Etiology Of Infective Endocarditis Research Articles

Infectious endocarditis due to Bacillus Cereus in a patient with a pacemaker

Introduction: Infective endocarditis (IE) is an infectious process of the cardiac endothelium, often related to the use of pacemakers and valve prostheses, which may facilitate microorganism” proliferation. Case Report: In this article, we describe the case of an 81-year-old man with infective endocarditis due to Bacillus Cereus related to the use of a pacemaker and perform a brief literature review. Discussion: Bacillus Cereus is a Gram-positive, aerobic, spore-forming, large, and generally motile bacterium that constitutes a rare cause of endocarditis, but few cases like this are described in the literature. Conclusion: Determining the etiology of IE through culture-guided methods plays a pivotal role in selecting appropriate antibiotic treatment. Maintain a high clinical suspicion for IE is paramount, especially when fever arises in patients with cardiac devices after surgical or dental procedures.

Evaluation of epidemiological and microbiological characteristics, clinical features, and outcomes of adult patients with infective endocarditis in Mashhad, Iran.

Infective endocarditis (IE) is a serious problem with high morbidity and mortality. However, there is a paucity of data regarding its epidemiology in non-high-income settings. Here, we described the characteristics of patients with IE. Between March 2012 to March 2020, all adults (≥ 16 years) with a diagnosis of IE who were admitted to a university hospital in Mashhad, Iran, were included in the study. We evaluated 46 cases of IE with a median age of 42 years (interquartile range 31 to 58.3 years), of whom 21 (46%) had a definite diagnosis. The presence of a prosthetic valve or intracardiac device was the leading predisposing factor (N = 14, 30%). The etiology of IE in 22 subjects (48%) remained unknown. Staphylococcus aureus (N = 12, 26%) was the most common causative pathogen. Echocardiography revealed the mitral valve as the most affected valve (N = 18, 39%). Intravenous drug users (IVDU) had a higher chance of right-sided IE, as compared to no IVDU patients (odds ratio: 35, 95% CI: 3.7 to 425.0). The most prevalent complications were lung infarction, acute heart failure, and neurologic involvement (N = 5, 11% for each), and 15 patients (33%) died because of IE. In our study, the median age of IE onset was relatively low. The most frequent predisposing factor was a prosthetic valve or intracardiac device. The proportion of negative blood cultures was unacceptably high. Thus, our findings emphasize promoting laboratory infrastructure, developing a national protocol for early initiation of appropriate treatment, and eliminating predisposing factors.

Microbiological Etiology in Patients with IE Undergoing Surgery and for Patients with Medical Treatment Only: A Nationwide Study from 2010 to 2020.

Microbiological etiology has been associated with surgery for infective endocarditis (IE) during admission, especially Staphylococcus aureus. We aimed to compare patient characteristics, microbiological characteristics, and outcomes by treatment choice (surgery or not). We identified patients with first-time IE between 2010 and 2020 and examined the microbiological etiology of IE according to treatment choice. To identify factors associated with surgery during initial admission, we used the Aalen-Johansen estimator and an adjusted cause-specific Cox model. One-year mortality stratified by microbiological etiology and treatment choice was assessed using unadjusted Kaplan-Meier estimates and an adjusted Cox proportional hazard model. A total of 6255 patients were included, of which 1276 (20.4%) underwent surgery during admission. Patients who underwent surgery were younger (65 vs. 74 years) and less frequently had cerebrovascular disease, cardiovascular disease, diabetes, and chronic kidney disease. Patients with Staphylococcus aureus IE were less likely to undergo surgery during admission (13.6%) compared to all other microbiological etiologies. One-year mortality according to microbiological etiology in patients who underwent surgery was 7.0%, 5.3%, 5.5%, 9.6%, 13.2, and 11.2% compared with 24.2%, 19.1%, 27,6%, 25.2%, 21%, and 16.9% in patients who received medical therapy for Staphylococcus aureus, Streptococcus spp., Enterococcus spp., coagulase-negative Staphylococci, "other microbiological etiologies", and blood culture-negative infective endocarditis, respectively. Patients with IE who underwent surgery differed in terms of microbiology, more often having Streptococci than those who received medical therapy. Contrary to expectations, Staphylococcus aureus was more common among patients who received medical therapy only.

