PREVENTION OF HIV TRANSMISSION IN THE UNITED
Though about 30,000 people are living with HIV,
the UK remains a relatively low-prevalence country, probably because
of the early interventions against HIV in the late 1980s. Since
1996, however, numbers living with HIV have been rising steadily,
by about 10 per cent per annum. This is due to two factors. Firstly,
there are new transmissions and infections being added to the
population. Secondly, combined anti-viral drugs are now allowing
people to survive who would previously have died. A consequence
of this success is that the medical costs of HIV (over £250
million in 1998-99 in England) are also rising, by more than 10
per cent per annum.
The epidemiology of HIV in the UK is also changing.
The contribution of heterosexually acquired infections is increasing
and in 1999, newly diagnosed infections acquired through this
route for the first time exceeded those acquired through sex between
men. Though many of the heterosexual infections are acquired abroad,
heterosexual transmission is also occurring in the UK, albeit
at quite low levels. Data collected by the PHLS and others indicate
that behaviours that place heterosexuals and homosexuals at risk
of acquiring HIV have probably been increasing recently. For instance,
rates of gonorrhoea have risen in both groups, with the greatest
increases being among young heterosexuals.
The main burden of HIV infection falls on homosexual
males and African ethnic minority groups, but there are also inequalities
of access, with heterosexuals in general and black Africans in
particular finding it less easy to access diagnostic and care
services. London has the largest number of people in groups at
high risk of HIV, and the capital accounts for 60 per cent to
70 per cent of all diagnosed HIV. In a broad-ranging review of
opinion among health professionals in 1999, conducted by the PHLS
(the Overview of Communicable Diseases), HIV was considered the
top priority infection.
A paradoxical effect of the success of combined
antiviral HIV therapies in sustaining healthy life, is that treatment
for HIV infected adults or children has risen dramatically. On
the other hand, the potential saving resulting from preventing
a single HIV infection has also risen. This means, for example,
that it is now justified to screen pregnant women for HIV even
in very low prevalence areas. Furthermore, preventing one infection
will often prevent others by interrupting the chain of transmission.
There is an element of complacency over HIV,
which is sometimes presented as having been "stabilised"
in western countries by international agencies. Other industrialised
countries have recently seen increases in HIV transmission among
drug injectors (Canada) and gay men (USA) which could happen here.
In the UK, the risk to homosexuals, injecting drug users and multi-partnered
heterosexuals is unabated. Perhaps the most vulnerable heterosexual
group is the Afro-Caribbean. They experience higher levels of
bacterial STDs which probably facilitate HIV transmission.
Because of its close links with developing countries,
the UK is especially likely to feel the influence of unfavourable
trends in HIV infection in these resource-poor settings. Over
60 per cent of HIV infection world-wide is in Commonwealth countries
and there are continuing close links with them at all levels.
It should not be assumed that the UK will maintain low levels
of heterosexual transmission and that the present unacceptably
high levels of homosexual HIV transmission will be contained.
Without greater preventive efforts both may rise.
The response to HIV requires co-ordination of
agencies within and beyond the health sector. Early diagnosis
of HIV infection will in future play a more important role and
health agencies, including the Department of Health, the NHS Executive,
the Health Development Agency, District Health Authorities, NHS
Hospital and Community Trusts, and Primary Care Groups/Trusts
must support testing initiatives. However, agencies outside the
health sector are equally important in reducing male homosexual
transmission and containing heterosexual transmission with voluntary,
non-governmental and community based organisations playing a crucial
role for this infection. Education, youth and social services
all play a vital role in promoting sexual health.
The role of the PHLS is to provide primary and
reference HIV testing, epidemiological data, and data analyses
to support policy development, performance monitoring and specialist
advice. In England a new AIDS Strategy will update that of 1995
which had too little impact except in the field of antenatal HIV
testing. A key issue is how this new Strategy will relate to the
broader Sexual Health Strategy and drug abuse intervention. The
PHLS feels strongly that the responsibilities of agencies over-lap
and should be shared. Risky drug and sexual behaviours that put
young people at risk of HIV also place them at considerably greater
risk of acquiring other sexually transmitted infections (such
as gonorrhoea and chlamydia) and blood borne viruses (such as
hepatitis B and C).
HIV remains the most important infection in
the UK. There are substantial opportunities for health gain but
to achieve these there needs to be a new AIDS strategy within
a broader sexual health agenda. PHLS seeks both to promote this
and monitor its progress.
Unlinked Anonymous Surveys Steering Group. Prevalence
of HIV in the United Kingdom 1998. Report of the Unlinked Anonymous
Seroprevalence Monitoring Programme in England and Wales. Department
of Health, Public Health Laboratory Service, Institute of Child
Health (London), Scottish Centre for Infection and Environmental
Health, December 1999.
Prepared by Drs Angus Nicoll and Philip Mortimer.