Carrying group B Strep
Group B Streptococcus (GBS, group B Strep or Strep B) is a normal bacterium that 20 to 40% of UK adults carry, most commonly in the gut and in the vagina. Carrying group B Strep doesn’t cause any symptoms or side effects.
Carrying GBS bacteria is perfectly normal and natural, whether you are pregnant or not. Carrying GBS does not need treatment. The fact you carry GBS does not mean you have a sexually transmitted disease – carrying GBS is not a disease at all.
A positive test result for GBS means the person was carrying GBS at the time the samples were taken – not that they are ill.
How is group B Strep spread?
Group B Strep is not a sexually transmitted disease.
Like many bacteria, GBS may be passed from one person to another through direct contact, for example, hand-holding, kissing, close physical contact, etc. As GBS bacteria are often found in the vagina and rectum, they can also be passed on during sex.
Around 20 to 40% of adults carry GBS.
How would I know if I had group B Strep?
Most people carrying GBS have no symptoms, so GBS is often found by chance, through a vaginal or rectal swab or a urine test for another reason. Carrying GBS is normal and doesn’t require treatment, so there is no reason for most people to have a test to find out if they carry GBS.
Pregnant women and people may be tested to find out if they carry the GBS bacteria, as GBS can sometimes cause serious problems in new born babies. So it can be useful to know whether you carry GBS if you are pregnant.
To find out whether you carry GBS bacteria, you would need to have a test, which involves taking a swab sample from the vagina and rectum (back passage). Culturing the material from the swab using sensitive ECM (‘enriched culture medium’) is the ‘gold standard’ test for determining whether you carry GBS – find out more about how to get a GBS test.
Does group B Strep cause any vaginal symptoms?
We know of no good evidence that carrying GBS causes vaginal symptoms.
Even when GBS bacteria are grown from a sample taken from the vagina, this only means that GBS bacteria were present in the vagina when the swab was taken. It does not mean that GBS is the cause of any symptoms that prompted the test being done.
Group B Strep in the urine (UTI)
GBS detected in the urine usually means a GBS urinary tract infection (UTI) is present. This should be treated like other UTIs: with oral antibiotics until urine tests come back clear.
Group B Strep infection in adults
While carrying group B Strep doesn’t cause any harm for most people, it can sometimes cause infections in adults.
When GBS infection occurs in adults, it’s usually (but not always) in those with serious underlying medical conditions which reduce the effectiveness of their immune system and so make them more susceptible to all kinds of infections, including GBS. Infections sometimes also occur in the elderly and in pregnant women.
The severity of GBS infections in adults can vary, from easily treated to very serious, particularly in non-pregnant adults.
GBS infections in adults come in many different forms:
- skin and soft tissue infections (such as infection of skin ulcers caused by poor circulation and diabetes, or pressure sores in patients confined to bed);
- sepsis (blood infection);
- pneumonia (lung infections);
- urinary tract infections (such as kidney or bladder infections).
Rarer GBS infections in adults include:
- meningitis (infection of the membranes that surround the brain and spinal cord);
- bone infections (typically septic arthritis or osteomyelitis);
- deep eye infections
In 2021, GBS was detected in the blood of about 1 in 28,000 people (3.6 per 100,000) in England. Among adults, infection rates were highest in those aged 75 and over: 13.2 per 100,000 in males and 9.9 per 100,000 in females.
Treating GBS infection in adults
No treatment is needed for people who are found to be carriers of GBS. Those with GBS infections in the urine (UTI) will need to take oral antibiotics.
For adults who have GBS infections elsewhere in the body, early diagnosis and treatment are crucial to provide the best chance of a full recovery.
Most GBS infections can be treated successfully, usually with high doses of antibiotics such as penicillin. However, some people will require treatment in intensive care facilities. Not all hospitals have such a facility, so some patients will need to be transferred to another hospital.
GBS infections, especially the more serious ones, require expert care, prolonged courses of antibiotics, and sometimes more than one antibiotic at the same time. In some cases, surgery may be needed to drain infected sites and remove damaged tissue. Due to the varied nature of these infections, it is impossible to generalise about the most appropriate treatment.
If you have any questions about Group B Strep, please call our helpline
Mon-Fri 9am-5pm
0330 120 0796
Or email us at info@gbss.org.uk