Outcomes of Endocarditis in Pregnancy: A Single-Center Experience.

The incidence of infective endocarditis (IE) in pregnancy is rare (0.006%), with increasing prevalence during the opioid epidemic. IE in pregnancy is associated with high rates of mortality and morbidity, and existing data on outcomes in pregnancy are limited. Our study compares the outcomes of pregnant patients with IE with those of nonpregnant patients. Patients diagnosed with IE during pregnancy and 30 days postpartum between 2014 and 2021 were identified by International Classification of Diseases, Clinical Modification, Ninth and Tenth Edition codes. Pregnant cases were matched to nonpregnant reproductive-age endocarditis patients in a 1:4 ratio. Data were collected and validated through chart review. One hundred eighty patients with IE were identified; 34 were pregnant or within 30 days postpartum at diagnosis. There were higher rates of hepatitis C and opioid maintenance therapy in the pregnant patients. The etiology of IE in pregnant patients was predominantly S. aureus (methicillin-resistant/sensitive S. aureus), whereas nonpregnant woman had greater microbiological variation. We observed comparable rates of valve replacement (32.4% vs 29%; P = .84) and 2-year mortality (20.6% vs 17.8%; P > .99) in pregnant patients. There were nonsignificantly higher rates of pulmonary emboli (17.6% vs 7.5%; P = .098) and arrhythmia (17.6% vs 9.6%; P = .222) among pregnant patients. There were high rates of intravenous drug use relapse in both groups (>40%). We observed similar rates of mortality in the pregnant IE patients. We observed a microbial predilection for S. aureus in pregnancy, suggesting that the pregnancy physiology may select for this microbiologic etiology. This study, which represents the largest single-center retrospective review of IE in pregnancy, suggests that surgical intervention may be performed safely in the postpartum period.

Infective endocarditis: association between origin of causing bacteria and findings during oral infection screening

BackgroundOral streptococci represent the causing microorganism for infective endocarditis (IE) in many patients. The impact of oral infections is questioned, and it has been suggested that bacteraemia due to daily routines may play a bigger part in the aetiology of IE. The aim of this study was to examine the association between oral health and infective endocarditis caused by oral bacteria in comparison with bacteria of other origin than the oral cavity.MethodsA retrospective study was conducted at Haukeland University Hospital from 2006- 2015. All consecutive adult patients admitted to hospital for treatment of IE and subjected to an oral focus screening including orthopantomogram, were included. The clinical, radiological and laboratory characteristics of the patients, collected during oral infectious focus screening, were analysed. Patient survival was calculated using Kaplan–Meier and mortality rates were compared using Cox-regression.ResultsA total of 208 patients were included, 77% (n = 161) male patients and 23% (n = 47) female, mean age was 58 years. A total of 67 (32%) had IE caused by viridans streptococci. No statistically significant correlation could be found between signs of oral infection and IE caused by viridans streptococci. The overall mortality at 30 days was 4.3% (95% CI: 1.6–7.0). There was no statistical difference in mortality between IE caused by viridans streptococci or S. aureus (HRR = 1.16, 95% CI: 0.57–2.37, p = 0.680).ConclusionThe study indicates that the association between origin of the IE causing bacteria and findings during oral infection screening might be uncertain and may suggest that the benefit of screening and elimination of oral infections in patients admitted with IE might be overestimated. However, the results should be interpreted with caution and further studies are needed before any definite conclusions can be drawn.

Microbial Cell-Free DNA Identifies the Causative Pathogen in Infective Endocarditis and Remains Detectable Longer Than Conventional Blood Culture in Patients with Prior Antibiotic Therapy.

