Docstoc

GBS Group Strep Support

Document Sample
GBS Group Strep Support Powered By Docstoc
					Preventing early-onset group B
   Streptococcal infection
      in newborn babies


                                                      January 2009
         Charity No. 1112065 Company Reg No 5587535
Group B Streptococcus – overview 1

 Streptococcus agalactiae
    Group B Strep, Strep B, beta haemolytic Strep

 First recognised as a major perinatal pathogen in the 1970s
 Incidence of GBS infection increasing in the UK

                           Culture proven cases of GBS infection (all ages)
                                       in England, Wales & NI

                    2007

                    2006

                    2005

                    2004

                    2003

                    2002

                           0                500             1000              1500

                                                                       Source: Health Protection Agency



                               Charity No. 1112065 Company Reg No 5587535                                 2
Group B Streptococcus – overview 2

 Commonest cause of bacterial infection in newborn babies
     Underlying rate estimated at 1:1000 newborn babies in the UK
            UK research suggests actual rate 3.5 per 1000 (Luck et al, 2003)
     Mortality rate approximately 11%
     50% of survivors of GBS meningitis will have neurological sequelae

 Early-onset and late-onset presentation of GBS infection
       Up to 90% GBS infection apparent within 48 hours of birth
 Remains uniformly sensitive to penicillin
    Some tolerance to other antibiotics
            Clindamycin around 8% is resistant
            Erythromycin around 11% is resistant




                             Charity No. 1112065 Company Reg No 5587535         3
Reported cases of GBS bacteraemia in infants*,
England & Wales 2000-2007


 450
 400
 350
                                                                                            6-11 months
 300
                                                                                            3-5 months
 250
                                                                                            1-2 months
 200
                                                                                            1-3 weeks
 150
                                                                                            <1week
 100
  50
    0
     2000     2001      2002      2003     2004       2005      2006       2007


Source: Health Protection Agency, 2008                           *excludes a small number of infants with imprecise age data


                                   Charity No. 1112065 Company Reg No 5587535                                                  4
 GBS – Colonisation

 Normal flora in intestinal tract and vagina
    Carriage can be intermittent
    Carriage is asymptomatic
    Up to 30% adults carry GBS in intestines
    Up to 25% of women carry GBS in the vagina
    Occasionally in the throat (around 5%)

 90% of adults do not have protective antibodies to GBS

 GBS can cross intact amniotic membranes
       GBS grows well in amniotic fluid

 GBS survives well on skin of newborn infants

 GBS colonisation at delivery – risk factor for early-onset GBS disease
       Cultures late in pregnancy can predict GBS colonisation status at delivery



                               Charity No. 1112065 Company Reg No 5587535            5
Testing Antenatally for GBS carriage

                                     GBS carriage can be intermittent so best to swab
                                     close to delivery.
  Between 35 and 37 weeks            Sensitive tests taken within 5 weeks of delivery are highly
                                     predictive of carriage at delivery (Yancey et al 1996)

                                     Low vaginal plus anorectal swabs (can use either
     Must take vaginal
                                     one or two swabs) are much more effective than
     and rectal swabs                high vaginal swabs
                                        LIM broth (10mL Todd-Hewitt broth supplemented
                                         with 10µg/mL colistin and 15µg/mL nalidixic acid) then
                                         subcultured to blood agar)
     Must use selective                 Recognised as optimal for detecting GBS
   enrichment medium to                  carriage by the Royal College of Obstetricians
                                         & Gynaecologists and The Health Protection
       culture swabs                     Agency (BSOP 58)
                                        Available privately and from a handful of NHS
                                         hospitals (contact GBSS for availability)
    STANDARD CULTURE                 Standard culture method (direct plating) instead
  METHOD TOO INSENSITIVE             of using enriched culture medium reduces
                                     detection by 50%
        FOR testing
                         Charity No. 1112065 Company Reg No 5587535                                6
Options to reduce GBS infection in newborn babies

 Waiting & treating babies after delivery
    Too late for some & won’t prevent most GBS infection
    Difficult to justify

