HIV-infected Rwandan women have a high frequency of long-term survival

Abstract

Objectives: To evaluate rates of long-term survival in a prospective, longitudinal, closed HIV cohort in Africa between 1986 and 2006.

Methods: A total of 548 HIV-infected Rwandan women were recruited from prenatal clinics in Kigali and followed at 3-6 month intervals to February 2006. Overall, 401 women (73%) were HIV positive at initial cross-sectional testing in 1986 (seroprevalent cohort) and 147 women (27%) were initially HIV negative but seroconverted during follow-up from 1986 to 1993 (seroincident cohort). Kaplan-Meier survival methods were used to calculate survival times censored in mid-2003.

Results: In February 2006, 109 women (20%) remained alive in the cohort. Time to 50% non-genocide mortality was 11.9 years among seroincident women and 8.9 years among seroprevalent women. Smoothed mortality rates increased with duration of follow-up to a peak of 0.12 deaths per person-year at 9.5 years of follow-up but subsequently declined. After 15 years of follow-up (pre-HAART introduction), the survival probability was 36% for seroincident women and 26% for seroprevalent women. Most survivors had virological and immunological evidence of disease progression. The median CD4 cell count of survivors declined from 447 cells/mul in 1998 to 268 cells/mul in 2003. Among survivors, 57 women (52%) met treatment criteria and initiated antiretroviral treatment by 2006.

Conclusion: Although median survival times in this cohort were similar to those observed in high-income countries, the rates of long-term survival after 15 years of follow-up were higher than expected. A levelling off of mortality rates during the late stages of follow-up may explain this high rate of long-term survival.