preventing life-threatening GBS infections in newborn babies
Group B Strep screening in pregnancy
Why it should be introduced & responses to arguments against
Issue
Section and / or
page number
Comment
1. The UK’s
current
prevention
strategy isn’t
working
Current Strategy
The number of newborn babies infected with group B Strep has
increased by 32% since the risk-based prevention strategy was
introduced in 2003 and 17% since the 2008 NSC review. In 20031 there
were 229 early-onset GBS (EOGBS) infections occurring in the first six
days of life reported in England, Wales & Northern Ireland. In 20102,
there were 302 (248 in 2007)3. Even with the best medical care, 10% of
these sick babies die and others suffer long-term disabilities, including
up to 50% of survivors of group B Strep meningitis4. (These data give the
P4-5
minimum disease burden, based on voluntarily-reported, culture-proven cases in liveborn babies only, excluding stillbirths.)
2. Countries
which have
introduced
screening
have seen
incidence
drop
significantly
Antenatal Screening
for maternal GBS
colonisation
3. Screening
will prevent
more earlyonset group
B Strep
infections
than a riskbased
prevention
strategy
Summary
4. Screening is
more cost
effective
than a riskbased
prevention
strategy
The opportunity cost
of the screening
programme
(including testing,
diagnosis and
treatment,
administration,
training and quality
assurance) should
be economically
balanced in relation
to expenditure on
medical care as a
P4
Wherever data has been published on the incidence of early onset GBS
infection in babies, before and after the introduction of screening, the
incidence has fallen dramatically – for example, in the US by over 80%5,
in Spain by 86%6, in Australia by 82%7 and in France by 71%.8 The
review only mentions the US, not the experience from other countries.
Summary
P6-8
P6-8
80-90% of early-onset group B Strep infection16 could be preventable if
intravenous antibiotics were offered in labour to all GBS carriers
identified by universal sensitive testing late in pregnancy, plus to the
mothers of babies in the recognised higher risk situations. A risk factor
approach on its own, assuming all risk factors trigger antibiotics in
labour (which doesn’t happen in practice in the UK), can prevent only
50-60% of all cases of early-onset GBS infection. A population based
study from 20029 found that the screening approach was more than
50% effective than the risk-based approach at preventing early-onset
GBS infection.
Preventing early-onset GBS infection in babies will save money
compared with treating the effects. Within the last five years, four
reports have been commissioned through the Government’s Health
Technology Assessment Programme10 11 12 13 to establish how to combat
preventable GBS infection in newborn babies. All have found screening
to be more cost effective than risk-based prevention and
recommended that steps to introduce screening should be explored.
This research seems to have been ignored and no explanation given as
to why.
Group B Strep Support, P O Box 203, Haywards Heath, West Sussex RH16 1GF
www.gbss.org.uk info@gbss.org.uk Tel: 01444 416176
Fax: 0870 803 0024
Registered Charity No: 1112065 Registered Co No: 5587535
September 2012
whole
(ie value for
money).
Assessment against
this criteria should
have regard to
evidence from cost
benefit and/or cost
effectiveness
analyses and have
regard
to the effective use
of available
resource
P65-67
5. Screening
identifies
women most
likely to be
carrying GBS
at delivery
and allows
antibiotics to
be targeted
to women
whose
babies are
most at risk
of earlyonset GBS
infection.
6.
Summary: Criterion
2 Partly Met
P20-21
Government
focus on
preventative
medicine
7. Women
want to be
told about
group B
Strep and
offered GBS
screening
during
pregnancy
Using screening to identify women carrying GBS will allow antibiotics
to be targeted to women who are actually most likely to be carrying
GBS at delivery and whose babies are at greatest risk. Risk factors are
ineffective at identifying which women are likely to be carrying GBS at
delivery. Error! Bookmark not defined. Currently many women given
antibiotics during labour based on risk factors do not require them,
while others, whose babies would benefit, are ignored. With screening,
fewer women who are not carrying group B Strep at delivery will be
given unnecessary antibiotics. Error! Bookmark not defined.
With the recent Government focus on preventative medicine, now is
the ideal time to introduce screening for GBS in pregnancy.