The diagnosis of infective endocarditis (IE) can be difficult, particularly if blood cultures fail to yield a pathogen. This study evaluates the potential utility of microbial cell-free DNA (mcfDNA) as a tool to identify the microbial etiology of IE. Blood samples from patients with suspected IE were serially collected. mcfDNA was extracted from plasma and underwent next-generation sequencing. Reads were aligned against a library containing DNA sequences belonging to >1400 different pathogens. mcfDNA from organisms present above a statistical threshold were reported and quantified in molecules per milliliter (MPM). Additional mcfDNA was collected on each subject every 2-3 days for a total of 7 collections or until discharge. Of 30 enrolled patients with suspected IE, 23 had definite IE, 2 had possible IE, and IE was rejected in 5 patients by modified Duke Criteria. Only the 23 patients with definite IE were included for analysis. Both mcfDNA and blood cultures achieved a sensitivity of 87%. The median duration of positivity from antibiotic treatment initiation was estimated to be approximately 38.1 days for mcfDNA versus 3.7 days for blood culture (proportional odds, 2.952; P = .02771), using a semiparametric survival analysis. mcfDNA (log10) levels significantly declined (-0.3 MPM log10 units, 95% credible interval -0.45 to -0.14) after surgical source control was performed (pre- vs postprocedure, posterior probability >0.99). mcfDNA accurately identifies the microbial etiology of IE. Sequential mcfDNA levels may ultimately help to individualize therapy by estimating a patient's burden of infection and response to treatment.

Abstract 12143: Differences in Outcomes Among Adults Hospitalized for Infective Endocarditis in the United States: The Impact of Congenital Heart Disease

Introduction: Increased life expectancy for patients with adult congenital heart disease (ACHD) has created new and unique challenges, including management of complications such as infective endocarditis (IE). Hypothesis: Significant IE outcome differences exist between ACHD and non-ACHD patients. Methods: Hospital discharges with IE in patients >=18 years from the National Inpatient Sample were identified between 2001 and 2016. Weighting was used to create national annual estimates indexed to the United States (U.S.) population. Patients were categorized into age groups: 18-44 years, 45-64 years, and 65+ years. Demographic, clinical, microbiologic, and outcome data were compared stratifying by ACHD status. Results: ACHD-related IE hospitalizations increased over time, from 1.6% in 2001 to 3.5% in 2016 (p<0.001 for trend) with a 315% increase in annualized number of ACHD IE hospitalizations from 0.41/100,000 adults to 1.29/100,000 adults. ACHD patients were younger (mean age 49 vs. 65 years, p<0.001). In-hospital mortality was lower in ACHD patients than non-ACHD patients (5.9% vs. 9.5%, respectively, p<0.001); mortality did not change significantly over time among ACHD patients, while mortality decreased in non-ACHD patients (p<0.001). Mortality was lower in ACHD patients across all age groups (all p<0.01). ACHD patients were more likely to undergo valve surgery during their IE hospitalization (29.8% vs. 6.4%, p<0.001). The etiology of IE varied between groups (p<0.001), with increased streptococcal disease in ACHD patients (29.4% vs. 14.4%). Conclusions: A significant increase in the overall proportion of ACHD IE hospitalizations in the U.S. was identified between 2001 and 2016. ACHD patients had lower in-hospital mortality than non-ACHD patients and were more likely to undergo valve surgery. Further research is needed to better understand factors underlying the increase in ACHD IE cases as well as why ACHD patients have decreased mortality.

