Concordance between a New Rapid Point-Of-Care Assay and Standard ELISA in the Detection of Cysticercosis Antigens in Urine

Abstract

Neurocysticercosis is a parasitic disease of major public health importance. Definitive diagnosis requires neuroimaging, which is typically unavailable in rural impoverished regions of endemicity. Screening immunoassays can support diagnosis in this setting by identifying individuals most likely to have severe forms of disease for referral to imaging. Urine sampling is convenient, painless, and generally well accepted. We developed a rapid point-of-care (POC) assay to detect urinary antigens and assessed concordance with a standard antigen ELISA (Ag-ELISA), both using monoclonal antibodies TsW8/TsW5. From 28,145 stored community samples with Ag-ELISA results, we selected 843 for comparison, 281 each from nonreactive (ratio <1), reactive-below-cutoff (ratio 1:3), and positive (ratio ≥3) samples. Overall agreement was 73.6%, with strong agreement observed in the nonreactive (280/281, 99.6%) and positive (255/281, 90.8%) groups. This affordable noninvasive POC test can be applied to identify individuals in the community most at risk of developing severe disease.

Figure 1.

Antigen ELISA (Ag-ELISA) ratio levels and point-of-care (POC) assay results by study group.