infective endocarditis

Question 1

staph aureus IE

Answer 1

35-40% of native valve cases
most common cause of acute IE, including persons who inject drugs and patient with prosthetic valves or pacemakers/ICD
typically affects healthy valves
usually fatal within 6 weeks if left untreated

Question 2

viridans streptococci

Answer 2

approx 20% of native valve IE cases
most common cause of subacute IE, especially in pre-damaged valves (mainly mitral)
common following dental procedures, respiratory tract incision and biopsy
produce dextrans that facilitate bindings of fibrin-platelet aggregates on heart valves

Question 3

staph epidermitis

Answer 3

less than 15% of native IE cases
bacteraemia from infected peripheral venous catheters
common cause of subacute IE in patients with prosthetic heart valves, pacemakers, or ICDs

Question 4

other agents/causes of IE

Answer 4

enterococci (especially enterococcus faecalis)
streptococcus gallolyticus
gram negative HACEK group
fungal endocarditis
coxiella burnetii
bartonella species