HIV transmission is preventable; however, the rate of new HIV infections in the UK still remains high. A comprehensive, ‘combination prevention’ approach comprising a package of biomedical, behavioural and structural interventions, tailored to local populations, is the only effective way of tackling the spread of the epidemic. HIV prevention should go beyond primary prevention for HIV-negative people, and also work with people living with HIV as important partners in prevention. There is an ever-increasing array of evidence-based, HIV prevention tools available. These include condoms, STI screening and treatment, partner notification (see Standard 1a), motivational interviewing, peer support, comprehensive harm-reduction strategies (e.g. needle exchange programmes and opioid substitution therapy) and ARVs.
Particularly notable in recent years is the use of ARVs by HIV-negative and -positive people to reduce HIV acquisition and transmission in the form of pre-exposure prophylaxis (PrEP) and treatment as prevention (TasP), respectively. The promotion of TasP has been strengthened recently by the production of an international consensus statement which, in summary, is that a person living with HIV who is on ART and has achieved an undetectable viral load in their blood for at least 6 months cannot transmit HIV to their sexual partners. All people living with HIV should be made aware of this (see Appendix 2).
PrEP consisting of oral tenofovir disoproxil fumarate–emtricitabine taken daily or ondemand prior to and following potential risk exposure is highly effective in preventing HIV infection. The PROUD and IPERGAY studies have provided strong evidence for a large reduction (>85% in both) in HIV incidence when PrEP is offered to MSM having condomless anal sex. Other groups have collected similar strong evidence for the benefits of PrEP in heterosexual men and women at risk of acquiring HIV. No single intervention has provided as dramatic a reduction in HIV transmission as PrEP. However, all studies have emphasised that PrEP should be delivered as part of a comprehensive package of HIV/STI prevention and targeted risk-reduction support.
At the time of writing, NHS access to PrEP is variable across the UK, with widespread accessibility only in Scotland and Wales. People in England currently have two options for accessing PrEP: either by purchasing PrEP from pharmacies selling generic products outside the European Union or from pharmacies within the UK with a private prescription, or by enrolling on the NHS England-funded Impact study (a pragmatic non-interventional study to determine need, uptake and use of PrEP when delivered in sexual health clinics). The Public Health Agency for Northern Ireland is reviewing PrEP provision and a report is expected in late 2018. In the interim, PrEP monitoring is being provided in some sexual health clinics. Primary care is not expected to issue PrEP but like other non-HIV and sexual health services, it can contribute to the broader HIV prevention strategy, for example HIV testing, provision of condoms, encouraging adherence to ART for those tested positive, and discussion about PrEP where available.
In 2017, at least five London sexual health clinics reported a dramatic reduction in the number of new HIV diagnoses over 2 years. This was thought to be primarily due to increased testing of the most high-risk people, earlier ART initiation (to effect TasP) and the increasing use of PrEP obtained privately and via research studies.
HIV transmission is a major concern for people living with HIV and their sexual partners. Awareness of the effectiveness of treatment is a powerful tool to support people living with HIV and a challenge to the stigma that they often face; all people living with HIV should be provided with this information and its implications.
We know there is a wide array of highly effective prevention interventions, we must now determine how best to deliver these. In an increasingly financially constrained environment, clinicians, community providers, patients and advocates should work collaboratively with commissioning bodies to design comprehensive prevention strategies to realise the full public health potential of all available prevention tools.