 Intravenous antibiotics in labour (IAL)
    Only effective method of prevention available at present
    Largest study performed in Chicago (Boyer et al. N Eng J Med
         1986;314:1665)
        Penicillin G recommended (Clindamycin for penicillin-allergic women)
 Oral antibiotics
    Don’t eradicate colonisation or reduce infection
    Likely to increase resistance
    Exception is GBS cultured from urine (treat with oral antibiotics and offer
      IAL)
 Intramuscular antibiotics
    Theory – reduces GBS presence ≤6 weeks, so given at 35+ weeks
    One small study – poorly designed & no GBS grown in control or active
       group

                                Charity No. 1112065 Company Reg No 5587535         7
Who should be offered intravenous antibiotics in
labour (IAL)?

      women who have one or more risk factors (including incidental finding of
      GBS carriage or GBS +ve urine culture) during the current pregnancy OR
      women identified as GBS carriers through testing (using enriched culture
      media) at 35-37 weeks of pregnancy OR
      women identified as GBS carriers through enriched culture media testing at
      35-37 weeks of pregnancy and who have one or more other risk factors OR
      women found to carry GBS through enriched culture media testing at 35-37
      weeks of pregnancy PLUS women who have one or more other risk factors



                Women should be offered an informed choice




                        Charity No. 1112065 Company Reg No 5587535                 8
Option 1: Risk Factor Approach
IAL offered to all women with one or more risk factors

Offer intravenous antibiotics in labour (IAL)                             Pros and Cons
to women who have:
                                                                     >40% of cases will still occur,
  a previous baby with GBS infection                                 since this will only prevent
                                                                      GBS infections where risk
  GBS bacteria found in the urine during                             factors are apparent in time
   the current pregnancy (which should be                             for IAL to be offered
    treated at the time of diagnosis)
                                                                     Supported by RCOG Green
  GBS found on a vaginal or rectal swab                              Top Guideline No 36
   during the current pregnancy                                      Not tested in a trial
  a raised temperature (≥37.8°C) during                             Relatively cheap to introduce
   labour                                                             & operate (no bacteriological
                                                                      testing costs involved)
  preterm labour or membrane rupture
    (<37 completed weeks of pregnancy)                               Relatively large amounts of
                                                                      antibiotics prescribed (about
  prolonged rupture of membranes (≥18                                30% of all women)
    hours before delivery)


                             Charity No. 1112065 Company Reg No 5587535                                 9
Option 2: Testing Approach
IAL offered only to women identified as GBS carriers

 Offer sensitive enriched                                    Pros and Cons
  culture medium (ECM)
                                                  Up to 80% potential cases prevented
  testing to all women at 35-
                                                          A few women will acquire carriage
  37 weeks of pregnancy                                    between testing and delivery*; some
                                                           carriers will miss or decline testing and
 Offer intravenous                                        some will deliver before test result
                                                           available
  antibiotics in labour (IAL)
                                                  Not tested in a trial
  to women identified as
                                                  ECM testing for GBS carriage not
  GBS carriers during their
                                                   routinely or widely available in the NHS
  current pregnancy                                    (despite being recognised as optimal by
                                                       RCOG & HPA)
                 * Yancey research found          More expensive to introduce
                 4% of women with negative
                 results at 35-37 weeks of        Relatively large amounts of antibiotics
                 pregnancy would become            prescribed (~30% of women)
                 positive and 13% of women
                 with positive results would
                 become negative



                             Charity No. 1112065 Company Reg No 5587535                                10
Option 3: Combined Approach 1
IAL offered to GBS carriers with a risk factor

 Offer all women sensitive                                       Pros and Cons
  enriched culture medium (ECM)                    >40% of cases will still occur – this
  testing at 35-37 weeks                            can only prevent GBS infection where
                                                    risk factors are apparent in time for
 Offer intravenous antibiotics in
                                                    IAL to be offered
  labour (IAL) to those identified
  as GBS carriers during the                               A few women will acquire carriage
  current pregnancy who also                                between testing and delivery (see
  have one or more risk factors:                            previous slide), some carriers will miss or
                                                            decline testing and some will deliver
      Preterm labour or membrane                           before test result is available
       rupture (<37 completed weeks of
       pregnancy)                                  Well researched
      Prolonged rupture of membranes              ECM testing for GBS carriage not
       (≥18 hours before delivery)
                                                    routinely or widely available in the
      Maternal pyrexia (≥ 37.8oC)                  NHS (despite being recognised as optimal by
      GBS from a urine culture during the             RCOG & HPA)
       current pregnancy
                                                   More expensive to introduce
      Previous baby with GBS infection
                                                   Fewer women receive antibiotics ~5%
                               Charity No. 1112065 Company Reg No 5587535                                 11
Option 4: Combined Approach 2
IAL to GBS carriers & to women with 1+ risk factors

