Group B Streptococcus (GBS) in Adults: Commonly Asked Questions
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What is Group B Streptococcus (GBS)?
GBS is a bacteria that is found in the bowel, genital tract, urinary tract, throat, or respiratory tract of some adults. Many people carry GBS in their bodies but do not become ill.
GBS can cause mild disease in adults, such as urinary tract infections (bladder infections).
GBS can also cause serious infections in adults that include bloodstream infections, pneumonia (infection in the lung), skin and soft-tissue infections, and bone and joint
infections. Rarely in adults, GBS can cause meningitis (infection of the fluid and lining surrounding the brain).
Who is at highest risk for GBS disease?
Most GBS disease occurs in adults with serious medical conditions. These conditions include persons with diabetes, liver disease, and cancer. Others at risk include people with recent trauma and those having certain types of invasive surgical procedures.
How is GBS diagnosed?
GBS is diagnosed when the bacteria are grown from cultures of the blood, cerebral spinal fluid (CSF) or other normally sterile body site. Cultures take a few days to grow.
How is GBS treated?
GBS infections are usually treated with penicillin. Sometimes other types of antibiotics are used. Soft tissue and bone infections may require surgery to treat. Treatment often depends on where the bacteria in found in the body.
Is there a vaccine for GBS in adults?
Researchers are currently working on developing a vaccine against GBS.
If you have questions about GBS, please talk with your health care provider.
Last Updated: 10/20/2022
Group B Strep found in the urine does not always mean an infection is present, particularly when the level of the bacteria detected is low. Sometimes it is just that the urine has picked up some GBS from vaginal or rectal carriage on its way out of the body. If GBS is detected from a urine sample or from a vaginal or rectal swab at any level during pregnancy, you
should be offered intravenous antibiotics once labour has started. Treatment for GBS found in the urine during pregnancy depends on the level of GBS found and whether you have any symptoms. If you have symptoms of a urinary tract infection (for example, frequent or painful urination or fever) : If you do not have symptoms of a urinary tract infection :
- GBS in the urine ≥ 10^5 cfu/ml without Mum having symptoms of a urinary tract infection – this is treated with oral antibiotics. Mum should also be offered intravenous antibiotics when she goes into labour.
- GBS in the urine 10^4-10^5 cfu/ml with Mum having no symptoms of a urinary tract infection – the midstream stream urine test (preferably with labia separated) is usually repeated. If the same level of GBS is still present, then treatment will be considered. Mum should also be offered intravenous antibiotics when she goes into labour.
- GBS in the urine ≤ 10^3 cfu/ml or less with Mum having no symptoms of a urinary tract infection – this is considered to be contamination and no treatment is offered. Mum should be offered intravenous antibiotics when she goes into labour.
Treatment for a urine sample which detects the growth of GBS in the urine ≥10^5 cfu/ml, whether you have symptoms of a urine infection or not, is important since, if left untreated, such infections can cause kidney damage and have been linked to preterm labour.
When treatment is recommended for GBS bacteria in the urine during pregnancy, oral antibiotics are given, usually for 5 days. The urine should be retested 7-10 days after finishing the antibiotics and treatment repeated if necessary until the urine tests come back clear.
GBS detected from a urine sample or from a vaginal or rectal swab at any level during pregnancy means Mum should be offered intravenous antibiotics once labour has started.
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Group B Streptococcus in Pregnancy & Newborn Babies leaflet
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