RESUMEN
Avian cerebrospinal nematodiasis was studied in chickens experimentally inoculated with infective eggs of Baylisascaris procyonis of raccoon origin. Birds each received 3,200, 1,600, 800, 400, 200, or 0 eggs, one dose per group of 10 birds. Central nervous system (CNS) disease developed in 17 of the 50 infected birds. Birds receiving the higher dosages exhibited the worst clinical signs, had higher mortality rates, lived for shorter duration, and had the most severe brain lesions. Onset of CNS disease was consistent between groups and averaged 20.4 days, and duration varied from less than one to 23 days. No gross lesions were present. Histologically, multifocal areas of malacia and necrosis, hemorrhage, perivascular cuffing, nonsuppurative meningoencephalitis, focal granulomas, and migrating larvae were seen in the brains. No larvae were recovered from the brains by the Baermann method. Extraneural lesions were limited to focal choroiditis and a granuloma in an extrinsic ocular muscle.
Asunto(s)
Enfermedades del Sistema Nervioso Central/veterinaria , Pollos , Infecciones por Nematodos/veterinaria , Enfermedades de las Aves de Corral/patología , Animales , Ascaridoidea , Encéfalo/parasitología , Encéfalo/patología , Enfermedades del Sistema Nervioso Central/patología , Masculino , Infecciones por Nematodos/patologíaRESUMEN
To assess the danger of Baylisascaris procyonis (the common roundworm of raccoons) to subhuman primates, as well as the zoonotic potential of the parasite, 4 squirrel monkeys were inoculated by stomach tube with 5,000 or 10,500 infective B procyonis eggs. Fulminating severe CNS disease developed at 10-15 days after inoculation, and the monkeys died or were euthanatized at 12-19 days. At necropsy, numerous hemorrhagic migration tracks were visible in coronal brain slices. Histologically, numerous migration tracks and larvae were seen in the brain as well as the spinal cord. Larvae measured 60-65 micrometers in midbody diameter. Migration tracks averaged 508 micrometers X 354 micrometers in cross section and consisted of foci of malacia and microcavitation, with an influx of macrophages and leukocytes, and various degrees of hemorrhage. Also seen were extensive perivascular cuffing, gliosis, astrocytosis, and a mixed inflammatory cell infiltrate. Numerous larval granulomas were seen grossly and microscopically throughout the body; they were particularly abundant in the tissues of the head, neck, and thorax. It was concluded that B procyonis should be considered a threat to the health of subhuman primates and an important potential zoonosis in situations wherein infection of monkeys or human beings could take place.