Forecasting the effect of HIV-targeted interventions on the age distribution of people with HIV in Kenya.

OBJECTIVES: To provide accurate forecasts of the age distribution of people with HIV (PWH) in Kenya from 2025 to 2040. DESIGN: Development of a compartmental model of HIV in Kenya, calibrated to historical estimates of HIV epidemiology. METHODS: We forecasted changes in population size and age distribution of new HIV infections and PWH under the status quo and under scale-up of HIV services. RESULTS: Without scale-up, new HIV infections were forecasted to fall from 34 000 (28 000-41 000) in 2,025 to 29 000 (15 000-57 000) in 2,040; the percentage of new infections occurring among persons over 30 increased from 33% (20-50%) to 40% (24-62%). The median age of PWH increased from 39 years (38-40) in 2025 to 43 years (39-46) in 2040, and the percentage of PWH over age 50 increased from 26% (23-29%) to 34% (26-43%). Under the full intervention scenario, new infections were forecasted to fall to 6,000 (3,000-12 000) in 2,040. The percentage of new infections occurring in people over age 30 increased to 52% (34-71%) in 2,040, and there was an additional shift in the age structure of PWH [forecasted median age of 46 (43-48) and 40% (33-47%) over age 50]. CONCLUSION: PWH in Kenya are forecasted to age over the next 15 years; improvements to the HIV care continuum are expected to contribute to the growing proportion of older PWH.