Prevalence and sociodemographic predictors of comprehensive HIV/AIDS knowledge among university students in Southern India

Young adults aged 18–25 years bear a disproportionate HIV burden globally, yet institution-level data on HIV/AIDS knowledge among university students in India remain scarce. This study estimated the prevalence of comprehensive HIV/AIDS knowledge and identified independent socio-demographic predictors among university students in southern India. A cross-sectional survey was conducted among 404 consented students aged 18–25 years at Apollo University, Chittoor, Andhra Pradesh (September–November 2025). A 28-item validated, self-administered questionnaire assessed knowledge across five domains: transmission routes, prevention strategies, testing and treatment, misconception correction, and general awareness. Cronbach’s alpha for the 28-item instrument was 0.847, indicating good internal consistency. Adequate domain-level knowledge was defined as correctly answering ≥ 60% of items within a domain; overall adequate knowledge required achieving this threshold in ≥ 3 of 5 domains. Multivariable logistic regression identified independent predictors ( p < 0.05). Overall, 376 of 404 participants (93.1%; 95% CI: 90.1–95.3%) demonstrated adequate comprehensive HIV/AIDS knowledge. Domain-specific adequacy was highest for General Awareness (93.3%) and Testing & Treatment (92.8%), and lowest for Misconception Correction (79.7%). Critical item-level gaps persisted for the window period concept (65.8%), first HIV/AIDS country recognition (55.2%), MTCT certainty (71.8%), and saliva as a non-transmitting fluid (75.5%). Age group was the only independent predictor: students aged 20 years and above were 3.62 times more likely to demonstrate adequate knowledge than 18–19-year-olds (AOR = 3.62, 95% CI: 1.49–8.81, p = 0.005). No significant associations were found for gender, education, residence, or income. A substantial majority of university students demonstrated adequate HIV/AIDS knowledge by domain-composite criteria; however, critical item-level gaps in the window period concept, MTCT transmission, fluid-specific facts, and confirmatory diagnostics represent targeted priorities for campus-based HIV education, particularly for first-year students aged 18–19 years.