WHAT IS GROUP B STREP
Since the 1970s, group B Streptococcus (GBS) has been recognised as the primary cause of bacterial infection in newborn babies, resulting in disease at birth and up to 3 months of age.

Up to a third of all men and women carry GBS in their intestines without symptoms and roughly a quarter of women of childbearing age carry GBS in the vagina at any one time. GBS is a normal body commensal (an organism that lives on another without harming it). A positive swab result for GBS means a woman is colonised with GBS at the time the swab was taken - not that she or her baby will become ill.

IS GBS COLONISATION ABNORMAL? NO
GBS colonisation is normal and does not require treatment with antibiotics. The time when antibiotics are effective against GBS infection in newborn babies is when they are given intravenously (through a vein) to a pregnant woman when she goes into labour or her waters break.

(If GBS is found in the urine, this should be treated at the time of diagnosis with oral antibiotics and the treatment repeated if necessary until urine tests come back clear. This is also an indication that the pregnant woman should be offered intravenous antibiotics once labour starts or her waters break.)

Medical research shows the prevention measures described in these pages stop GBS infections developing in babies in at least 6 out of every potential 10 cases - this saves lives!

GBS AND ADULTS
GBS colonises up to 30% of adults in the UK, without symptoms or side-effects. However, GBS can also cause infection, most commonly in newborn babies before, during or shortly after birth. 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 AND NEWBORN BABIES
In newborn babies, there are two types of GBS disease: early and late-onset. Roughly 80% of GBS disease is early-onset, occurring in the first 2 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 2 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 infections cause death in approximately 1 in every 10 infected babies.

GBS is also a recognised cause of preterm delivery, maternal infections, stillbirths and late miscarriages. GBS infections are rare in adults, especially so for men and women who are not pregnant.

HOW OFTEN DOES GBS CAUSE HARM?
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 2 days of birth; and 75 babies (10% of infected babies) die.
Of the survivors of GBS meningitis, up to a third suffer long-term mental and/or physical handicaps, from mild learning disabilities to severe mental retardation, 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.

GBS can be present in a woman's first pregnancy, or in subsequent pregnancies. It can be a threat during pregnancy, at the time of delivery and afterwards.

WHAT ARE THE RISK FACTORS FOR GBS INFECTION IN BABIES?
There are recognised situations which increase the likelihood that a baby will be exposed to GBS and, if susceptible, of developing infection. These are as follows:

Clinical risk factors: each one increases the risk at least 3 times:
-where labour or membrane rupture is preterm (prior to 37 completed weeks of pregnancy);
-where there is prolonged rupture of membranes (more than 18-24 hours before delivery;
-where the pregnant woman has a raised temperature (37.8°C or higher) during labour*.

*If the woman has an epidural, a slightly raised temperature may be of less significance than in a woman with no epidural

Mothers who carry GBS: the presence of one or both of these factors multiplies the risk about 4 times:
-where the pregnant woman is known to carry GBS; and
-where the mother has GBS bacteria in her urine at any time during the present pregnancy (which should be treated at the time of diagnosis).

Mother has had a baby infected with GBS: multiplies the risk about 10 times:
-where the pregnant woman has had a baby who developed a GBS infection.

Colonisation combined with one or more clinical risk factor increases the risk at least 12-fold.

75% of early-onset GBS disease and 90% of resultant deaths follow deliveries with one or more of these risk factors.

About half of the babies born to mothers colonised with GBS at the time of delivery will become colonised themselves and, of these, only around 1 in 200 will develop GBS disease.

CAN I FIND OUT IF I CARRY GBS?
Reliable testing for GBS carriage is not available on the NHS and, although if you get a positive result from the standard test (often called an HVS) this is highly reliable, these tests give up to 50% of GBS carriers a falsely negative result.

WHAT IS THE BEST WAY TO DETECT GBS?
The Enriched Culture Method (ECM) test, recognised as optimal for detecting GBS carriage by both the Royal College of Obstetricians & Gynaecologists and by the Health Protection Agency, it is not available routinely or on the NHS. This test is much more sensitive and has been specifically designed for the isolation of GBS. An even better test was launched late in 2006 using PCR and this test is also carried out alongside the ECM test for maximum detection.

The ECM/PCR low vaginal swab and rectal swab tests should be performed at 35-37 weeks' gestation to best predict colonisation with GBS at delivery since GBS carriage can be intermittent. Research shows that, if the ECM/PCR test is performed within 5 weeks of delivery, a negative result is more than 96% predictive of not carrying GBS at delivery (so 4% of women acquired carriage between the test and giving birth) and a positive result is more than 87% predictive of carrying GBS at delivery (so 13% of women lost carriage between performing the test and giving birth).

HOW CAN I GET THE ECMPCR TEST GBS?
At present, there are few laboratories in the UK that offer this test (The Doctors Laboratoy on 020 7460 4800 or e-mail them at gbs@tdlplc.co.uk.). The vaginal and rectal swabs can be taken by our staff at Innermost Secrets at the Spire Hospital in Cardiff at 35 to 37 weeks of pregnancy.

The result of the test will be available within 3-5 working days of receipt of test and the report will be sent to the referring healthcare professional for discussion with the pregnant woman and a copy of the results sent direct to her.

