Group B Strep (GBS) Infection

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Group B Streptococcus (GBS) Disease

Group B Streptococcal (GBS) disease is caused by Streptococcus agalactiae or group B Streptococcus bacteria.

These bacteria can be present in areas of the body such as mucous membranes (for example, in the throat or vagina) and skin. A streptococcal infection is considered to be invasive when the bacteria have entered a part of the body that is normally not exposed to bacteria such as blood, bone, or spinal fluid. 

For infected infants, the mother may pass the bacteria to the baby or the bacteria may come from another source. The source of infection for adults is unknown. Since group B strep is a common organism in the gastrointestinal tract of men and women, this may be a source of some adult infections.

According to the Centers for Disease Control and Prevention (CDC), GBS is the most common cause of sepsis (blood infection) and meningitis (infection of the fluid and lining around the brain) in newborns. GBS disease can occur in the first week of life ("early-onset disease") or one week to several months after birth ("late-onset disease"). The symptoms of group B strep disease can seem like other health problems in newborns and infants. Most newborns with early-onset disease have symptoms on the day of birth. Babies who develop late-onset disease may appear healthy at birth and develop symptoms of group B strep disease after the first week of life. Some symptoms that might be seen in an infant with GBS are fever, difficulty feeding, irritability, lethargy (limpness or hard to wake up the baby), difficulty breathing, and a blue-ish color to the skin. Some babies have complications from illness that include deafness, developmental disabilities, or death.

In adults, GBS disease is more common among older adults who have serious medical conditions such as diabetes mellitus or kidney, liver, or chronic heart disease. The most common problems caused by group B strep in adults are bloodstream infections, pneumonia (infection in the lungs), skin and soft-tissue infections, and bone and joint infections. Rarely in adults, group B strep can cause meningitis (infection of the fluid and lining surrounding the brain). Serious group B strep infections in adults can be fatal.


For women who are pregnant, the Centers for Disease Control and Prevention recommends a GBS screening between weeks 35 and 37 of pregnancy. To prevent GBS from spreading from a pregnant woman to her baby during labor, a mother can take an antibiotic when labor begins.

Antibiotic treatment during labor is also recommended if the mother:

  • Has a urinary tract infection
  • Delivered a previous baby with GBS disease
  • Develops a fever during labor
  • Has not delivered her baby within 18 hours of her water breaking
  • Goes into labor before 37 weeks and has not been tested for GBS 

Antibiotics usually are not needed if the mother has a C-section delivery.  

If a pregnant woman tests positive for GBS, she should remind her health care team during labor. Her reminders will help her health care team provide the best possible care during labor and delivery. GBS typically does not affect the length of time a mother and her baby spend in the hospital, and it does not affect the mother’s ability to breastfeed safely.  

Although it is not available yet, researchers are working on a GBS vaccine that could, in the future, help prevent GBS infections among adults.

School Exclusion Policy
Children with a fever should be kept out of school or childcare until they are fever free for 24 hours without the use of fever suppressing medications.  Rules for exclusion of sick children from school and childcare are outlined in the Texas Administrative Code, specifically Rule 97.7 for schools and Rule 746.3603 for childcare.

Recent Texas Trends
GBS is no longer a reportable condition in Texas. The number of invasive GBS cases reported in Texas has increased 457.8% over the past fifteen years, increasing from 464 (1.5 cases per 100,000 population) in 2005 to 2,124 (7.3 cases per 100,000 population) in 2019. Among the cases in 2019, 68.3% of the GBS cases in Texas occurred in adults aged 50 years or more. The highest age-specific incidence rates of invasive GBS in Texas are seen in children less than one year of age (52.6 cases per 100,000 population) followed by adults aged 60 years or more (19.5 cases per 100,000 population).

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