Therefore, actual infection rates are estimated to be higher than the reported data. (bracpet.com)
Coccidian parasites are relatively common residents of the intestinal tracts of animals, and actual infection of host animals often only occurs in young animals and after stress. (petpeoplesplace.com)
Some titers... rather than indicating protection... either indicate actual infection (e.g. Feline Immunodeficiency Virus «FIV» which is diagnosed by the presence of antibodies)... or simply indicate exposure without indicating infection or protection (e.g. Ehrlichiosis) (stevedalepetworld.com)