Nosocomial infective endocarditis in critically ill patients: a report of three cases and review of the literature

Indoor concentrations of particulate matter 2.5 in a pediatric emergency service

Objective:

To evaluate air quality in the waiting room of a pediatric emergency service considering the serial concentrations of particulate matter (PM_2.5), and to determine if the number of people present in the room can have an influence on the pollutant concentrations.

Methods:

Cross-sectional study, carried out in the waiting room of a reference pediatric hospital in the city of Porto Alegre, conducted in a one-year period, in a continuous-time sample including all of the four seasons of the year. The monitoring of PM_2.5 was performed using a real-time aerosol monitor (DustTrak II). The number of people in the room was determined every hour and the climatic characteristics per daily mean. The concentration of PM2.5 and the number of people were expressed by mean and standard deviation. The means were compared by Analysis of Variance and Pearson's correlation coefficient.

Results:

There was a significant increase in the concentration of PM_2.5 in the autumn, when compared to other seasons (p<0.001). The pollutant increase, in this season, was accompanied by the higher number of people in the emergency room (p=0.026). The association between PM_2.5 and the number of people is confirmed by the positive correlation between these two variables (r=0.738; p<0.001).

Conclusions:

The pediatric emergency waiting room showed elevated PM_2.5 in all seasons. The number of people in the room had a positive correlation with the concentration of the pollutant in the environment.

Endocarditis in Liver Transplant Recipients: A Systematic Review

Infective Endocarditis (IE) is associated with significant mortality. Interestingly, IE in patients with liver transplantation has not been adequately described. The aim of this review was to systematically review all published cases of IE in liver transplant recipients and describe their epidemiology, microbiology, clinical characteristics, treatment and outcomes. A systematic review of PubMed, Scopus and Cochrane Library (through 2 January 2021) for studies providing epidemiological, clinical, microbiological, treatment data and outcomes of IE in liver transplant recipients was conducted. A total of 39 studies, containing data for 62 patients, were included in the analysis. The most common causative pathogens were gram-positive microorganisms in 69.4%, fungi in 25.8%, and gram-negative microorganisms in 9.7% of cases, while in 9.3% IE was culture-negative. The aortic valve was the most commonly infected valve followed by mitral, tricuspid and the pulmonary valve. Aminoglycosides, vancomycin and aminopenicillins were the most commonly used antimicrobials, and surgical management was performed in half of the cases. Clinical cure was noted in 57.4%, while overall mortality was 43.5%. To conclude, this systematic review thoroughly describes IE in liver transplant recipients and provides information on epidemiology, clinical presentation, treatment and outcomes.

Endocarditis in kidney transplant recipients: a systematic review

Infective Endocarditis (IE) carries significant mortality. Bacteremia, which is a predisposing factor for IE, occurs more frequently in immunocompromised individuals. Interestingly, IE in kidney transplant recipients has not been adequately described. The aim of this study was to systematically review all published cases of IE in kidney transplant recipients and describe their epidemiology, microbiology, clinical characteristics, treatment and outcomes. A systematic review of PubMed (through 13^th December 2019) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE in kidney transplant recipients was performed. A total of 60 studies, containing data of 117 patients, were included in the analysis. The most common causative pathogens were gram-positive microorganisms in 57.4%, gram-negative microorganisms in 14.8%, fungi in 20%, while in 18.9% of cases, IE was culture-negative. Aortic valve was the most commonly infected valve followed by mitral, tricuspid and the pulmonary valve. Diagnosis was set with a transthoracic ultrasound in half the cases, followed by transesophageal ultrasound and autopsy. Fever was present in most cases, while embolic phenomena were noted in two out of five cases. Aminoglycosides, cephalosporins and aminopenicillins were the most commonly used antimicrobials, and surgical management was performed in one out of three cases. Clinical cure was noted in 60.9%, while overall mortality was 45.3%. To conclude, this systematic review thoroughly describes IE in kidney transplant recipients and provides information on epidemiology, clinical presentation, treatment and outcomes. Moreover, it identifies the emerging role of Enterococci, gram-negatives and fungi in IE in this population.

