Group B strep (GBS) bacteria commonly live in people’s bodies and usually are not harmful. Babies can be exposed to GBS bacteria during delivery. How other people are exposed to these bacteria is not completely known.
Bacteria called group B Streptococcus (group B strep, GBS) cause GBS disease. GBS bacteria commonly live in people’s gastrointestinal and genital tracts. The gastrointestinal tract is the part of the body that digests food and includes the stomach and intestines. The genital tract is the part of the body involved in reproduction and includes the vagina in women.
Most of the time the bacteria are not harmful and do not make people feel sick or have any symptoms. Sometimes the bacteria invade the body and cause certain infections, which are known as GBS disease.
How it spreads
How people spread GBS bacteria to others is generally unknown. However, experts know that pregnant women can pass the bacteria to their babies during delivery. Most babies who get GBS disease in the first week of life are exposed to the bacteria this way. It can be hard to figure out how babies who develop GBS disease later got the bacteria. The bacteria may have come from the mother during birth or from another source. Other people who live with someone who has GBS bacteria, including other children, are not at increased risk of getting sick.
In the United States, there’s no evidence that GBS bacteria spread through food, water, or anything that people might have come into contact with.
Fast Facts: Group B Strep: Fast Facts and Statistics | CDC
Rates of serious group B strep (GBS) infections are higher among newborns, but anyone can get GBS disease. Below are some other important facts about GBS disease in babies, pregnant women, and others.
GBS disease can be very serious, especially for babies.
In the United States, GBS bacteria are a leading cause of meningitis and bloodstream infections in a newborn’s first three months of life.
Newborns are at increased risk for GBS disease if their mother tests positive for the bacteria late in pregnancy.
2 to 3 in every 50 babies (4–6%) who develop GBS disease die.
Pregnant women should get tested for GBS bacteria.
About 1 in 4 pregnant women carries GBS bacteria in their body.
Doctors and midwives should test pregnant women for GBS bacteria when they are 36 through 37 weeks pregnant.
Giving pregnant women who carry GBS bacteria antibiotics through the vein (IV) during labor can prevent most cases of GBS disease in newborns during the first week of life.
Non-pregnant adults can get serious GBS disease.
The most common GBS infections among non-pregnant adults include bloodstream infections, pneumonia, and skin and bone infections.
The rate of serious GBS disease increases with age.
On average, about 1 in 20 non-pregnant adults with serious GBS infections dies.