RESUMO
When 1,711 bovine faecal samples from 113 farms in eight dairy areas of Colombia were examined for the presence of helminth eggs Fasciola hepatica eggs were found in the faeces from 60% of the farms and samples from animals kept above 2,000 m. Strongyle eggs were found in faeces from 82% of the farms and in 18% of the samples.
Assuntos
Doenças dos Bovinos/epidemiologia , Fasciolíase/veterinária , Enteropatias Parasitárias/veterinária , Infecções por Nematoides/veterinária , Altitude , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Clima , Colômbia , Indústria de Laticínios , Fasciolíase/epidemiologia , Fezes/parasitologia , Feminino , Enteropatias Parasitárias/epidemiologia , Infecções por Nematoides/epidemiologia , Contagem de Ovos de ParasitasRESUMO
Soluble extracts prepared from Babesia bigemina merozoites were tested for antigenicity in class-specific enzyme immunoassays currently being evaluated for the differential serodiagnosis of bovine babesiosis. Intact merozoites were harvested from erythrocytes from an experimentally-infected calf by controlled hypotonic lysis and differential ultra-centrifugation. The merozoites were disrupted by ultrasonication and a crude soluble extract obtained by ultracentrifugation. Fractionation of the crude extract on calibrated Sephadex G-200 columns consistently produced 4 fractions with molecular weights of 600, 40, 15 and 5 k (k = 10(3) daltons). Only the 600 and 15 k fractions proved to be antigenic when reacted against bovine immune sera. These fractions were incorporated into IgM- and IgG-specific enzyme immunoassays and used to determine the kinetics of the host-antibody responses to infection. The use of semi-defined antigens allowed assay standardization and good reproducibility of the results. A calf infected with a cryopreserved stabilate of B. bigemina originating from adult Boophilus microplus ticks developed a mild transient fever from 6-4 days post-infection (d.p.i.) and low parasitaemia levels from 7-16 d.p.i. IgG-antibodies first appeared at 7 d.p.i., peaked in intensity at 12 d.p.i. and then persisted at these levels until the end of the test period at 49 d.p.i. IgM-antibodies appeared at 7 d.p.i., peaked in intensity from 12-22 d.p.i., but then declined to low levels by 28 d.p.i. The importance of this transitory IgM-antibody response in the serodiagnosis of acute B. bigemina infections remains to be determined in clinical and field situations.