Risk assessment and prognostic analysis of patients with splenic infarction in emergency department: a multicenter retrospective study

Splenic infarction is a thromboembolic disease that is frequently missed in acute settings. Previous reviews were rarely presented from a clinical perspective. We aimed to evaluate the clinical characteristics, risk factors with diagnostic value, and prognostic factors using large cohort data and a matched case–control study method. A retrospective medical record review of six hospitals in Taiwan from January 1, 2005, to August 31, 2020, was conducted. All patients who underwent contrast CT with confirmed the diagnosis of splenic infarction were included. Their characteristics were presented and compared to a matched control group with similar presenting characteristics. Prognostic factors were also analyzed. A total of 130 cases were included, two-thirds of whom presented with abdominal pain. Atrial fibrillation was the most common associated predisposing condition, followed by hematologic disease. A higher proportion of tachycardia, positive qSOFA score, history of hypertension or atrial fibrillation, leukocytosis, and thrombocytopenia were found in splenic infarction patients compared to their counterparts. An underlying etiology of infective endocarditis was associated with a higher proportion of ICU admission. Splenic infarction patients often presented with left upper abdominal pain and tachycardia. A history of hypertension, atrial fibrillation, a laboratory result of leukocytosis or thrombocytopenia may provide a clue for clinicians to include splenic infarction in the differential list. Among the patients diagnosed with splenic infarction, those with an underlying etiology of infectious endocarditis may be prone to deterioration or ICU admission.

Abstract 16259: Gemella Morbillorum Infective Endocarditis: A Systematic Review

Introduction: Gemella morbillorum is a facultative anaerobic gram positive bacterium that resides as normal flora in the oral cavity and gastrointestinal system. This organism has uncommonly presented as an etiology of infective endocarditis, with varying reports of resistance and complications. Methods: Transparent Reporting of Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for the systematic review. A medical librarian (T.R.S) versed in evidence-based medicine systematically searched databases for studies assessing Gemella morbillorum infective endocarditis in patients. Publication year included inception until December 31, 2019. Using Rayyan software, 134 abstracts were screened for eligibility after duplicates were removed. Inclusion criteria was age greater than 18 years old, infective endocarditis with positive culture for Gemella morbillorum, and publication in English. 39 full text articles were reviewed for eligibility, and 38 were included in the final analysis. Results: A total of 40 cases of infective endocarditis caused by Gemella morbillorum were identified. The average age of the patients was 54 years old, 72.5% were male patients (29), 20% female (8), 7.5% unknown sex (3). Native valve endocarditis (NVE) was present in 28 of the cases, with prosthetic valve involvement in 5 cases. Left sided endocarditis was more common than right sided with 70% of cases (28) and 12.5% (5) respectively, with 17.5% (7) of cases not listing which valve was infected on echocardiography. The most common predisposing risk factor was thought to be poor dentition in 9 cases. The most common antibiotic regimen in penicillin susceptible NVE was concordant with most recent guidelines, a beta lactam with gentamicin or vancomycin in 57.5% of the cases (23). Complications occurred in 65% of cases (26), with most common complication being need for surgical intervention occurring in 30% of the cases (12). Conclusions: Gemella morbillorum infective endocarditis cases reported in literature had a high burden of complications with nearly two thirds of cases. Most common was the need for surgery with valve replacement. Antibiotic regimens in the most recent endocarditis guidelines were effective in treatment for a majority of the cases.

Changes in the Etiology and Clinical Characteristics of Pediatric Infective Endocarditis in South Korea.

Changes in the epidemiology, clinical manifestations, and outcomes of infective endocarditis (IE) have been reported in recent years. This study was performed to analyze changing trends in the etiology of IE in children in South Korea. A retrospective study of children with IE was conducted from 2 hospitals in Korea from 2004 to 2019. IE was defined according to the Modified Duke criteria. We analyzed the etiology and clinical outcome of 96 cases and compared the etiology with that during 1987-1997, as described in a previous study. A total of 96 cases in 89 children satisfied the modified Duke criteria. The median age was 9.5 years. Preexisting structural heart diseases were identified in 81 cases (84.4%). Ten of the 15 cases with normal heart anatomy had a history of indwelling central venous catheters and underlying noncardiac conditions. Of the 72 identified organisms, common pathogens included Staphylococcus aureus, 24 (32.9%); viridans streptococci, 22 (30.2%); coagulase-negative staphylococci, 14 (19.2%); and Candida species, 7 (9.6). Sixty-three cases (66.7%) required surgical intervention, and the overall fatality rate was 7.9%. Compared with the period of 1987-1997, an increasing trend in the proportion of staphylococci as the etiology of IE in 2004-2019 was observed (26.7% vs. 51.8%, P = 0.029). In addition, S. aureus was associated with the high rate of developing complications (P < 0.05). In South Korea, Gram-positive cocci represent 85% of all etiologic agents of IE in children with an increasing trend in the proportion of staphylococci.

