C. Streptococcus viridans infection – Explanation
Infective endocarditis – streptococcal infection carries a good prognosis
Infective endocarditis: prognosis and management
Poor prognostic factors
- Staph aureus infection (see below)
- prosthetic valve (especially ‘early’, acquired during surgery)
- culture negative endocarditis
- low complement levels
Mortality according to organism
- staphylococci – 30%
- bowel organisms – 15%
- streptococci – 5%
Current antibiotic guidelines (source: British National Formulary)
| Scenario Suggested | antibiotic therapy |
| Initial blind therapy | Flucloxacillin + gentamicin (benzylpenicillin + gentamicin if
symptoms less severe) |
| Initial blind therapy if prosthetic valve is present or patient is penicillin allergic |
Vancomycin + rifampicin + gentamicin |
| Endocarditis caused by staphylococci | Flucloxacillin (add rifampicin if prosthetic valve, vancomycin +
rifampicin if penicillin allergic or MRSA) |
| Native valve endocarditis caused by fully-sensitive streptococci (e.g. viridans) |
Benzylpenicillin (large vegetation, intracardial abscess or infected emboli then (e.g. viridans) benzylpenicillin + gentamicin, vancomycin if penicillin allergic) |
| Native valve endocarditis caused by less sensitive streptococci OR prosthetic valve endocarditis caused by streptococci |
Benzylpenicillin + gentamicin (vancomycin + gentamicin if penicillin allergic) |
Indications for surgery
- severe valvular incompetence
- aortic abscess (often indicated by a lengthening PR interval)
- infections resistant to antibiotics/fungal infections
- cardiac failure refractory to standard medical treatment
- recurrent emboli after antibiotic therapy
