HIV-tuberculosis co-infection in Liangshan, a resource-limited region of Southwest China: trends and implications in the context of integrated prevention, 2019-2024.

BACKGROUND: Tuberculosis (TB) and HIV co-infection remains a major public health challenge in resource-limited settings. Liangshan Yi Autonomous Prefecture in Southwest China bears a dual high burden of HIV and TB. This study aimed to analyze the epidemiological trends of HIV-TB co-infection in Liangshan from 2019 to 2024 and to inform integrated prevention strategies. METHODS: A retrospective analysis was conducted on 3367 HIV-TB co-infected cases extracted from the National HIV/AIDS and TB surveillance systems. Records were linked via unique identifiers. Descriptive statistics and chi-square tests for trend assessed incidence trends, demographics, transmission routes, treatment outcomes, and drug resistance. RESULTS: From 2019 to 2024, HIV-TB incidence declined from 12.26 to 8.76 per 100,000 (χ2trend = 40.459, P < 0.001), driven by high-burden counties and populations under 45 years (all P < 0.001). Patients were predominantly young males (61.10%) and farmers (92.37%). The main HIV transmission routes were heterosexual contact (48.29%) and injection drug use (41.31%), with marked sex and age disparities: injection drug use predominated in males (50.92%) and those aged 30 - < 45 years (50.32%), while heterosexual transmission prevailed in females (77.07%) and older adults (≥ 60 years, 87.62%). Treatment success rate was 81.76%, significantly lower in the elderly (69.52%, P < 0.05). Any drug resistance (3.30%) increased from 1.54% to 3.10% (χ2trend = 8.481, P trend = 0.004). CONCLUSION: During the implementation of integrated strategies, HIV-TB incidence showed a declining trend, particularly in high-burden areas and younger populations. Persistent challenges-stagnant incidence and poor outcomes in the elderly, high loss to follow-up (10.87%), rising drug resistance-require targeted interventions: leveraging the Yi "clan" (Jiazhi) system, strengthening active screening and nutritional support for older adults, optimizing drug resistance surveillance, and integrating digital health tools.