Prevalence of Asymptomatic Group A Streptococcus Carriage Based on Rapid Antigen Detection Test in Healthy Adults in Poland

Background: Acute pharyngitis is one of the most prevalent disorders seen in general practitioners' consultations. Most cases of acute pharyngitis in adults are caused by respiratory viruses and are self-limited. However, clinical manifestations of viral pharyngitis can overlap with bacterial pharyngitis, mainly caused by group A Streptococcus (GAS). A rapid antigen test for GAS can help diagnose streptococcal pharyngitis, but misdiagnosing S. pyogenes infection in a patient with a viral condition can lead to inappropriate antibiotic use. Some patients with a sore throat due to a virus or other causes will test positive for GAS because of carriage. The aim of our study was to analyze rapid strep test results in healthy adults. Methods: A cohort study was conducted in an outpatient clinic in Wroclaw. We used the rapid strep test BIOSYNEX STREP A. Results: A total of 350 healthy volunteers (≥18 years old) were enrolled in this study. The presence of Streptococcus pyogenes, based on a rapid strep test, was detected in 17 adults (4.9%). The strep test positivity rate was higher in younger adults. Conclusions: In healthy individuals in Poland, the prevalence of pharyngeal carriage of GAS is 4.9%. This finding emphasizes that the rapid antigen detection test should only be used in cases of suspected bacterial pharyngitis to avoid inappropriate antibiotic use.