Topic Overview

What is group B streptococcal infection?

Group B
streptococcal (group B strep) infection is a serious bacterial infection that
is a leading cause of death and disability in newborns.

In the
1970s, about half of newborns with group B strep infection died. Today, due to
early recognition and aggressive treatment of the infection, far fewer cases
end in death.

What causes group B streptococcal infection?

B strep bacteria normally exist in the intestine, vagina, or rectum. A pregnant
woman can transmit the bacteria to her baby during delivery. Some women are
carriers of group B streptococcal bacteria, which means that they carry the
bacteria but have no illness from it. It is unclear why some babies get group B
strep infection and others do not.

Newborns may develop the
infection hours after birth or during the first week of life, or it may happen
several months later. Newborns who develop group B strep within the first week
are most always infected by their mothers. It’s not clear how babies who
develop the infection later are exposed to the bacteria.

What are the symptoms?

Symptoms of group B strep may include high or low body temperature,
irritability, low energy, raised respiratory rate, and trouble feeding. Newborns infected with
group B strep may get a blood infection (sepsis) or lung infection (pneumonia). An
infection of the fluid or tissues that surround the brain and spinal cord
(meningitis) can also occur. Newborns thought to be infected with group B strep need medical care right
away, as the infection can be deadly.

How is group B streptococcal infection diagnosed?

Pregnant women get tested for group B strep in the third trimester of
pregnancy. Babies suspected of being infected are
diagnosed at birth by testing their blood or spinal fluid or both for group B
strep bacteria.

How is it treated?

Pregnant women who have group B
strep infection or who are carriers of
group B strep will be given
antibiotics prior to delivery to prevent transmission
of the bacteria to the newborn during delivery. If a woman is pregnant and has previously given birth to a child with group B strep infection or has had tests that show she carries the bacteria, she should be treated with

Newborns with the infection will also be given
antibiotics. In addition to antibiotics, supportive care including fluids and
ventilation will be given if needed. In some cases, a doctor will treat a
newborn that is suspected of having group B strep infection before test results
have shown infection. This is because not treating strep B infection in
newborns can result in illness or death.

Having a baby by
cesarean section does not prevent the transmission of
group B strep bacteria.

Other Places To Get Help


Centers for Disease Control and Prevention (U.S.)

National Institute of Allergy and Infectious Diseases (U.S.)


Other Works Consulted

  • American Academy of Pediatrics (2012). Group B streptococcal infections. In LK Pickering et al., eds., Red Book: 2012 Report of the Committee on Infectious Diseases, 29th ed., pp. 680-685. Elk Grove Village, IL: American Academy of Pediatrics.
  • American College of Obstetricians and Gynecologists (2011). Prevention of early onset group B streptococcal disease in newborns. ACOG Committee Opinion No. 485. Obstetrics and Gynecology, 117(4): 1019-1027.
  • Verani JR, et al. (2010). Prevention of perinatal group B streptococcal disease: Revised guidelines from CDC, 2010. MMWR, 59(RR-10): 1-36. Also available online:


ByHealthwise Staff
Primary Medical Reviewer Susan C. Kim, MD – Pediatrics
Specialist Medical Reviewer John Pope, MD – Pediatrics

Current as ofMay 4, 2017

Current as of:
May 4, 2017