Group B Streptococcus (GBS) is a bacterium present in around 35% of women. It doesn’t cause health issues for most people.

However, it can lead to GBS disease and other complications, like GBS meningitis, in newborns. Older adults may also deal with GBS-related illnesses, particularly if they have other health issues, like diabetes, congestive heart failure, or cancer.

Keep reading to learn more about GBS, how it can lead to meningitis, and what questions you may want to ask your doctor.

Language matters

Sex and gender exist on spectrums. We may use “women” and “men” in this article to reflect the terms that have been historically used to gender people, especially in research. But your gender identity may not align with how your body responds to this disease. Your doctor can better help you understand how your specific circumstances will translate into diagnosis, symptoms, and treatment.

GBS typically resides in the digestive and genital tracts.

GBS doesn’t always cause symptoms or sickness. For example, most people with GBS bacteria show no signs or symptoms.

When GBS does cause illness, it may lead to various infections. One possibility is meningitis, an infection of the tissues surrounding the brain and spinal column. Other possible infections include:

  • sepsis (infection of the blood)
  • pneumonia (infection of the lungs)
  • skin and soft tissue infections
  • bone and joint infections

Complications from GBS are rare in adults. Instead, issues like GBS-related sepsis, pneumonia, and meningitis tend to impact newborns more than other age groups.

GBS meningitis in newborns

GBS bacteria can start to grow in newborns in the birth canal during labor and delivery. If a baby is exposed to GBS, meningitis or other complications may arise soon after birth.

Risk factors for newborns include:

  • a birthing parent who tested positive for GBS bacteria in the weeks before delivery
  • a birthing parent who had a fever during labor
  • a birthing parent who had GBS urinary tract infections during pregnancy
  • labor with ruptured membranes that lasted 18 hours or longer

With newborns, there’s early onset and late onset GBS disease:

  • Early onset: The infection (meningitis, sepsis, pneumonia) begins within 7 days of birth. Exposure to GBS in the birth canal or other contact with the birthing parent in delivery is usually the cause.
  • Late onset: The infection, which is typically meningitis, begins a week to a few months after birth. Exposure to GBS from the mother or any other person who carries it can cause late onset GBS infection.

GBS meningitis in adults

Adults at higher risk for developing GBS meningitis and other GBS-related complications tend to be over 65 years old.

They may also have other health conditions that affect their overall health, including:

Early signs of GBS meningitis, a type of bacterial meningitis, tend to develop within 3 to 7 days after exposure. Symptoms may come on suddenly and not necessarily seem specific to any particular illness.

Meningitis symptoms in newborns include:

Meningitis symptoms in adults include:

When to contact a doctor

It’s important to contact a doctor as soon as you see possible symptoms, particularly in newborns. While initial symptoms may be difficult to spot, they can develop quickly and progress to seizures, coma, or even death.

Contact a doctor if:

  • signs or symptoms come on suddenly
  • you experience a stiff neck, headache, or confusion
  • your newborn has a fever of 100.4ºF (38ºC) or higher
  • your newborn has a bulging fontanelle

While most people recover from GBS meningitis, some may experience serious complications. If left untreated or if not treated in time, GBS meningitis can lead to death in as little as a few hours.

Complications in infants

Some 4% to 6% of babies with GBS disease, including meningitis, will die from their infections. Those who recover may deal with complications like:

Complications in pregnant adults

Pregnant people don’t typically develop GBS meningitis. Instead, they may develop other GBS-related infections, like blood infections or post-delivery wound infections.

Other complications of GBS for pregnant people include:

Complications in non-pregnant adults

GBS meningitis and other related infections can be serious for older adults. About 1 in 20 adults with GBS infection die, particularly those with preexisting conditions.

If you or your child show signs of GBS meningitis, your doctor will likely order a blood test or cerebrospinal fluid (CSF) test via spinal tap. Blood and spinal fluid are both sterile. If GBS is present in these fluids, it’s a sure sign of infection.

Results from these tests may take a few days.

Treatment for meningitis involves taking various antibiotics. The Centers for Disease Control and Prevention (CDC) notes that it’s important to start antibiotic treatment as soon as possible.

Initial drugs may include ampicillin and gentamicin. Once an additional spinal tap shows the GBS has cleared, doctors may switch you or your child to penicillin G for another 14 days of treatment.

Your doctor will adjust treatment as needed, depending on how your case or your child’s case is progressing or resolving.

Screening for GBS bacteria during late pregnancy (35 to 37 weeks) is key to prevention.

If the bacteria is detected, your doctor will likely suggest treatment with intravenous (IV) antibiotics during labor. The drug of choice is generally penicillin, but your doctor may suggest other medications in cases of allergy.

Pregnant people who receive IV medications during labor have a 1 in 4,000 chance of passing on GBS disease to their babies. Without antibiotics, the chance increases to 1 in 200.

There’s currently no vaccine against GBS disease. Oral antibiotics are also not considered a good prevention method, as bacteria can grow back quickly.

If you have had GBS infections in the past or have other risk factors, speak with your doctor about any additional prevention measures that may help.

Most people recover from GBS meningitis. In newborns, the mortality rate is between 3% to 10% for early onset infection and between 1% and 6% for late onset infection.

Babies born before 37 weeks tend to have the highest mortality rate: 20%.

Recurrence is also a possibility in older adults. Some 4% of non-pregnant adults who deal with GBS infections and recover may go on to have another GBS infection within a year.

GBS bacteria don’t cause sickness in all people. Newborns and older adults with certain health conditions are at the highest risk.

That said, symptoms of GBS meningitis may come on suddenly and progress quickly. Without treatment, meningitis can lead to serious complications and even death.

If you or your newborn have symptoms, contact your doctor to find out the next steps. Treatment with medications can be effective, especially when started as soon as possible.