Epidemiology, diagnostic algorithm, and prognostic role of immunological and inflammatory markers in people living with HIV-2 in West Africa.

Human immunodeficiency virus type 2 (HIV-2) is a retrovirus responsible for an AIDS epidemic confined to West Africa, where the co-circulation of HIV-1 and HIV-2 leads to co-infections with both viruses. HIV-2 infection is characterized by a longer asymptomatic phase and slower disease progression than HIV-1 infection, as well as by HIV-2’s intrinsic resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs). It is therefore recommended to differentiate between HIV-2 and HIV-1 infection before initiating antiretroviral therapy. However, diagnosis remains difficult, particularly in cases of HIV-1 and HIV-2 coinfection. 
It is therefore essential to explore new diagnostic algorithms based on routinely used rapid HIV tests to improve the diagnosis of dual-infected patients in peripheral HIV care centers in West Africa. The difficulty in characterizing the epidemiology of HIV-2 infection and dual infection with HIV-1 and HIV-2 poses another significant challenge in the fight against HIV-2 in West Africa. Contradictory data from recent years on the evolution of the HIV-2 epidemic and the lack of up-to-date data have led to insufficient consideration of patients living with HIV-2 in WHO treatment guidelines. 
Given the limited access to integrase inhibitors in Africa, generating up-to-date data on the epidemiology of HIV-2 infection is essential to strengthen advocacy and improve the holistic care of people living with HIV-2. 
Furthermore, the high mortality rates reported among patients living with HIV-2 may result from immune activation and the persistence of soluble inflammatory biomarkers, as has been reported for HIV-1 infection. However, the role and mechanisms of action of immunological and inflammatory markers in disease progression and the long-term prognosis of patients living with HIV-2 remain largely unexplored. Thus, a better understanding of the role of inflammatory biomarkers in the onset of morbidity, disease progression, and prognosis in patients living with HIV-2 could improve the holistic care of these patients.
A mixed-methods approach, combining longitudinal analyses, demographic surveys, spatial modeling, and molecular biology tests, will be developed over the course of this three-year research project. The more precise epidemiological data, improved diagnosis of HIV-2 infection, and a better understanding of the dynamics and factors associated with disease progression resulting from this project will help guide international treatment recommendations specific to HIV-2 infection.