The experience of rapid diagnostics for acute Streptococcal tonsillopharyngitis in clinical practice

Group A streptococcus (GAS) is the leading bacterial cause of acute tonsillopharyngitis, as well as infections in other locations, most commonly skin infections, phlegmon, and erysipelas. It is important to start early specific antibacterial therapy in a timely manner especially to prevent possible complications. Rapid antigen tests have high sensitivity and specificity (95-97%), facilitate the rapid and accurate detection of GAS antigen in throat swabs. Objective: validation of the rapid test “RAPID-Streptococcus-A-LF” for detecting GAS (Streptococcus pyogenes) antigen in throat swabs from patients with suspected Streptococcal tonsillopharyngitis using the RAPID-StreptococcusALF immunochromatographic assay and to determine its diagnostic characteristics (sensitivity, specificity, and crossreactivity with Streptococcus agalactiae). Materials and Methods : sample type – throat swabs from patients with acute tonsillopharyngitis. 34 rapid antigen tests “RAPID-Streptococcus-A-LF” were tested on 28 samples with different colony-forming unit (CFU) counts of GAS and 6 comparison samples. The study was performed in two phases: the first phase involved sample selection according to the study plan and determination of CFU values in the samples, while the second phase included testing biological samples on the antigen tests and recording the results. Results: the “RAPID-Streptococcus-A-LF” antigen test showed high diagnostic sensitivity (93-100%) and specificity (100%) similar to the leading imported tests on Russian market. Conclusion: rapid testing, as an auxiliary method for detecting GAS, can significantly optimize the diagnostic algorithm for acute tonsillopharyngitis, ensuring timely etiotropic treatment of GAS infection and reducing the incidence of unnecessary antibiotic therapy.