Choice disability as a target for non-medical HIV intervention

Even though medical intervention measures against HIV transmission are available, the epidemic continues to spread in several sub-Saharan African countries. Empirical studies indicate that many people are unable to implement prevention strategies because of individual factors, such as extreme poverty or lack of education, but also because or relational factors, such as gender-based violence or transactional sex. This phenomenon, known as choice disability, may be such a large obstacle in the effectiveness of medical interventions that several field trials of structural (non-medical) interventions are underway that address these issues. While dynamical-systems models are frequently used to advise management and policy around infectious diseases, they typically assume that individuals are free to make optimal choices. We derive and analyze a novel model where individuals have a certain choice status, based on which they are more or less likely to transmit or receive the infection. Choice status is affected by social interactions. When studying the model in the absence of an infectious disease, we find that structural interventions aimed at raising the status of one group can have the unintended side effect of lowering the status of another group. When combined with an epidemic model, we find that the same structural interventions can even increase the total prevalence of a disease in the population. Our model provides a framework to evaluate the possible effectiveness of structural intervention in an epidemic.