Validation of clinic-based cryptococcal antigen lateral flow assay screening in HIV-infected adults in South Africa

Drain, P. K., Hong, T., Krows, M., Govere, S., Thulare, H., Wallis, C. L., Gosnell, B. I., Moosa, M. Y., Bassett, I. V. and Celum, C.

Since rapid cryptococcal antigen lateral flow assays (CrAg LFA) may expedite treatment of HIV-associated cryptococcal infections, we sought to validate clinic-based CrAg LFA testing. Among newly-diagnosed HIV-infected adults in South Africa, a trained nurse performed clinic-based testing of urine, fingerprick capillary and venous whole blood with rapid CrAg LFA (Immy Diagnostics, Norman, USA). We performed matched laboratory-based serum cryptococcal antigen testing with an enzyme immunoassay (EIA). We assessed diagnostic accuracy using EIA as the gold-standard, and performed additional validation testing on serum and among hospitalized adults with cryptococcal meningitis. Among 5,618 participants enrolled, 1,296 were HIV-infected and screened for cryptococcal antigenemia. Overall CrAg prevalence by serum EIA was 3.6% (95% CI 2.0-6.0%) for adults with CD4 < 200 cells/mm(3), and 5.7% (95% CI 2.8-10.2%) for adults with CD4 < 100 cells/mm(3). Using expanded screening guidelines (CD4 < 200 cells/mm(3)), CrAg LFA testing of venous whole blood, fingerprick capillary blood, and urine had diagnostic sensitivities of 46% (95% CI 19-75%), 38% (95% CI 14-68%), and 54% (95% CI 25-81%), and specificities of 97%, 97%, and 86%, respectively. When tested on serum samples, CrAg LFA had sensitivity of 93% (95% CI 66-100%) and specificity of 100% (95% CI 88-100%). All venous and fingerprick whole blood CrAg LFA tests were positive among 30 hospitalized adults with cryptococcal meningitis. Two independent readers had strong agreement for all LFA results (p < 0.0001). When performed at the point-of-care by trained nurses, CrAg LFA testing was feasible, had the highest accuracy on serum specimens, and may accelerate treatment of HIV-associated cryptococcal infections.

April 12, 2019
Year of publication
2019
Resource types
Journal and research articles
Countries
Tags
HIV-positive adults, HIV-associated cryptococcal disease, cryptococcal antigen (CRAG), newly diagnosed

Similar Resources

Initiation of antiretroviral therapy (ART) following diagnosis of HIV infection at birth is an emerging area of paediatric HIV care. We present outcomes of HIV-infected infants identified at birth at Rahima Moosa Mother and Child Hospital in Johannesburg, South Africa.
Community-based GeneXpert MTB/RIF testing may increase detection of prevalent TB in the community and improve rates of TB treatment completion.
Community-based HIV testing and counseling (HTC) programs have become an important part of the healthcare system in South Africa and other low- and middle-income countries with a high HIV prevalence and strained primary healthcare system. Current HTC programs excel at identifying people living with…

This issue of the Southern African HIV Clinicians Society's "HIV Nursing Matters" online magazine focuses on vulnerable populations, including TB in prisons and intimate partner violence in the context of HIV.

This issue of the Southern African HIV Clinicians Society's "HIV Nursing Matters" online magazine focuses on key populations.

BACKGROUND:

Attrition along the HIV care continuum slows gains in mitigating the South African HIV epidemic. Understanding population-level gaps in HIV identification, linkage, retention in care and viral suppression is critical to target programming.

BACKGROUND:

The goal of virtual elimination of horizontal and mother-to-child HIV transmission in South Africa (SA) has been proposed, but there have been few systematic investigations of which interventions are likely to be most critical to reducing HIV incidence.

Identifying gaps in HIV testing and treatment is essential to design specific strategies targeting those not accessing HIV services. We assessed the prevalence and factors associated with being HIV untested, unaware, untreated, and virally unsuppressed in KwaZulu-Natal, South Africa.

Many countries are working to reduce or eliminate mother-to-child transmission (MTCT) of HIV. Prevention efforts have been conceptualized as steps in a cascade but cascade completion rates during and after pregnancy are low.

Achieving the promise of antiretroviral therapy (ART) to reduce HIV-associated mortality and transmission in sub-Saharan Africa relies on increasing behavioral change toward earlier engagement and sustained retention in HIV care after HIV diagnosis. Health communication may be an…