Which of the following best describes subacute endocarditis?

• A. It usually develops rapidly and presents with severe symptoms.
• B. It is typically caused by low-virulence bacteria such as Streptococcus viridans.
• C. It is most commonly associated with intravenous drug use.
• D. It rarely affects individuals with preexisting heart conditions.

Answer: (B)

Verified step by step guidance

1. Understand the definition of subacute endocarditis: it is a type of infective endocarditis characterized by a slower onset and less severe symptoms compared to acute endocarditis.
2. Recall that subacute endocarditis is commonly caused by bacteria with low virulence, such as Streptococcus viridans, which are part of the normal oral flora and can enter the bloodstream during dental procedures or minor injuries.
3. Recognize that subacute endocarditis typically affects individuals with preexisting heart conditions, such as damaged or prosthetic heart valves, because these conditions provide a surface for bacterial colonization.
4. Differentiate subacute endocarditis from acute endocarditis, which develops rapidly and is often caused by highly virulent bacteria like Staphylococcus aureus, frequently associated with intravenous drug use.
5. Conclude that the best description of subacute endocarditis is that it is typically caused by low-virulence bacteria such as Streptococcus viridans, reflecting its slower progression and association with preexisting heart conditions.