Affiliations: Department of Newborn Services, The George Washington
University Medical Center, Washington, DC, USA | Department of Pathology, The George Washington
University Medical Center, Washington, DC, USA
Abstract: Early-onset group B streptococcus (GBS) is transmitted vertically
from the birth canal of colonized mothers. The mode of transmission of
late-onset GBS is less clear, although it is believed to reflect a delayed
infection after early colonization from either vertical or horizontal
transmission. We present a premature female infant whose mother was GBS
negative at the time of delivery but later had GBS bacteriuria in postpartum.
The infant had an initial blood culture and multiple weekly nasal surveillance
cultures that were all negative for GBS. The infant's nasal culture grew GBS
after 25 days, 1 day after she had signs of sepsis and her blood grew GBS. This
is the first case in preterm infants to demonstrate the horizontal transmission
of late-onset GBS bacteremia without the need for early-onset colonization.