Download Ante-Natal screening

To screen or not to screen
ANTENATAL SCREENING
Jim Gray
Consultant Microbiologist
Birmingham Women’s Hospital
[email protected]
Overview
• Current infection screening arrangements
o National Screening Committee Programme
o Other
• How screening might change
• Future research opportunities
To Screen or Not to Screen
Antenatal screening
Stakeholders
• National Screening
Committee
• Department of Health
• Public Health England
• NICE
• RCOG
NHS Infectious Diseases in Pregnancy
Screening Programme
Uptake >97%
•
•
•
•
1,749/688,755 (0.25%) HIV-positive
3,982/690,760 (0.58%) hepatitis B positive
944/678,611 (0.14%) syphilis-positive
44,650/677,479 (6.59%) rubella non-immune
Infection screening in pregnancy
NSC Infectious Diseases in Pregnancy Screening
Programme
•
•
•
•
HIV
Hepatitis B
Syphilis
Rubella immunity
NSC endorsed screening
• Asymptomatic bacteriuria
Other screening
• Chlamydia
• GBS
• AMR bacteria
NHS Infectious Diseases in Pregnancy
Screening Programme (2013)
Uptake >97%
•
•
•
•
1,749/688,755 (0.25%) HIV-positive
3,982/690,760 (0.58%) hepatitis B positive
944/678,611 (0.14%) syphilis-positive
44,650/677,479 (6.59%) rubella non-immune
HIV screening
AIM
• To prevent paediatric HIV infection
OBJECTIVES
• To identify all HIV positive women
• To ensure the rapid referral of all HIV positive
women for assessment and management within a
multi-disciplinary team
Hepatitis B screening
AIM
• To prevent perinatal hepatitis B infection
OBJECTIVES
• To ensure all hep B +ve women are identified
• To ensure all hep b +ve women are referred for
specialist assessment and management within 6
weeks
• To ensure infants are appropriately vaccinated; 1st
dose within 24 h & schedule completed
Syphilis screening
AIM
• To prevent congenital syphilis infection
OBJECTIVES
• To identify all women with positive syphilis
screening test results early in pregnancy
• To ensure their rapid assessment by an
appropriate specialist, e.g. GUM within a multidisciplinary environment
Rubella screening
AIM
• To reduce the risk of congenital rubella in future
pregnancies
OBJECTIVES
• To ensure all women susceptible to rubella infection
(<10 IU/ml) are identified
• To ensure these women are offered postnatal MMR
• To ensure that the 1st dose is administered prior to
discharge from maternity services, & the GP is
contacted regarding the 2nd dose
How accurate is rubella immunity screening?
UK NEQAS distribution 3148
Method
Range
Median
5-95%
Abbott Architect
7-30
8
7-10
Abbott AxSYM
8-34
12
9-22
Beckman Access
12-18
14
12-17
Biokit Bioelisa
7-28
14
8-19
bioMerieux Vidas
1-23
17
14-19
DiaSorin
7-11
9
8-11
DiaSorin Liaisaon
5-11
8
6-11
OCD Vitros
9-12
10
9-12
Roche
12-230
194
179-222
Siemans Immunlite
12-33
13
12-25
Siemans ADVIA
29-43
34
29-41
Siemens EIA
9-28
12
10-21
ALL METHODS
12
How accurate is rubella immunity screening?
UK NEQAS distribution 3148
Method
Range
Median
5-95%
Abbott Architect
7-30
8
7-10
Abbott AxSYM
8-34
12
9-22
Beckman Access
12-18
14
12-17
Biokit Bioelisa
7-28
14
8-19
bioMerieux Vidas
1-23
17
14-19
DiaSorin
7-11
9
8-11
DiaSorin Liaisaon
5-11
8
6-11
OCD Vitros
9-12
10
9-12
Roche
12-230
194
179-222
Siemans Immunlite
12-33
13
12-25
Siemans ADVIA
29-43
34
29-41
Siemens EIA
9-28
12
10-21
ALL METHODS
12
How accurate is rubella immunity screening?
UK NEQAS distribution 3148
Method
Range
Median
5-95%
Abbott Architect
7-30
8
7-10
Abbott AxSYM
8-34
12
9-22
Beckman Access
12-18
14
12-17
Biokit Bioelisa
7-28
14
8-19
bioMerieux Vidas
1-23
17
14-19
DiaSorin
7-11
9
8-11
DiaSorin Liaisaon
5-11
8
6-11
OCD Vitros
9-12
10
9-12
Roche
12-230
194
179-222
Siemans Immunlite
12-33
13
12-25
Siemans ADVIA
29-43
34
29-41
Siemens EIA
9-28
12
10-21
ALL METHODS
12
Rubella screening
• Screening for rubella susceptibility does not meet the
UK NSC criteria for a screening programme.
• The IDPS programme is currently working
collaboratively with the PHE Immunisation team and
plan to cease antenatal screening for rubella
susceptibility. The present arrangements for antenatal
screening and post-partum immunisation will
continue until other arrangements are in place.
Screening for asymptomatic bacteriuria
External review of screening for ASB in pregnancy
for the UKNSC July 2011
• Policy should continue but justification changed from
prevention of preterm delivery to prevention of
pyelonephritis
• Not clear whether the test should use culture
NICE CG62: Antenatal care for
uncomplicated pregnancies
Women should be offered routine screening for
asymptomatic bacteriuria by midstream urine
culture early in pregnancy. Identification and
treatment of asymptomatic bacteriuria reduces the
risk of pyelonephritis.
