The diagnosis of group A, beta-hemolytic streptococcal pharyngitis in the office setting. Rapid latex test vs throat culture

B. Taubman, R. P. Barroway and K. L. McGowan
Department of Pediatrics, Children's Hospital of Philadelphia.

We compared a rapid latex agglutination test with cultures of throat specimens to diagnose group A beta-hemolytic streptococcal pharyngitis in an office setting. The throat cultures were interpreted by two pediatricians independently and evaluated by a reference laboratory. Five hundred seventy-two children participated in the study. The latex agglutination test had a sensitivity of 89.4% and a specificity of 85.7%. Cultures of throat specimens obtained in the office had a sensitivity of 91.9% and a specificity of 91.7% when interpreted by investigator 1, and a sensitivity of 90.0% and a specificity of 95.1% when interpreted by investigator 2. There was no statistically significant difference between the numbers of false-negative results generated by the two procedures. We conclude that although somewhat less specific, the latex test is as sensitive as cultures of throat specimens in the office setting.