Rapid identification of group B streptococci carriers

Sensitivity and specificity of three commercial latex agglutination tests, i.e. Streptex, Wellcogen (Wellcome Diagnostics, Dartford, England) and Directigen (Becton Dickinson, Baltimore, USA) were evaluated on 233 vaginal swabs and 208 urine specimens after 4h culture in comparison with traditional cultural and identification methods. On vaginal swabs sensitivity of Wellcogen and Streptex was shown to be comparable (43% and 37% respectively), but both tests gave several false positive results; Directigen test showed higher (100%) specificity, but its sensitivity was very low. On urine cultures all the tests were shown to be unsatisfactory in comparison with traditional methods, sensitivity and specificity being demonstrated to be poor.