One in four people with HIV not on treatment, according to new estimates

One in four people with HIV not on treatment, according to new estimatesSouth Africa’s HIV testing programme has been a huge success over the last decade, largely due to the use of rapid tests. (File photo: Unicef)
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Despite South Africa’s impressive HIV testing figures, a subset of people started taking antiretroviral therapy far later than is ideal for their health, shows new data from the leading mathematical model of HIV in the country. These new estimates present a synthesis of the best sources of data of HIV in the country as it factors in numbers from multiple sources.


Around 50 000 people died of HIV-related causes and around 7.8 million were living with HIV in South Africa in 2023. This is according to new estimates from Thembisa, the leading mathematical model of HIV in South Africa.

The new figures were particularly keenly anticipated since they factor in numbers from both Statistic South Africa’s Census 2022 and the Human Sciences Research Council’s Sixth South African National HIV Prevalence, Incidence and Behaviour survey.

Of the estimated 7.8 million people living with HIV in South Africa in 2023 (12.6% of the population), just under 5.9 million were on treatment. This translates to treatment coverage of 75%, or one in every four people living with HIV not being on treatment. Antiretroviral treatment is recommended for all people living with the infection.

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The new Thembisa outputs for the first time include an estimate of people disengaging with treatment. It is calculated that in the region of one million people living with HIV who have previously taken antiretroviral treatment were not taking the treatment in mid 2023. Of the roughly two million people living with HIV who are not on treatment, half were thus previously on treatment. This suggest that helping and supporting people to start and stay on HIV treatment should be a high priority for the Department of Health.

Around 237 000 people started taking antiretroviral therapy in 2023 in South Africa. Concerningly, over 46 000 adults started taking treatment only once their CD4 counts had dropped below 200 cells per cubic millimetre of blood. A CD4 count of less than 200 indicates a compromised immune system and is associated with a higher risk of falling ill with co-infections such as tuberculosis. These numbers suggest that, despite South Africa’s impressive HIV testing figures, there is a subset of people who are falling through the cracks and who only start taking treatment far later than is ideal for their health.

New infections declining

There was around 149 000 new HIV infections in South Africa in 2023, according to the new Thembisa estimates. Here, as in most areas, the long term trend is downward, with new infections having been above 500 000 per year around the turn of the century and declining ever since. As with other indicators, the sex differences are stark. There was around 91 000 new HIV infections in women aged 15 and older, compared to 50 000 in men in the same age group.

HIV infections and deaths

Since the number of new HIV infections is still higher than the total number of deaths in people living with HIV (as shown in the above graph), the absolute number of people living with HIV in South Africa is still rising and is anticipated to keep rising for some years to come.

One indicator that the HIV response in South Africa is generally heading in the right direction is that the number of people starting HIV treatment is significantly higher than the number of new infections. The ratio between these two numbers was estimated at 1.6 in 2023 – in other words, for every 10 people newly infected, 16 were started on treatment. In the 2010s this ratio was often above 2.

95-95-95 indicators

According to UNAIDS HIV targets, also included in South Africa’s National Strategic Plan for HIV, TB and STIs 2023-2028, countries should aim that 95% of people living with HIV are diagnosed, 95% of those diagnosed should be on treatment, and 95% of those on treatment should have viral suppression, all by 2025.

South Africa is on track to meet the first of these three targets with an estimated 95.4% of people living with HIV in 2023 having been diagnosed.

On the second target, performance is much weaker. An estimated 78.7% of people who have been diagnosed with HIV were on treatment in 2023. In other words, more than one in five people who know they are living with HIV are not taking treatment. (Note: If you expand the definition of the second 95 target to include both diagnosed and undiagnosed people then you get the 75% treatment coverage figure quoted near the top of this article.)

On the third target, South Africa is doing well, with an estimated 91.3% of people who are on HIV treatment being virally suppressed. If one however throws the net wider and asks what percentage of all people living with HIV – not just those on treatment – are virally suppressed, the number plummets down to 68.6%. (These figures are for a viral load threshold of 1 000 copies per millilitre of blood. If a threshold of 400 is used, the estimates are 89% and 66.8% respectively)

Life expectancy

The latest Thembisa figures also indicate that life expectancy in South Africa has continued its upward trend following a blip in 2020 and 2021 caused by the COVID-19 pandemic.

Life expectancy at birth over time in SA

The broader picture of the last 30 years show a clear decline caused by the HIV pandemic, reaching a low point of 53.6 in 2004, followed by a steady recovery as antiretroviral treatment became available and fewer and fewer people died of HIV.

Life expectancy in 2023 was estimated at 65.9 – 62.3 for males and 69.7 for females.

Note: This article is based on outputs from Thembisa version 4.7 – which was published at the end of March 2024. Spotlight will soon publish several more articles and visualisations unpacking these outputs in more detail. Graphs in this article were made using the R package ggplot2.

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