WHEN SHOULD ANTIBIOTICS BE GIVEN TO TREAT GBS?
Waiting to give antibiotics to the baby after delivery will sometimes be too late. Clinical randomised medical trials have proven that most early-onset GBS infection can be prevented by giving intravenous (through a vein) from the onset of labour through until delivery to women whose babies are at increased risk.

Research shows intravenous antibiotics take between 2 and 3 hours to cross the placenta and reach therapeutic levels in the baby, although lesser times have proved beneficial: something is better than nothing.

Babies who develop GBS infection can require long stays in hospital and expensive supportive treatment.

The Group B Strep Support Group (UK) have a medical advisory panel who have made the following recommendations which they believe are the most appropriate for Britain in the light of all currently available data. They will need periodic reappraisal to incorporate advances in technology, new research or other refinements.

PREVENTION STRATEGY
To stop as many cases of GBS infection in newborn babies as possible, women with any risk factor would need to be given intravenous antibiotics during labour for ideally at least 4 hours before delivery.

Some women will prefer not to receive antibiotics if their risk is only slightly increased since it would inevitably complicate an otherwise natural birth, plus antibiotic therapy is associated with rare but significant complications. The risk of a GBS infection in the baby must be balanced against the wishes and beliefs of the woman in labour and against her risk of an adverse reaction to the antibiotics.

Medical research shows the chance of a baby developing early-onset GBS infection can be reduced by over 70% (and the number of fatalities by 75-80%) by adopting the following measures.

MEDICAL ADVISORY PANEL'S RECOMMENDATIONS
The GRoup B Strep Support Group (UK's medical advisory panel's 6 key recommendations for preventing GBS infection in newborn babies are:

women whose babies are at increased risk of developing GBS infection should be offered antibiotics immediately at the onset of labour or rupture of membranes (this includes women known to carry the GBS bacteria where no other risk factors are present, and women not known to carry the GBS bacteria but who have another risk factor present).

women whose babies are at particularly high risk should be strongly advised to accept intravenous antibiotics immediately at the onset of labour or rupture of membranes until delivery (this includes women who are known GBS carriers with one or more clinical risk factors and women who have previously had a baby infected with GBS, regardless of other risk factors. It also includes women who are not known to be GBS carriers but who have multiple risk factors).

for women in labour, the recommended doses of penicillin G are 3 g (or 5 mU) intravenously initially and then 1.5 g (or 2.5 mU) at 4-hourly intervals until delivery. For women who are allergic to penicillin, the recommended doses of clindamycin are 900 mg intravenously every 8 hours until delivery.

intravenous antibiotics should be given for at least 4 hours prior to delivery where possible.

babies born in situations where there is increased risk and the mother has received at least 4 hours of intravenous antibiotics should be assessed carefully by a paediatrician and, if completely healthy, intravenous antibiotics should not be given to them (see paediatric prevention).

babies born in a higher risk situation where the mother has not received at least 4 hours of intravenous antibiotics should be investigated and initially commenced on antibiotics until it has been proven the baby is not infected (see paediatric prevention).

MANAGEMENT OF THE NEWBORN BABY
With any policy that involves treating certain women with penicillin to prevent the acquisition of GBS infection following rupture of membranes or the start of labour, a strategy for the management of the newborn baby is required.

In all cases, the newborn baby should be assessed as soon as possible by a paediatrician and the threshold for giving antibiotics to babies born in the high risk situations should be low.

WHAT ARE THE SYMPTOMS OF EARLY_ONSET GBS INFECTION?
Typical symptoms of early-onset GBS infection include:
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).
Typical symptoms of late-onset GBS infection are
fever;
poor feeding and/or vomiting; and
impaired consciousness.

WHAT ARE THE SYMPTOMS OF MENINGITIS?
Typical symptoms of meningitis in babies, including GBS meningitis (any of these could develop but some may not be present at all) include:

fever, which may include the hands and feet feeling cold, and/or diarrhoea;
refusing feeds or vomiting;
shrill or moaning cry or whimpering;
dislike of being handled, fretful;
tense or bulging fontanelle (soft spot on the head);
involuntary body stiffening or jerking movements;
floppy body;
blank, staring or trance-like expression;
abnormally drowsy, difficult to wake or withdrawn;
altered breathing patterns;
turns away from bright lights; and
pale and/or blotchy skin.

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

The risk of a baby developing a GBS infection decreases with age - GBS infection in babies is rare after one month of age and virtually unknown after three months.

TREATING GBS INFECTION
The recommended minimum length of in-patient intravenous antibiotic treatment for babies who develop GBS infection is 14 days if the baby has meningitis, otherwise 10 days.

Before discharge, a full work up needs to be done on the baby, including a full examination by a paediatrician, review of clinical parameters, FBC and differential and CRP.

Treatment should also be given to an infected baby's twin, even if that baby appears to be well at the time, since infection of the second twin is common.

Reports suggest that a baby who has recovered from a GBS infection is at raised risk of re-infection. For such a baby, it may be worth discussing with the paediatrician whether giving penicillin prophylaxis orally once or twice a day for the first 3 months of life could be beneficial.

WHERE CAN I GET FURTHER INFORMATION
See the GROUP B STREP SUPPORT (UK) website www.gbss.org.uk