The number of people in South Africa on antiretroviral treatment remained roughly unchanged from 2024 to 2025, according to just-published estimates from the leading mathematical model of HIV in the country. This suggests that the disruption of US aid for HIV services has slowed the growth of our HIV treatment programme, but the impact so far is not as severe as some researchers feared it might be.

South Africa's HIV treatment programme grew by a mere 40,000 from 2024 to 2025, taking the tally of people on antiretroviral treatment from 6.14 million to 6.18 million. This is according to just published figures from Thembisa, the leading mathematical model of HIV in South Africa. The last time year-on-year growth of the HIV programme was below 100,000 was 20 years ago.

The new estimates provide the most reliable big-picture numbers so far on how the withdrawal of US aid has affected HIV in South Africa. The numbers are somewhat complicated to interpret given that year-on-year growth of the HIV programme had already been slowing before the US aid cuts (as shown in the below graph). You can explore the new estimates on Spotlight's HIV dashboard.

Though concerning, the local impact of disruptions to US aid appears not to be as severe as some worried it might be. In a study published last year in the journal AIDS, researchers estimated that in a worst-case scenario, US aid cuts might lead to a 28% reduction in the number of people receiving antiretroviral treatment, a 56% increase in new HIV infections and a 38% increase in the number of...