Introduction
Maternal group B streptococcal (GBS) colonization is one of the most
important risk factors for GBS disease in neonates. In 2002, the Centers
for Disease Control (CDC) recommended universal culture-based screening
of all pregnant women between 35-37 weeks gestation in order to treat
all those positive for GBS with intrapartum antibiotics prior to
delivery to prevent against early onset neonatal GBS sepsis.1 Ever since the institution of this policy, the
incidence of early onset GBS sepsis has continued to fall dramatically
from a rate of 1.5/1,000 to a rate of 0.24/1,000 live
births.2
However, the prevalence of maternal GBS colonization among the
population in this region has not been recently explored. The
colonization rate varies from country to country, the geographic
location, and the method used in determining the colonization. In the
USA, carriage rates in the 70’s and 80’s ranged from 20% to
35%.3-5 In Africa, rates ranged from 20% to
30%.6-8 In Eastern Europe rates of 30+% have also
been determined.9 In Western Europe rates ranged from
a low of 14% to a high of 36%.5,10 In India the
rates were as low as 15%,11 while in Korea, the rate
was as low as 8%.12 In Australia, rates as high as
35% have been demonstrated.13 In summary, rates of
GBS colonization have remained remarkably stable over the past 40 years.
Potential sociodemographic risk factors for GBS colonization among
pregnant women have not been recently explored. Perusal of the
literature within the last 2 decades demonstrates a paucity of
information on other potential sociodemographic risk factors associated
with maternal GBS colonization during pregnancy. One risk factor of GBS
colonization of mothers of term or near term neonates not yet adequately
explored is tobacco smoke exposure during pregnancy. Tobacco smoke has
been shown to be associated with increased colonization of the
respiratory, gastrointestinal, and even genital tract with various
bacterial pathogens.14-21Because over 10% of women in
the United States smoke during pregnancy, 22 it is
important to determine whether smoking is a risk factor for GBS
colonization. We therefore hypothesized that tobacco smoking during
pregnancy is independently associated with increased GBS colonization
among women delivering term or near term neonates in this tertiary care
hospital in Virginia.