A viridans streptococcus such as Streptococcus sanguis is most commonly linked to which condition?

• A. Otitis media
• B. Pharyngitis
• C. Relapsing fever
• D. Subacute bacterial endocarditis

Answer: (D)

Viridans streptococci are part of the normal oral flora and have a strong ability to adhere to damaged heart valves. When dental work or other events cause transient bacteremia, these bacteria can lodge on an abnormal valve and form vegetations, leading to subacute bacterial endocarditis. This infection tends to progress slowly with symptoms like low-grade fever, fatigue, weight loss, and a new or changing heart murmur, rather than an abrupt, severe illness. The other conditions listed are typically caused by different organisms (otitis media mainly by pneumococcus or H. influenzae; pharyngitis by group A strep; relapsing fever by Borrelia species), so the connection with viridans streptococci is most clearly with subacute endocarditis.