Group B Strep in
pregnancy &
newborn babies
25th January 2012
Jane Plumb MBE
Chief Executive
Group B Strep Support
GBSS Medical Advisory Panel
Prof Philip Steer
(Chair)
Dr Alison Bedford
Russell
Emeritus professor at
Imperial College &
consultant obstetrician at
the Chelsea and
Westminster Hospital,
London
Neonatal Consultant,
Birmingham Women's
Clinical Lead, South
West Midlands
Newborn Network &
Hon Associate Clinical
Professor, Warwick
Medical School
Dr Christine
McCartney OBE,
Executive Director,
Health Protection
Agency’s
Microbiology
Services, London
Philippa Cox
Consultant Midwife,
Supervisor of
Midwives, Homerton
Hospital, London
Streptococci
Classified into Lancefield groups (1938)
• Group A Streptococcus
S. pyogenes
– necrotising fasciitis
– toxic shock syndrome
– 1574 cases in England, Wales & NI (2010)
• Group B Streptococcus
• S. agalactiae
– Wound infections & septicaemia in adults
– 1610 cases in England, Wales & NI (2010)
What does group B Strep do?
• Colonisation
– Asymptomatic and intermittent
– Intestinal (<30% of adults)
– Vaginal (<25% of women)
• Infection
– Newborn babies
– Adults: the elderly, pregnant/postpartum
women, others with underlying disease
Age-specific rates of group B Strep
bacteraemia reports: England, Wales &
Northern Ireland, 2010
Source: Health Protection Report Vol. 5 No. 46 – 18 November 2011
Group B Strep infection
• “Early onset” 0-6 days (~75% cases)
–
–
–
–
90% show within 12 hours
Usually septicaemia and pneumonia
11% mortality, 7% morbidity
90% preventable IV Penicillin
• “Late onset” 7-90 days (~25% cases)
–
–
–
–
Usually meningitis and septicaemia
8% mortality, 21% morbidity (up to 50% with meningitis)
No current prevention: good hygiene/education
Vaccine: future hope for both late & early onset
Neonatal GBS disease in the
UK – age at onset
Source: Heath PT, Balfour G, Weisner AM, Efstratiou A, Lamagni TL, Tighe H et al.
Group B streptococcal disease in UK and Irish infants younger than 90 days. Lancet
2004; 363(9405):292-294.
EOGBS Infection Incidence
per 1,000 live births
• 0.41 culture proven cases
– Cultures growing GBS from blood & CSF
– Voluntarily reported to Health Protection Agency
for England, Wales & NI 2010
• 3.6 proven plus probable cases
– Sick babies with cultures growing GBS from nonsterile sites (S Luck, Lancet 2003)
• Plus stillborn babies > 3.6/1,000
Known risk factors for
EOGBS infection
•
•
•
•
•
•
Previous GBS baby
GBS bacteriuria current pregnancy
GBS found current pregnancy
Maternal intrapartum fever (>380C)
PROM >18 hours before birth
Preterm labour
10 x
4x
3x
3x
3x
3x
Reducing EOGBS risk
• Intrapartum antibiotic prophylaxis
– Only proven effective method of prevention available
– 90% prevention
• Intramuscular antibiotics pre-labour
– May eradicate GBS colonisation for up to 6 weeks
– Small studies & no GBS infection in control or treated group
• Vaginal flushing with Chlorhexidine
– No evidence it reduces EOGBS infection
• Oral Antibiotics
– No evidence it reduces EOGBS infection (treats GBS UTI)
UK Guidelines
• Royal College of Obstetricians &
Gynaecologists 2003 Guideline (update 2012)
– Antibiotics in labour for women with recognised risk
factors, including carriage
– 2007 audit – few units comply fully
• UK National Screening Committee (review 2012)
– Screening not recommended: “clinical and cost
effectiveness uncertain”
• RCT trial proposed (2007 £11.3M) but not funded
• Trial now ethical ?
• Consultation Spring 2012 - do comment
England, Wales & NI Cultureproven EOGBS infection 2003-10
Introduction of
RCOG
Guidelines
Source: Health Protection Agency
USA - Incidence of early- and late-onset
invasive group B Strep disease — Active
Bacterial Core surveillance areas, 1990–2008
Prevention of
Perinatal Group B
Streptococcal
Disease
Revised
Guidelines from
CDC, 2010
and adapted from
Jordan HT, et al.
Revisiting the need
for vaccine prevention
of late-onset neonatal
group B streptococcal
disease.
Pediatr Infect Dis J
2008;27:1057–64.
Countries routinely screening
pregnant women for GBS

