Group B Strep Disease in Adults

Rates of serious group B strep (GBS) infections are higher among newborns than among any other age group. However, serious GBS disease can occur in other age groups in both men and women.

Spread to Others

The sources of disease caused by GBS bacteria are unknown. GBS bacteria are common in the gastrointestinal tract of men and women. The gastrointestinal tract is the part of your body, including the stomach and intestines that digests food. Since the bacteria are so common, their presence in the gastrointestinal tract could be a source of some infections.

Types of Infection and Symptoms

Symptoms depend on the part of the body that is infected. Listed below are common diseases caused by GBS bacteria in adults and their symptoms.

Bacteremia (bloodstream infection) and sepsis (the body’s extreme response to an infection) symptoms include:

  • Fever
  • Chills
  • Low alertness

Pneumonia (lung infection) symptoms include:

  • Fever
  • Chills
  • Cough
  • Rapid breathing or difficulty breathing
  • Chest pain

Skin and soft-tissue infections often appear as a bump or infected area on the skin that may be:

  • Red
  • Swollen or painful
  • Warm to the touch
  • Full of pus or other drainage

People with skin infections may also have a fever.

Bone and joint infections often appear as pain in the infected area and might also include:

  • Fever
  • Chills
  • Swelling
  • Stiffness or inability to use affected limb or joint

GBS bacteria can cause meningitis in adults, but this is very uncommon. Meningitis is an infection of the tissue covering the brain and spinal cord.

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If doctors suspect an adult has a serious GBS infection, they will take samples of sterile body fluids. Examples of sterile body fluids are blood and spinal fluid. Doctors look to see if GBS bacteria grow from the samples (culture). It can take a few days to get these results since the bacteria need time to grow.

Sometimes GBS bacteria can cause urinary tract infections (UTIs or bladder infections). Doctors use a sample of urine to diagnose urinary tract infections.


Doctors usually treat GBS disease with penicillin or other common antibiotics. Sometimes people with soft tissue and bone infections may need additional treatment, such as surgery. Treatment will depend on the kind of infection caused by GBS bacteria. Patients should ask their doctor about specific treatment options.

Risk Factors

In adults, most cases of GBS disease are among those who have other medical conditions. Other medical conditions that put adults at increased risk include:

  • Diabetes
  • Heart disease
  • Congestive heart failure
  • Cancer or history of cancer
  • Obesity

Risk for serious GBS disease also increases as people get older. Adults 65 years and older are at increased risk compared to adults under 65 years old.


Serious GBS infections, such as bacteremia, sepsis, and pneumonia, can be deadly for adults. On average, about 1 in every 20 non-pregnant adults with serious GBS infections die. Risk of death is lower among younger adults and adults who do not have other medical conditions.

Disease Trends

The rate of serious group B strep disease among non-pregnant adults increases with age. The rate of invasive disease is about 10 cases out of every 100,000 non-pregnant adults. However, 25 out of every 100,000 adults 65 years or older will get group B strep disease each year.


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