What is group B streptococcus?

Group B streptococcus is a type of bacteria. It may also be called GBS, group B strep, or streptococcus agalactiae. In healthy people it is commonly found in the gastrointestinal system (gut), urethra and vagina.

Healthy people of any age can be carriers of group B streptococcus without having any symptoms or becoming sick.

What is group B streptococcal infection?

Group B streptococcus can cause infections in some people, making them unwell. It is the most common cause of serious infections in newborn babies.

Group B streptococcus can also cause infections in people who:

• are pregnant
• are older
• live with diabetes
• have problems with their immune system

What are the symptoms of group B streptococcal infection?

Group B streptococcal infections can cause a wide range of symptoms, depending on where the infection is in your body. One common symptom of this infection is fever.

Types of group B streptococcal infections include:

• cellulitis (infection of the skin)
• urinary tract infection
• pneumonia
• joint infection
• meningitis
• sepsis

If you are pregnant, a group B streptococcal infection can cause both you and your unborn baby to become very unwell. It can lead to an infection in the fluid that surrounds your baby, known as the amniotic fluid.

Symptoms of group B streptococcal infection in newborn babies

Group B streptococcal infections can cause your baby to become sick shortly after they are born. Symptoms of serious infections in newborn babies include:

• difficulty breathing
• being very sleepy or irritable
• poor or reduced feeding
• vomiting
• being too hot or too cold
• pale or mottled skin
• floppy arms and legs

If your baby develops signs of group B streptococcal infection, they need urgent medical attention.

If your baby is under 3 months and has a fever above 38°C, vomiting or breathing problems, go to your nearest hospital emergency department or call triple zero (000) and ask for an ambulance.

If symptoms in newborn babies develop in the first week of life, it is called early-onset group B streptococcal infection. Most of these babies will show symptoms in the first 12 hours after birth.

If symptoms develop after one week but within 3 months it is called late-onset group B streptococcal infection.

Both early-onset and late-onset group B streptococcal infection can cause infection of the blood and sepsis. Early-onset group B streptococcal infection is more likely to cause breathing problems or pneumonia. Late-onset group B streptococcal infection is more likely to cause meningitis, an infection around the brain.

What causes group B streptococcal infection?

Group B streptococcal infections are caused by group B streptococcus bacteria.

Group B streptococcus is commonly found in healthy people. These people are not considered to be 'infected', but they are 'carriers' of the bacteria. This means they don't have symptoms, but can pass it on to other people.

Pregnant carriers of group B streptococcus can pass the bacteria on to their baby during a vaginal birth.

When should I see my doctor?

If you are concerned that you or your baby may have a group B streptococcal infection, you should see a doctor immediately.

If your baby has difficulty breathing, a high fever, is vomiting repeatedly or has floppy arms or legs, this is an emergency. Call triple zero (000) and ask for an ambulance.

How is group B streptococcal infection diagnosed?

Your doctor will ask about your symptoms and about your health in general. They will examine you (or your baby) for any signs of an infection.

Your doctor may recommend testing your blood and urine (wee) for group B streptococcus bacteria.

Swab testing during pregnancy

If you're pregnant, you can have a test for group B streptococcus at around week 35 to 37 of pregnancy.

A vaginal swab — and sometimes an anal swab — is used to test for group B streptococcus. You can do this test yourself at home or at the doctor's clinic. You can also ask your doctor or nurse to do the swab for you.

If the test is positive, your health team will recommend intravenous antibiotics (IV — through a drip into your vein) during labour.

If your baby is born by planned caesarean section (C-section), you do not need antibiotics.

Monitoring your baby after birth

If you have antibiotics during labour, your baby's health team will check them for signs of group B streptococcal infection. This includes regular checks of your baby's:

• breathing
• heart rate
• temperature

If they show signs of group B streptococcal infection, your doctor will recommend a blood test and maybe other tests too, depending on your baby's symptoms.

If your baby is less than one month old and has a group B streptococcal infection, your doctor may need to check the fluid in their spine using a lumbar puncture.

How is group B streptococcal infection treated?

Group B streptococcal infections in both adults and babies can be treated with antibiotics.

If you or your baby is diagnosed with an infection, IV antibiotics will be given urgently. Both early-onset and late-onset group B streptococcal infections need these antibiotics.

Can group B streptococcal infection be prevented?

Group B streptococcal infection cannot be prevented, but you can reduce the risk of passing an infection on to your baby during childbirth.

IV antibiotics are recommended for some people during labour to help prevent infection in your newborn. These antibiotics may be started 4 or more hours before your baby's birth.

These antibiotics can be helpful in preventing early-onset infection but are not helpful in preventing late-onset group B streptococcal infection.

Talk to your doctor or midwife about your risk of infection, and if you need antibiotics during labour.

What are the complications of group B streptococcal infection?

Complications depend on the type of infection you have and where the group B streptococcal infection is in your body. Your doctor may talk to you about antibiotics, and how they can help prevent complications — this is especially important during childbirth.

Resources and support

The Royal Women's Hospital has a fact sheet on group B streptococcal screening in pregnancy.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

Languages other than English

NSW Health has fact sheets on pregnancy screening for Group B streptococcus and sepsis in different languages.

The Royal Children's Hospital has translated fact sheets on fever in children available in many community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

The Australian government has resources on sepsis for Aboriginal and Torres Strait Islander peoples available.

Find an Aboriginal Community Controlled Health Organisation (ACCHO) or Affiliate near you.