Background: The carrier rate of group B Streptococcus (GBS) in the genital tract of women in the late stage of pregnancy and its correlation with the genital tract microenvironment were investigated in a group of pregnant women in Dongguan, China, to provide a basis for the clinical prevention and treatment of GBS.
Methods: A retrospective analysis was done of the results of routine testing for GBS, leucorrhea and bacterial vaginosis (BV) in 6,166 women in the late stage of pregnancy (35 - 37 weeks of gestation) who underwent a prenatal examination at Dongguan Southeast Central Hospital from January 2018 to December 2020. GBS positivity was detected by RT-PCR. Normal saline floating microscopy was used to detect routine indicators of leucorrhea, including white blood cells (WBCs), Lactobacillus (Lab), vulvovaginal Candida (VVC), and trichomoniasis (TV). BV was detected based on an enzymatic reaction. The correlation between GBS infection and age and the vaginal microenvironment was determined statistically.
Results: The rate of GBS positivity was 10.53% (649/6,166) and was statistically significant for women 20 years of age (p < 0.05). Logistic regression showed that abnormal VVC, TV, BV, WBCs, and Lactobacillus were associated with GBS infection. The results of a rank sum test of the WBC group showed that the infection risk in groups with < 15 WBCs/hpf increased as the WBC count increased, but there was no statistical difference between groups with > 15 WBCs/hpf. The rank sum test results for Lactobacillus showed a significant difference between the abnormal and normal and other groups, but no significant difference between the other groups.
Conclusions: The overall carrier rate of GBS in the genital tract of late-stage pregnant women in Dongguan was 10.53%. GBS infection is related to the genital tract microenvironment. Our results provide a basis for the prevention and treatment of clinically confirmed GBS.