Screening for group B Streptococcus (GBS) at labour onset using PCR: accuracy and potential impact - a pilot study

Area of Science:

• Microbiology
• Clinical Diagnostics
• Obstetrics

Background:

• Group B Streptococcus (GBS) poses a risk of neonatal infection.
• Current GBS screening methods and intrapartum antibiotic prophylaxis (IAP) strategies have limitations in accurately identifying carriers during labor.
• Rapid diagnostics are needed for real-time GBS detection in laboring women.

Purpose of the Study:

• To evaluate the diagnostic accuracy of a rapid PCR test for GBS detection at labor onset.
• To assess the potential impact of this rapid test on optimizing IAP.
• To compare PCR results with conventional culture methods.

Main Methods:

• Pilot study involving 158 women at labor onset.
• Collection of vaginal and rectal swabs.
• Analysis using conventional broth-enriched culture and a rapid PCR test.

Main Results:

• GBS carriage rates were similar between PCR (19.62%) and culture (18.98%).
• PCR demonstrated high sensitivity (93.1%) and specificity (96.67%) for GBS detection.
• A significant proportion of GBS-positive mothers and their infants did not receive appropriate IAP or surveillance, respectively.

Conclusions:

• A rapid PCR test at labor onset is a sensitive and reliable tool for identifying GBS carriers.
• Universal GBS screening via PCR at labor onset can facilitate timely IAP for appropriate women.
• Implementation requires consideration of healthcare costs and laboratory workload.