ELISA is themost commonly serologicalmethod to detect Trichinella
infection in humans and animals. In comparison with other serological
methods, it is easy to conduct, relatively inexpensive, readily standardized
and can be automated for large-scale testing. Moreover, it is the
only serological method recommended by the Office International de
Epizooties to detect Trichinella infection in domestic pigs. ELISA for
detecting Trichinella infection has a higher sensitivity than digestion
methods in lightly infected animals. Infections as low as one larva/
100 g of tissue have been detected with ELISAs. The sensitivity and
specificity of ELISAs are largely dependent upon the antigen that is chosen;
however, it is also relative to the host species (Table 3). At present,
different antigens, such as crude antigens, ES antigens, purified antigens
and synthetic carbohydrate antigens have been used in ELISA for detection
of Trichinella infection [19,20]. Additionally, the sample quality and
the individual immune response also influence the reliability of the test.
Poor sample quality (e.g., samples with extensive haemolysis or bacterial
growth) may decrease the specificity and sensitivity of the tests.
Initially, somatic ML antigens were used in ELISA tests. The practical
advantage of somatic antigens is that they are easier to prepare with a
low cost and a high yield. However, a problem with the ELISA based
on somatic antigens is that cross-reactions with antibodies that
are elicited by other parasites, such as A. suum, T. suis, filariae, and
Schistosoma, occur [35], which is why somatic ML antigens are not
recommended for serological testing.