Prepatent is a term that refers to the period between the infection of an animal or a human by a pathogen and the detection of the pathogen in their blood or other bodily fluids. This term has no direct antonyms. However, some phrases could be used as indirect antonyms for prepatent, including 'postpatent,' 'patent,' or 'detected.' When a patient is diagnosed with a pathogen, they are said to be postpatent. Patent refers to a state of a disease, which is easily detected, and so, the term could describe a disease that has passed its prepatent stage. Detected, on the other hand, refers to the act of discovering a disease, particularly during its prepatent stage, and so could be an antonym.