SiphonapteraPlagueHIV SerosortingYersinia pestisSexually Transmitted DiseasesHomosexuality, MaleFlea InfestationsInsect VectorsTransmissible gastroenteritis virusGastroenteritis, Transmissible, of SwineGenetic VectorsCtenocephalidesPrion DiseasesEctoparasitic InfestationsXenopsyllaPrionsCoronaviridaeScrapiePrPSc ProteinsRickettsia felisEncephalopathy, Bovine SpongiformDisease VectorsPrPC Proteins