What is GBS?

Group B Streptococcus (GBS) is a normal bacterium which colonises between 20-30% of adults in the UK, without symptoms or side-effects. It is most commonly found in the intestines, as part of the normal gut flora (bacteria living in the gastrointestinal tract). It is also often found in the vagina of adult women. It is known as a ‘commensal’ – an organism which lives on another without causing any harm.
GBS can, however, occasionally cause infection, most commonly in new-born babies. GBS can more rarely cause infection in adults (typically women during pregnancy or after birth, the elderly and people with serious underlying medical conditions which impair their immune system).
GBS is not a sexually transmitted disease and treatment of the woman and of her partner does not prevent re-colonisation.

Group B Strep infection in Newborn babies

In newborn babies, there are two types of GBS disease: early and late-onset. Roughly 75% of GBS disease is early-onset, occurring in the first 6 days of life and usually apparent at birth. Early-onset GBS disease is normally characterised by the rapid development of breathing problems, associated with blood poisoning. Late-onset disease – which usually presents as GBS meningitis – occurs after the baby is 6 days old and, normally, by age 1 month but, rarely, up to age 3 months. After age 3 months, GBS infection in babies is extremely rare.




GBS is a recognised cause of preterm delivery, maternal infections, stillbirths and late miscarriages.
Preterm babies are known to be at particular risk of GBS infection as their immune systems are not as well developed as those of full-term babies.
Overall, without preventative medicine, GBS infections affect an estimated 1 in every 1,000 babies born in the UK. Each year, based on 700,000 babies born annually in the UK, approximately:

• 230,000 babies are born to mothers who carry GBS; 88,000 babies (1 in 8) become colonised with GBS; 700 babies develop GBS infections, usually within 24 hours of birth; and
• 75 babies (11% of infected babies) die.

Of the survivors of GBS meningitis, up to one half suffer long-term mental and/or physical problems, from mild to severe learning disabilities, loss of sight, loss of hearing and lung damage (in around 12% of the survivors, the disabilities may be severe). The great majority of survivors of early-onset disease do so with no long-term damage.

Early-onset GBS infection in babies (0-6 days of life)

In the UK, up to 75% of GBS disease is early onset (apparent within the first week), although assuming that current risk-based prevention prevents a significant proportion of infections, then without such preventative medicine, the figure is likely to be nearer 90%. It is the early-onset GBS infections that are potentially preventable when Mum is given intravenous antibiotics in labour.
Early onset GBS infection usually presents as septicaemia with pneumonia. These “early-onset” infections are usually apparent at or soon after birth, with the typical symptoms of early-onset GBS infection including:

• grunting;
• lethargy;
• irritability;
• poor feeding;
• very high or low heart rate;
• low blood pressure;
• low blood sugar;
• abnormal (high or low) temperature; and
• abnormal (fast or slow) breathing rates with blueness of the skin due to lack of oxygen (cyanosis).

Late onset GBS infection in babies age 6 days to 3 months

Up to 25% of GBS infections are late-onset, occurring after the baby’s first 6 days, usually as meningitis with septicaemia. It is uncommon after a baby reaches one month old and very rare after age three months. Currently there are no known ways of preventing late-onset GBS infections so identifying signs and symptoms of these infections is vital for early diagnosis and treatment.
Late onset GBS infection usually presents as septicaemia, pneumonia and/or meningitis, but can also present as osteomyelitis (bone infection) and septic arthritis (joint infection). Typical signs of late-onset group B Strep infection are similar to those associated with early onset infection and also include signs associated with meningitis such as:

• Being irritable with high pitched or whimpering cry, or moaning
• Blank, staring or trance-like expression
• Floppy, may dislike being handled, be fretful
• Tense of bulging fontanelle (soft spot on babies’ heads)
• Turns away from bright light.
• Involuntary stiff body or jerking movements
• Pale, blotchy skin

If a baby shows signs consistent with GBS infection or meningitis, call your doctor immediately. If your doctor isn’t available, go straight to your nearest Paediatric Casualty Department. If a baby has late-onset GBS infection or meningitis, early diagnosis and treatment are vital: delay could be fatal.