Infective endocarditis at a tertiary-care hospital in China

BackgroundThe aim of this study was to describe the clinical features and outcome of infective endocarditis at a general hospital in China and to identify the risk factors associated with in-hospital mortality.MethodsA retrospective study was conducted and all patients diagnosed with definite or possible infective endocarditis between January 2013 and June 2018 according to the modified Duke criteria were included.ResultsA total of 381 patients were included. The mean age was 46 years old and 66.9% patients were male patients. Community acquired IE was the most common type of infective endocarditis and Viridans Group Streptococci (37.5%) was still the most common causative pathogen. The microbial etiology of infective endocarditis varied with location of acquisition. 97 (25.5%) patients had culture-negative infective endocarditis. Vegetations were detected in 85% patients and mitral valve was the most common involved valve. Operations were performed in 72.7% patients and in-hospital mortality rate was 8.4%. The risk factors of in-hospital mortality were age old than 70 years old, heart failure, stroke and medical therapy.ConclusionsOlder age, heart failure, stroke and medical therapy were risk factors of in-hospital mortality. Infective endocarditis, were mainly caused by Viridans Group Streptococci, characterized by younger patients and lower mortality rate in China.

Nosocomial Vs. Community-Acquired Infective Endocarditis in Spain: Location, Trends, Clinical Presentation, Etiology, and Survival in the 21st Century.

Major changes have occurred in the epidemiology and etiology of infective endocarditis (IE). Nevertheless, the differences between nosocomial infective endocarditis (NIE) and community-acquired infective endocarditis (CIE) have not been addressed in a population-based study. We conducted a retrospective, nationwide, temporal trend study from 1997 to 2014 analyzing the epidemiology, clinical, geographical, meteorological characteristics of patients diagnosed with IE in Spain, to distinguish NIE from CIE. Among 25,952 patients with IE (62.2 ± 18·6 years; 65.9% men), 45.9% had NIE. The incidence of IE increased from 2.83 to 3.73 due to the NIE incidence increment with a decline in CIE. Patients with NIE were older (63.8 years vs. 60.8 years, p < 0·001), presented a higher Charlson index (1.22 vs. 1.03, p < 0.001), a greater history of implanted cardiac devices (8.7% vs. 4.6%, p < 0.001), and higher mortality (31.5% vs. 21.7%, p < 0.001). The most frequent microorganism for both NIE and CIE was Staphylococcus (p < 0.001), and the North reported a higher incidence (p < 0.001). Risk factors of mortality for NIE were age, Charlson index, hemodialysis, shock, heart failure, and stroke. Risk factors for CIE included female sex, renal disease, and cardiac-device carriers. The etiology of IE shifted from community origins to mostly nosocomial-associated infections. Higher morbidity, mortality, and poorer outcomes are associated with NIE.

