Final answer:
The most common cause of subacute endocarditis of native valves is viridans streptococci, which typically affects the mitral valve. This condition is characterized by progressive heart valve damage and requires intensive antibiotic treatment.
Step-by-step explanation:
The most common bug for subacute endocarditis of a native valve is viridans streptococci, which typically affects the mitral valve.
Subacute bacterial endocarditis is an infection of the heart valves wherein the damage occurs progressively over a period of months. Signs such as fever may arise, and individuals with prior heart damage or a history of rheumatic fever are at elevated risk. Bacteria like Staphylococcus aureus, Viridans streptococci, and Enterococcus faecalis, among others, can cause infectious vegetations on the valves. Infections often arise from bacteria entering the bloodstream via invasive procedures or injuries. An echocardiogram and blood cultures are used for diagnosis, and treatment involves high doses of intravenous antibiotics.
Rheumatic fever, often caused by Streptococcus pyogenes, can lead to valvular disorders by provoking inflammation of the heart (carditis). Complications resulting from endocarditis, such as extensive damage to heart valves, can require surgical intervention like valve replacement.