Infective endocarditis

Question 1

What are the most common pathogens causing Infective Endocarditis in naive valves?

Answer 1

Staphylococcus aureus/epidermidis - native valve endocarditis in IVDU (30-40% of native valve IE)

Staph aureus - most common overall (in all IVDU/native and prosthetics)

Question 2

What is the most common pathogen causing infective endocarditis in prosthetic valves?

Answer 2

Prosthetic valves - Staphylococcus aureus/epidermidis

• Group of Gramm-positive cocci with Alpha-haemolytic properties
• Viridans group present in oral mucosa: often cause for IE due to poor dental hygiene

Others include:
□ streptococcus bovis (associated with colorectal malignancy)

Question 3

What is the most common valve affected in patients with Infective endocarditis?

Answer 3

Mitral valve>aortic valve>tricuspid valve> pulmonary valve

Tricuspid most ocmmonly involved in IVDU

Question 4

What investigatitons should be used for diagnosis of Infective endocarditis?

Answer 4

1. Blood cultures (at least 3 sets) 30min apart
2. Echo (TTE 75% sensitivity vs 90% sensitivity in TOE therefore Fist line. TTE, TOE generally performed if nothing seen on TTE and still suspicion of IE)

Other Bloods for infective/ differentials/ organ involvement e.g. U&E

ECG for changes (e.g. PR prolongation)

Question 5

What is usually the first line choice of antibiotics for Infective endocarditis?

Answer 5

Vancomycin + beta-lactam (e.g. Ceftriaxone, cefepime) 4-6 Weeks course