Mortality and immunovirological outcomes on antiretroviral therapy in HIV-1 and HIV-2-infected individuals in the Gambia

OBJECTIVES: This study's objective was to assess outcomes in HIV-1 and HIV-2 infected antiretroviral therapy (ART)-naive patients starting ART in the Gambia, West Africa. DESIGN: A cohort design was used to estimate survival in ART patients and determine whether survival and time to virologic failure varied across patient subgroups. METHODS: Mortality, virologic failures and CD4(+) cell recovery were assessed in a clinical cohort of patients from the Genito-Urinary Medicine (GUM) clinic of the MRC Laboratories in the Gambia. Kaplan-Meier estimates of survival were determined for mortality and virologic failure. A Cox proportional hazards model was used to identify baseline demographic, clinical, immunologic and virologic factors associated with increased risk of death. RESULTS: The overall Kaplan-Meier estimate of survival to 36 months was 73.4% (66.5, 80.3). Survival was marginally higher in HIV-2-infected patients compared to HIV-1-infected patients; it was significantly higher in patients with a baseline CD4(+) lymphocyte cell count of greater than 50 cells/mul compared to those with a baseline CD4(+) count of less than 50 cells/mul. CD4(+) cell recovery was faster in HIV-1-infected individuals compared to HIV-2-infected patients up to 24 months, although this did not result higher mortality in the latter group. No differences in virologic failure were observed by HIV type. CONCLUSION: HIV-1 and HIV-2-infected patients receiving ART in a clinical setting in the Gambia had good survival to 36 months. HIV-2-infected patients did as well as HIV-1-infected patients in terms of long-term immunological and virological responses and overall survival.