Clinical Information

Streptococcus agalactiae (group B streptococcus) is a cause of morbidity and mortality among infants. Infections occurring within the first week of life are considered early-onset; those occurring in infants greater than 1 week of age are considered late-onset. Maternal vaginal or rectal colonization with S agalactiae is a risk factor for early-onset disease. 10-30% of pregnant women are vaginally or rectally colonized with S agalactiae and may transmit the organism to their infant during labor and delivery. The American College of Obstetricians and Gynecologists recommends screening for colonization with S agalactiae at 36 to 37 weeks' gestation as a guide for intrapartum antibiotic prophylaxis to decrease the risk of infection with Streptococcus agalactiae in the infant.  RX: Recommendations for intrapartum prophylaxis for group B streptococci are penicillin or ampicillin. Although cefazolin is recommended for penicillin -allergic women at low risk for anaphylaxis, those at high risk for anaphylaxis may receive clindamycin. Group B streptococci are susceptible to ampicillin, penicillin, and cefazolin, but may be resistant to clindamycin. When a group B streptococci is isolated from a pregnant woman with severe penicillin allergy (high risk for anaphylaxis), clindamycin (including ICR, inducible clindamycin resistance) should be tested and reported.