Fungal endocarditis in transplant recipients: A systematic review

BACKGROUND

Invasive fungal infections remain a major cause of morbidity and mortality in transplant recipients. Moreover, Fungal Infective Endocarditis (FIE) is a rare infection that carries a higher mortality than bacterial IE in normal host, while in transplant recipients may be even higher. The purpose of this study was to systemically review all published cases of FIE in solid organ and allogeneic bone marrow transplant recipients, describe the epidemiology, microbiology, clinical characteristics, treatment and outcomes of these infections, and to identify risk factors for mortality by FIE.

METHODS

A systematic review of PubMed, Scopus and Cochrane Library (through 20 May 2020) for studies providing epidemiological, clinical, microbiological and treatment data and outcomes of FIE in transplant recipients was performed.

RESULTS

A total of 60 studies, containing data of 72 patients, were included. The most common transplants were those of the kidney and the liver, while the commonest causative pathogen was Aspergillus. Mitral valve was the commonest infected intracardiac site, followed by mural endocardium. Diagnosis was made with transthoracic echocardiography in 44.3%, while the diagnosis was made at autopsy in 37.3%. Embolic phenomena were the commonest clinical presentation, followed by fever, heart failure and endophthalmitis. Amphotericin B, voriconazole and caspofungin were the commonest antifungals used for treatment of FIE. Clinical cure was noted in 26.9%, while overall mortality was 78.6%. Amphotericin B or caspofungin use was negatively associated with overall mortality.

CONCLUSIONS

This systematic review thoroughly describes IE in transplant recipients and provides information on epidemiology, clinical presentation, treatment and outcomes.

Difficult to Treat Infections in the Burn Patient

Background: Unusual infections can lead to complications in more severely burned patients and pose major challenges in treatment. Methods: The published literature of retrospective reviews and case series of the uncommon infections of osteomyelitis, polymicrobial bacteremia, recurrent bacteremia, endocarditis, central nervous system (CNS), and rare fungal infections in burned patients have been summarized and presented. Results: When compared with infections occurring in the non-burn population, these infections in burn patients are more likely to be because of gram-negative bacteria or fungi. Because of hyperdynamic physiology and changes in immunomodulatory response secondary to burns, the clinical presentation of these infections in a patient with major burns differs from that of the non-burn patient and may not be identified until the post-mortem examination. Some of these infections (osteomyelitis, endocarditis, CNS, rare fungal infections) may necessitate surgical intervention in addition to antimicrobial therapy to achieve cure. The presence of the burn and allograft can also present unique challenges for surgical management. Conclusions: These difficult and unusual infections in the severely burned patient necessitate an index of suspicion, appropriate diagnosis, identification and sensitivities of the putative pathogen, effective systemic antimicrobial therapy, and appropriate surgical intervention if recovery is to be achieved.

Inhalable microorganisms in Beijing's PM2.5 and PM10 pollutants during a severe smog event

Particulate matter (PM) air pollution poses a formidable public health threat to the city of Beijing. Among the various hazards of PM pollutants, microorganisms in PM2.5 and PM10 are thought to be responsible for various allergies and for the spread of respiratory diseases. While the physical and chemical properties of PM pollutants have been extensively studied, much less is known about the inhalable microorganisms. Most existing data on airborne microbial communities using 16S or 18S rRNA gene sequencing to categorize bacteria or fungi into the family or genus levels do not provide information on their allergenic and pathogenic potentials. Here we employed metagenomic methods to analyze the microbial composition of Beijing's PM pollutants during a severe January smog event. We show that with sufficient sequencing depth, airborne microbes including bacteria, archaea, fungi, and dsDNA viruses can be identified at the species level. Our results suggested that the majority of the inhalable microorganisms were soil-associated and nonpathogenic to human. Nevertheless, the sequences of several respiratory microbial allergens and pathogens were identified and their relative abundance appeared to have increased with increased concentrations of PM pollution. Our findings may serve as an important reference for environmental scientists, health workers, and city planners.

