Comparison of Cryptococcal Antigenemia between Antiretroviral Naive and Antiretroviral Experienced HIV Positive Patients at Two Hospitals in Ethiopia

Background: Cryptococcal meningitis is a major cause of HIV/AIDS-related deaths in Africa. Cryptococcosis is a neglected killer. However, meningitis can be prevented by early cryptococcal antigen (CrAg) screening and preemptive antifungal treatment during a prolonged period of detectable, subclinical infection. We determined the prevalence of cryptococcal antigenemia in comparison to CD4 count and clinical symptoms. Methods: We surveyed 254 consenting HIV-infected participants to obtain demographic information and clinical history. Serum CrAg was measured by latex agglutination at two sites in the Oromia region of Ethiopia among all persons receiving a CD4 count. Results: Of the 254 participants, 127(50.0%) were ART-naive, 121(47.6%) were ART-experienced, and 6(2.4%) were ART-defaulters. The prevalence of cryptococcal antigenemia was 10.2% overall being 14.2% among ART-naive, 4.1% among ART-experienced, and 50% (3/6) among ART-defaulters, irrespective of CD4 count. Cryptococcal antigenemia was more frequently detected from ART-naive patients (p = 0.012) and ART-defaulters (p = 0.001) compared with ART-experienced. Serum CrAg positivity was 20.9% in persons with CD4 <= 150 cells/mu L, 12.2% in 151-200 cells/mu L, 5.8% among 201-350 CD4/mu L, and none above 350 cells/mu L. Potential meningitis symptoms were common in the outpatient cohort irrespective of CrAg-status, with only fever and altered mental status statistically more common in CrAg-positive compared to CrAg-negative persons (P<0.05), yet no symptom had a positive predictive value >33%. Conclusion: We report a 20.9% cryptococcal antigenemia prevalence among those with CD4+ T cells count <= 150 cells/mu L, irrespective of ART status, with even higher CrAg prevalence in ART-naives and ART-defaulters. These groups are target populations for CrAg screening at entry into HIV care.