Experience in the diagnosis of group B Streptococcus infections in pregnant women and newborns in a perinatal center

Abstract

Serogroup B streptococci (Streptococcus agalactiae) are one of the main etiological agents responsible for the occurrence of severe perinatal infections in both postpartum women and newborns. The experience of microbiological diagnostics of infections caused by streptococcus serogroup B (GBS) according to the data of the microbiological laboratory of the perinatal center is generalized. In the study of biomaterial from patients, the proportion of positive cultures of Streptococcus agalactiae was 2.2% in cervical samples, 8.8% in vaginal contents, 6.6%; 2.8% and 0.7% in amniotic fluid, placenta and urine, respectively. In 57% of cases, GBS was released at a concentration of more than 5 lg / ml and in 73% of cases as part of polymicrobial associations with other opportunistic microorganisms. In the biomaterial from newborns, GBS was found in 2.5% of positive findings in blood samples, 4.6% in tracheobronchial lavages and 2.7% in detachable skin of the armpit when taking material immediately after childbirth and 1, 1% and 0.7%, respectively, during examination in the second stage of nursing. 5 cases of GBS isolation in newborns ended in early neonatal mortality with definitive diagnoses of congenital pneumonia and IUI of newborns, while there was only partial coincidence of the results of microbiological studies of the genital tract of the mother and biomaterials from the newborn. Relatively frequent findings of GBS in newborns of the high-risk group in intensive care unit indicate intrauterine infection with this pathogen. The examination of smears from the cervical canal is not informative in relation toGBS infection in comparison with the examination of the vaginal contents and recto-vaginal smears. The results of the introduction of microbiological screening and its effectiveness in real practice to prevent the development of early and late forms of GBS infections in newborns require further analysis.