Utility of Detecting sof Gene as Evidence of Streptococcus pyogenes Infection in Acute Rheumatic Fever

ABSTRACT

Objectives: To determine the diagnostic accuracy of polymerase chain reaction-baseddetection of sof gene compared to throat swab culture for S. pyogenes infection in patientswith acute rheumatic fever and those with recurrence of rheumatic activity. Methods: 40patients between 3 to 18 years of age, with clinical diagnosis of acute rheumatic fever or newactivity in established rheumatic heart disease were included. The amplicon of 228bp of sofgene was detected using a polymerase chain reaction-based technique and the results werecompared with throat swab culture for Streptococcus pyogenes. Results: 10 patients hada positive throat swab culture and 11 had sof gene detected. The sensitivity and specificityof the test was 100% and 96.7%, respectively compared to throat swab culture (P=0.001).The positive predictive value and the negative predictive value was 90.9% and 100%respectively. Conclusions: Polymerase chain reaction-based detection of sof geneprovides an alternative to throat swab culture in diagnosing activity in Acute RheumaticFever or established Rheumatic heart disease.