B. Hoen

Preeminence of Staphylococcus aureus in Infective Endocarditis: A 1-Year Population-Based Survey

BACKGROUND Observational studies showed that the profile of infective endocarditis (IE) significantly changed over the past decades. However, most studies involved referral centers. We conducted a population-based study to control for this referral bias. The objective was to update the description of characteristics of IE in France and to compare the profile of community-acquired versus healthcare-associated IE. METHODS A prospective population-based observational study conducted in all medical facilities from 7 French regions (32% of French individuals aged ≥18 years) identified 497 adults with Duke-Li-definite IE who were first admitted to the hospital in 2008. Main measures included age-standardized and sex-standardized incidence of IE and multivariate Cox regression analysis for risk factors of in-hospital death. RESULTS The age-standardized and sex-standardized annual incidence of IE was 33.8 (95% confidence interval [CI], 30.8-36.9) cases per million inhabitants. The incidence was highest in men aged 75-79 years. A majority of patients had no previously known heart disease. Staphylococci were the most common causal agents, accounting for 36.2% of cases (Staphylococcus aureus, 26.6%; coagulase-negative staphylococci, 9.7%). Healthcare-associated IE represented 26.7% of all cases and exhibited a clinical pattern significantly different from that of community-acquired IE. S. aureus as the causal agent of IE was the most important factor associated with in-hospital death in community-acquired IE (hazard ratio [HR], 2.82 [95% CI, 1.72-4.61]) and the single factor in healthcare-associated IE (HR, 2.54 [95% CI, 1.33-4.85]). CONCLUSIONS S. aureus became both the leading cause and the most important prognostic factor of IE, and healthcare-associated IE appeared as a major subgroup of the disease.

Temporal Trends in Infective Endocarditis in the Context of Prophylaxis Guideline Modifications: Three Successive Population-Based Surveys

OBJECTIVES The goal of this study was to evaluate temporal trends in infective endocarditis (IE) incidence and clinical characteristics after 2002 French IE prophylaxis guideline modifications. BACKGROUND There are limited data on changes in the epidemiology of IE since recent guidelines recommended restricting the indications of antibiotic prophylaxis of IE. METHODS Three 1-year population-based surveys were conducted in 1991, 1999, and 2008 in 3 French regions totaling 11 million inhabitants age ≥20 years. We prospectively collected IE cases from all medical centers and analyzed age- and sex-standardized IE annual incidence trends. RESULTS Overall, 993 expert-validated IE cases were analyzed (323 in 1991; 331 in 1999; and 339 in 2008). IE incidence remained stable over time (95% confidence intervals given in parentheses/brackets): 35 (31 to 39), 33 (30 to 37), and 32 (28 to 35) cases per million in 1991, 1999, and 2008, respectively. Oral streptococci IE incidence did not increase either in the whole patient population (8.1 [6.4 to 10.1], 6.3 [4.8 to 8.1], and 6.3 [4.9 to 8.0] in 1991, 1999, and 2008, respectively) or in patients with pre-existing native valve disease. The increased incidence of Staphylococcus aureus IE (5.2 [3.9 to 6.8], 6.8 [5.3 to 8.6], and 8.2 [6.6 to 10.2]) was not significant in the whole patient population (p = 0.228) but was significant in the subgroup of patients without previously known native valve disease (1.6 [0.9 to 2.7], 3.7 [2.6 to 5.1], and 4.1 [3.0 to 5.6]; p = 0.012). CONCLUSIONS Scaling down antibiotic prophylaxis indications was not associated with an increased incidence of oral streptococcal IE. A focus on avoidance of S. aureus bacteremia in all patients, including those with no previously known valve disease, will be required to improve IE prevention.

Estimated Risk of Endocarditis in Adults with Predisposing Cardiac Conditions Undergoing Dental Procedures With or Without Antibiotic Prophylaxis

BACKGROUND Although antibiotic prophylaxis for infective endocarditis (IE) has been recommended for persons with predisposing cardiac conditions (PCCs) for many years, its efficacy, which has not been demonstrated, has been recently challenged. To assess its usefulness, we estimated the risk of developing IE after undergoing a dental procedure for which subjects would be eligible for prophylaxis, both in subjects having (protected procedure) or not having (unprotected procedure) received antibiotic prophylaxis. METHODS The number of French persons with PCCs, the annual number of dental procedures in which subjects would be eligible for antibiotic prophylaxis, and the number of procedures that were unprotected were estimated on the basis of a survey performed on a sample of 2805 subjects aged 25-84 years. The annual number of IE cases possibly due to an unprotected procedure was estimated on the basis of a 1-year epidemiological study of IE conducted in an area inhabited by 16 million people. RESULTS After standardization, extrapolation of results to the age-equivalent general population (39 millions subjects) indicated the following: first, 3.3% (95% confidence interval [CI], 2.6%-4%) of the subjects had PCC, 2.7 million (95% CI, 2.3-3.2 million) of whom had undergone at least 1 at-risk dental procedures within the survey year, and the procedures were unprotected in 62% of cases; second, 37 (95% CI, 18-68; 2.7%) of the 1370 annual IE cases in France were possibly related to unprotected procedures. Thus, the risks of developing IE were estimated to be 1 in 46,000 for unprotected procedures (1 in 10,700 and 1 in 54,300 for subjects with prosthetic and native valve PCC, respectively) and 1 in 150,000 for protected procedures. CONCLUSIONS A huge number of prophylaxis doses would be necessary to prevent a very low number of IE cases.

