A number of different techniques and kits are available to detect parasitic antigens in stool specimens, including the following described in Table 3.
Table 3. Techniques for Parasitic Antigen Detection.Antigen Detection Method | Examples of Organisms Diagnosed |
Enzyme immunoassay (EIA) | Cryptosporidium spp., Giardia sp., Entamoeba histolytica /Entamoeba dispar group |
Direct Fluorescent Antibody (DFA) | Cryptosporidium spp., Giardia sp. |
Rapid antigen test | Cryptosporidium spp., Giardia sp., Entamoeba histolytica /Entamoeba dispar group) |
Whereas detection of parasite antigens in the stool is commonly done, antibody detection from blood (serodiagnosis) is not as commonly performed especially for parasites in the stool. Antibody detection is more commonly done for other parasites such as Toxoplasma (found in tissues).