The test should be
acceptable to the
population
A survey undertaken by ComRes14 on behalf of GBSS showed that

over half (54%) the women aged 20-35 surveyed had heard of
group B Strep, only 20% knew what it was
P44-45

once aware of the dangers of group B Strep in pregnancy, over
90% of young women believe pregnant women should always be
offered information, tests and, when the bacteria is detected,
antibiotics in labour

92% believe that information on GBS should be given to all
pregnant women

92% would welcome the opportunity for pregnant women to be
screened for group B Strep in the later stages of pregnancy and
believe that such screening should be offered to women routinely

95% believe antibiotics should be offered to women in labour
with group B Strep and that they themselves would definitely or
Group B Strep Support, P O Box 203, Haywards Heath, West Sussex RH16 1GF
www.gbss.org.uk info@gbss.org.uk Tel: 01444 416176
Fax: 0870 803 0024
Registered Charity No: 1112065 Registered Co No: 5587535
September 2012
probably accept the offer (89%)
8. Incidence of
early-onset
GBS
infection in
babies –
anticipated
effect of riskbased
prevention
in 2003
ignored
Summary
P6-8
The condition
should be an
important health
problem, EOGBS
Incidence
9. Implication
that any
antenatal or
intrapartum
risk factor
for earlyonset GBS
infection in
babies will
mean
mothers will
be offered
intravenous
antibiotics in
labour which
does not
happen in
practice
Presentation of
EOGBS,
10. Risk of
antibiotic
resistance as
a result of
antibiotics
given in
labour
against
early-onset
group B
Strep
infection
Summary
P6-8
3. All the costeffective primary
prevention
interventions should
have been
implemented as far
as practicable
P21-22
Antibiotic resistance
P61-62
15. The benefit from
the screening
programme should
outweigh the
physical
and psychological
harm (caused by
the test, diagnostic
procedures and
treatment)
P9-11
P19-20
The review compares the incidence of early-onset GBS infection
voluntarily reported to the Health Protection Agency in 2003 of 0.37
per 1,000 live births reported in England, Wales & Northern Ireland1
with 0.41 in 20102.
This ignores the fact that the preventative strategy against EOGBS
infection recommended in 2003 by the Royal College of Obstetricians &
Gynaecologists15 should have reduced UK incidence by 50-60%16. The
effectiveness of our existing strategy, with the relatively unchanged
incidence from 2003 to 2010, must be viewed taking this into
consideration.
The review states that “a third of EOGBS cases might be born to women
with no known risk factors for GBS, and therefore not targeted with IAP
[intrapartum antibiotic prophylaxis – antibiotics given as preventative
medicine in labour] in the absence of universal screening.” This
presupposes that all women with any risk factor would be offered
antibiotics in labour, which does not happen in practice.
The Royal College of Obstetricians & Gynaecologists’ 2012 GBS
guideline17 does not recommend antibiotics in labour for mothers in
preterm labour or for those with prolonged rupture of membranes.
Excluding these risk factors would mean that not 32% but 48% of babies
with EOGBS infection in the Vergnano study18 referred to would have
been born to women without known risk factors and where no
prevention would take place. As a result, significantly fewer cases of
EOGBS infection in babies will be prevented using the risk factor
approach recommended by the Royal College of Obstetricians &
Gynaecologists than the expert review suggests – almost half of all
EOGBS infections in babies would still occur.
Antibiotic resistance of group B Strep is of concern although is not
currently an issue when the recommended penicillin is used, although
there is increasing resistance with clindamycin or erythromycin.
Likewise, concerns about encouraging antibiotic resistance in other
organisms, such as E coli, have not been realised so long as penicillin is
used. Experience from other countries shows the risk of antibiotic
resistance to be very small when the recommended antibiotics are
used.19
A UK study12 showed that similar percentages of women would be
offered antibiotics in labour regardless of whether they were identified
by screening late in pregnancy or through recognised risk factors.
Therefore, the issue of antibiotic resistance is of equal concern for
either strategy. However, a screening strategy would mean that the
antibiotics in labour would be more accurately targeted to women
actually carrying group B Strep at the time, would prevent more EOGBS
infections and would minimise antibiotic use in women not carrying
GBS.
