A Longitudinal Cohort Study of the HIV, Tuberculosis, and Food Insecurity Syndemic Among Pregnant Adolescents in Malawi

This longitudinal cohort study investigates the syndemic interaction of HIV, tuberculosis (TB), and food insecurity among pregnant adolescents in Malawi, a critically under-researched group facing compounded vulnerabilities. We aimed to determine the prevalence, bidirectional relationships, and synergistic health impacts of these conditions throughout pregnancy and the early postpartum period. Between March 2023 and February 2025, we enrolled 512 pregnant adolescents aged 15–19 from four antenatal clinics in Central and Southern Malawi. Participants underwent baseline and trimonthly follow-up assessments for HIV and TB, alongside detailed household food insecurity evaluations using the validated Household Food Insecurity Access Scale. Longitudinal data were analysed using generalised estimating equations to model temporal associations. Findings revealed a high baseline co-prevalence, with 28.7% of participants experiencing severe food insecurity. This was significantly associated with a 1.8-fold increased odds of latent TB infection progression (95% CI: 1.2–2.7) and poorer antiretroviral therapy adherence among adolescents living with HIV. The syndemic demonstrated a cyclical nature: an incident HIV or TB diagnosis more than doubled the subsequent risk of severe food insecurity (adjusted odds ratio >2.0). This analysis provides novel longitudinal evidence that food insecurity is not merely a comorbidity but a critical driver and consequence of HIV/TB pathology in this group. The findings underscore the urgent need to integrate nutritional support and social protection into existing adolescent-focused antenatal and HIV/TB services to disrupt this detrimental cycle.