McIsaac Modification of Centor Score in Diagnosis of Streptococcal Pharyngitis and Antibiotic Sensitivity Pattern of Beta-hemolytic Streptococci in Chennai, India

ABSTRACT

Objective: Toassess the validity of modified Centor Score in predicting streptococcalpharyngitis, and describe the antibiotic sensitivity of streptococcal strains. Methods: A cross-sectional study of 120 children (age 1-18 y) with signs and symptoms of pharyngitis wasundertaken in the pediatric department of a tertiary care teaching hospital in Chennai fromJuly 2015 to April 2016. Modified Centor score was calculated for all children, andstreptococcal sore throat was confirmed by throat swab culture. Predictive validity of Centorscore was assessed by Receiver Operating Curve (ROC) analysis. Results: Streptococcalculture positivity was 35%. The Area Under the Curve (AUC) value for modified Centor scorewas 0.589 (95% CI 0.481 to 0.697, P=0.11) in predicting streptococcal pharyngitis. Coughhad the highest sensitivity (63.4%), but poor specificity (36.7%) for streptococcal pharyngitisconfirmed by culture. The specificity was 100% for palatine petechiae, followed by palatineexudates (97.5%) and tender anterior cervical nodes (88.6%) to diagnose streptococcalpharyngitis. The proportion of antibiotic resistance was highest for cotrimoxazole (16.7%).Conclusion: Predictive validity of modified Centor score was not satisfactory, and resistanceto cotrimoxazole, fluoroquinolones and macrolides was high among S. pyogenes strains.