page 7
Safe male circumcision
Safe male circumcision has been implemented in a number of countries in recent years, and there has been greater uptake among men than many observers expected. It is the biggest recent change to prevention of sexual transmission, alongside PMTCT and the three behavioural options of abstinence, having one HIV-negative partner, and using condoms. It is a population-wide prevention approach, and is only indicated in settings where HIV prevalence is high and rates of male circumcision are low. Experts believe the greatest impact will be in countries where HIV prevalence in the general adult population is more than 15%, HIV is spread mostly through heterosexual transmission, and more than 80% of men are not circumcised. 2 Treatment as prevention is an idea that has some merit – in a given population, overall transmission rates will slow if a greater number of people living with HIV are taking anti-AIDS drugs.
Treatment as prevention
However, as a population-wide intervention it is part of a complicated picture. Treatment rarely reaches people when they are most infectious, because they usually don’t know they are HIV-positive. That is why a prevention method aimed at individuals – by testing viral load among PLHIV, and then advising about infectivity and how to have sex – is not yet available. Also, the “treatment as prevention” idea exists in a global context of a huge shortfall in “treatment as treatment” – the number of people living with HIV who need treatment to save their lives remains very large, and this poses a major challenge to implementing prevention as treatment.
ARV-based prevention for HIV-negative people
These include the following: − Post-exposure prophylaxis (PEP): in some countries this has been available for more than a decade. PEP can be effective if taken quickly after possible exposure to HIV. It involves taking anti-AIDS drugs for several weeks. It works for many people, but some cannot stick with the drugs due to side effects (diarrhoea, nausea, headaches and tiredness). It is also a serious one-time intervention, and clearly not a replacement for safer sex. − Pre-exposure prophylaxis (PrEP): this involves HIV-negative people taking anti-HIV pills regularly. PrEP is under development, with encouraging results for some individuals – greatly reducing risk for people who are able to take the pills all the time. However, so far it has not been effective at a population-wide level; it includes severe side effects; and it is expensive. − Microbicides: these are usually creams or gels that include lower doses of anti-AIDS drugs for application by HIV-negative people in the vagina or rectum. This is also under development. Like PrEP, the theory has been demonstrated – it could work biologically, but as a public health intervention it is not yet available.
AIDS vaccine
As with PrEP and microbicides, there is some evidence that an effective AIDS vaccine could be developed. Unfortunately, however, a longer-term investment is needed for an effective AIDS vaccine to be made available.
It is important to understand specific aspects of different biomedical prevention services – what they are designed to do, who they are most likely to benefit (and who is left out), and whether they offer individual or population-wide protection. To focus 2
WHO and UNAIDS (2007). New Data on Male Circumcision and HIV Prevention: Policy and Programme Implications.