Group B Strep Infection

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What is group B strep?

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.


What are the symptoms of group B strep?

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:

  • Fever
  • Difficulty feeding
  • Lethargy (the baby is tired, hard to wake up, limp, or inactive)
  • Difficulty breathing (with severe breathing problems, the baby’s skin, lips, or nails may turn blue)

Diagnosis & Tests

How will I know I have group B strep?

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.


If I’m infected, what can I do?

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.

What if my baby has group B strep?

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.


What problems can group B strep cause?

In healthy adults, group B strep doesn’t usually cause any problems. Certain groups are more likely to have complications from group B strep:

  • Infants who have group B strep can develop an infection of the lungs (called pneumonia), bloodstream (called sepsis), or the fluid around the brain and spinal cord (called meningitis).
  • Some pregnant women who have group B strep may develop an infection of the urinary tract (also called a UTI), placenta, amniotic fluid, or bloodstream.
  • Older adults and people who have a chronic illness or a weak immune system are more likely to develop problems due to group B strep infection. These problems may include infections of the skin, bloodstream, urinary tract, lungs, bones and joints, heart valve (called endocarditis), or the fluid around the brain and spinal cord.

Questions to Ask Your Doctor

  • Is testing for group B strep infection a standard part of my prenatal care?
  • When should I schedule the test?
  • What do my test results mean?
  • If I have group B strep, how do we keep my baby from getting it too?
  • Will I need antibiotics? Are they safe for the baby?
  • Will I need a C-section, or can I still deliver my baby vaginally?