Serodiagnosis of bovine cysticercosis by detecting live Taenia saginata cysts using a monoclonal antibody-based antigen-ELISA

Abstract

Anantemortemantigen-ELISA-baseddiagnosisofTaeniasaginatacysticercosiswasstudied in artificially (n = 24) and naturally (n = 25) infected cattle with the objective of further validating the assay as a field diagnostic test. Based on total dissection as the definitive method of validity, the assay minimally detected 14 live cysticerci in artificially infected calvesand2innaturallyinfectedsteers.Innaturalinfections,theminimumnumberoflive cysticerciconsistentlydetectedbyAg-ELISAwas5whileinartificialinfectionsitwasabove 14.However,otheranimalswith12and17livecysticerciinartificiallyinfectedcalves,and 1and2livecysticerciinnaturallyinfectedsteers,escapeddetectionforunknownreasons. Animalsharbouringdeadcysticercigavenegativereactionsintheassayaswasthecasein non-infectedexperimentalcontrolcalves.Therewasastatisticallysignificantpositivelinear correlation between Ag-ELISA optical density values and burdens of live cysticerci as obtained by total dissection of both artificially infected calves (r = 0.798, n = 24; P < 0.05) and naturally infected steers (r = 0.631, n = 25; P < 0.05). These results clearly show the potentialeffectivenessofantemortemmonoclonalantibody-basedantigendetectionELISA in the diagnosis of bovine cysticercosis in cattle. Its value lies in the diagnosis of infection incattleasascreeningtestinaherd,ratherthanasadiagnostictestattheindividuallevel, due to false positive and negative reactions. In a herd of heavily infected cattle, the assaymay,however,provideforindividualdiagnosis.Nevertheless,moreworkisrecommendedtoincreaseitssensitivitysoastobeabletodiagnoselightinfectionsconsistentlyin the field.