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Bureau of Disease Control

Group B Streptococcal (GBS)

What Is Group B Streptococcus?

Group B streptococcus (GBS) is a type of bacterium that causes illness in newborn babies, pregnant women, the elderly, and adults with other illnesses, such as diabetes or liver disease. GBS is the most common cause of life-threatening infections in newborns. It is the most common cause of sepsis (blood infection) and meningitis (infection of the fluid and lining surrounding the brain) in newborns. GBS is a frequent cause of newborn pneumonia and is more common than other, better known, newborn problems such as rubella, congenital syphilis, and spina bifida. Before prevention methods were widely used, about 8,000 babies in the United States would get GBS disease each year. In the year 2001, there were about 1,700 babies in the U.S. less than one week old who got early-onset group B strep disease. One of every 20 babies with GBS disease dies from infection. Babies that survive, particularly those who have meningitis, may have long-term problems, such as hearing or vision loss or learning disabilities.

What are the symptoms?

Many people carry GBS in their bodies but do not become ill. These people are considered to be "carriers." People who carry GBS typically do so temporarily, they do not become lifelong carriers of the bacteria. Most pregnant women have no symptoms when they are carriers for group B strep bacteria. Sometimes, group B strep can cause bladder infections during pregnancy, or infections in the womb during labor or after delivery.

The symptoms for early-onset group B strep can seem like other problems in newborns. Some symptoms are fever, difficulty feeding, irritability, or lethargy (limpness or hard to wake up the baby). If you think your newborn is sick, get medical help right away. Three-fourths of the cases of GBS disease among newborns occur in the first week of life ("early-onset disease"), and most of these cases are apparent a few hours after birth. Sepsis, pneumonia, and meningitis are the most common problems.

How is Group B Streptococcus treated?

GBS infections are caused by bacteria. In both newborns and adults the infections are usually treated with antibiotics given through a vein.

How do people catch this disease?

The bacteria that cause group B strep disease normally live in the intestine, vagina, or rectal areas. Group B strep colonization is not a sexually transmitted disease (STD)..One of every four or five pregnant women carries GBS in the rectum or vagina. A fetus may come in contact with GBS before or during birth if the mother carries GBS in the rectum or vagina. Approximately one of every 100 to 200 babies whose mothers carry GBS develop signs and symptoms of GBS disease. Premature babies are more susceptible to GBS infection than full-term babies, but most (75%) babies who get GBS disease are full term.

Being a carrier (testing positive for group B strep, but having no symptoms) is quite common. Around 25% of women may carry the bacteria at any time. This doesn’t mean that they have group B strep disease, but it does mean that they are at higher risk for giving their baby a group B strep infection during birth.

What can be done to stop the spread of this disease?

GBS can be detected during pregnancy by taking a swab of both the vagina and rectum for a culture. Most GBS disease in newborns can be prevented by giving GBS infected pregnant women antibiotics through the vein during labor or membrane rupture. Any pregnant woman who previously had a baby with GBS disease or who has a urinary tract infection caused by GBS should receive antibiotics during labor.