Prevalence and Factors Associated With Late Diagnosis of Infection by the Human Immunodeficiency Virus in Santa Catarina, 2019–2024

Late diagnosis of HIV infection evidences weaknesses in efforts to confront the virus. The objective of this study was to estimate the prevalence and factors associated with late diagnosis of human immunodeficiency virus infection in individuals from Santa Catarina, between 2019 and 2024. Cross-sectional study conducted with a sample of confirmed HIV/AIDS cases in the state of Santa Catarina (2019 to 2024; ≥ 13 years). Diagnosis was considered late (dependent variable) when the person is identified as seropositive (through immunological or virological tests standardized by the Ministry of Health), characterized by the presence of AIDS-indicative diseases and/or CD4+ T-lymphocyte count below 350 cells/mm³. Independent variables included sociodemographic characteristics and case outcomes. Poisson regression with robust variance was used, estimating crude and adjusted prevalence ratios. Variable selection was performed using the backward stepwise method, retaining in the final model those with p < 0.05. Stata 14 was used. Submission to an Ethics Committee was not required, as these were anonymized and public data. A total of 17,915 people were analyzed, most male (70%). The prevalence of late diagnosis was 35.7%. Female sex was associated with an 11% lower prevalence of late diagnosis compared to males (PR = 0.89; 95%CI: 0.85–0.93). Higher schooling levels were protective factors, with an 8% reduction for high school (PR = 0.92; 95%CI: 0.88–0.96) and 15% for higher education (PR = 0.85; 95%CI: 0.80–0.90). There was a rising trend in the prevalence ratio of late diagnosis with increasing age. Individuals aged 70–79 years had a 2.67-fold higher prevalence of late diagnosis compared to the 13–19-year group (95%CI: 2.14–3.34). Individuals who progressed to death from AIDS had a 92% higher prevalence of having been diagnosed late compared to those who remained alive (PR = 1.92; 95%CI: 1.81–2.04). For those who died from other causes, prevalence was 31% higher (95%CI: 1.15–1.49). Late diagnosis was associated with male sex, low schooling, older age and progression to death from AIDS and other causes. On the other hand, female sex and higher schooling were protective factors.