Performance of a Sandwich Antigen-Detection ELISA for the Diagnosis of Porcine Taenia solium Cysticercosis

Abstract

The pig is the natural intermediate host of Taenia solium, a parasite causing significant burden of disease in both humans and pigs. Porcine cysticercosis is traditionally detected via tongue palpation and slaughterhouse meat inspection, both with limited sensitivity. Serum antibody detection has a better performance; however, it does not discriminate past from present infection. Serum antigen detection can demonstrate viable infection and gives a good estimate of parasitic load. This study evaluated a sandwich antigen-detection ELISA using monoclonal antibodies (MoAbs) 158C11 and 60H8 for the diagnosis of viable cysticercosis in pigs. Serum samples were used from 35 naturally T. solium cysticerci-infected pigs, 31 cysticercosis-negative pigs, and 22 pigs with Taenia hydatigena infection (to assess cross-reactions). Positive cysticercosis samples were subcategorized at necropsy according to parasitic burden as mild (1-10 viable cysts, n = 10), moderate (11-100 cysts, n = 5), or severe infection (more than 100 cysts, n = 20). This Ag-ELISA showed a sensitivity of 82.9% and a specificity of 96.8% when not considering cross-reactions with T. hydatigena. Hundred percentage of severely infected, 80% of moderately infected, and 50% of mildly T. solium-infected pigs tested positive. Twenty of 22 pigs with only T. hydatigena infections were positive, with 13 reaching saturating levels in the ELISA. The Ag-ELISA revealed the presence of live cysts and is, thus, a fairly reliable test to monitor experimental infection, response to treatment, and follow-up in animal models of cysticercosis. It should, however, be carefully interpreted when used in regions where T. hydatigena is endemic in pigs.

Performance of Ag-ELISA in the diagnosis of Taenia solium cysticercosis in naturally infected pigs in Tanzania

“…However, contrary to this study, in the latter study in Zambia, full carcase dissection was performed in case no cysticerci were detected in the first carcase half. In a much recent study in Peru by Bustos et al [ 24 ] B158/B60 Ag-ELISA showed a sensitivity 82.9% and a specificity of 96.8%, when not considering cross-reactions with T. hydatigena .…”

Immunodiagnostic usefulness of monoclonal antibodies specific to conformational epitopes of Taenia solium oncosphere protein TSOL18

“…The current monoclonal antibody-based Ag-ELISA detects circulating excretory-secretory antigens of cysticerci and not oncospheral antigens ( Brandt et al, 1992 ; Paredes et al, 2016 ; Bustos et al, 2019 ). Obviously, in epidemiological studies, these tests cannot measure proportion of pigs and humans with exposure to T. solium eggs that does not lead to the establishment of cysticerci.…”

Neurocysticercosis: Current Perspectives on Diagnosis and Management

“…Despite this, specific ELISAs are useful in confirming diagnosis and evaluating treatment of extraparenchymal cysts ( 30 ). Detection of circulating cysticercus antigens can be done by using monoclonal antibody-based antigen capturing ELISA (Ag-ELISA) ( 23 , 31 ). These tests only detect the presence of active viable cysts.…”

“…These tests only detect the presence of active viable cysts. In combination with antibody-detecting tests, Ag-ELISA can be used to differentiate between live parasite infections and dead larvae in degenerating cysts ( 23 , 31 ); high antigen levels are associated with extraparenchymal NCC, whereas low or undetectable antigen levels are associated with intraparenchymal NCC ( 23 , 31 ).…”