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Group B Strep Infection in Adults

While the rates of serious group B strep infections are higher among newborns than among any other age group, serious group B strep disease can occur in other age groups in both men and women.

Spread to Others

The sources of disease caused by group B strep bacteria are unknown. Group B strep bacteria are common in the gastrointestinal tract (the part of your body that digests food, including the stomach and intestines) of men and women and may be a source of some infection.

Types of Infection and Symptoms

Symptoms depend on the part of the body that is infected. Below are common diseases caused by group B strep bacteria in adults and their symptoms.

Bacteremia and sepsis (blood infections) symptoms include:

  • Fever
  • Chills
  • Low alertness

Pneumonia (lung infection) symptoms include:

  • Fever and 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

These skin infections may also be accompanied by a fever.

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

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

Rarely in adults, group B strep bacteria can cause meningitis (infection of the fluid and lining surrounding the brain and spinal cord).

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If doctors suspect an adult has an invasive group B strep infection (infections where the bacteria have entered a part of the body that is normally not exposed to bacteria), they will take a sample of sterile body fluids, such as blood or spinal fluid. These samples are cultured (bacteria grown in the laboratory) to see if group B strep bacteria are present, which can take a few days. Sometimes group B strep bacteria can cause urinary tract infections (UTIs, also called bladder infections), which also can be diagnosed in the lab with a sample of urine.


Group B strep disease is usually treated with penicillin or other common antibiotics (medicine that kills bacteria in the body). Sometimes soft tissue and bone infections may need additional treatment, such as surgery. Treatment will depend on the kind of infection caused by group B strep bacteria. Patients should ask their doctor about specific treatment options.

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Risk Factors

Most cases of group B strep disease in adults are among those who have other medical conditions that put them at increased risk, such as:

  • Diabetes mellitus
  • Cardiovascular disease
  • Congestive heart failure
  • History of cancer
  • Obesity


Serious group B strep infections, such as sepsis (infection of the blood) and pneumonia (infection of the lungs) in adults can be fatal. On average1 out of every 20 (5%) non-pregnant adults with invasive group B strep 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.


  • Skoff TH, Farley MM, Petit S, et al. Increasing burden of invasive group B streptococcal disease in non-pregnant adults, 1990-2007. Clin Infect Dis. 2009;49:85–92.
  • Farley, M M. Group B streptococcal disease in nonpregnant adults. Clin Infect Dis. 2001;33:556–61.
  • Jackson LA, Hilsdon R, Farley MM et al. Risk factors for group B streptococcal disease in adults. Ann Intern Med. 1995;B123:415–20.

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