Prognostic Factors in 61 Cases of Staphylococcus aureus Prosthetic Valve Infective Endocarditis from the International Collaboration on Endocarditis Merged Database

Staphylococcus aureus prosthetic valve infective endocarditis (SA-PVIE) is associated with a high mortality rate, but prognostic factors have not been clearly elucidated. The International Collaboration on Endocarditis merged database (ICE-MD) contained 2212 cases of definite infective endocarditis (as defined using the Duke criteria), 61 of which were SA-PVIE. Overall mortality rate was 47.5%, stroke was associated with an increased risk of death, and early valve replacement was not associated with a significant survival benefit in the whole population; however, patients who developed cardiac complications and underwent early valve replacement had the lowest mortality rate (28.6%).

Emergence of endocarditis due to group D streptococci: findings derived from the merged database of the International Collaboration on Endocarditis

The aim of the present study was to compare the epidemiological and clinical characteristics of Streptococcus bovis endocarditis with those of endocarditis caused by oral streptococci, using data obtained from a large international database of uniformly defined cases of infective endocarditis. S. bovis, a well-known cause of infective endocarditis, remains the common name used to designate group D nonenterococcal streptococci. In some countries, the frequency of S. bovis endocarditis has increased significantly in recent years. Data from the International Collaboration on Endocarditis merged database was used to identify the main characteristics of S. bovis endocarditis and compared them with those of infective endocarditis (IE) due to oral streptococci. The database contained 136 cases of S. bovis IE and 511 cases of IE due to oral streptococci. Patients with S. bovis IE were significantly older those with IE due to oral streptococci (63±16 vs. 55±18 years, P<0.00001). The proportion of streptococcal IE due to S. bovis increased from 10.9% before 1989 to 23.3% after 1989 (P=0.0007) and was 56.7% in France as compared with 9.4% in the rest of Europe and 6.0% in the USA (P<0.00001). Patients with S. bovis IE had more comorbidity and never used intravenous drugs. Complication rates, rates of valve replacement, and mortality rates were similar in the two groups. In conclusion, this study confirmed that S. bovis IE has unique characteristics when compared to endocarditis due to oral streptococci and that it emerged in the 1990s, mainly in France, a finding that is yet unexplained.

Enterococcal prosthetic valve infective endocarditis: report of 45 episodes from the International Collaboration on Endocarditis-merged database

Enterococcal prosthetic valve infective endocarditis (PVE) is an incompletely understood disease. In the present study, patients with enterococcal PVE were compared to patients with enterococcal native valve endocarditis (NVE) and other types of PVE to determine differences in basic clinical characteristics and outcomes using a large multicenter, international database of patients with definite endocarditis. Forty-five of 159 (29%) cases of definite enterococcal endocarditis were PVE. Patients with enterococcal PVE were demographically similar to patients with enterococcal NVE but had more intracardiac abscesses (20% vs. 6%; p=0.009), fewer valve vegetations (51% vs. 79%; p<0.001), and fewer cases of new valvular regurgitation (12% vs. 45%; p=0.01). Patients with either enterococcal PVE or NVE were elderly (median age, 73 vs. 69; p=0.06). Rates of in-hospital mortality, surgical intervention, heart failure, peripheral embolization, and stroke were similar in both groups. Patients with enterococcal PVE were also demographically similar to patients with other types of PVE, but mortality may be lower (14% vs. 26%; p=0.08). Notably, 93% of patients with enterococcal PVE came from European centers, as compared with only 79% of patients with enterococcal NVE (p=0.03). Thus, patients with enterococcal PVE have higher rates of myocardial abscess formation and lower rates of new regurgitation compared to patients with enterococcal NVE, but there are no differences between the groups with regard to surgical or mortality rates. In contrast, though patients with enterococcal PVE and patients with other types of PVE share similar characteristics, mortality is higher in the latter group. Importantly, the prevalence of enterococcal PVE was higher in the European centers in this study.

