Group B Streptococcus (GBS or Strep B) is a germ which is carried by 20-40% of adults. 25% of women carry it in their vagina, usually without symptoms or side-effects. If a woman carries GBS in her vagina, her baby is at risk of catching the bug at birth. In rare cases, it can cause serious disease (including pneumonia, sepsis and meningitis) and even death in their babies. GBS causes the death of 150,000 children around the world each year.
During the late stages of pregnancy, antibodies (natural immunity) are transferred across the placenta from the mother to the child, which protects the baby in the first few weeks of life from potential infections, including GBS infection. However, if the mother has insufficient antibodies against GBS, the infant will also not be protected.
Infection during the first 6 days of life may be prevented by antibiotics given to the mother during labour, but will offer no protection for infections occurring later. It may be possible to prevent GBS disease in these babies by giving a vaccine containing antibodies to pregnant women, allowing her to pass on the antibody to her baby.
A vaccine is currently being developed against GBS and to help this progress faster we are running studies to identify how much antibody is actually needed to protect babies from GBS disease. In identifying this, we will be able to help the licensing of a GBS vaccine.
How do I get involved?
Please speak to your midwife at your antenatal visits if you are interested in taking part. Additionally please contact a member of the study team under the ‘contact us' section.
Eligible Participants
For this study, participants will be pregnant women of at least 18 years of age who are giving birth at one of five hospitals: St George's Hospital, Kingston Hospital, Croydon Hospital, East Surrey Hospital or Poole Hospital.
Study Involvement
For women who agree to participate, we will obtain a small blood sample from the mother and/or umbilical cord at delivery at each of these hospitals. These blood samples are to look for antibodies against GBS and will be about a tablespoon of blood from you and the cord/placenta after it is delivered by the midwife caring for you in labour.
In 2 of the 5 hospitals (St George's Hospital and Kingston Hospital) we will ask you for a swab from your back passage/vagina prior to or during labour (which you can take if you wish), in order to identify if the woman carries GBS. If you are found to be carrying GBS, you will be offered antibiotics in labour according to the Royal College of Obstetrics and Gynaecology guidelines.
If your swab is GBS positive, we will ask for your permission to take a blood test from your baby at either 4, 8 or 12 weeks of age to look for antibodies against GBS. This will be about a teaspoon of blood. Finally, we will ask you for your permission to obtain a sample from your baby's Guthrie card (blood spot test). This is routinely taken in all babies around 5 days of age.
For women at all 5 hospitals, if, during the 3 months following the birth of your baby, your baby develops GBS disease, we will ask you for a swab from your vagina and rectum in order to see if you are carrying GBS, as well as an additional sample of blood from you and from your baby. The swab may be obtained by you, or by study staff if you prefer. We would also like to call you when your baby is around 3 months old to check on your baby's health. The call will last around 5 minutes.
Project lead
Dr Kirsty Le Doare, St George's Hospital NHS Foundation Trust
Project duration
6 months (1 June 2018 – 1 December 2018)
How can I get more information
Study documents including the protocol and patient information leaflet can be found in 'further information'. You are able to contact the research team by telephone on 0208 725 5382 or via email.
In September 2018, the iGBS surveillance was expanded throughout the country. Paediatricians and microbiologists from all the Trusts of England and Wales have been asked to make contact with study staff should a case of iGBS occur at their hospitals. When a case of iGBS occurs, the relevant paediatrician will provide study information to the parents and seek their permission for inclusion in the study.