A 45-year-old woman with known rheumatic mitral valve disease presents with 3 weeks of low-grade fever, malaise, and weight loss following a dental extraction. Blood cultures grow Streptococcus viridans. This form of infective endocarditis is best described as:

• A Acute endocarditis involving a previously normal valve with highly virulent organisms
• B Culture-negative endocarditis due to fastidious intracellular organisms
• C Prosthetic valve endocarditis occurring within 60 days of surgery
• D Subacute endocarditis involving a previously damaged valve with organisms of low virulence ✓

Explanation

Subacute infective endocarditis is caused by organisms of low virulence such as Streptococcus viridans, typically seeding a previously abnormal valve after procedures producing transient bacteremia such as dental work. It runs an indolent course over weeks to months. Acute endocarditis involves normal valves with virulent organisms like Staphylococcus aureus, early prosthetic valve endocarditis occurs within 60 days and is usually coagulase-negative staphylococcal, and culture-negative cases involve organisms such as Coxiella burnetii.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.