Iotrophia defectiva: A Rare Gut Pathogen Resulting Endocarditis in Inflammatory Bowel Disease

Abiotrophia defectiva (formerly referred to as nutritionally variant Streptococcus) is a normal flora of the human gastrointestinal tract. Abiotrophia defectiva is associated with high morbidity and mortality, yet timely diagnosis is challenging. Higher incidence of endocarditis was reported among patients with inflammatory bowel disease (IBD) from a retrospective study. We highlighted the diagnostic and management challenges of a case of rare subacute endocarditis by Abiotrophia defectiva in an IBD patient without predisposing valvular defect, prior central catheter insertion or intravenous drug abuse, suggesting gut translocation as a possible etiology of infective endocarditis among IBD patients. J Microbiol Infect Dis 2017; 7(4):217-219

Heart Valve Culture and Sequencing to Identify the Infective Endocarditis Pathogen in Surgically Treated Patients

Testing excised valves in surgically treated infective endocarditis (IE) patients provides an opportunity to identify the microbial etiology of IE. Microbial sequencing (universal bacterial, mycobacterial, or fungal polymerase chain reaction followed by DNA sequencing) of valves can identify microorganisms accurately, but the value it adds beyond information provided by blood and valve cultures has not been adequately explored. Three hundred fifty-six patients who underwent surgery for active IE from January 1, 2010, to January 1, 2013, were identified from our cardiovascular information registry and outpatient parenteral antibiotic therapy registry. Their records were reviewed to identify 174 patients whose valves were sent for sequencing. The microbial etiology of IE was defined using comprehensive clinical, pathologic, and microbiological criteria. Blood culture, valve culture, and valve sequencing were examined to determine how frequently they identified the definitive cause of IE. Of the 174 patients, 162 (93%) had acute inflammation on histopathologic examination of their valves. Valve sequencing was significantly more sensitive than valve culture in identifying the causative pathogen (90% versus 31%, p < 0.001), and yielded fewer false positive results (3% versus 33%, p <0.001). The pathogen would not have been identified in 25 patients (15%) had it not been for valve sequencing. All the value provided by sequencing was attributable to bacterial DNA sequencing; mycobacterial and fungal sequencing provided no additional information beyond that provided by blood culture, histopathology, and valve culture. Valve sequencing, not valve culture, should be considered the primary test for identifying bacteria in excised cardiac valves.

Infective endocarditis in Rio de Janeiro, Brazil: a 5-year experience at two teaching hospitals.

Despite the recent advances in diagnosis and treatment, mortality rates due to infective endocarditis (IE) remain high if not aggressively treated with antibiotics, whether or not associated with surgery. Data on the prevalence, epidemiology and etiology of IE from developing countries remain scarce. The aim of this observational, prospective cohort study was to report a 5-year experience of IE at two teaching hospitals in Rio de Janeiro, Brazil. Demographical, anamnestic and microbiological characteristics of 71 IE patients were evaluated during the period of January 2009 to March 2013. The mean age of the IE patients was 49.8 ± 2.4 years, of which 41 (57.7%) were males. The median time between the onset of symptoms and diagnosis of IE was 35.8 ± 4.8 days. A total of 31 (43.6%) cases of community-acquired infective endocarditis (CAIE) and 40 (56.3%) cases of healthcare-acquired infective endocarditis (HAIE) were observed. Staphylococcus aureus (30%) was the predominant cause of IE. Streptococcus spp. (45.1 %) was the predominant cause of the CAIE while S. aureus (32.5%) and Enterococcus spp. (27.2 %) were the main etiological agents of HAIE. For 64 (90.1 %) patients with native valve endocarditis, the mitral valve was the most commonly affected (48.3%). The main source of IE in this cohort was intravascular catheter. The tricuspid valve and renal chronic insufficiency were more frequent in patients with HAIE than CAIE (p = 0.001). The risk factors associated with in-hospital mortality rate (46.4%) in IE patients were: age over 45 (OR 3.4; 95% CI 1.03-11.24; p = 0.04) and chronic renal insufficiency (OR 38.3; 95% CI 3.2-449.4; p = 0.004). At two main teaching hospitals in Brazil, Streptococcus spp. was the principal pathogen of CAIE while S. aureus and Enterococcus spp. were the most frequent causes of HAIE. IE remains a serious disease associated with high in-hospital mortality rate (46.6%); especially, in individuals over 45 years of age and with renal failure. Data suggest that early surgery may improve the outcome of IE patients.

