Screening of Group B Streptococcus in pregnancy: A systematic review for the laboratory detection.

Abstract

Background: Group B Streptococcus (GBS) is important since almost 1/3 of pregnant women are colonized with GBS, and as much as 50% passes to the newborns, sometimes resulting in severe neonatal infections; that is why there are mandatory guidelines for antepartum screening for GBS vaginal/rectal colonization. Also, bacteria other than GBS and yeasts may affect newborns; therefore, an increase in the current knowledge and improving the guidelines related to the prediction and prevention of neonatal early-onset infections are needed.

Methods: A systematic review was performed to investigate risks, types of specimens, sampling methods, media for GBS recovery, identification tests, gestation week for testing, GBS prevalence, sensitivity, specificity, turnover time for cultures, antigen, and molecular-based tests. A literature search was conducted through the Web of Science, Scopus, and PubMed.

Results: A total of 20 studies were identified with 10,288 patients and 1,334 GBS positive (13%). Eight studies were performed in adequate gestation week and revealed prevalence from 0.2 to 20.8% (conventional tests) and 37 to 45% (molecular tests). In only three studies, vaginal/rectal swab recommended by guidelines was applied.

Conclusions: The heterogeneity of the detection and identification of GBS reduces the scientific and clinical utility of laboratory-based data, and universal antepartum screening with affordable, high-sensitivity traditional tests is needed.