Abstract
INTRODUCTION: HIV infection continues to be a major contributor to morbidity and mortality in developing countries, including the Republic of the Congo. The progression of the infection to advanced stages is influenced by various factors such as viral genetics, host immune responses variation, body mass index (BMI), treatment interruption or lack of treatment access. This study describes the characteristics of HIV patients on ART and identifies factors associated with viral load suppression in a Congolese urban population. METHODS: This cross-sectional study was conducted from June to July 2021 in Pointe Noire. Patients were recruited at the ‘Centre Association Avenir Positif’. Following a clinical evaluation by a healthcare provider, socio-behavioral, sociodemographic, and clinical data were extracted from patients updated medical records, in addition 5 mL of individual blood was sampled for viral load measurement, using Xpert(®)-HIV-1 Viral Load assay. RESULTS: A total of 510 known HIV positive patients were included in this study. Most of them were women 311 (61%). The analysis revealed a positive association (p = 0.022) between age groups and HIV disease stage, with stage II more prevalent in younger patients (1–17 years) and stage III more common in adults (18–50 years). Tuberculosis (15.6% at Stage I, 36.44% at Stage II, and 51.7% at Stage III) (p < 0.001) and candidiasis (p = 0.023) were two opportunistic infections significantly associated with the advanced stages of the disease. In addition, a significant association was found between treatment interruption (11.6%) and the advanced phase of the disease (Stage III, p < 0.01). Body mass index was significantly associated with advanced stage of the disease: the proportion of cases with elevated BMI was high in Stage III (58.6%; p = 0.041). Finally, patients who delayed initiating antiretroviral treatment more than five years after being tested HIV positive were 2.33 times more likely to have an unsuppressed viral load (p = 0.073). CONCLUSION: Factors such as tuberculosis, candidiasis, treatment interruption, underweight and delaying antiretroviral treatment initiation were significantly associated with the disease severity. Regular monitoring of these factors is essential for tracking HIV/AIDS status and improving patient management and clinical counseling. CLINICAL TRIAL NUMBER: Not applicable. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-025-12178-6.