Infective Endocarditis Related to Unusual Microorganisms: A Prospective Population-Based Study
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Published on: June 4, 2012
Silvia Limonta1, Emmanuelle Cambau2, Marie-Line Erpelding3
1Maladies Infectieuses et Reanimation Médicale, Inserm CIC 1414, Hôpital Pontchaillou, Centre Hospitalo-Universitaire, Université Rennes 1, Rennes, France.
Background:
Increased access to heart valves through early surgery and progress in molecular microbiology have reduced the proportion of infective endocarditis (IE) with no microbiological documentation and increased the proportion of IE associated with unusual microorganisms.
Methods:
We performed an ancillary study of a large prospective population-based survey on IE. Unusual-microorganism IE was defined as definite IE (Duke-Li criteria) due to microorganisms other than streptococci, staphylococci, or enterococci.
Results:
Of 471 cases of documented IE, 46 (9.8%) were due to unusal microorganisms; the following were involved in >1 case: Candida albicans (n = 4), Cutibacterium acnes (n = 4), Pseudomonas aeruginosa (n = 3), Cardiobacterium hominis (n = 3), and Coxiella burnetii (n = 2). Cases were documented with blood cultures (n = 37, 80.4%), heart valve polymerase chain reaction (PCR; n = 5), heart valve culture (n = 2), PCR on vertebral biopsy (n = 1), or serology (n = 1). As compared with IE due to staphylococci, streptococci, or enterococci (n = 420), IE due to unusual microorganisms occurred more frequently in patients with previously known heart disease (69.0% vs 44.3%; P = .002), prosthetic valve (40.5% vs 18.1%; P = .0006), longer duration of fever (mean, 35.1 ± 46.8 days vs 12.5 ± 17.8; P = .003), and who were more often nosocomial (38.1% vs 20.2%; P = .02).
Conclusions:
In this population-based study, 9.8% of IE cases were due to unusual microorganisms, with a predominance of anaerobes, yeast, and gram-negative bacilli. As compared with IE related to staphylococci, streptococci, or enterococci, IE cases related to unusual microorganisms were associated with previously known heart disease, prosthetic valve, longer duration of fever, and nosocomial acquisition.
Trial Registration:
ORCID 0000-0003-3617-5411.
Insights
Unusual microorganisms cause nearly 10% of infective endocarditis (IE) cases. These infections are linked to pre-existing heart conditions, prosthetic valves, prolonged fever, and hospital-acquired infections.
Area of Science:
- Infectious Diseases
- Cardiology
- Microbiology
Background:
- Advances in cardiac surgery and microbiology have shifted the landscape of infective endocarditis (IE).
- There is an increasing proportion of IE cases associated with less common or unusual microorganisms.
Purpose of the Study:
- To investigate the incidence and characteristics of IE caused by unusual microorganisms.
- To compare the clinical features and risk factors of unusual-microorganism IE with those caused by common pathogens.
Main Methods:
- An ancillary study of a large prospective population-based survey on IE was conducted.
- Unusual-microorganism IE was defined as definite IE (Duke-Li criteria) caused by pathogens other than streptococci, staphylococci, or enterococci.
- Data on patient demographics, clinical presentation, diagnostic methods, and outcomes were analyzed.
Main Results:
- Of 471 documented IE cases, 9.8% were attributed to unusual microorganisms.
- Common unusual pathogens included Candida albicans, Cutibacterium acnes, and Pseudomonas aeruginosa.
- IE due to unusual microorganisms was significantly associated with prior heart disease (69.0% vs 44.3%), prosthetic valves (40.5% vs 18.1%), longer fever duration, and nosocomial acquisition (38.1% vs 20.2%).
Conclusions:
- Unusual microorganisms account for a notable proportion of IE cases, predominantly anaerobes, yeast, and gram-negative bacilli.
- IE caused by unusual pathogens presents with distinct epidemiological and clinical characteristics compared to IE from common bacteria.
- These findings highlight the importance of considering unusual organisms in the diagnosis and management of IE, particularly in high-risk patients.
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