Rapid tests for group B Streptococcus colonization in laboring women: a systematic review

We set out to determine the accuracy and rapidity of various intrapartum group B Streptococcus (GBS) colonization tests.

We performed a systematic review of test-accuracy studies, which were identified without language restriction from Medline and Cochrane databases; bibliographies of known primary and review articles; and contact with authors, experts, and manufacturers. Studies were selected if they tested pregnant women intrapartum for GBS colonization and confirmed by "gold-standard" laboratory cultures. Two reviewers independently selected studies and extracted data on their characteristics, quality, and results. Accuracy data were used to form 2 x 2 contingency tables. Heterogeneity was assessed, and LRs for positive and negative test results were pooled in subgroups of studies of various tests.

There were 29 test-accuracy studies in 15,691 women, evaluating 6 different tests: polymerase chain reaction (PCR), optical immunoassay (OIA), DNA hybridization, enzyme immunoassay, latex agglutination, and Islam starch medium tests. The methodologic quality of the studies was generally poor. The most accurate was the real-time PCR test, but it was less rapid than OIA test. Real-time PCR took 40 minutes to complete, whereas the OIA took 30 minutes.

Real-time PCR and OIA are candidates for rapid near patient intrapartum GBS testing to determine the need for antibiotic prophylaxis to prevent neonatal GBS disease. Before implementation in practice, a robust technology assessment of their accuracy, acceptability, and cost-effectiveness is required.