Distribution of bacterial contamination in a teaching hospital in Tehran - a special focus on Staphylococcus aureus

There are documents that confirm the cycle of bacterial transmission between patients, staff, and the inanimate environment. The environment may have more effect on intensive care units (ICUs), because the patients who require intensive care have unstable clinical conditions and are more sensitive to infections. The aim of this study was to determine the prevalence of bacteria in air and inanimate surface in the ICUs and to compare the microbial levels to standard levels.Air and inanimate surface in the four ICUs of a teaching hospital underwent weekly surveillance by means of air sampler and swabs for a period of six-month. Total bacterial counts were evaluated onto trypticase soy agar and mannitol salt agar (MSA).A total of 725 samples [air (168) and inanimate surfaces (557)] were collected. The total mean ± SD CFU/m3 of airborne bacteria in all of the ICUs were 115.93 ± 48.04. The most common bacteria in air of the ICUs were Gram-positive cocci (84.2%). The total mean ± SD airborne of Staphylococcus aureus was 12.10±8.11 CFU/m3. The highest levels of S. aureus contamination were found in ventilators and bed ledges. More suitable disinfection of hospital environments and monthly rotation in utilization of the various disinfectant agents are needed for the prevention of airborne and inanimate transmission of S. aureus.

Risk factors of mid-term mortality of patients with infective endocarditis

In-hospital and long-term mortality of infective endocarditis (IE) are well noted, but the studies for mid-term (90-day) mortality of IE is still limited. We determine the mid-term mortality rate of IE and its significant predictors. Seventy patients with IE were hospitalised at St. Luke's International Hospital between January 1996 and March 2009, of whom 62 consecutive patients could be followed up for 90 days after diagnosis. We then calculated Kaplan-Meier (KM) estimates and performed time-to-event analysis. The mean (standard deviation, SD) age was 66.6 (15.3) years. Thirty-five patients (56%) were male. Blood cultures were positive in 87%. Causative microorganisms were: viridans group streptococci (23%), β-streptococci (16%), Staphylococcus aureus (15%), including methicillin-resistant S. aureus (MRSA) (5%). Thirty-three cases (53%) had at least one complication such as heart failure (34%), central nervous system (CNS) complication (29%) or emboli peripheral to CNS (6%). KM estimates (95% CI) of the 90-day mortality was 14.5% (7.8-25%). In multiple regression analysis using the Cox proportional hazards model, hazard ratios of at least one complication for the 90-day mortality was 8.2 (1.4-155). Mid-term mortality of IE continues to be high and the presence of at least one complication may be considered as an independent risk factor of mid-term mortality.

Endocarditis complicating central venous catheter bloodstream infections: a unique form of health care associated endocarditis

BACKGROUND

Endocarditis complicating central venous catheter blood stream infection (CVC-BSI) is a serious complication and is being seen with increasing frequency.

METHODS

All patients discharged from our institution with International Classification of Disease (ICD-9) codes of endocarditis and CVC-BSI were identified. The medical records of those meeting our inclusion criteria were reviewed.

RESULTS

From October 1, 1998 until December 31, 2006, 24 patients were identified with inpatient mortality of 20.8%. Nine cases were nosocomial and 15 were non-nosocomial. The most common comorbidities were diabetes mellitus (45.8%), chronic kidney disease (58.4%), prior valvular abnormalities (37.5%), and multiple prior hospitalizations (65.2%). There were 13 external lines, 9 tunneled lines, and 2 implantable ports. Responsible microorganisms included Staphylococcus aureus in 54.6%, coagulase-negative staphylococci in 37.5%, Candida species (spp.) in 16.6%, and enterococci in 12.5%. Five cases were polymicrobial. The line tip was within the right atrium (RA) in 37.5%, the superior vena cava (SVC)-RA junction in 20.8%, the SVC in 33.3%, and the pulmonary artery in 4.2% of patients. Sites of endocardial involvement were the aortic valve in 6 patients, mitral valve in 7 patients, tricuspid valve in 6 patients, right atrial wall in 11 patients, and pacemaker wire in 2 patients. Isolated right-sided involvement occurred in 50% of cases, isolated left-sided in 33.4%, and bilateral involvement in 16.6%. Transesophageal echocardiography (TEE) was necessary for diagnosis in 10 cases (41.6%).

