Proteomic identification of immunodiagnostic antigens for <i>Trypanosoma vivax </i>infections in cattle and generation of a proof-of-concept lateral flow test diagnostic device

Trypanosoma vivax is one of the causative agents of Animal African Trypanosomosis in cattle, which is endemic in sub-Saharan Africa and transmitted primarily by the bite of the tsetse fly vector. The parasite can also be mechanically transmitted, and this has allowed its spread to South America. Diagnostics are limited for this parasite and in farm settings diagnosis is mainly symptom-based. We set out to identify, using a proteomic approach, candidate diagnostic antigens to develop into an easy to use pen-side lateral flow test device. Two related members the invariant surface glycoprotein family, TvY486_0045500 and TvY486_0019690, were selected. Segments of these antigens, lacking N-terminal signal peptides and C-terminal transmembrane domains, were expressed in E. coli. Both were developed into ELISA tests and one of them, TvY486_0045500, was developed into a lateral flow test prototype. The tests were all evaluated blind with 113 randomised serum samples, taken from 37 calves before and after infection with T. vivax or T. congolense. The TvY486_0045500 and TvY486_0019690 ELISA tests gave identical sensitivity and specificity values for T. vivax infection of 94.5% (95% CI, 86.5% to 98.5%) and 88.0% (95% CI, 75.7% to 95.5%), respectively, and the TvY486_0045500 lateral flow test prototype a sensitivity and specificity of 92.0% (95% CI, 83.4% to 97.0%) and 89.8% (95% CI, 77.8% to 96.6%), respectively. These data suggest that recombinant TvY486_0045500 shows promise for the development of a pen-side lateral flow test for the diagnosis of T. vivax animal African trypanosomosis

Comparative application of antigen detection enzyme-linked immunosorbent assay and buffy coat parasitological technique for diagnosis of bovine trypanosomosis in Nigeria

Antigen-detection enzyme-linked immunosorbent assay (Ag-ELISA) and buffy coat parasitological technique (BCT) were employed for the diagnosis of bovine trypanosomiosis in trade cattle slaughtered at the Bodija Municipal abattoir in Ibadan, Oyo State, between March and November, 2002 and in some sedentary herds located in Oyo, Ondo and Kwara States of Nigeria between September and November, 2002. The results obtained by the BCT showed that the prevalence rates of the disease were: 8.5%; in trade cattle and 9.2%; 14.6%; 16.8% in herds in Oyo, Ondo, and in Kwara State respectively. Comparatively, the use of Ag-ELISA gave higher prevalence rates as follows: trade cattle 16%; Oyo State 16.4%, Ondo 25.0% and Kwara 25%. At species level Trypanosoma congolense was the most frequently detected parasite by both the BCT and Ag. ELISA, revealing a shift in the occurrence of the species in cattle against the background that T. vivax is the most commonly found trypanosome species in Nigeria. With these results, Ag. ELISA has an obvious role in the epizootiological studies of bovine trypanosomiosis in Nigeria. KEY WORDS: Trypanosomosis, Bovine, ELISA, Buffy-coat, Diagnosis Nigerian Veterinary Journal Vol.25(2) 2004: 13-1

The application of enzyme immunoassays to assess the efficacy of chemotherapy in goats experimentally infected with &lt;I&gt;Trypanosoma vivax&lt;/I&gt;

A group of West African Dwarf goats was experimentally challenged with an isolate of Trypanosoma vivax ‘Y58' stock. The goats were monitored serologically by using antigen-ELISA and Antibody-ELISA before and after Berenil treatment for a period lasting about sixty two days. The mean prepatent period before trypanosomes were detected in their bloodstreams was five days post-infection; circulating antigens and antibodies were detected in the goat sera at an average of four and five days respectively. While parasitaemia fluctuated with time, both antigens and antibodies were consistently detected until after treatment with Berenil. Following treatment, parasites were no longer detected in the bloodstreams. Both the antigens and antibodies dissappeared between 7 and 11 days post-treatment. The study clearly shows that enzyme-immunoassays have values in validating the host immune responses and the efficacy of chemotherapic control methods in animal trypanosomosis. KEY WORDS: Trypanosomosis, Drugs, Goats, Diagnosis, ELISA Nigerian Veterinary Journal Vol.25(2) 2004: 27-3