Group B Streptococcal (GBS) meningitis is caused by the bacterium Streptococcus agalactiae.
These bacteria can also cause septicaemia and pneumonia. Together these are known as GBS disease.
GBS bacteria usually live harmlessly in the vagina and intestinal tract of approximately 20–40% of women. These bacteria can sometimes be passed to the baby during delivery. The result is usually colonisation of the skin surfaces and only a small percentage of babies go on to become ill with serious infection.
When a baby becomes ill in the first six days of life this is called early onset disease and is usually septicaemia. When a baby becomes ill between seven and 28 days after birth this is called late onset disease which is more likely to be meningitis. Rarely, infection may occur as late as three months of age.
GBS disease in newborns
The risk of GBS disease in babies is higher if:
- The mother had a previous baby with GBS
- Swabs and urine samples of the mother are positive for GBS
- The mother has a high temperature during labour
- The baby is part of a multiple birth
- The baby is born prematurely
- The time between the waters breaking and the delivery of the baby is prolonged
Early and late onset disease
About 60 – 70% of GBS disease is early onset. Early onset disease, which more commonly presents as pneumonia or septicaemia, occurs less than seven days after birth and is most likely due to infection being passed on from the mother before or during birth.
Late onset disease, which more commonly presents as meningitis, develops between seven and 28 days after birth and is probably transmitted when babies come into contact with hands contaminated with GBS bacteria.
What are the symptoms of GBS disease?
Can GBS disease be prevented?
Unfortunately, there is currently no vaccine to protect against GBS disease. All pregnant women should be given information about GBS infection In the UK, there is no national screening programme to routinely check all pregnant women to see if they are carrying GBS bacteria
However, a risk-based strategy is used and antibiotics can be given to women at increased risk of GBS disease during labour and also to babies immediately after birth
It’s possible to be tested for GBS in late pregnancy. Sensitive tests designed to detect carriage are available, but rarely offered within the NHS. Ask you GP or midwife for details of the ECM (or Enriched Culture Medium) test which is recognised as the ‘gold standard’ for detecting GBS carriage.