Rapid Intrapartum Screening for Group B Streptococci: How Efficient Is It Really?
August 01, 2008
A new study confirmed the value of real-time polymerase chain reaction (PCR) assay as a rapid method of screening for group B streptococci (GBS) colonization during parturition.1 Using real-time automated PCR assay, DNA amplification testing, and standard culture, Edwards and colleagues1 comparatively looked at the detection of GBS colonization in women who were in the 35th to 37th week of pregnancy and in women who were about to give birth. A true-positive result was defined as a positive molecular test and a positive culture finding. Compared with culture, the sensitivity rate of PCR was 91.1%, the specificity was 96.0%, the predictive value was 87.8%, the negative predictive value was 97.1%, and the accuracy was 94.8%. As anticipated, PCR assay was more sensitive than DNA amplification testing (91.1% vs 79.3%). Neither specificity, positive predictive value, nor detection of GBS prevalence was statistically divergent.