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Group B Strep (GBS): When Harmless Bacteria Turn Bad

Medically reviewed by Carmen Fookes, BPharm. Last updated on Feb 7, 2022.

We Are A Petri Dish: Bacterial Cells Outnumber Human Cells

Regardless of whether or not you are a hand-washing fanatic or refuse to touch unclean surfaces, we humans are a reservoir of bacteria. Scientists have calculated that bacterial cells outnumber human cells by about 10 to one. Even our navel is home to over 1400 different bacterial species. Ewwww!!!

Luckily, we have a win-win existence with bacteria...most of the time. But there are some types of bacteria that occasionally cause trouble. Group B streptococcal (GBS) are one of these GOOD/BAD bacterial types. And when they cause trouble, it can be very serious.

Small, Usually Well-Behaved, Can Occasionally Turn Nasty

All bacteria are small, and GBS are no exception. About a tenth of the width of a strand of a spider's web, these microbes require a microscope to be seen. That is, if you can find them. They love warm, airless, cavities in our body, such as our bowel, intestines, or genital tract.

Scientists don't know why some people carry GBS and other's don't. If you test positive for the bacteria, you are said to be colonized. But colonization doesn't always equate to infection, and MOST people with GBS have no problems whatsoever.

Should I Panic? What Should I Do?

If you are healthy, then there is nothing you need to do about GBS.
However, it is a different story if you are pregnant. An estimated 25% of all pregnant women carry GBS and a screening test during week 35 to 37 of pregnancy is the only way to confirm that you are a carrier. If you come back positive, you and your baby can be protected with antibiotic treatment.

GBS can also cause dangerous infections in adults with certain chronic medical conditions such as diabetes or liver disease. Seniors are also at an increased risk of illness due to GBS.

Serious Infections And Fatalities Reported During Pregnancy

Infections of the urinary tract, placenta, womb, and amniotic fluid caused by GBS can occur in pregnant women.

Most pregnant women who carry group B streptococcus (GBS) bacteria have healthy babies, but uncommonly, some newborns develop serious or life-threatening blood infections (sepsis), brain infections (meningitis), or lung infections (such as pneumonia). Extremely rarely, GBS infection during pregnancy can also cause miscarriage, early (premature) labor, or stillbirth.

Some babies who have survived GBS have been left blind, deaf, mentally impaired, or with cerebral palsy. Babies are still susceptible to GBS infection up until about 6 months of age due to their underdeveloped immune systems.

Prevention Is Easy, So Why Take The Risk?

Although only one out of every 100-200 babies born to a GBS-infected mother go on to develop GBS infection themselves, prevention of infection is easy.

All pregnant women in the U.S. are routinely screened for GBS infection between 35-37 weeks gestation with a simple swab test. Since babies are most often infected with GBS as they pass through the birth canal, women who test positive will be given 4 hours of intravenous (IV) antibiotics (usually penicillin) when labor starts or if their waters break. Some women may receive an earlier course of antibiotics if bladder or vaginal infections show the presence of GBS.

After Your Baby Is Born Watch For GBS Signs

Symptoms of GBS infection may not develop in your baby until after delivery. Get immediate medical care if your baby:

  • Has a high-pitched cry
  • Feeds poorly
  • Is irritable, inconsolable
  • Constantly grunts, as if constipated
  • Projectile vomits
  • Has a fever
  • Has red, blue, or gray skin
  • Has difficulty breathing
  • Jerks uncontrollably
  • Has a bulgy fontanelle
  • Develops an umbilical cord infection or a scalp infection from the fetal monitor.

What You Can Do

Most pregnant women who have GBS have no symptoms, which is why screening is so important. But if you do have any vaginal burning, irritation or unusual discharge see your health care provider promptly for an exam and possible GBS testing.

GBS can also cause bladder infections, with or without symptoms. At your first prenatal visit, your provider should do a urine culture for GBS and other bacteria.

Once your baby is born, monitor for symptoms of GBS infection and insist that EVERYBODY washes their hands before handling your precious little one.

Other GBS infections

Although newborns are far more likely than any other age group to suffer from serious GBS infections, infection can still occur in other age groups.

Most adult GBS infections occur in those with other medical conditions, such as diabetes, heart disease, heart failure, cancer, or in those who are obese.

GBS infections in adults can cause:

Antibiotics Treat Adult GBS Infection

Penicillin, or similar antibiotics, are usually used to treat GBS infections. Serious infections may need intravenous antibiotics (for example, Bicillin L-A) and treatment may go on for several weeks. Sometimes soft tissue and bone infections are managed with surgery, as well.

Antibiotics cure most people of GBS infections; however, approximately 4% experience a recurrence of the infection within a year. Usually, people with a weakened immune system or a long-term medical condition are more at risk.

Is A GBS Vaccine In The Pipeline?

Currently, the only way to find women at risk of passing GBS onto their newborn during delivery is to screen for it during their third trimester of pregnancy and to administer a course of antibiotics to the mother before the birth. However, this system is not foolproof and not practical in many overseas countries where health care systems are not as robust as in the United States.

Despite decades of research, there is still no effective vaccine against Group B streptococcus (GBS), but several experimental vaccines are currently undergoing trials. Hopefully a vaccine will soon become available to prevent pregnant women from passing the Group B Strep bacteria to their newborn.

Finished: Group B Strep (GBS): When Harmless Bacteria Turn Bad

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