Abstract:
An ante mortem antigen-ELISA-based diagnosis of Taenia saginata cysticercosis was studied
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
calves and 2 in naturally infected steers. In natural infections, the minimum number of live
cysticerci consistently detected by Ag-ELISA was 5 while in artificial infections it was above
14. However, other animals with 12 and 17 live cysticerci in artificially infected calves, and
1 and 2 live cysticerci in naturally infected steers, escaped detection for unknown reasons.
Animals harbouring dead cysticerci gave negative reactions in the assay as was the case in
non-infected experimental control calves. There was a statistically significant positive linear
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
potential effectiveness of ante mortem monoclonal antibody-based antigen detection ELISA
in the diagnosis of bovine cysticercosis in cattle. Its value lies in the diagnosis of infection
in cattle as a screening test in a herd, rather than as a diagnostic test at the individual level,
due to false positive and negative reactions. In a herd of heavily infected cattle, the
assay may, however, provide for individual diagnosis. Nevertheless, more work is recom-
mended to increase its sensitivity so as to be able to diagnose light infections consistently in
the field.
