Left behind? A longitudinal analysis of need for PrEP services among middle-aged and older adults in South Africa.

Introduction: Despite 1.3 million cumulative Pre-exposure prophylaxis (PrEP) initiations in South Africa, 150,000+ people newly acquire HIV every year. A significant proportion of these are middle-aged adults, a population not previously prioritized for PrEP. Evidence on how many middle-aged and older adults in South Africa may benefit from PrEP services is needed.

Methods: We estimate the need for PrEP counselling in a sample of 40+ year-old, rural South Africans in 2018 and 2022, using "Health and Aging in Africa: A Longitudinal Study in South Africa (HAALSI)" data. We first identify potential PrEP eligibility based on a negative HIV status and a body weight of 35+ kg. Within this sample, we define the population that should be counselled on PrEP as per South African Guidelines for the Provision of PrEP based on a recent history of having had sex without a condom. We estimate cross-sectional and longitudinal need for PrEP counselling at the pooled level and disaggregated by sex and age.

Results: Of the 1,654 individuals considered potentially eligible for PrEP in 2022, 39.6% overall, 55.7% of males, 26.7% of females, and 63.3% of 40-49 year-olds should be counselled on PrEP. Longitudinally, 29.9% and 22.9% should be counselled on PrEP in both waves or only one wave respectively. Further, we found significantly higher odds of need for PrEP counselling in male, younger, and married individuals.

Conclusion: We find a high need for PrEP counselling among middle-aged and older South Africans - calling for greater attention to HIV prevention, including targeted PrEP for these age groups.