 Offer all women sensitive enriched                          Pros and Cons
  culture medium (ECM) testing at
  35-37 weeks                                      Most >80% potential cases
                                                    prevented
 Offer intravenous antibiotics in
  labour (IAL) to those identified as              Not tested in a trial
  GBS carriers during the current
  pregnancy plus to any with one or
  more risk factors:                               ECM testing for GBS carriage not
                                                    routinely or widely available in the
      Preterm labour or membrane                   NHS (despite being recognised as optimal
       rupture (<37 completed weeks)                    by RCOG & HPA)
      Prolonged rupture of membranes
                                                   Less expensive – fewer women
       (≥18 hours before delivery)
                                                    offered sensitive testing as higher-risk
      Maternal pyrexia (≥ 37.8oC)                  women offered IAL without testing
      GBS from a urine culture during             Relatively large amounts of antibiotics
       the current pregnancy
                                                    prescribed (~30% of pregnant women)
      Previous baby with GBS infection


                            Charity No. 1112065 Company Reg No 5587535                         12
Incidence of EO and LO GBS in 3 active surveillance
areas in USA


     2
   1.8
   1.6
   1.4
   1.2
                                                                                early-onset
     1
   0.8                                                                          late-onset
   0.6
   0.4
   0.2
     0
   90

   91

   92

   93

   94

   95

   96

   97

   98

   99

   00
 19

 19

 19

 19

 19

 19

 19

 19

 19

 19

 20
Source: N Engl J Med 2000;342:15-20 & p.c. A Schuchat

                                   Charity No. 1112065 Company Reg No 5587535                 13
UK Guidelines for Prevention:
NICE Antenatal Care Guideline CG6 Oct 03 - 1

Guideline updated March 2008 - No update to GBS sections despite
significant new evidence since 2003 and despite requests by a number of
stakeholders. Next review due March 2010

 Don’t recommend screening as “evidence of its clinical
  effectiveness and cost effectiveness remains uncertain.”
       All the evidence shows testing and offering intravenous
        antibiotics in labour (IAL) to higher-risk women is clinically
        effective. Where introduced, reductions of over 70% in incidence,
        including the US, Australia, New Zealand, Belgium, France, Spain & Italy.
       The cost/benefit analysis sponsored by the HTA, published
        September 2007 shows current practice is not cost effective –
        testing low-risk women and offering IAL to high risk women was shown to
        be most cost effective while limiting antibiotic use (Preventative strategies for
        group B streptococcal and other bacterial infections in early infancy: cost
        effectiveness and value of information analyses. BMJ. 2007 Sep. Colbourn et al)


                             Charity No. 1112065 Company Reg No 5587535                     14
UK Guidelines for Prevention:
NICE Antenatal Care Guideline CG6 Oct 03 - 2
Guideline updated March 2008 - No update to GBS sections despite
significant new evidence since 2003 and despite requests by a number of
stakeholders. Next review due March 2010


 “Pregnant women should be offered information based on the
  current available evidence together with support to enable
  them to make informed decisions about their care..”
      Yet information on GBS is not widely nor routinely available.
      Sensitive tests for GBS are only available privately and from a
       handful of NHS hospitals.
      Women are not told about the availability of sensitive tests for
       detecting GBS late in pregnancy.
How can women make an informed decision when they’re not
              being given the information?

