Abstract |
Background: Group B streptococcus (GBS) is an opportunistic commensal, part of the
intestinal and vaginal physiologic flora, that converts to a major bacterial pathogen
causing invasive infections. Since 1970s GBS has been a leading cause of serious
neonatal infections, while maternal colonization seems to be the main risk factor for early
GBS neonatal disease. The American College of Obstetricians and Gynecologists now
recommends performing universal GBS screening between 36+0 and 37+6 weeks of
gestation. All women whose vaginal–rectal cultures are positive for GBS should receive
appropriate intrapartum antibiotic prophylaxis, unless a prelabor cesarean birth is
performed in the setting of intact membranes. Antibiotic prophylaxis should receive, as
well, those with GBS bacteriuria, gestational age less than 37 weeks, prolonged rupture
of membranes or a previous newborn affected by GBS early disease. GBS rates and
prevention strategies vary considerably worldwide and data in Greece are scarce. The aim
of this study was to determine GBS colonization rate and estimate the effectiveness of
prevention strategies in our region.
Methods: All pregnant women and newborns in Crete’s two major hospitals from
1/1/2015 to 31/12/2019 were retrospectively included in the study. GBS colonization by
vaginal cultures was evaluated and potential risk factors (age, nationality, residence
area, multiparity, comorbidities, visits, gestational age when culture performed, mode of
delivery) were recorded. The rates of antibiotic prophylaxis and neonatal disease were,
also, assessed.
Results: A total of 7,362 pregnant women was reviewed, 4,984 (67.7%) underwent
screening and 83 (1.7%) were colonized by GBS. Most of GBS(+) women (34.9%)
were 31-35 years old, 45.8% were examined early in gestation (<35th week) and only
9.6% appeared to have comorbidities (diabetes, hypertension). Multiparity (³2) was associated with colonization in 66.3%, whereas other factors were not determinant. All
GBS(+) women were given peripartum prophylaxis and none of their newborns
developed disease. Nevertheless, from the rest of hospitalized neonatal population, 3
developed early and 1 late-onset disease.
Conclusions: GBS colonization in our area is among the lowest reported. Peripartum
antibiotic prophylaxis seems to sufficiently prevent transmission, but there is still
morbidity. Thus, not only better compliance to recommendations, but also more
effective prevention strategies, including maternal vaccination, are needed.
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