From the Guidelines
Infective endocarditis with repeated positive cultures for Streptococcus (Strep) bovis is a significant condition that requires prolonged antibiotic treatment, typically lasting 4-6 weeks, as outlined in the American Heart Association's 2015 update on infective endocarditis in childhood 1.
Key Considerations
- The treatment duration for native valve endocarditis caused by relatively resistant streptococci, including Strep bovis, is 4 weeks 1.
- For prosthetic material infections caused by viridans streptococci or Strep bovis, the recommended treatment duration is 6 weeks 1.
- Bacteremia generally resolves within several days after appropriate therapy has begun, but repeated blood cultures are necessary to assess the adequacy of treatment and document the cessation of bacteremia 1.
Treatment Options
- A combination of penicillin G and an aminoglycoside, such as gentamicin, may be used for treatment, but the specific regimen and duration should be guided by the patient's individual circumstances and the results of repeated blood cultures 1.
- Alternative regimens, such as ceftriaxone with or without gentamicin, may also be considered, but the treatment duration should still be 4-6 weeks 1.
- Valve replacement surgery may be necessary in patients with complicated disease or persistent bacteremia despite adequate antibiotic therapy.
From the Research
Significance of Repeated Positive Cultures for Streptococcus bovis
- Repeated positive cultures for Streptococcus bovis in a patient with a history of infective endocarditis may indicate persistent infection, which is a significant predictor of in-hospital mortality 2.
- The presence of persistent positive blood cultures, including those with Streptococcus bovis, is an independent risk factor for in-hospital mortality, doubling the risk of death in patients with left-sided infective endocarditis 2.
- Streptococci, including Streptococcus bovis, are common causative microorganisms in infective endocarditis, with a prevalence of 48.4% in one study 3.
- The clinical characteristics of infective endocarditis, including fever, heart murmur, and anemia, are similar regardless of the causative microorganism, including Streptococcus bovis 3.
Prognostic Implications
- Persistent positive blood cultures after 48-72 hours of antibiotic therapy are associated with a worse prognosis in patients with left-sided infective endocarditis 2.
- The guidelines for infective endocarditis establish a cut-off point of 7-10 days for persistent infection, but this may be arbitrary and too long 2.
- The presence of persistent positive blood cultures, including those with Streptococcus bovis, should be taken into account in the risk stratification of patients with infective endocarditis 2.
Clinical Characteristics
- Streptococcus bovis is a type of streptococci that can cause infective endocarditis, and its clinical characteristics are similar to those of other streptococci 3.
- The diagnosis of infective endocarditis caused by Streptococcus bovis can be established using blood cultures, echocardiography, and other diagnostic tools 3, 4.
- The treatment of infective endocarditis caused by Streptococcus bovis typically involves antibiotic therapy, and surgical intervention may be necessary in some cases 3, 4.