                          Charity No. 1112065 Company Reg No 5587535      15
UK Guidelines for Prevention:
Royal College of Obstetricians & Gynaecologists 1

RCOG Green Top Guideline No 36 "Prevention of early onset neonatal Group B
streptococcal disease" 2003 (currently being reviewed - due 2010)


    Risk factor approach
           Estimates relative risk for morbidity or mortality for
            recognised risk factors
    Incidence assumptions significantly underestimate GBS
     infection, so underestimate the relative risks and
     overestimate the numbers needed to treat for benefit
           Authors of the source of incidence figures (Heath et all,
            2004) estimate under-reporting of 21-42%
           Incidence figures exclude probable cases of GBS infection
            (Luck et al 2002), including only cases where GBS was culture-
            proven from a normally sterile site, eg CSF or blood
           Incidence of GBS infection in babies increasing (HPA)


                          Charity No. 1112065 Company Reg No 5587535         16
UK Guidelines for Prevention:
Royal College of Obstetricians & Gynaecologists 2

RCOG Green Top Guideline No 36 "Prevention of early onset neonatal Group B
streptococcal disease" 2003 (currently being reviewed - due 2010)

 Will prevent most lethal cases of EOGBS infection when fully
  implemented
      RCOG audit Jan 2007 shows few hospitals fully comply

 Until sensitive testing is routinely available for all pregnant
  women, GBSS endorses these guidelines
      They are a key starting position to preventing early onset GBS
       infection
      More infections in babies could be prevented by offering sensitive
       testing to pregnant women




                         Charity No. 1112065 Company Reg No 5587535          17
GBSS Recommendation: 1


    Sensitive (enriched culture medium) tests for GBS carriage
     using rectal & vaginal swabs should be freely available to
         all low-risk women at 35-37 weeks of pregnancy

    Pregnant women should be informed about GBS, including
       about testing, as a routine part of their antenatal care

   Intravenous antibiotics in labour should be offered to women:
      identified as GBS carriers in the current pregnancy
      with ≥ 1 other risk factors (no testing required)
            previous baby with GBS infection
            positive urine sample during this pregnancy
            preterm labour or rupture of membranes <37 completed weeks of pregnancy
            prolonged rupture of membranes ≥18 hours before delivery
            maternal pyrexia ≥ 37.8oC



                          Charity No. 1112065 Company Reg No 5587535                   18
GBSS Recommendation: 2

  Until sensitive tests for GBS carriage are freely and routinely
      available to all women at 35-37 weeks of pregnancy:

  Pregnant women should be informed about GBS as a routine
     part of their antenatal care
  Where sensitive GBS tests are unavailable in the NHS, pregnant
      women should be informed how to obtain them privately
  Intravenous antibiotics in labour should be offered to women:
        who have previously had a GBS baby
        where GBS is found in the urine during the current pregnancy (also
         treated at diagnosis)
        identified as carriers (any test method) during the pregnancy
        not tested using sensitive tests but with ≥ 1 other risk factors:
             Prolonged rupture of membranes ≥18 hours before delivery
             Preterm labour or membrane rupture <37 completed weeks of pregnancy
             Maternal pyrexia ≥ 37.8oC


                           Charity No. 1112065 Company Reg No 5587535               19
Intrapartum Antimicrobial Prophylaxis


                     Penicillin G

                                3 g (or 5 mU) IV initially and then 1.5 g (or
                                 2.5 mU) at 4-hourly intervals until delivery.

                     Clindamycin

                                For women who are allergic to penicillin,
                                 900 mg IV every 8 hours until delivery.


                     Intravenous antibiotics should be given for at least
                     4 hours before delivery, where possible

                                lesser times are better than nothing and 2+
                                 hours should give considerable reassurance.



                 Charity No. 1112065 Company Reg No 5587535                      20
Option 6: Intravenous Antibiotics in Labour Chart



                                                                                    One of:
      Offer                                                   Women found to carry GBS during
      Intravenous antibiotics at the start of, and
                                                                 pregnancy
      at intervals during, labour to women at
      raised risk of their baby developing GBS                GBS found in urine during pregnancy
      infection
                                                              Preterm labour or membrane rupture
                                                                 <37 weeks of pregnancy
                                                              Prolonged rupture of membranes
      Strongly                                                   ≥ 18-24 hours before delivery
                                                              Maternal pyrexia 37.8°C or higher during
      recommend                                                  labour*
      Intravenous antibiotics at the onset of,
      and during, labour to women
                                                              Two or more of above risk factors
      at particularly high risk of their baby
      developing GBS infection
                                                              Previous baby developed GBS infection



