Species: Ovine, bovine
Container: Red top or gel tube (Note: only undertaken on 10 or more samples)
Collection protocol: Venepuncture
Special handling/shipping requirements: Standard
General information about the disease:
Neospora caninum, an apicomplexan protozoan parasite infection, causes abortions in cattle of all ages. These events may take the form of sporadic or low-level endemic occurrences of abortion, or be of epidemic, “storm-like” proportions. These abortion storms, in particular, can affect large proportions of the at-risk (i.e. in-calf) cow population and cause large economic losses. The dog is the definitive host.
Some work suggests sheep may be affected too, but the likely seroprevalance is low. The ELISA can be used to investigate Neospora exposure in sheep flocks.
General information about when this test is indicated:
The ELISA is most suitable for herd or flock investigations, and (as titres persist longer) for the detection of chronically infected animals. To demonstrate an association between abortions/reproductive failure and N caninum infection, a blood sample should be taken from 10 empty cows (or ewes), and a control group of 10 pregnant cows (ewes). All should be tested by ELISA for Neospora antibodies. To establish if there is a correlation between the Neospora results and pregnancy status calculate the relative risk ([a / (a + b)] / [c / (c + d)]; where a is ELISA positive and aborted, b is ELISA positive but not aborted, c is ELISA negative and aborted and d is ELISA negative but not aborted). A relative risk greater than 1 indicates an association. Also use the ELISA if you want to determine if cattle have been infected or not.
Comparison with other related tests::
For investigating the neospora status of individual animals, especially related to abortion use the Neospora IFAT.
The ELISA test is reported as a positive or negative result. The ELISA and IFAT tests correlate well and a positive ELISA means that the IFAT titre is >1:600. Neospora serology is preferred in epidemiological investigations or where no fetal tissue is available. For the initial abortion investigation on a farm, histopathology of a range of tissues is recommended.