EVALUATION OF GENOMERA GBS (ABACUS) ASSAY FOR DETECTION OF GROUP B STREPTOCOCCI (GBS), AFTER 4 H OF ENRICHMENT CULTURE, IN INTRAPARTUM VAGINAL SCREENING

Background: Neonatal infection with GBS is a leading case of sepsis and meningitides in newborns. Intrapartum antibiotic treatment, based on positive GBS screening bacteriological culture results, is effective in prevention of neonatal infection. However in cases of no preknowledge about GBS colonization, lack of risk based data, or intrapartum alarm situation, an immediate guidance is needed for antimicrobial prophylaxis. In Israel, GBS screening is performed at 35-37 weeks of gestation, only in pregnant women with defined risk factors. Vaginal cultures are still a gold standard method for GBS screening, but with one great disadvantage-the final results are obtained only after 48 h. Rapid molecular methods for detection of GBS became available, making intrapartum screening possible. The aim of our study was to evaluate a new molecular Genomera assay for identification of GBS in 4 h enrichment vaginal specimens, obtained intrapartum. Method: We conducted a prospective study in which women with risk factors, giving birth at the maternity ward, were screened for GBS. The culture (the reference method) and molecular GBS assay (after 4 h enrichment culture) were performed on intrapartum specimens. Results: Performing the assay on 177 vaginal enriched samples yielded 97.7% specifity, 98.1% sensitivity 94.4% PPV, 99.2% NPV. Conclusions: The new method has an excellent potential, at point of care, to enhance the exact identification of candidates for intrapartum antibiotic prophylaxis including women with preterm rapture of membranes or preterm labor.