   *In the presence of an epidural, a slightly raised temperature may be of less significance than in a
   woman without
                                       Charity No. 1112065 Company Reg No 5587535                         21
Paediatric prevention strategy for babies born
at higher risk

Signs of possible                            Full work up
infection in neonate or          YES         Intravenous antibiotics
mother
                                             Review at 48 hours
            NO
Gestational age ≤ 35                         Full work up
weeks of pregnancy               YES         Intravenous antibiotics
                                             Review at 48 hours
           NO                                                               BABY WORK UP

Maternal intravenous                         Full work up                   FBC (Full Blood Count)

antibiotics pre-delivery                                                    CRP (C reactive protein)
                                  YES        Intravenous antibiotics        x2, 12 – 24 hours apart
< 4 hours
                                             Review at 48 hours             Blood Culture
           NO                                                               2 swabs – throat and
                                                                            periumbilical
Maternal intravenous                         No work up
antibiotics Pre-delivery > 4                 Baby discharged                Urine antigen Optional,
                                 YES         Parental awareness of          according to availability
hours AND mother with no
signs of infection
                                             early signs of infection       and personal preference
                                             Handout
                               Charity No. 1112065 Company Reg No 5587535                           22
Babies Colonised with GBS



       Culture results are ‘history’
             Swabs from baby
             Vaginal swab at time of delivery


       Antibiotic treatment for a healthy colonised baby
        is not indicated


       Can send baby home, but ‘educate’ parents
             what symptoms to watch for
             what to do if they develop




                       Charity No. 1112065 Company Reg No 5587535   23
Transmission of GBS to baby



                                  Mother colonised
                                                      GBS GBS at
                                Mother colonised with with at delivery
                                              delivery
                                               (up to 30% of women)
                                             (up to 30%of women)




                                             50%
                                            50%                                     50%
                                                                                    50%
                                 Baby colonised with GBS
                               Baby colonisedwith GBS                      Newborn baby not colonised
                                                                         Newborn baby not colonised




                     0.6%
                     0.6%
        Early-onset GBS infection
                                                                99.4%
                                                                99.4%
           Early-onset GBS infection
       septicaemia, pneumonia and/or                         Asymptomatic
                                                            Asymptomatic
                  meningitis
    (septicaemia, pneumonia and/or meningitis)



                                    Charity No. 1112065 Company Reg No 5587535                          24
Types of GBS infection (1)


     Early-onset GBS infection (EOGBS)

       Apparent within first 6 days of life, and usually within 12 -24
        hours of delivery
       Usually septicaemia with pneumonia
       Typical symptoms
             Grunting                         Abnormally high or low temperature
             Poor feeding                     Abnormally high or low heart rates
             Lethargy                         Abnormally high or low breathing rates
             Low blood pressure
             Irritability
             Low blood sugar

       Even with the best medical care, 10% of babies with EOGBS die



                        Charity No. 1112065 Company Reg No 5587535                       25
Types of GBS infection (2)


      Late-onset GBS infection (LOGBS)

       Develops 6 days - 3 months
       Usually meningitis with septicaemia
       Typical symptoms of late-onset GBS infection
             Fever
             Poor feeding and/or vomiting
             Impaired consciousness
             Plus any symptoms of meningitis

       Even with the best medical care
             5% of babies sick with LOGBS die
             up to 50% of survivors of GBS meningitis suffer long term handicaps




                         Charity No. 1112065 Company Reg No 5587535                 26
Baby successfully treated for GBS infection




           GBS infections have a               Consider low dose oral
        relatively high incidence of            penicillin daily for 3
             recurrence (1-3%)                        months




                       Charity No. 1112065 Company Reg No 5587535        27
The Future

    Rapid Near Patient Testing
          Better than testing at 35-37 weeks in informing which women are
           carrying GBS in labour
          Unfortunately, no tests currently both fast and accurate enough
          More costly than enriched culture medium testing

    Vaccine
          Best approach for preventing both EOGBS and LOGBS infection, plus
           maternal GBS infection and other adult GBS infection
          Target would be pregnant women or women before they become
           pregnant
          Vaccine needs to be multivalent
          Research is urgently needed into developing a viable vaccine for
           group B Strep infection
          Decades away – big concerns re medico-legal issues



