RESUMEN
Lesions due to Dracunculus insignis in the legs of raccoons (Procyon lotor) in southern Ontario occur seasonally as most larvigerous females emerge in the spring and early summer (April-June). The pathology of dracunculiasis in the raccoon is described and the transmission of the parasite in the wild is discussed with respect to seasonality and local agricultural practices. Crayfish, fishes and frogs (including tadpoles) were given infective third-stage larvae of D. insignis to test their suitability as paratenic hosts. Most of the larvae fed to adult Rana pipiens and R. clamitans were recovered from the somatic musculature. Larvae had increased in size and were highly infective to raccoons.
Asunto(s)
Dracunculiasis/veterinaria , Mapaches , Animales , Crustáceos/parasitología , Dracunculiasis/patología , Dracunculiasis/transmisión , Femenino , Peces/parasitología , Masculino , Ontario , Rana pipiens/parasitología , Estaciones del AñoRESUMEN
Dracunculus medinensis and D. insignis are morphologically indistinguishable. Experiments to test the susceptibility of various mammalian hosts to these two guinea worm species are described. Infective 3rd-stage larvae of D. medinensis were administered to each of four raccons (Procyon lotor): infective 3rd-stage larvae of D. insignis were administered to a rhesus monkey (Macaca mulatta), two dogs, two ferrets (Mustela putorius furo), and a marten (Martes americana). D. medinensis was not found in the raccoons when necropsies were performed on days 247, 283, 354, and 390 post-infection, respectively. Nine female D. insignis containing eggs, embryos, and motile 1st-stage larvae were found in the rhesus monkey 180 days post-infection. Lesions had not formed and the larvae were presumed to be immature and not yet infective as they were comparatively inactive and attempts to infect suitable copepods failed. D. insignis was not found in the dogs or the marten, although both ferrets were successfully infected. Variations in susceptibility of various mammalian species to the guinea worm are discussed together with comments on variations in migration routes and sites of emergence in hosts which may be partially refractory. D. insignis and D. medinensis may represent physiological strains of a single species, or they may in fact be two distinct species which have evolved in different geographical locations.