The study investigates the sexual behaviour and social conditions that act as motivators or barriers to the risk of HIV and the epidemiological context in Plateau State and Nasarawa State, Nigeria for sustainable sexual health and to halt the spread of HIV. Based on the social epidemiology of HIV scholarship, a sequential explanatory mixed-methods design was adopted, which demonstrates the significance in understanding the complex factors surrounding sexual behaviour and the risk of HIV transmission. The first phase of the study used Nigerian Demographic and Health Surveys datasets from 2003 to 2013, and District Health Information System datasets from 2013 to 2017 for Plateau State and Nasarawa State. The second phase of the study deployed qualitative research tools involving in-depth interviews, participant observations, and a document review to collect data on sexual experiences, social relationships, and the prevailing conditions that facilitate or constrain HIV risky behaviour. The research results show that in Nasarawa, being female, married and aged ≥ 25 years predicted HIV high-risk behaviour. The lack of education, being from a poor home, and possessing unsafe HIV/AIDS attitudes increased the chance of acquiring or transmitting HIV.The personal risk factors were driven by gender control, when the man controls resources and dictates heterosexual relationships; this has deprived women of agency to demand safe sex. The most at-risk groups were found to border HIV hotspot states, and doubts about the reality of HIV heightened HIV risk. Also, family and community norms stigmatised, discriminated and criminalised the sexual and social attitudes of some people who perceived they were rejected and became isolated. Social distances created tension and distress thus impacting the receipt of HIV prevention services. The health seeking behaviour among the most at-risk groups exposed them to unsafe behaviours linked with HIV and health-related conditions. All these factors have contributed to the high prevalence of HIV in Nasarawa State. In Plateau State, more people engaged in safe sexual activity than in Nasarawa State. Completing primary education, and being a polygamist, female, and married were unlikely to be associated with high-risk transmission. Relationships within and between social groups kept people together and enabled access to resources to reduce exposure to risky behaviours. The behaviour change contributed to a significant decline in HIV rates. The study suggests that sexual behaviour and a combination of HIV prevention strategies would address behavioural, socio-economic, cultural practices, and laws within the broader policy environment in order to mitigate and deliver sustainable health and zero HIV/AIDS.
