rate between adults who empirically received atypical coverage versus those who did not. We searched PubMed and EMBASE for randomized controlled trials (RCTs), comparing the clinical failure rate of CAP associated with individual atypical bacteria between adults who received empiric atypical coverage versus those who did not. Risk differences (RDs) with 95% confidence intervals (CIs) were calculated using random-effects models. Eight double-blind RCTs (65 patients with Legionella spp., 176 patients with M. pneumoniae, and 78 patients with C. pneumoniae) were included in the meta-analysis. The rate of clinical failure was significantly lower with empiric atypical coverage in CAP associated with Legionella spp. (RD, −42.6%; 95% CI, −69.8% to −15.4%; p-value = 0.002; I2 = 0%) and Mycoplasma pneumoniae (RD, −9.5%; 95% CI, −18.9% to −0.1%; p-value = 0.048; I2 = 0%), but not with Chlamydia pneumoniae (RD, 7.1%; 95% CI, −9.0% to 23.1%; p-value = 0.390; I2 = 0%). This meta-analysis of RCTs found that empiric atypical coverage decreased the clinical failure rate of CAP associated with Legionella spp. and M. pneumoniae, but not with C. pneumoniae.

Nosocomial Respiratory Infections in a Rural Zambian Hospital

The burden of nosocomial respiratory infections in rural southern Africa is poorly understood. We established a surveillance program at a rural Zambian hospital to detect influenza-like illness (ILI) and respiratory infections among hospitalized patients and a cohort of healthcare workers (HCWs). Nasopharyngeal specimens from symptomatic patients and HCWs underwent broadly multiplexed molecular testing to detect viruses and atypical bacteria. During 1 year of surveillance, 15 patients (1.7% of admissions) developed ILI more than 48 hours after admission. Among 44 HCWs, 19 (43%) experienced at least one ILI episode, with a total of 31 ILI episodes detected. Respiratory viruses were detected in 45% of patient and 55% of HCW specimens. The cumulative incidence of influenza infection among HCWs over 1 year was 9%. Overall, respiratory viruses were commonly found among patients and HCWs in a rural Zambian hospital with limited infection control infrastructure.

A tool to distinguish viral from bacterial pneumonia

Establishing the etiology of community-acquired pneumonia (CAP) in children at admission is challenging. As a result, most children receive antibiotics that do not need. This study aims to build and validate a diagnostic tool combining clinical, analytical and radiographical features to sequentially differentiate viral from bacterial CAP, and among bacterial CAP, typical from atypical bacteria, to improve choice of treatment. Methods Consecutive hospitalized children between 1 month and 16 years of age with CAP were enrolled. An extensive microbiological workup was performed. A score was built with a training set of 70% patients, to first differentiate between viral and bacterial CAP and secondly, typical from atypical bacterial CAP. To select variables, a Ridge model was used. Optimal cut-off points were selected to maximize specificity setting a high sensitivity (80%). Weights of each variable were calculated with a multivariable logistic regression. The score was validated with the rest of the participants. Results In total, 262 (53%) children (median age, 2 years, 52.3% male) had an etiological diagnosis. The step 1 discriminates viral from bacterial CAP. Bacterial CAPs were classified with a sensitivity=97%, a specificity=48%, and a ROC area under the curve (AUC)=0.81. If a CAP was classificated as bacterial, it was assessed with step 2. The step 2 differentiates typical vs. atypical bacterial CAP. Typical bacteria were classified with a sensitivity=100%, a specificity=64%, and AUC=0.90. Conclusion This two-steps tool can facilitate the physician decision to prescribe antibiotics without compromising patient safety.

Metabolomic profiling of microbial disease etiology in community-acquired pneumonia

Diagnosis of microbial disease etiology in community-acquired pneumonia (CAP) remains challenging. We undertook a large-scale metabolomics study of serum samples in hospitalized CAP patients to determine if host-response associated metabolites can enable diagnosis of microbial etiology, with a specific focus on discrimination between the major CAP pathogen groups S. pneumoniae, atypical bacteria, and respiratory viruses. Targeted metabolomic profiling of serum samples was performed for three groups of hospitalized CAP patients with confirmed microbial etiologies: S. pneumoniae (n = 48), atypical bacteria (n = 47), or viral infections (n = 30). A wide range of 347 metabolites was targeted, including amines, acylcarnitines, organic acids, and lipids. Single discriminating metabolites were selected using Student’s T-test and their predictive performance was analyzed using logistic regression. Elastic net regression models were employed to discover metabolite signatures with predictive value for discrimination between pathogen groups. Metabolites to discriminate S. pneumoniae or viral pathogens from the other groups showed poor predictive capability, whereas discrimination of atypical pathogens from the other groups was found to be possible. Classification of atypical pathogens using elastic net regression models was associated with a predictive performance of 61% sensitivity, 86% specificity, and an AUC of 0.81. Targeted profiling of the host metabolic response revealed metabolites that can support diagnosis of microbial etiology in CAP patients with atypical bacterial pathogens compared to patients with S. pneumoniae or viral infections.

Infectious Myelopathies

In the setting of both globalization and increasing use of immunosuppressive therapy, infectious myelopathies are an important cause of morbidity worldwide. Clinical spinal cord syndromes related to infection are varied, including transverse myelitis, acute flaccid paralysis related to anterior horn cell involvement, spinal cord compression, chronic spastic paraparesis, and myeloradiculitis. Causative pathogens include viruses, parasites, pyogenic and atypical bacteria, and fungi. The epidemiology, clinical characteristics, diagnosis, and treatment of selected organisms will be discussed in this article.

Atypical pathogen infection of respiratory system

The frequency of respiratory infections, especially atypical pneumonia, is increasing significantly. Most often, atypical pneumonia is caused by Mycoplasma pneumoniae and Chlamydophila pneumoniae. Human is the only reservoir of these atypical bacteria. The infection occurs via droplets or direct contact with a sick person or convalescent. Pneumonia of the etiology of Mycoplasma pneumoniae and Chlamydophila pneumoniae most often affects children without comorbidities and is usually mild, while most patients with Legionella infection require intensive care treatment. Symptoms of mycoplasma infection can range from mild symptoms in the upper respiratory tract to pneumonia and extrapulmonary symptoms. The infection is often underdiagnosed, and patients usually do not seek medical attention and treatment. Chlamydial pneumonia is, in most cases, mild, similar to Mycoplasma pneumoniae, and tends to heal itself. The drugs of choice in the treatment of atypical pneumonia are macrolides, and because of the best compliance in children – azithromycin.