The utility of 16S RRNA gene PCR and sequencing in endocarditis: an 8 year review

<h3>Background</h3> Up to 31% of patients with infective endocarditis (IE) have negative blood cultures, often due to prior antibiotic therapy or fastidious organisms. In surgically treated patients, 16S rDNA PCR applied to excised heart valve tissue is a useful tool for determining the bacterial aetiology of endocarditis. We sought to evaluate the clinical utility of this technique by reviewing data over the last 8 years. <h3>Methods</h3> Patients who underwent cardiac surgery and had valve specimens submitted for 16S rDNA PCR at Auckland City Hospital between January 2004 and July 2011 were retrospectively reviewed. Clinical records and laboratory databases were used to classify each patient according to modified Duke criteria and to record whether PCR determined the bacterial aetiology and impacted on antibiotic management. <h3>Results</h3> PCR was applied to 50 excised valve specimens from 40 patients. Twenty-four patients (60%) were PCR positive. For 13 of 40 patients (33%), the aetiology of IE was determined by valve PCR alone. In seven patients, this PCR result lead to a modification in antibiotic therapy to target the pathogen identified. <h3>Conclusions</h3> 16s rDNA PCR of excised valves from patients with suspected IE has had substantial clinical utility in our setting and should be considered for patients with blood culture negative endocarditis whose valves are culture negative.

Incidence, predisposing factors, and aetiology of infective endocarditis in the Czech Republic

The aim of this study was to evaluate the incidence and epidemiological characteristics of infective endocarditis (IE) in the Czech Republic. These results represent the first data on the epidemiology of IE from the post-communist countries. This was a prospective multi-centre observational study monitoring the occurrence of IE in the catchment areas of 29 hospitals during a 12-month period. The total monitored territory involved a population of 3.9 million people (37.7% of the total Czech population). Patients were included in the study if they had a diagnosis of possible or definite endocarditis according to the modified Duke criteria. One hundred and thirty-four episodes of IE in 132 patients were reported. Thus the crude incidence of IE was 3.4 cases/100,000 inhabitants/y. Vegetations were most frequently found on the aortic and mitral valves. The most frequent agent was Staphylococcus aureus (29.9%). The aetiology remained unexplained in 33.6% of cases, mainly because of previous antibiotic therapy. Surgical intervention during antibiotic therapy was performed in 36 patients (27.5%). Thirty-six patients died during hospitalization (in-hospital mortality rate 27.5%). The most common predisposing cardiac factors were remote cardiac surgery (19.4%) and degenerative valvular changes (11.9%). The most common extracardiac factors were pyogenic infections of skin and soft tissues (13.0%) and chronic haemodialysis (8.2%). Our results document the changing epidemiological characteristics of IE, namely an increasing incidence of the disease and an increasing role of Staphylococcus aureus as a major pathogen. A shift was evident in predisposing factors for IE: almost 39% of IE episodes were associated with both cardiac and extracardiac modern medical procedures.

Epidemiology of infective endocarditis in Chennai, South India

Infective endocarditis (IE) is an infection of the endocardial surface of the heart. Despite recent advances in diagnosis and treatment, mortality rates remain high. Data on the prevalence, epidemiology and etiology of IE from India are sparse. The aim of this study was to evaluate the clinical, laboratory, microbiological, and echocardiographic characteristics of IE patients in Chennai, south India. Patients were classified based on modified Duke criteria. Details of the clinical profile of the patients and laboratory data were recorded. Blood cultures were performed to establish the etiology. Ninety six percent of patients had native valve endocarditis. Mitral valve was the most commonly affected valve. Rheumatic heart disease was the most common predisposing factor and fever was the most common clinical feature. Viridans group streptococci accounted of the culture positive cases.

