A measurement related to anti-parasite antibodies in blood, the fluid that circulates through the heart, arteries, capillaries and veins carrying nutrients and oxygen to the body tissues and metabolites away from them. An anti-parasite antibody is an immunoglobulin molecule possessing a specific amino acid sequence that binds to a specific antigen found on or in a parasite, an organism that grows, feeds, and is sheltered on or in a different organism while contributing nothing to the survival of its host and possibly causing damage to that host. An antigen is a substance introduced into an organism which initiates an immune response, including the production of the very antibodies which bind to it in an effort to destroy it.