Modelling the role of denial in sustaining HIV transmission in South Africa

Abstract

HIV/AIDS remains a major public health challenge in South Africa, where denialism continues to undermine prevention and treatment efforts. This study develops a mathematical transmission model that explicitly incorporates denial behaviours, including refusal of preventive measures, refusal to initiate antiretroviral therapy (ART), and discontinuation of ART. Analytical and simulation results show that denial substantially increases HIV incidence, accelerates progression to AIDS, and raises the likelihood of a backward bifurcation, an occurrence where HIV may persist even when the basic reproduction number falls below one. Sensitivity analysis identified denial-related transmission as a key driver of epidemic dynamics. These findings underscore the need to address denialism by strengthening HIV testing, ART uptake and retention, and community-level education to counter misinformation and stigma.