Comparison between Different Types of Surveillance Samples for the Detection of GBS Colonization in Both Parturient Mothers and Their Infants

Objective: To find the optimum screening method in detecting group B streptococcal (GBS) colonization in both mother and infant, and to identify the risk factors that influence GBS colonization in the infants. Patients and Methods: 1,120 singleton pregnant women were evaluated for GBS colonization by combined lower vaginal-anorectal swabs (LVRS) and urine tests, while their infants were evaluated for colonization with skin, ear and gastric aspirate samples. Results: LVRS swabs were positive in 14.2% of mothers while urine was positive in 7.6%. Among the infants skin, ear and gastric aspirate samples were positive in 7.0, 6.9 and 3.5%, respectively. Prolonged rupture of the membrane was the only significant factor associated with colonization in these infants (p < 0.001). Conclusions: Lower vaginal-anorectal swab is an effective method in detecting colonization in mothers especially when combined with urine culture. Skin or ear swabs are equally effective in detecting colonization in neonates. GBS colonization rate in our parturient and neonatal population is comparable to that was reported from other countries. A well-developed screening program and appropriate management strategies for both GBS colonized mothers and infants are recommended.