AIDS and non-AIDS morbidity and mortality across the spectrum of CD4 cell counts in HIV-infected adults before starting antiretroviral therapy in Cote d'Ivoire.

BACKGROUND

In Western Europe, North America, and Australia, large cohort collaborations have been able to estimate the short-term CD4 cell count-specific risk of AIDS or death in untreated human immunodeficiency virus (HIV)-infected adults with high CD4 cell counts. In sub-Saharan Africa, these CD4 cell count-specific estimates are scarce.

METHODS

From 1996 through 2006, we followed up 2 research cohorts of HIV-infected adults in Côte d'Ivoire. This included follow-up off antiretroviral therapy (ART) across the entire spectrum of CD4 cell counts before the ART era, and only in patients with CD4 cell counts >200  cells/μL once ART became available. Data were censored at ART initiation. We modeled the CD4 cell count decrease using an adjusted linear mixed model. CD4 cell count-specific rates of events were obtained by dividing the number of first events occurring in a given CD4 cell count stratum by the time spent in that stratum.

RESULTS

Eight hundred sixty patients were followed off ART over 2789 person-years (PY). In the ≥650, 500-649, 350-499, 200-349, 100-199, 50-99, and 0-49  cells/μL CD4 cell count strata, the rates of AIDS or death were 0.9, 1.7, 3.7, 10.4, 30.9, 60.8, and 99.9 events per 100 PY, respectively. In patients with CD4 cell counts ≥200 CD4  cells/μL, the most frequent AIDS-defining disease was tuberculosis (decreasing from 4.0 to 0.6 events per 100 PY for 200-349 and ≥650 cells/μL, respectively), and the most frequent HIV non-AIDS severe diseases were visceral bacterial diseases (decreasing from 9.1 to 3.6 events per 100 PY).

CONCLUSIONS

Rates of AIDS or death, tuberculosis, and invasive bacterial diseases are substantial in patients with CD4 cell counts ≥200 cells/μL. Tuberculosis and bacterial diseases should be the most important outcomes in future trials of early ART in sub-Saharan Africa.