A multi-center study on realtime polymerase chain reaction assay for group B Streptococcus in pregnant ;women / 中华围产医学杂志

ABSTRACT

Objective To evaluate the accuracy of realtime polymerase chain reaction (PCR) assay in the detection of group B Streptococcus (GBS) in pregnant women. Methods Samples were collected from 1 395 women at 35-37 weeks of gestation from March 1 to December 31, 2009 at three hospitals in Beijing. Samples were obtained from the lower one third vaginal wall and perianal area and tested for GBS using standard culture and PCR. Standard culture and gene analysis for GBS were applied as the gold standard, and the sensitivity and specificity of the rapid assay were determined. Results Of the 1 395 women qualified for PCR testing, 40(2.9%) were identified as GBS positive on the basis of the results of specimen culture, compared to 114 (8.2%) on the basis of PCR assay. The culture was negative and the PCR positive in 77 patients. The results which were not in agreement using the two tests were evaluated by the gene analysis for GBS. Among the 77 samples which were GBS positive by PCR, 66 samples were determined as GBS positive by gene analysis. The sensitivity of the PCR assay was 97.2%(103/106) and specificity was 99.1%(1 278/1 289), the maternal GBS colonization was 7.6%(106/1 395). Conclusions Realtime PCR assay allows rapid and reliable detection of GBS in last trimester with high sensitivity and specificity.