                         Charity No. 1112065 Company Reg No 5587535            28
Key References


         Centers for Disease Control & Prevention. Prevention of Perinatal Group B Streptococcal
          Disease: Revised Guidelines from CDC. MMWR Reports & Recommendations Vol. 51(No. RR
          11) 16 August 2002.
         Heath PT, Balfour G, Weisner AM, Efstratiou A, Lamagni TL, Tighe H, O'Connell LAF,
          Cafferkey M, Verlander NQ, Nicoll A & McCartney AC on behalf of the PHLS GBS Working Group.
          Group B streptococcal disease in UK and Irish Infants <90 days of age. Lancet 2004 Jan 24, Vol
          363(9405):292.
         Luck S, Torny M, d'Agapeyeff K, Pitt A, Heath P, Breathnach A & Bedford Russell A. Estimated
          early-onset group B streptococcal neonatal disease. Lancet, 2003 Jun 07; 361(9373): 1953-1954
         PHLS Communicable Disease Surveillance Unit. Incidence of group B streptococcal disease in
          infants aged less than 90 days. CDR weekly Vol. 12(No 16):3. 18 April 2002.
         Colbourn TE, Asseburg C, Bojke L, Philips Z, Welton NJ, Claxton K, Ades AE, and Gilbert RE.
          Preventive strategies for group B streptococcal and other bacterial infections in early infancy: cost
          effectiveness and value of information analyses. BMJ 2007 335: 655
         Royal College of Obstetricians & Gynaecologists Clinical Green Top Guideline. Prevention of
          Early Onset Neonatal Group B Streptococcal Disease (36) – Nov 2003
         Law MR, Palomaki G, Alfirevic Z, Gilbert G, Heath P, McCartney C, Reid T, Schrag S on behalf
          of the Medical Screening Society Working Group on GBS disease. The prevention of neonatal
          group B streptococcal disease. J Med Screen 2005;12:60-68.
         Yancey MK, Schuchat A, Brown LK, Ventura VL, Markenson GR. The accuracy of late antenatal
          screening cultures in predicting genital GBS colonization at delivery. Obstet Gynecol Nov 1996;
          88(5):811-5.




                                Charity No. 1112065 Company Reg No 5587535                                        29
Group B Strep Support



               Registered charity set up in 1996

       Aims:          To inform health professionals and
                       individuals how most EOGBS infection can
                       be prevented; and
                      To offer information and support to families
                       affected by GBS;
                      To generate continued support for research
                       into preventing GBS infections.


                       Funded by donations


                    Charity No. 1112065 Company Reg No 5587535        30
GBSS Materials Available




  LEAFLETS                                                        POSTERS
     GBS & pregnancy (introduction for pregnant                      Pregnant? (for pregnant women)
      women)
                                                                      Labour & Delivery Prevention Guidelines
     Congratulations on the safe arrival of
      your baby (introduction for parents of a healthy                Understanding your baby’s GBS
      baby)                                                            infection    – for SCBUs
     Understanding your baby’s GBS                                   Saving Babies’ Lives – A2
      infection (introduction for parents of a GBS baby)
     For women who carry GBS (detailed leaflet
      for women who know they carry GBS)                          STICKERS
     If your baby was infected by GBS
      (detailed leaflet for parents of babies affected by GBS)        GBS Alert - 35 per page for pregnant women’s notes
     GBS: The Facts (detailed leaflet, including                     I am GBS Aware - 35 per page for pregnant women’s
      medical reference list)                                          notes




                                         Charity No. 1112065 Company Reg No 5587535                                         31
GBSS Medical Advisory Panel



      Professor Philip Steer, BSc, MD, FRCOG (Chair)
       Emeritus professor at Imperial College and consultant
       obstetrician at the Chelsea and Westminster Hospital in
       London


      Dr Alison Bedford-Russell MRCP
       Consultant Neonatologist, Birmingham Heartlands Hospital


      Dr A Christine McCartney OBE FRCPath
       Director, Regional Microbiology Network, Health Protection
       Agency Central Office




                     Charity No. 1112065 Company Reg No 5587535     32
What it’s all about ….




                                                        ……. healthy babies

                   Charity No. 1112065 Company Reg No 5587535                33

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:2
posted:9/8/2012
language:English
pages:33