Fast Five Quiz: Do You Know the Manifestations of and Best Treatment Practices for Streptococcal Infections?

Michael Stuart Bronze, MD


September 03, 2015

Because pharyngitis and tonsillitis may result from various infectious etiologies other than S pyogenes infection, the diagnosis should be confirmed. Throat culture remains the standard diagnostic test for streptococcal pharyngitis. If performed correctly, culture of a single throat swab on a blood agar plate has a sensitivity of 90%-95% for the detection of group A streptococci in the pharynx. Although some throat culture results are false-positive (eg, they do not reflect acute infection but, rather, asymptomatic carriage), all patients with positive culture results are treated with antibiotics.

Blood culture, antistreptolysin O titer, sputum culture, and tissue culture should be performed in patients with systemic infections. In patients with acute pharyngitis, group A beta-hemolytic streptococcal infection should be ruled out. With appropriate antibiotic treatment, the duration of illness is decreased, suppurative complications are prevented, infectivity is decreased, and serious nonsuppurative sequelae can be prevented. Of note, delaying antimicrobial therapy for a short period does not diminish its efficacy in preventing rheumatic fever.

For more on the workup of patients with group A streptococcal infections, read here.


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