This is a multicenter prospective cohort evaluation of the implementation of a cryptococcal antigen (CrAg) screening program at selected outpatient HIV clinics (OPCs) and network laboratories in Vietnam.

The project will be implemented in 2 phases; Phase 1: From August 2015 to March 2017 [projected], HIV-infected patients who present for HIV care and undergo CD4 testing will be reviewed to determine the proportion of newly presenting patients with advanced disease (CD4 ≤100 cells/μL). Reflex CrAg screening will be performed using Lateral Flow Assay (LFA) for those with CD4≤100 cells/μL, per Vietnam national guidelines.

Patients with CD4≤100 cells/μL who present for antiretroviral treatment (ART) at a study OPCs-CRICS Sites- will be recruited into the longitudinal study and followed up with assessments and the collection of routine and supplemental data for 12 months or through September 2017 (whichever comes sooner). Those who are CrAg-positive, but have no features of central nervous system (CNS) disease, will be treated with high-dose fluconazole. Those with symptoms of CNS disease will be treated according to national guidelines. Survival, retention in care, and other clinical outcomes will be documented for patients who test CrAg-positive and are treated with fluconazole and those who test CrAg-negative. Data from those tested at participating labs but not eligible for enrollment in the longitudinal study will contribute to the estimation of the prevalence of CrAg.

Phase 2: From April 2017 to September 2017, a cost and cost-effectiveness analysis of CrAg screening will be conducted, a routine screening will be continued at existing sites and expanded to additional sites (preferentially to hospitals affiliated with Phase 1 OPCs and to other OPCs whose CD4 testing is conducted at laboratories already conducting CrAg screening as part of Phase 1). CrAg tests will also be made available to screen all patients with CD4≤100 cells/μL including those who are treatment-experienced. The test will also be made available for use among symptomatic patients for diagnostic purposes, including cerebral spinal fluid (CSF) and blood testing. Investigators will monitor prevalence at each testing site, but screened patients will not be enrolled in longitudinal follow-up. Phase 2 will last for at least 6 months based on the availability of funding and fluconazole for those who screen CrAg positive and the availability/stability of CD4 testing.

[Note that follow up of patients enrolled in Phase 1 will continue during this time period, but is considered to be part of Phase 1 rather than Phase 2. Also, sites included in Phase 2 may change over time as a result of the instability of CD4 testing (e.g., if participating laboratories stop conducting CD4 testing, those sites might no longer be included; if participating laboratories begin CD4 testing for other sites, those sites might be included).]

Inclusion Criteria:

• Aged ≥ 18 years (having passed 18th birthday using Western calendar)
• Confirmed HIV infection using National Testing Algorithm
• CD4 ≤100 cells/μL
• Able to provide written informed consent
• Enrolled at and plan to receive ongoing outpatient care at one of the selected study OPCs

Exclusion Criteria:

• History of prior CM
• Receipt of systemic antifungal medication for more than 4 consecutive weeks within the past 6 months
• Receipt of ART for more than 4 consecutive weeks within the past year
• For CrAg-positive patients only: Known to be currently pregnant or planning to become pregnant during the study period

Patients with advanced HIV infection (CD4<100 cells/microliters) who are eligible to inclusion and exclusion criteria are recruited and followed up into the study.

Please contact principal investigators for any inquiries.