P63-64
Group B Strep Support, P O Box 203, Haywards Heath, West Sussex RH16 1GF
www.gbss.org.uk info@gbss.org.uk Tel: 01444 416176
Fax: 0870 803 0024
Registered Charity No: 1112065 Registered Co No: 5587535
September 2012
11. Risk of
anaphylaxis
as a result of
antibiotics
given in
labour
against
early-onset
group B
Strep
infection
Summary
P6-8
5. The benefit from
the screening
programme should
outweigh the
physical
and psychological
harm (caused by
the test, diagnostic
procedures and
treatment)
12. Evidence of
the on-going
benefit of
screening in
continued
reduced
rates of
early-onset
group B
Strep
infection in
other
countries
Summary
13. Studies on
the accuracy
of the ‘gold
standard’
ECM test
should keep
to those
where the
correct
procedures
were
followed.
P63-64
P6-8
Anaphylactic shock is very serious but extremely rare - EOGBS infection
is both more common and more easily preventable.
As for the issue of antibiotic resistance (see row above), similar
percentages of women would be offered antibiotics in labour through
either a risk based or screening prevention strategy, so the issue of
anaphylaxis is of equal concern with each strategy. However, a
screening strategy would prevent more EOGBS infections, target
antibiotics at women most likely to be carrying GBS at the time of
delivery and mean fewer women not carrying GBS being given
antibiotics inappropriately. Again, experience from other countries
shows the risk to be extremely small.Error! Bookmark not defined.
The review states there has been little new evidence on the
effectiveness of screening at preventing EOGBS infection. However in
countries that do screen and have data from before and after the
introduction of screening, their incidence has dropped by up to
86%5,6,7,8 and this has remained low20. This is new evidence showing
continued benefit.
The review fails to make a case why the UK should not see a similar
drop in incidence were screening introduced; we can see every reason
why it should and no reason why it shouldn’t.
The review focuses heavily on the accuracy of the ‘gold standard’
enriched culture medium (ECM) test, but majors on studies where it has
been implemented poorly, with recommended procedures not
followed. Even in those cases where the ECM test is poorly done, it is
still more accurate than the standard NHS test would be.
When procedures are correctly followed, a positive ECM test result is
87% predictive of whether a woman will still be carrying GBS (and a
negative ECM test result is 96% predictive of her still not carrying GBS)
when done within 5 weeks of delivery.21 Countries which have
implemented screening have seen their incidence of EOGBS infection
fall dramatically (see 2 above), whilst in the UK, where a risk based
strategy is used, the incidence has increased. This suggests that
screening using the ECM test is enormously effective at reducing the
burden of EOGBS infection even when sometimes implemented poorly.
1 Health Protection Agency, Pyogenic & non-pyogenic streptococcal bacteraemia, England, Wales &Northern Ireland: 2003, CDR
Weekly Volume 14 No 16, 16 April 2004. http://www.hpa.org.uk/cdr/archives/2004/cdr1604.pdf
2 Health Protection Agency, Pyogenic &non-pyogenic streptococcal bacteraemia, England, Wales & Northern Ireland: 2010. Health
Protection Report Vol. 5 No. 46, 18 Nov 2011 http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317131482001
3 Health Protection Agency, Pyogenic and non-pyogenic streptococcal bacteraemia, England, Wales & Northern Ireland: 2007. Health
Protection Report 2008; 2 (47): Bacteraemia http://www.hpa.org.uk/hpr/archives/2008/hpr4708.pdf#strepbact07
4 Edwards MS, Rench MA, Haffar AA, Murphy MA, Desmond MM, Baker CJ. Long-term sequelae of group B streptococcal meningitis in
infants. J Pediatr 1985; 106(5):717-722
Group B Strep Support, P O Box 203, Haywards Heath, West Sussex RH16 1GF
www.gbss.org.uk info@gbss.org.uk Tel: 01444 416176
Fax: 0870 803 0024
Registered Charity No: 1112065 Registered Co No: 5587535
September 2012
5 Jordan HT, Farley MM, Craig A, Mohle-Boetani J, Harrison LH, Petit S et al. Revisiting the need for vaccine prevention of late-onset
neonatal group B streptococcal disease: a multistate, population-based analysis. Pediatr Infect Dis J 2008; 27(12):1057-1064.
