A study on early-onset neonatal group B streptococcal infection, Bulgaria, 2007-2011

[Group B streptococcus colonization in pregnant women and group B streptococcus infection in their preterm infants]

OBJECTIVE

To study the incidences of group B streptococcus (GBS) colonization in pregnant women and GBS infection in their preterm infants, and to investigate the risk factors for GBS colonization in preterm infants.

METHODS

A total of 859 women who delivered before term from January 2017 to January 2018 were enrolled in this prospective cohort study. Bacterial culture was performed for GBS using the swabs collected from the rectum and the lower 1/3 of the vagina of the pregnant women on admission. A total of 515 of the above cases underwent real-time PCR assay for testing of GBS DNA. Bacterial culture was performed for GBS using the oropharyngeal secretion, gastric fluid or blood samples in preterm infants born to the 859 pregnant women. Peripheral blood samples from the pregnant women and umbilical cord blood samples from their preterm infants were collected to determine the level of anti-GBS capsular polysaccharide antibody. The incidence of GBS infection and perinatal risk factors for GBS colonization in the preterm infants were examined.

RESULTS

The positive rate for GBS in the rectal and vaginal cultures was 14.8% (127/859) among the 859 pregnant women, and the positive rate in the GBS DNA testing was 15.1% (78/515). There were 976 live-birth preterm infants delivered by 859 pregnant women, and 4.4% (43/976) of whom were GBS positive. Four preterm infants had early-onset GBS diseases, including pneumonia in two cases and sepsis in two cases. In 127 preterm infants delivered by 127 GBS-positive pregnant women, the preterm infant group with a gestational age between 34 and 37 weeks had a significantly lower GBS positive rate and a significantly higher level of anti-GBS capsular polysaccharide antibody compared with the preterm infant group with a gestational age of less than 34 weeks (P=0.013 and 0.001 respectively). A multivariate logistic regression analysis revealed that premature rupture of membranes time >18 hours and chorioamnionitis were independent risk factors for GBS colonization in preterm infants (OR=6.556 and 6.160 respectively; P<0.05).

CONCLUSIONS

GBS positive rate and anti-GBS capsular polysaccharide antibody level in preterm infants are correlated with gestational age. premature rupture of membranes time >18 hours and chorioamnionitis may increase the risk of GBS colonization in preterm infants.

Late Onset Streptococcus agalactiae Meningitis following Early Onset Septicemia: A Preventable Disease?

We report a neonate who presented with early onset Streptococcus agalactiae or group B streptococcus (GBS) septicemia within 24 hours of birth. After discharge at day 14, she went on to develop late onset GBS meningitis at 36 days of age. The infant was treated with intravenous antibiotics on both occasions and eventually discharged home with no apparent sequelae. We address issues associated with GBS infection in infancy including the demographics, risk factors, and the risk of late onset GBS meningitis following an early onset GBS infection. The major source of GBS in early onset GBS disease is maternal birth canal GBS colonization. On the other hand, nosocomial cross-infection is an important source of GBS in late onset disease. Penicillin remains the current treatment of choice for GBS infection. Given the rapid onset and progression within hours of birth and lack of an effective solution for preventing late onset GBS, administration of an effective GBS vaccine in pregnancy could provide a sensible and cost-effective solution in all settings.

Group B streptococcal immunisation of pregnant women for the prevention of early and late onset Group B streptococcal infection of the neonate as well as adult disease

INTRODUCTION

Early onset neonatal Group B streptococcal disease is preventable. Intrapartum antibiotic prophylaxis has resulted in a significant reduction in neonatal mortality and morbidity. National guidelines for the selection of women eligible for intrapartum antibiotic prophylaxis, whether screening-based or risk-based, differ according to the local burden of disease. Despite the introduction of intrapartum antibiotic prophylaxis, there remains a significant burden of disease, which can be resolved by better adherence to guidelines, rapid identification of maternal colonization or in the future, vaccination. Areas covered: The introduction of a vaccine to women in the third trimester is likely to further reduce the burden of disease and provide benefits beyond the prevention of early neonatal disease, including meningitis and disability following late onset disease. Development of specific polyvalent vaccines continues, but testing has challenges and may require surrogate markers or molecular-based techniques to manipulate antigenicity and immunogenicity. Expert commentary: Group B streptococcal vaccination using conjugated polyvalent vaccines against the major disease causing serotypes of Group B streptococcus, either alone, or in combination with a policy of intrapartum antibiotic prophylaxis, may decrease the burden of Group B streptococcus beyond that achieved by current use of intrapartum antibiotic prophylaxis alone.