Attachment 10
PROTECTING BABIES AGAINST INFECTIONS CARRIED
BY THEIR MOTHERS
PUBLIC HEALTH
IMPORTANCE
Around 300 babies are born to HIV infected mothers
in the UK each year, a more than fivefold increase since the early
1990s. In the UK, hepatitis B infections are mainly acquired in
adulthood. Estimates indicate that there are between 600 and 2,000
women with infectious hepatitis B giving birth each year in England
and Wales. Although hepatitis B perinatal transmission accounts
for only 5 per cent of infections in England and Wales, it is
responsible for 30 per cent of the infections leading to chronic
hepatitis B carriage. Consequently each year substantial numbers
of children become infected by their mothers with HIV or hepatitis
B virus (HBV). Almost all these infections are preventable.
There are substantial health inequalities in
this burden of infection and in the availability of prevention
services. Mothers who have lived in Africa (for HIV) and other
resource-poor countries (hepatitis B) are mostly affected. Though
there have been improvements, eg in parts of London, it remains
the case that the majority of pregnant women infected with HIV
are unaware of their infection and cannot take advantage of recent
medical advances that could protect their children. The situation
is little better for Hepatitis B.
OPPORTUNITY FOR
HEALTH GAIN
An HIV positive mother can now almost completely
eliminate the risk of passing her infection on to her child by
taking antiviral drugs. This relatively inexpensive medication
has reduced the probability of her child becoming infected from
one in three to less than one in 50. In this way the number of
babies born with HIV in the UK could be reduced from around 60
to under 10 per annum. Aside from the personal benefit, with overall
HIV care already costing over £200 million per annum in England,
the importance of maximising the chances of preventing new infections
is obvious. Similarly, a mother with acute or chronic hepatitis
B infection can reduce the risk of passing on her infection to
her baby by 90 per cent by agreeing to immunisations of her baby
at birth and in the first year of life. To take advantage of these
interventions mothers with HIV and HBV infections must, of course,
be aware of the risk. While testing before pregnancy would be
optional the most pragmatic approach to it is through routine
antenatal testing.
ORGANISATIONAL ARRANGEMENTS
Following reviews by the UK National Screening
Committee, the Department of Health has indicated that HIV testing
should be routinely offered and recommended across England as
of December 2000 (Health Services circular No 1999/183). That
has also been the case for HBV since April 2000 (HSC 1998/127).
The organisation of antenatal HIV testing requires everyone involved
in antenatal care, including GPs, to make HIV a priority and to
present a consistent message to mothers. The same is true for
HBV. Microbiology services have to deliver a highly accurate testing
service for both viruses, with particular emphasis on avoidance
of false positive results which might undermine confidence in
the programme. Once a mother is discovered to be infected with
HIV she must receive prompt high quality care, advice and support,
including treatment of her own infection. For both infections,
a crucial issue is to ensure that children are followed up and
the required treatment/immunisations are delivered in primary
or other care contexts. These arrangements require co-ordination
across a wide range of agencies including Department of Health,
NHS Executive, District Health Authorities, NHS Hospital and Community
Trusts, and Primary Care Groups/Trusts. Voluntary, non-governmental
and community based organisations play a crucial role in promoting
antenatal testing and care of infected women.
CURRENT ORGANISATIONAL
DIFFICULTIES
Data gathered by the PHLS and its collaborators
indicate that, for HIV, the greatest determinant of whether a
pregnant woman is offered and receives an HIV test, and HIV infection
is diagnosed, has been the hospital or practitioner giving antenatal
care, and/or where she lives. In London the proportion of all
births to HIV infected mothers that were detected rose from 15
per cent in 1996 to 50 per cent in 1999, but there are still areas
of poor performance and outside the capital it remains the case
that a woman will rarely be routinely offered a test. Antenatal
screening services are often unco-ordinated locally, and the statistics
required for performance monitoring (such as the proportion of
women screened or offered screening) are often not routinely available.
A Department of Health Task Force, supported by the PHLS and others,
is starting to address this but the new arrangements for primary
care may not help, especially as infections are not a priority
in Our Healthier Nation and progress on the national Communicable
Disease Strategy has been slow.
POTENTIAL SOLUTIONS
PHLS provides primary and reference testing,
epidemiological data, data for policy development performance
monitoring and specialist advice. However, national and local
roles and responsibilities must be clarified and antenatal screening
services co-ordinated. Data systems should provide data for monitoring
the offering and acceptance of HBV, HIV and other routine antenatal
tests. All HIV and HBV positive blood samples should be sent for
confirmation to the network of reference laboratories co-ordinated
by PHLS.
CONCLUSION
Despite the public health importance and potential
for health gain, the UK is still under-performing on antenatal
screening for HIV and HBV. A more co-ordinated approach is essential
for success.
REFERENCE
Intercollegiate Working Party for Enhancing
Voluntary Confidential HIV Testing in Pregnancy Reducing mother
to child transmission of HIV infection in the UK. Royal College
of Paediatrics and Child Health, London, 1998.
Prepared by Drs Angus Nicoll, Philip Mortimer
and Koye Balogun and Mrs Susan Cliffe, Public Health Laboratory
Service.
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