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





Australia
Argentina
Belgium
Canada
Czech Republic
France
Germany
Hong Kong







Italy
Kenya
Poland
Spain
Slovenia
Switzerland
USA
Reduction of EOGBS
incidence in other countries
•
•
•
•
Australia 82%
Spain 86%
France 71%
USA 86%
(Daley et al, 2004)
(Andreu et al, 2003)
(Albouy-Llaty et al, 2011)
(Jordan et al, 2008)
Known risk factors for
EOGBS infection
• Previous GBS baby
• GBS bacteriuria current pregnancy
10 x
• GBS found current pregnancy
• Maternal intrapartum fever (>380C)
• PROM >18 hours before birth
• Preterm labour
4x
3x
3x
3x
3x
40% of EOGBS babies have no risk factors
Without routine testing mums, these aren’t identified as
being at risk - not preventable without testing
“Gold Standard” test for
GBS carriage
• When?
– 35-37 weeks of pregnancy
• Where & who?
– Low vagina & anorectal swab/s (no speculum)
– Health care professional or pregnant woman
• What culture method?
– Enriched Culture Medium (ECM) - 24-48 hours to grow
HPA BSOP58 Processing Swabs for GBS carriage
What GBS tests for carriage
are available in the UK?
• NHS: not routine but if offered, usually:
– High vaginal swab, sometimes using speculum
– Direct agar plating (misses up to 50% of carriers)
• Privately + a few NHS trusts:
– Low vaginal & rectal swab(s)
– Enriched Culture Medium (very predictive for 1-5 weeks)
• Private PCR:
– Low vaginal & rectal swab(s)
– Potentially intrapartum (some less than 2 hours)
– Not validated for use in the UK (though approved by FDA &
Health Canada & bears CE mark for Europe)
BMJ 2007. Preventive strategies for group B
streptococcal & other bacterial infections in
early infancy: cost effectiveness & value of
information analyses. (Colbourn et al)
• Current best practice (treating only high
risk women) not cost effective
• Adding culture testing for low risk term
women & treating all preterm & high risk
women would be the most cost effective
option
Health Technology Assessment 2009.
Rapid testing for group B Streptococcus during
labour: a test accuracy study with evaluation of
acceptability & cost-effectiveness. (Daniels et al)
• Routine intrapartum antimicrobial prophylaxis
to all women without screening most cost
effective (rejected).
• After this, culture based screening at 35–
37 weeks’, with antibiotics to all women
screen positive most cost effective
(assuming all women in premature labour
receive intrapartum antimicrobial prophylaxis)
BJOG 2010. Cost-effectiveness of rapid
tests & other existing strategies for screening
and management of EOGBS during labour.
(Kaambwa et al)
• Routine intrapartum antimicrobial prophylaxis
to all women without screening most cost
effective strategy (rejected).
• Next, intrapartum antibiotic prophylaxis
directed by screening with enriched
culture cost-effective. Risk-factor-based
screening is not cost-effective compared
with screening based on culture.
Bounty Survey – May 2010
• Bounty’s Word of Mum™ omnibus surveys are
run bi-monthly from January until November.
• Word of Mum™ omnibus survey carried out
between the 19th and 31st May 2010
• 2,226 interviews with women from the early
stages of pregnancy those with a youngest child
aged 2 years.
Group B Strep awareness
Aware of Group B Strep
How/ where heard about GBS
Base: All respondents (2,226)
Base: All who are aware of GBS (1,277)
Nearly 3 in 5 mums/ mums-to-be are aware of GBS. The majority first
heard about GBS from a non-HCP source – 42% from a pregnancy book
or magazine and 21% from a friend or other mum. Only 20% of those
aware of GBS found out about it from a midwife.
Group B Strep testing
Base: All respondents (2,226)
Yes
No
All women should be informed about GBS by GP/ midwife during
pregnancy
95%
5%
Reliable test should be offered on NHS to all pregnant women
94%
6%
Would have/ would have had test if it had been offered
94%
6%
All pregnant women should be told about option to have private test
costing £32
94%
6%
The is widespread though amongst mums that they should be made more
aware of GBS testing – from awareness in pregnancy through to being
offered a test on the NHS or the option to pay for one. 56% would pay to
have the private test. A quarter would like to have the test but couldn’t
afford to pay for it.
What happens after delivery?
• Mums of most babies identified as at
risk will receive 4+ hours antibiotics
in labour to prevent EOGBS infection
• Those who don’t?
• No clear guidance
• 90% EOGBS <12 hours
Babies born at increased risk
Mum has had less than 2 hours IAP:
• Examined thoroughly & investigated by a
Paediatrician as appropriate
• Observed for at least 12 hours (ideally 24)
Mum has had more than 2 hours IAP:
• Carefully assessed by appropriately trained
Paediatrician or ANNP
• Monitoring (12-24 hours) for those at highest risk
No antibiotics for baby if completely healthy – if
any doubt, antibiotics until infection ruled out
Typical signs of early-onset
GBS infection
•
•
•
•
•
•
•
•
•
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 signs of late onset
GBS infection
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
fever;
poor feeding and/or vomiting;
impaired consciousness;
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.
Topical issues
Reinfection risk 1-3%
Multiple Births:
• IV antibiotics to other baby/babies if one infected.
GBS carriers breastfeeding:
• Recommended antibiotics safe for breastfeeding
• Advantages of breastfeeding outweigh remote risk of
transmitting GBS
Hand washing:
• Everyone should before handling a baby 0-3 months.
www.gbss.org.uk
Key facts
GBSS Stand 12
• Approx 25% of women carry GBS
• 1 : 300 babies develop EOGBS born GBS
carriers (no IAP)
• 1 : 6000 babies develop EOGBS born GBS
carriers (with IAP)
• 40% of EOGBS babies have no known risk
factors (unknown maternal carriage)
http://www.gbss.org.uk/epetition
seeking better prevention of EOGBS infection