Understanding HIV epidemiology: a comprehensive analysis of demographic, clinical, and virological profiles of patients with HIV at a tertiary care center.

Objectives: Updated, center-specific cohort data on people living with human immunodeficiency virus (HIV) (PLWH) from the Arabian Peninsula remain limited. We describe the demographic, clinical, and laboratory profiles of PLWH receiving antiretroviral therapy (ART) at Oman's main national referral center. Methods: We conducted a single-center retrospective cohort study of 454 PLWH between January 2010 and December 2023 at the Royal Hospital, Oman. Demographic, clinical, virological and immunological variables were extracted from the electronic medical records. Non-parametric tests, Spearman and Kendall correlations, the Kruskal-Wallis test, and a binomial logistic regression model were used to characterize the cohort and identify independent predictors of virological non-suppression. Results: The cohort was predominantly male (64.3%) and Omani (96.5%), with a mean age at diagnosis of 30.3 years (SD 13.8 years). Heterosexual transmission was the most common route. At presentation, 66.9% of patients were classified as World Health Organization clinical stage 1 and 15.5% as stage 4, followed by stage 2 (9.0%) and stage 3 (8.5%); the median initial cluster of differentiation 4 (CD4) count was 254 cells/µL, and the median baseline viral load was 71,141 copies/mL. The most frequent ART regimen was tenofovir disoproxil fumarate/emtricitabine/efavirenz (28.6%). In multivariable logistic regression ( Conclusion: This cohort reflects a predominantly male, heterosexually acquired HIV epidemic at this center, with a substantial burden of advanced disease at presentation and clinically relevant co-infection rates. Younger age at diagnosis was an independent risk factor for virological non-suppression, a finding that may support targeted retention and adherence interventions in younger PLWH.