Odontogenic Infections in the Etiology of Infective Endocarditis

Revised guidelines for the prevention of infective endocarditis published by the American Heart Association in 2007 do not support the indiscriminate use of antibiotic prophylaxis for dental procedures. However, they still recommend the use of prophylaxis for high-risk patients before dental treatments likely to cause bleeding. Given the high prevalence of bacteremia of dental origin due to tooth-brushing, mastication or other daily activities, it appears unlikely that infective endocarditis from oral microorganisms can be completely prevented. A good oral health status and satisfactory level of oral hygiene are sufficient to control the consequences of the systemic spread of oral microorganisms in healthy individuals. However, caution is still needed and prophylactic antibiotics must be administered to susceptible or medically compromised patients. This review briefly outlines the current concepts of odontogenic bacteraemia and antibiotic prophylaxis for patients undergoing dental treatment.

Complications of Infective Endocarditis

Infective endocarditis (IE) is a lethal disease if not promptly treated with antibiotics, either in association with surgery or not. The incidence of disease has not decreased over the last decades due to the change of risk conditions. Complications of IE may involve cardiac structures when the infection spreads within the heart, or extra cardiac ones when the cause is usually from embolic origin; they may also be due to medical treatment or to the septic condition itself. A variety of complications may occur in most of patients. The literature reports one complication of IE in 57%, two in 26% and three or more in about 14% of patients examined. The frequency of specific complications depends on variables as the infecting pathogen, duration of disease before therapy and type of treatment. However it is often difficult to assess the true incidence of complications because the published reviews in literature are frequently based on retrospective chart reviews and different diagnostic criteria are used. The decision over either indication or timing of surgery should be individualized and based on a multidisciplinary approach involving at least cardiologists and cardiac surgeons. Congestive heart failure (CHF) is the most important complication of IE, which has the greatest impact on prognosis. Periannular abscesses are a relatively common complication of IE (42% to 85% of cases during surgery or at autopsy respectively), associated with a higher morbidity and mortality. Systemic embolization occurs in 22% to 50% of cases; emboli may involve major arteries, mostly affecting the central nervous system, but also other organs. Splenic abscess is a rare complication of IE, due to direct seeding of spleen by an embolus or bacterial seeding of a bland infarction. Neurological complications develop in 20% to 40% of patients with IE and represent a dangerous subset of complications. Mycotic aneurysms are rare, resulting from diffusion of infection to the vessel wall. Actually the clinical profile, the best treatment (medical or surgical approach) and outcome of complicated IE are not well defined. Changing trends in aetiology of IE with emerging infections from Staphylococci, bacteria of the HACEK group and Fungi have resulted in an increased frequency of culture negative IE. Sepsis or persistent fever despite appropriate antimicrobial therapy, recurrent emboli, heart failure or new pathologic murmurs suggest haemodynamic impairment and/or infection extending beyond the valve leaflet or prosthetic valvular annulus. The course of the disease will consequently get worse with an increasing need of surgery. Patients who develop abscesses are more likely to undergo surgery than those who do not (84-91% vs 36%), and also their in-hospital mortality rate is higher (19% vs 11%). A prompt detection of complications often allows an earlier surgical treatment which represents the best way to improve the outcome. The introduction of molecular methods techniques has increased the ability to identify the causal agents of IE, mostly in cases of culture negative endocarditis. Echocardiography, mainly from transesophageal (TEE) approach, has significantly improved the evaluation of IE allowing to detect the specific signs of the disease as vegetations, abscesses, valve insufficiency, prosthetic valve dehiscence, fistulas. In our 3rd referral Hospital (Lancisi Heart Hospital, Ancona, Italy) we performed a follow-up (mean 8.26 years) of 15 patients with periannular complications associated with IE. The long term follow-up showed low mortality rate, high incidence of reintervention, improved New York Heart Association (NYHA) class in survivors and no changes of the lesions at the echocardiographic examination, suggesting that periannular complications have not significantly influenced the overall survival in our patients at the follow-up.