Comparison of throat culture and latex agglutination test for streptococcal pharyngitis.

Numerous reports have recently appeared in the clinical microbiology literature that describe agglutination tests for identifying patients with group A streptococcal pharyngitis. These studies have indicated a close correlation between the results of the agglutination tests and traditional throat culturing. This paper describes a comparison study of 100 consecutive throat swab specimens using a commercially available agglutination test and routine throat culturing. The cultures were interpreted by an individual who was blinded to the agglutination test results. All agglutination testing was done by two laboratory members of a family practice office staff. The agglutination procedure was easy to perform and clear to interpret. The test sensitivity and specificity compared well with that reported in the literature from microbiology laboratories. The new agglutination tests are useful in the office laboratory for the identification of group A streptococci. Their primary advantage compared with throat culturing is the rapid availability of test results.