The changing profile of bacterial endocarditis as seen at an australian provincial centre

The Changing Epidemiology of Infective Endocarditis in the Twenty-First Century

PURPOSE OF THE REVIEW

Infective endocarditis (IE) is a relatively infrequent infectious disease. It does, however, causes serious morbidity, and its mortality rate has remained unchanged at approximately 25%. Changes in IE risk factors have deeply impacted its epidemiology during recent decades but literature from low-income countries is very scarce. Moreover, prophylaxis guidelines have recently changed and the impact on IE incidence is still unknown.

RECENT FINDINGS

In high-income countries, the proportion of IE related to prior rheumatic disease has decreased significantly and has been replaced proportionally by cases related to degenerative valvulopathies, prosthetic valves, and cardiovascular implantable electronic devices. Nosocomial and non-nosocomial-acquired cases have risen, as has the proportion caused by staphylococci, and the median age of patients. In low-income countries, in contrast, rheumatic disease remains the main risk factor, and streptococci the most frequent causative agents. Studies performed to evaluate impact of guidelines changes' have shown contradictory results. The increased complexity of cases in high-income countries has led to the creation of IE teams, involving several specialties. New imaging and microbiological techniques may increase sensitivity for diagnosis and detection of IE cases. In low-income countries, IE remained related to classic risk factors. The consequences of prophylaxis guidelines changes are still undetermined.

Global and regional burden of infective endocarditis, 1990-2010: a systematic review of the literature

Infective endocarditis (IE) is a life-threatening disease associated with serious complications. The GBD 2010 (Global Burden of Disease, Injuries, and Risk Factors) study IE expert group conducted a systematic review of IE epidemiology literature to inform estimates of the burden on IE in 21 world regions in 1990 and 2010. The disease model of IE for the GBD 2010 study included IE death and 2 sequelae: stroke and valve surgery. Several medical and science databases were searched for IE epidemiology studies in GBD high-, low-, and middle-income regions published between 1980 and 2008. The epidemiologic parameters of interest were IE incidence, proportions of IE patients who developed stroke or underwent valve surgery, and case fatality. Literature searches yielded 1,975 unique papers, of which 115 published in 10 languages were included in the systematic review. Eligible studies were population-based (17%), multicenter hospital-based (11%), and single-center hospital-based studies (71%). Population-based studies were reported from only 6 world regions. Data were missing or sparse in many low- and middle-income regions. The crude incidence of IE ranged between 1.5 and 11.6 cases per 100,000 people and was reported from 10 countries. The overall mean proportion of IE patients that developed stroke was 0.158 ± 0.091, and the mean proportion of patients that underwent valve surgery was 0.324 ± 0.188. The mean case fatality risk was 0.211 ± 0.104. A systematic review for the GBD 2010 study provided IE epidemiology estimates for many world regions, but highlighted the lack of information about IE in low- and middle-income regions. More complete knowledge of the global burden of IE will require improved IE surveillance in all world regions.

Underlying heart disease and microbiological spectrum of adult infective endocarditis in one Chinese university hospital: a 10-year retrospective study

BACKGROUND AND AIM

To identify the underlying heart disease and microbiological pathogen associated with infective endocarditis (IE) in Chinese patients in one university hospital over a 10-year period.

METHODS

We recruited 115 adult patients admitted to Peking University First Hospital from 2002 to 2011 who were diagnosed with definite IE. Statistical analysis was performed to analyse data on demographics, clinical and laboratory findings, as well as microbiological pathogens.

RESULTS

The most common underlying heart diseases for IE were congenital heart disease (24.3%) followed by degenerative valvular disease (17.4%). Aortic (44.3%) and mitral (43.5%) valves were most frequently affected. The right-sided IE cases were all found in patients with congenital heart disease. The age of patients was younger in right-sided cases than that in left-sided ones (P = 0.001). There was no difference in the mortality among groups with different underlying heart disease (P = 0.841). Forty-four (38.3%) patients were infected with viridans group streptococci. The isolation rate of staphylococci in right-sided IE was higher than that in the left-sided IE group (P = 0.021). More than 85% of streptococci were susceptible to β-lactams.

CONCLUSIONS

Congenital heart disease and degenerative valvular disease have overtaken rheumatic heart disease as the major underlying heart diseases associated with IE. Viridans group streptococci are the most common microbial cause of IE.

Infective endocarditis in an Indian setup: Are we entering the 'modern' era?

Background:

The clinical profile of infective endocarditis (IE) has been continuously evolving over last 3-4 decades as highlighted by many studies from developed world.

Objectives:

To evaluate the recent changes in the spectrum and clinical profile, and outcome of IE in an Indian setup.

Materials and Methods:

This was a descriptive, cross-sectional study. Demographic, clinical, characteristics, treatment, and outcome were examined in ‘definite’ cases of IE admitted at our institute between July 2005 and December 2010.

Results:

61 ‘definite’ cases were identified. Mean patient age was 49.3 ± 13.7 years. Male to female ratio was 3.3:1. Rheumatic heart disease was the underlying heart disease in 23 (37.7%) patients. 33 (54.1%) patients had already received antibiotic therapy before presentation to us. Blood cultures were positive in 41 (67.2%) patients. Streptococci and staphylococci were the commonest microbial isolates, 9 (21.4%) patients each. Transesophageal echocardiography (TEE) was done for all the patients. Vegetations were detected in 54 (88%) patients. Surgery was done in 30 (49.2%) patients. In-hospital mortality happened in 4 (6.5%) patients.

Conclusions:

We recorded several new trends, like: 1) an increasing age, 2) an increasing proportion of patients with no previously known heart disease, 3) improving culture positivity rates, 4) rise in staphylococcal infections, 5) increased usage of TEE, 6) high elective surgical rate, and 7) apparent improved survival rates. These changes point to the fact that ‘modern era’ changes in the profile of IE have started to appear in a selected population in India.

A systematic review of population-based studies of infective endocarditis

BACKGROUND

We sought to summarize and critically appraise the literature on the epidemiology of infective endocarditis (IE) in the general population.

METHODS

We retrieved population-based IE surveys by searching MEDLINE and EMBASE. Two reviewers independently extracted relevant data. We performed a metaregression to determine if temporal trends of IE characteristics exist.

RESULTS

Fifteen population-based investigations with 2,371 IE cases from seven countries (Denmark, France, Italy, the Netherlands, Sweden, United Kingdom, and United States) from 1969 to 2000 were eligible. Different case definitions and procedures were used to capture all IE cases, including census of existing diagnoses, record-linkage system, and direct contact survey. In the unadjusted regression, there was a decline in the proportion of IE patients with underlying rheumatic heart disease (RHD; 12%; 95% confidence interval [CI], - 21 to - 3%; p = 0.01) and an increase in the proportion of patients undergoing valve surgery (9%; 95% CI, 3 to 16%) per decade. After adjusting for country, the decline in IE cases with underlying RHD became nonsignificant, but the proportions of IE patients undergoing valve surgery increased 7% per decade (95% CI, - 4 to 14%; p = 0.06), and those with underlying prosthetic valve increased 7% per decade (95% CI, - 1 to 16%; p = 0.07). There were no significant temporal trends in the causative organisms.

CONCLUSION

Evidence from well-planned, representative IE epidemiologic surveys is scarce in many countries. Available studies suggest a changing distribution of underlying valvular heart disease in patients with IE and an increase in its surgical treatment.