Treatment as Prevention

There is good evidence that being on effective HIV treatment reduces (but probably does not eliminate) the risk of transmitting HIV to sexual partners, but there have not yet been enough studies to quantify exactly how much risk reduction occurs in all situations where transmission is possible.

There is very good data that shows being on treatment almost eliminates the chances of passing HIV from mother to child during birth.

There is also an accumulation of data that suggests effective treatment can successfully reduce transmission rates for vaginal intercourse to a minimum, so long as:

  • The person with HIV takes their medication at the correct dose and on time, every time (i.e. 100% adherence).
  • The person with HIV has regular viral load monitoring and has had consistent undetectable viral load results for more than six months.
  • Neither partner has a sexually transmissible infection (STI).

Condoms are still the safest way to avoid passing on or getting HIV, but the above for example, can allow for couples wishing to achieve pregnancy to do so in consultation with their Doctor and without needing to resort to methods such as sperm washing and IVF (see Swiss statement)

Unfortunately, there is not enough evidence at the moment to allow us to know how this risk reduction applies to risks such as anal intercourse, let alone injection drug use. Also, with rates of STIs in people with multiple sex partners rising in Australia, the requirement of neither partner having an STI may also limit the effectiveness of treatment as a risk reduction method.

However, with the above in mind, it has been proposed that, in addition to existing prevention measures (condom use, increasing disclosure and frequent testing for HIV and STIs), Australia implement a series of new policy and program actions, to revitalise our response to HIV, including:

  • Increasing testing rates and introducing new testing methods, such as rapid tests.
  • Promoting earlier initiation of HIV treatment to increase personal health and wellbeing and also as a way of reducing transmission.
  • Adopting and promoting the use of Pre-Exposure Prophylaxis (PrEP) for individuals at high risk.
  • Setting bold targets for achieving a substantial reduction in the numbers of people contracting HIV.

These actions and targets are based on important developments in our understanding of HIV prevention and treatment, as well on the measures endorsed by all countries under the 2011 United Nations Declaration on HIV/AIDS

HIV treatment and prevention must now be inextricably linked with well integrated treatment and prevention programs, this being critical to a successful HIV response, be it in Australia or anywhere else.