Prevalence, correlates, and outcomes of cryptococcal antigen positivity among patients with AIDS, United States, 1986-2012.

BACKGROUND: Cryptococcal meningitis (CM) is one of the most common causes of AIDS-related mortality worldwide, accounting for 33%-63% of all cases of adult meningitis in sub-Saharan Africa and >500 000 deaths annually. In sub-Saharan Africa, the World Health Organization recommends routinely screening AIDS patients with a CD4 count ≤100 cells/µL for cryptococcal infection. In the United States, there are no recommendations for routine screening. We aimed to determine the prevalence of cryptococcal infection and outcomes of those infected among people living with advanced AIDS in the United States, to inform updates in the prevention and management of CM.

METHODS: Using stored sera from participants in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study from 1986 to 2012, we screened 1872 specimens with CD4 T-cell counts ≤100 cells/µL for cryptococcal antigen (CrAg) using the CrAg lateral flow assay.

RESULTS: The overall prevalence of CrAg positivity within the study population was 2.9% (95% confidence interval, .2%-3.8%). Results from multivariable analysis revealed that a previous diagnosis with CM and a CD4 count ≤50 cells/µL were significantly associated with CrAg positivity. Participants who were CrAg positive had significantly shorter survival (2.8 years) than those who were CrAg negative (3.8 years; P = .03).

CONCLUSIONS: The prevalence of cryptococcal infection among advanced AIDS patients in the United States was high and above the published cost-effectiveness threshold for routine screening. We recommend routine CrAg screening among human immunodeficiency virus-infected patients with a CD4 count ≤100 cells/µL to detect and treat early infection.