6 Andreu A, Sanfeliu I, Vinas L, Barranco M, Bosch J, Dopico E et al. [Decreasing incidence of perinatal group B streptococcal disease
(Barcelona 1994-2002). Relation with hospital prevention policies]. Enferm Infecc Microbiol Clin 2003; 21(4):174-179.
7 Daley AJ, Isaacs D. Ten-year study on the effect of intrapartum antibiotic prophylaxis on early onset group B streptococcal and
Escherichia coli neonatal sepsis in Australasia. Pediatr Infect Dis J 2004; 23(7):630-634.
8 Albouy-Llaty M, Nadeau C, Descombes E, Pierre F, Migeot V. Improving perinatal Group B streptococcus screening with process
indicators. J Eval Clin Pract 2011.
9 Schrag S et al. A population based comparison of strategies to prevent EOGBS disease in neonates. NEJM, Vol 347(4) July 2002.
10 Colbourn T, Asseburg C, Bojke L, Philips Z, Claxton K, Ades AE et al. Prenatal screening and treatment strategies to prevent group B
streptococcal and other bacterial infections in early infancy: cost-effectiveness and expected value of information analyses. Health
Technol Assess 2007; 11(29):1–226, iii
11 Kaambwa B, Bryan S, Gray J, Milner P, Daniels J, Khan KS et al. Cost-effectiveness of rapid tests and other existing strategies for
screening and management of early-onset group B streptococcus during labour. BJOG 2010; 117(13):1616–1627.
12 Daniels JP, Gray J, Pattison HM, Gray R, Hills RK, Khan KS. Intrapartum tests for group B streptococcus: accuracy and acceptability of
screening. BJOG 2011; 118(2):257–26.5).
13 Colbourn TE, Asseburg C, Bojke L, Philips Z, Welton NJ, Claxton K et al. Preventive strategies for group B streptococcal and other
bacterial infections in early infancy: cost effectiveness and value of information analyses. BMJ 2007; 335(7621):655.
14 ComRes. Pregnancy Screening Survey. 1-11-2011. 6-6-2012
15 RCOG. Prevention of Early Onset Neonatal Group B Streptococcal Disease. Royal College of Obstetricians and Gynaecologists
Guidelines 36. 2003.
16 J Med Screen. Maternal screening to prevent neonatal Group B streptococcal disease. Journal of Medical Screening 2002; 9(4).
17 RCOG. Prevention of Early Onset Neonatal Group B Streptococcal Disease. Royal College of Obstetricians and Gynaecologists
Guidelines 36. 2012. http://www.rcog.org.uk/files/rcog-corp/GTG36_GBS.pdf
18 Vergnano S, Embleton N, Collinson A, Menson E, Russell AB, Heath P. Missed opportunities for preventing group B streptococcus
infection. Arch Dis Child Fetal Neonatal Ed 2010; 95(1):F72-F73.
19 Law MR, Palomaki G, Alfirevic Z, Gilbert R, Heath P, McCartney C et al. The prevention of neonatal group B streptococcal disease: a
report by a working group of the Medical Screening Society. J Med Screen 2005; 12(2):60-68.
20 Active Bacterial Core surveillance (ABCs) Surveillance Reports: series at http://www.cdc.gov/abcs/reports-findings/surv-reports.html
21 Yancey MK, Schuchat A, Brown LK, Ventura VL, Markenson GR. The accuracy of late antenatal screening cultures in predicting genital
group B streptococcal colonization at delivery. Obstet Gynecol 1996; 88(5):811-815
Group B Strep Support, P O Box 203, Haywards Heath, West Sussex RH16 1GF
www.gbss.org.uk info@gbss.org.uk Tel: 01444 416176
Fax: 0870 803 0024
Registered Charity No: 1112065 Registered Co No: 5587535
September 2012