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

OBJECTIVE

To determine the diagnostic accuracy of polymerase chain reaction-based detection of sof gene compared to throat swab culture for S. pyogenes infection in patients with acute rheumatic fever and those with recurrence of rheumatic activity.

METHODS

40 patients between 3 to 18 years of age, with clinical diagnosis of acute rheumatic fever or new activity in established rheumatic heart disease were included. The amplicon of 228bp of sof gene was detected using a polymerase chain reaction-based technique and the results were compared with throat swab culture for Streptococcus pyogenes.

RESULTS

10 patients had a positive throat swab culture and 11 had sof gene detected. The sensitivity and specificity of 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.

CONCLUSION

Polymerase chain reaction-based detection of sof gene provides an alternative to throat swab culture in diagnosing activity in Acute Rheumatic Fever or established Rheumatic heart disease.