Rapid detection of group B streptococcal antigen from vaginal specimens using a new Optical ImmunoAssay technique.

A total of 531 vaginal specimens were used to evaluate a new Optical ImmunoAssay (OIA) screening technique for the rapid detection of group B streptococcal antigen. The results of the OIA test, the ICON Strep B membrane immunoassay (Hybritech ICON), and conventional culture on sheep blood agar (direct TSA) were compared to broth enhanced culture. Results obtained from the OIA test, ICON, and direct TSA yielded 72, 39, and 68 positives, respectively, as compared to 100 positives using the Lim broth culture method as the standard. The Optical ImmunoAssay technique is as sensitive as the conventional plating method and is capable of providing results in 30 minutes.