Definition of Streptococcus, group B
Streptococcus, group B: A major cause of infections, including those involving pregnant women and newborn infants. Group B strep can infect the mother's uterus, placenta, and urinary tract; in fact, it is present in the vagina of around 10 to 25 percent of all pregnant women. Group B strep can be transferred between heterosexual couples via oral sex. Infants develop the infection in utero or at the time of delivery from women who have vaginal group B strep. Of infants who acquire the infection, about 1-2% develop the clinical disease. Neonatal sepsis from group B streptococci is more common in premature infants and in the setting of prolonged rupture of the membranes. Infections in the infant can be localized, or it may involve the entire body. In babies, strep infections are divided into early-onset and late-onset disease. Early-onset disease presents within the first 6 days of life, with breathing difficulty, shock, pneumonia, and occasionally infection of the spinal fluid and brain (meningitis). Late-onset disease presents between the seventh day and the third month of age, with a bloodstream infection (bacteremia) or meningitis. The bacteria can also infect an area of bone; a joint, such as the knee or hip; or the skin. Group B strep infection in a newborn is a serious and potentially life-threatening event, particularly because fever and warning signs are often minimal or absent and because the
newborn's immune system is not mature. Early signs of infection can be as subtle as poor feeding, lethargy, and poor temperature control. Antibiotic treatment can be considered for culture-positive women before delivery. Group B strep infection of the newborn is treated aggressively with antibiotics, usually in a neonatal intensive care unit, but the disease still carries a significant mortality rate. Prevention and early detection are critically important.
Last Editorial Review: 3/19/2012