Group B streptococcus, or group B strep for short, is a certain kind of bacteria (germ) that lives in the intestine, rectum, and vagina (in women). Group B strep doesn’t usually cause problems in healthy adults. Most of the people who get sick from group B strep are newborns who are exposed to the bacteria during birth.
About 25% of healthy pregnant women have group B strep. A woman who has group B strep is said to be "colonized" with this germ. If you are colonized with group B strep, your baby can become infected with these germs while being born and can get sick. There is less than a 1% chance that this will happen, but because group B strep infection is so dangerous for babies, it's important to find out if you're colonized while you're pregnant.
Group B strep doesn’t usually cause symptoms in healthy adults.
Babies who have group B strep may develop symptoms during their first week of life (this is called early-onset disease) or from 1 week to 3 months of life (this is called late-onset disease). The symptoms of group B strep in newborns may include the following:
If you’re pregnant, your doctor can do a test to see if you are “group B strep positive”. This test usually is done when you are 35 to 37 weeks pregnant. To perform the test, your doctor will swab your vagina and your rectum and will send the swabs to a lab to see if the strep bacteria grow. If you have group B strep, it’s important to understand that you aren’t sick and that you probably will not make your baby sick. Knowing that you carry the bacteria just helps you and your doctor make decisions that can protect your baby from infection.
Your doctor may have you take antibiotic pills during pregnancy until you give birth. Then, when you're in labor, you can also take antibiotics intravenously (through an IV) to kill the germs. If you take antibiotics while you're in labor, the chances are very good that your baby won't get this infection.
If your baby gets group B strep, he or she will be treated with IV antibiotics to kill the bacteria. Your baby will stay in the hospital until your doctor is sure your baby is better.
In healthy adults, group B strep doesn’t usually cause any problems. Certain groups are more likely to have complications from group B strep:
Written by familydoctor.org editorial staff