Prevention strategies for early-onset group B Strep infection Risk based prevention
Testing based prevention
In November 2003, the Royal College of Obstetricians &
Most developed countries with a group B Strep prevention
Gynaecologists1 recommended that women with selected
strategy offer pregnant women tests for carriage, with IAP
risk factors for early-onset group B Strep (EOGBS) infection
offered to those carrying group B Strep, plus to those who
in their babies should be offered intrapartum antimicrobial
do not have a test result but who have risk factors. In these
prophylaxis (IAP).
countries, the rate of EOGBS infection has fallen significantly.
It had been expected that a risk-based prevention would reduce the rate of EOGBS infection by 50%2. However, the rate of EOGBS infections in babies has not fallen since the guidelines were introduced.
In the US, guidelines on preventing EOGBS disease were issued in 1996 and revised in in 2002 and 2010. These recommend that all women have vaginal-rectal testing for group B Strep colonisation at 35-37 weeks’ gestation. Implementation of the guidelines has been good. One study4 found that 85% of pregnant women were screened for group B Strep. Among those screened, 98% had results available at delivery. Eighty-five percent of women with an indication for IAP received treatment.
Group B Strep bacteraemia in babies in England, Wales & Northern Ireland 2003-2013 Slight increase since RCOG GBS guidelines introduced in Nov 2003
0.4 0.35
2.0
0.3
Rate of early and late onset group B Strep disease. Active Bacterial Core surveillance areas, 1990-2008 Abbreviations: ACOG = American College of Obstetricians and Gynecologists and APP = American Academy of Pediatrics. Source: Adapted from Jordan HT, Farley MM, Craig A, et al. Revisiting the need for vaccine prevention of late-onset neonatal group B streptococcal disease. Pediatr Infects Dis J 2008;27:1057-64. *Incidence rates for 2008 are preliminary becauase the live birth denominator has not been finalised.
0.45
RCOG GUIDELINES INTRODUCED
1ST ACOG & APP STATEMENTS EARLY-ONSET
Incidence per 1,000 live births
0.25 0.2 0.15 0.1 0.05 0 2003
2004
2005
2006
2007
Early onset rate/1000 live births
2008
2009
2010
2011
2012
LATE-ONSET
1.5 CONSENSUS GUIDELINES
1.0 REVISED GUIDELINES
0.5
2013
Late onset rate/1000 live births
0.0 Year
This graph shows culture-proven early onset (0-6 days) and late onset (7-90 days) group B Strep infections voluntarily reported to Public Health England (and its predecessors)3. The true rate will be higher. The Royal College of Obstetricians & Gynaecologists states that “Routine bacteriological screening of all pregnant women for antenatal Group B Strep carriage is not recommended.”
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
The graph shows the rate of EOGBS infection in the US5 has fallen dramatically since the introduction of IAP and screening for group B Strep carriage, although the rate of LOGBS infection has not changed. Data published subsequently shows the rates of group B Strep infection have fallen to 0.24/1,000 live births for early and 0.25/1,000 for late onset group B Strep infections in 2013.6
1 | RCOG guidelines 2003, updated 2012 http://www.rcog.org.uk/womens-health/clinical-guidance/preventionearly-onset-neonatal-group-b-streptococcal-disease-green-# 2 | Prevention of early onset neonatal Group B Strep infection. McCartney AC. Journal of Medical Screening, 2001. 3 | PHE source data http://ow.ly/FEMfW 4 | Van Dyke et al. Evaluation of Universal Antenatal Screening for Group B Streptococcus. N Engl J Med. 2009 Jun 18;360(25):2626-36. 5 | Adapted from Jordan HT, Farley MM, Craig A, et al. Revisiting the need for vaccine prevention of late-onset neonatal group B streptococcal disease. Pediatr Infect Dis J 2008;27:1057-64. 6 | Centers for Disease Control and Prevention. 2013. Active Bacterial Core Surveillance Report, Emerging Infections Program Network, Group B Streptococcus, 2013. http://www.cdc.gov/abcs/reports-findings/ survreports/group B Strep13.html
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