New HIV infections in SA declining

By Marcus Low

Last week the latest estimates from the Thembisa mathematical model of the HIV epidemic in South Africa were published by Leigh Johnson, Rob Dorrington and Haroon  Moolla of the University of Cape Town. The Thembisa model provides what we consider to be the most reliable estimates of what is happening with HIV in South Africa.

We highly recommend that you explore the model’s wealth of fascinating estimates yourself. The “SA” sheet in this Microsoft Excel file is the place to start.

We believe that most estimates in this model up to 2016 provide relatively good approximations of reality. The model’s estimates for the future obviously have much greater uncertainty, given that those figures cannot be compared to various sources of real-world data as is the case with past figures. As pointed out by Nathan Geffen on GroundUp, “Mathematical models cannot take into account every last ebb and flow of how the world works. They are simplifications of reality that give us a useful idea of what’s going on.”

With those caveats in place, here are some of the highlights:

  1. In 2016 it is estimated there will be around 270,000 new HIV infections in South Africa. For a decade either side of the year 2000 this figure was above 500,000 – since then it has been coming down, a trend that is predicted to continue. The 270,000 new HIV infections per year works out to over 700 new infections per day.
  2. In 2016 around 7.1 million people in South Africa are estimated to be living with HIV. The model predicts that this number will continue to rise over the next ten years and then stabilise at around 7.8 million. This continued rise is due to the combined impact of people with HIV living longer due to antiretroviral treatment and the rate of new infections not coming down fast enough.
  3. The model suggests that HIV prevalence in South Africa is peaking in 2016 and 2017 at 12.8% (this is the percentage of the population who are living with HIV). After 2017 a slow decline in HIV prevalence is expected.
  4. In young women and girls in the 15-24 years age-group HIV prevalence is estimated 11.1% in 2016. This figure has shown a steady decline from a high of 14.5% in 2004.
  5. It is estimated that in 2015 around 3.3 million people living with HIV in South Africa were receiving antiretroviral treatment. This is around 48% of the 7 million people living with HIV in 2015. The model predicts that we’ll hit the 80% treatment coverage rate only in 2022. It is also estimated that by 2015 a total of around 4 million people had started antiretroviral therapy in South Africa (implying that around 700,000 people who have started treatment has either stopped taking treatment or died).
  6. It is estimated that in 2016 around 87.5% of adults living with HIV in South Africa knew their HIV status. For men this figure is estimated at around 83.5% and for women around 90%. The model predicts that the UNAIDS target of 90% of people who are HIV positive knowing their status will be reached in 2018. It is the only of the three 90s the model suggests South Africa will reach.
  7. In 2016 around 145,000 people in South Africa are expected to die of HIV-related causes. This figure has been coming down steadily since it peaked at around 280,000 in 2005 – a trend that the model predicts will continue.
  8. In 2016 life-expectancy in South Africa is estimated at around 63 years. The model paints a clear picture of the toll HIV has taken on South Africa with first the decline from around 63 in the early 90s, down to under 54 in 2005, and then back up as antiretroviral treatment finally became more widely available.

 

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