CONCLUSIONS

Endocarditis complicating CVC-BSI more often involves right-sided structures, with catheter tips in or near the right atrium, frequently requires TEE for diagnosis, and has significant inpatient mortality.

Distribution characteristics of airborne bacteria and fungi in the general hospitals of Korea

The objective of this study is to provide fundamental data related to size-based characteristics of bioaerosol distributed in the general hospital. Measurement sites are main lobby, ICU, surgical ward and biomedical laboratory and total five times were sampled with six-stage cascade impactor. Mean concentrations of airborne bacteria and fungi were the highest in main lobby as followed by an order of surgical ward, ICU and biomedical laboratory. The predominant genera of airborne bacteria identified in the general hospital were Staphylococcus spp. (50%), Micrococcus spp. (15-20%), Corynebacterium spp. (5-20%), and Bacillus spp. (5-15%). On the other hand, the predominant genera of airborne fungi identified in the general hospital were Cladosporium spp. (30%), Penicillium spp. (20-25%), Aspergillus spp. (15-20%), and Alternaria spp. (10-20%). The detection rate was generally highest on stage 5 (1.1-2.1 microm) for airborne bacteria and on stage 1 (>7.0 microm) for airborne fungi.

Post-operative aspergillosis

While invasive aspergillosis occurs typically in severely immunocompromised patients, cases of surgical site infection have been reported in immunocompetent individuals. The Medline, LILACS and EMBASE databases were searched for descriptions of cases of post-operative aspergillosis, and references from relevant articles and conference abstracts were reviewed. More than 500 cases of post-operative aspergillosis were found. Cardiac surgery (n = 188), ophthalmological surgery (n > 90) and dental surgery (n > 100) were associated with the majority of cases. Other cases involved wound infections (n = 22), bronchial infections (n = 30), mediastinitis (n = 11), pleural aspergillosis (n = 1), infections following orthopaedic surgery (n = 42), vascular prosthetic surgery (n = 22), breast surgery (n = 5), abdominal surgery (n = 10) and neurosurgery (n = 25). In most patients, the source was presumed to be airborne infection during the surgical procedure. Prevention of these infections requires special care of the ventilation system in the operating room. Successful treatment requires rapid diagnosis, surgical debridement and antifungal therapy, often with voriconazole. In order to improve the outcome, better diagnostic methods are needed, particularly for cases of endocarditis and aortitis.

Pacemaker-induced Staphylococcus aureus mitral valve acute bacterial endocarditis complicated by persistent bacteremia from a coronary stent: Cure with prolonged/high-dose daptomycin without toxicity

Continuous high-grade Staphylococcus aureus bacteremia suggests acute bacterial endocarditis (ABE), a protected focus, ie, an abscess, or a device-related infection. Daptomycin was curative of S. aureus ABE and coronary stent-related bacteremia. Prolonged high-dose daptomycin therapy (12 mg/kg per day for 41 days) is not associated with any toxicity. Persistent S. aureus bacteremia in ABE should suggest myocardial or perivalvular abscess. If intracardiac abscess can be ruled out and there is no extracardiac source of the S. aureus bacteremia, then a device-related infection should be considered.

Evolving trends in infective endocarditis

Infective endocarditis is a microbial infection of the endocardial surface and, despite improvements in diagnostic accuracy, medical therapy and surgical techniques, mortality remains high. This review focuses on changes in epidemiology, microbiology and diagnosis, as well as changes in medical and surgical management of infective endocarditis affecting native and prosthetic valves in adults, that have evolved during the past two decades. Significant changes have included an increasing involvement of prosthetic valves and nosocomially-acquired disease, an increased involvement of staphylococci as the causative agents, and a recognition that elderly individuals with degenerative valvular disease are the most vulnerable population. Topics still requiring study include whether and when valve replacement should be performed, and how to predict perivalvular complications or embolisation based on echocardiography findings. Optimisation of antimicrobial treatment schemes (choice of the antibiotic, dose and duration) also requires further investigation.