Cryptococcal Infection: Routine Screening in HIV?

Cryptococcus neoformans. Courtesy Wikipedia.

Patients with AIDS are at high risk for cryptococcal meningitis-a disease associated with high mortality that accounts for 33% to 63% of all cases of adult meningitis in sub-Saharan Africa and over 500,000 deaths annually.¹

In the US, early diagnosis and treatment of HIV using highly active antiretroviral therapy (HAART) have been successful in reducing morbidity and mortality from cryptococcal meningitis. However, the disease is still associated with mortality as high as 12%, even in the HAART era.² There are no recommendations for routine screening of patients for cryptococcal infections.³

A study published in the Clinical Infectious Diseases³ examined the prevalence of cryptococcal infection and clinical outcomes of infected patients with advanced AIDS in the US. The investigators tested 1872 serum specimens from participants in the Multicenter AIDS Cohort Study and the Women’s Interagency HIV Study from 1986 to 2012.³ The samples were screened for CD4 T-cell counts <100/μL for cryptococcal antigen (CrAg) using the CrAg Lateral Flow Assay. The investigators identified an overall prevalence of CrAg positivity in 2.9% (CI, 0.2-3.8) of tested samples.

To determine factors associated with a positive screening test for CrAg, the investigators conducted a multivariable analysis which showed that previous diagnosis of cryptococcal meningitis and a CD4 T-cell count <50/μL were significantly associated with CrAg positivity. Patients with CrAg positivity had significantly shorter survival (2.8 years) than those who were CrAg negative (3.8 years [P=.03]).³

Key Points

• This study shows that the prevalence of cryptococcal infection among patients with advanced AIDS in the US was high.

• The authors argue for routine screening to diagnose and treat early infections, which makes the study findings of significant importance to primary care physicians caring for patients with HIV infection.