Asymptomatic bacteriuria in pregnancy
• Symptomatic UTI in pregnancy is frequently
preceded by asymptomatic bacteriuria
o Prevalence is around 5%
o Untreated, at least 30% of women with ASB will develop
acute pyelonephritis
• Screening for ASB is considered to be a cost
effective approach to preventing pyelonephritis
A screening programme may prevent 6480 cases of pyelonephritis per
year
Asymptomatic bacteriuria in pregnancy
Many research questions
• What is the clinical & cost effectivness of
screening?
• How should screening be undertaken?
• When should screening be undertaken?
• How should women with ASB be monitored during
their pregnancy?
Until it is clear that antenatal screening for GBS
carriage does more good than harm and that the
benefits are cost-effective, the National Screening
Committee does not recommend routine screening in
the UK.
Is this statement not also true of the
antenatal ASB screening?
ASB screening – where does this leave us?
• Culture is said to be more accurate than dip
testing, but we don’t know whether dip testing is
accurate in identifying women at risk of PN
• We don’t know what the impact of ASB screening
is on antibiotic use antenatally
o Too much? (because we treat people who don’t need
treatment)
o Too little? (because without coordinated arrangements
to oversee patient management there is no assurance
that all women with ASB receive treatment )
Other NICE recommendations
Chlamydia trachomatis
• At the booking appointment, healthcare
professionals should inform pregnant women
younger than 25 years about the high prevalence
of chlamydia infection in their age group, and give
details of their local National Chlamydia Screening
Programme.
• Chlamydia screening should not be offered as part
of routine antenatal care.
More NICE recommendations
Do not screen for:
•
•
•
•
•
Bacterial vaginosis
CMV
Hepatitis C
Toxoplasmosis
Group B Streptococci (GBS)
The Prevention of Early-onset Neonatal
Group B Streptococcal Disease
RCOG Green–top Guideline No. 36
Until it is clear that antenatal screening for GBS
carriage does more good than harm and that
the benefits are cost-effective, the National
Screening Committee does not recommend
routine screening in the UK.
The Prevention of Early-onset Neonatal
Group B Streptococcal Disease
RCOG Green–top Guideline No. 36
IAP offered to:
• Women with a previous baby with neonatal GBS
disease
• Women with GBS in current pregnancy
• Women who are pyrexial in labour should be
offered broad-spectrum antibiotics including an
antibiotic for prevention of neonatal EOGBS
disease
The Prevention of Early-onset Neonatal
Group B Streptococcal Disease
RCOG Green–top Guideline No. 36
Role of IAP unclear for:
• Women with preterm labour (<37 weeks’
gestation) and prelabour rupture of membranes of
any duration
• Women with preterm labour & prolonged rupture
of membranes (>18 h)
What would be the aim of GBS screening?
• To prevent neonatal GBS disease by
administering intrapartum antibiotic
prophylxis (IAP) to mothers during labour
• To assist in ruling out infection in newborn
babies with soft signs of infection
What would be the aim of GBS screening?
600,000 deliveries pa
60,000 babies treated
with antibiotics
300 babies with GBS
early-onset neonatal
sepsis
300 babies with nonGBS early onset sepsis
59,400 babies without
infection treated with
antibiotics
ALL PREGNANT WOMEN:
RISK FACTORS FOR GBS
NO
YES
80% of women
20% of women
NO ANTIBIOTICS
GIVEN
INTRAPARTUM
ANTIBIOTICS
GIVEN
A small number of
these women will
deliver a GBS-infected
baby
Only around 30% of
these women will have
GBS; 70% (14% of all
labouring women) will
receive IAP that is of no
value
Cepheid GeneXpert GBS
• Moderately
complex testing
with < 1 min handson time
• Results turnaround
time 55 minutes
• Manufacturer
claims 99.0%
sensitivity and
92.4% specificity
GBS1
ALL PREGNANT WOMEN:
RISK FACTORS FOR GBS
Universal PCR
screening not
cost effective
NO
YES
80% of women
20% of women
NO ANTIBIOTICS
GIVEN
INTRAPARTUM
ANTIBIOTICS
GIVEN
A small number of
these women will
deliver a GBS-infected
baby
Only around 30% of
these women will have
GBS; 70% (14% of all
labouring women) will
receive IAP that is of no
value
GBS2
Implementation of modified admission
MRSA screening guidance for NHS (2014)
• Trusts should:
o Identify and screen patients in high MRSA risk
specialties, e.g. adult/paediatric ICUs, NICUs,
HDUs
o Identify and re-screen any patient previously
known to be MRSA positive
Public Health England: Acute trust toolkit for the early
detection, management and control of carbapenemaseproducing Enterobacteriaceae (CPE)
• Suspected case: a patient who, in the last 12 m,
has been an inpatient in a hospital abroad or a
UK hospital which has problems with spread of
CPE or is a previously +ve case
• Management: take rectal swab & isolate patient
(with en-suite). Apply strict standard precautions
until three conseutive negative rectal swabs
collected 48 h apart
Conclusions
• The UKNSC Infection Screening Programme is
highly effective
• However, there is a lot of additional antenatal
infection screening that is not performed in a
systematic and coordinated way
•
If this screening is clinically- and cost-effective why
could it not be incorporated into the highly effective
management arrangements that already exist for the
UKNSC Programme?