Prosthetic valve endocarditis due to coagulase-negative staphylococci: findings from the International Collaboration on Endocarditis Merged Database

Infective endocarditis due to coagulase-negative staphylococci is increasingly recognized as a difficult-to-treat disease associated with poor outcome. The aim of this report is to describe the characteristics and outcome of patients with prosthetic valve endocarditis (PVE) due to coagulase-negative staphylococci versus those of patients with PVE due to Staphylococcus aureus and viridans streptococci. Patients were identified through the International Collaboration on Endocarditis Merged Database. A total of 54 cases of coagulase-negative staphylococci PVE, 58 cases of S. aureus PVE, and 63 cases of viridans-streptococci-related PVE were available for analysis. There was no difference between the three groups with respect to the type of valve involved or the rate of embolization. However, heart failure was encountered more frequently with coagulase-negative staphylococci (54%) than with either S. aureus (33%; p=0.03) or viridans streptococci (32%; p=0.02). In addition, valvular abscesses complicated 39% of infections due to coagulase-negative staphylococci compared with 22% of those due to S. aureus (p=0.06) and 6% of those due to viridans streptococci (p<0.001). Mortality was highest in patients with S. aureus and coagulase-negative staphylococcal endocarditis (47 and 36%, respectively; p=0.22) and was considerably lower in patients with viridans streptococcal endocarditis (p=0.002 compared to patients with coagulase-negative staphylococcal endocarditis). The results of this analysis demonstrate the aggressive nature of coagulase-negative staphylococcal PVE and the substantially greater morbidity and mortality associated with this infection compared to PVE caused by other pathogens.

Influence of diabetes mellitus on the clinical manifestations and prognosis of infective endocarditis: A report from the International Collaboration on Endocarditis – Merged Database

The purpose of this investigation was to study the influence of diabetes mellitus (DM) on outcomes of infective endocarditis (IE). Outcomes were compared between 150 diabetic and 905 non-diabetic patients with IE from the International Collaboration on Endocarditis Merged Database. Compared to non-diabetic patients, diabetic patients were older (median age 63 vs 57 y, p<0.001), were more often female (42.0% vs 31.9%, p=0.01), more often had comorbidities (41.5% vs 26.7%, p<0.001), and were more likely to be dialysis dependent (12.7% vs 4.0%, p<0.001). S. aureus was isolated more often (30.7% vs 21.7%, p=0.02), and microorganisms from the viridans Streptococcus group less often (16.7% vs 28.2%, p = 0.001) in the diabetic group. There was no difference with respect to the presence of congestive heart failure, embolism, intra-cardiac abscess, new valvular regurgitation, or valvular vegetation. Diabetic patients underwent surgical intervention less frequently (32.0% vs 44.9%, p = 0.003), and had higher overall in-hospital mortality (30.3% vs 18.6%, p = 0.001). On multivariable analysis, DM was an independent predictor of mortality (odds ratio (OR) = 1.71, 95% confidence interval (CI) 1.08–2.70), especially in male patients, as diabetic males had higher mortality than non-diabetic males (OR 2.18, CI 1.08–4.35). DM is an independent predictor of in-hospital mortality among patients hospitalized with IE.

Validation of a diagnosis model for differentiating bacterial from viral meningitis in infants and children under 3.5 years of age.

Abstract The aim of this study was to validate, in a population of infants and children under 3.5 years of age, a diagnosis model that provides a figure for the probability of bacterial meningitis (pABM), based on four parameters collected at the time of the first lumbar tap: the cerebrospinal fluid (CSF) protein level, CSF polymorphonuclear cell count, blood glucose level, and leucocyte count. The best cut-off value for distinguishing between bacterial and viral meningitis was previously found to be 0.1, since 99% of meningitides associated with pABM<0.1 were viral. The charts of 103 consecutive children aged 0.1–3.5 years who had been hospitalised for acute meningitis were reviewed. Each case was sorted into the following three categories for aetiology: bacterial (positive CSF culture, n=48); viral (negative CSF culture and no other aetiology, and no antibiotic treatment after diagnosis, n=36); and undetermined (fitting neither of the first two definitions, n=19). After computation of pABM values in each case, the predictive values of the model were calculated for different pABM cut-off values. The results confirmed that the best cut-off pABM value was 0.1, for which the positive and negative predictive values in this model were 96% and 97%, respectively. Only one case of bacterial meningitis (lumbar tap performed early in an infant with meningococcal purpura fulminans with negative CSF culture) was associated with a pABM value of <0.1. This model is quite reliable for differentiating between bacterial and viral meningitis in children under 3.5 years of age, and it may enable physicians to withhold antibiotics in cases of meningitis of uncertain aetiology.

Candida Endocarditis: Contemporary Cases from the International Collaboration of Infectious Endocarditis Merged Database (ICE-MD)

Candida infective endocarditis (IE) is increasingly common, yet most reports have been single-center reviews. We evaluated 16 patients with Candida IE nested within a cohort of 2,022 patients with IE. Prosthetic valve IE was more common in patients with Candida (50% vs 17%); mortality was 37% for patients with Candida.