Evaluation of screening and treatment of cryptococcal antigenaemia among HIV-infected persons in Soweto, South Africa

Abstract

We retrospectively evaluated clinic-based screening to determine the prevalence of cryptococcal antigenaemia and management and outcome of patients with antigenaemia. Methods: Cryptococcal antigen (CrAg) screening of HIV-infected adults who attended the HIV clinic at Chris Hani Baragwanath Hospital was conducted over 19 months. Data collected from CrAg-positive patients included CD4 T-lymphocyte count at screening, prior or subsequent cryptococcal meningitis (CM), antifungal and antiretroviral treatment and outcome after at least 8 months. Results: Of 1460 patients with no prior CM, 30 (2.1%) had a positive CrAg test. The prevalence of antigenaemia among patients with a CD4 count <100 cells/μl and no prior CM was 2.8% (20 of 708). Of 29 evaluable CrAg-positive patients with no prior CM, 14 (48%) did not return for post-screening follow-up. Of these 14, five developed CM and one (7%) was known to be alive at follow-up. Of 15 patients who returned for follow-up, two already had evidence of nonmeningeal cryptococcosis. Overall, 11 received fluconazole, one did not and fluconazole treatment was unknown for three. Among these 15, one developed CM and 10 (67%) were known to be alive at follow-up. Overall, 18 (62%) of 29 CrAg-positive patients died or were lost to follow-up. Seven (0.5%) of 1430 CrAg-negative patients developed CM a median of 83 days post-screening (range 34 to 219 days). Conclusions: Loss to follow-up is the major operational issue relevant to scale-up of screen-and-treat. Patient outcomes may be improved by rapid access to CrAg results and focus on linkage to and retention in HIV care.