| serological studies of australian and papua new guinean cattle and australian sheep for the presence of antibodies against bluetongue group viruses. | following isolation of a virus (csiro19) from insects in australia and its identification as bluetongue virus serotype 20 (btv20), a nationwide survey of antibodies in cattle and sheep sera was undertaken. initial studies using the serum neutralization (sn) test showed that the distribution of btv20 antibodies in cattle was confined to the northern part of australia. group-reactive antibody tests (agar gel diffusion precipitin, agdp, and complement-fixation, cf) showed group-reactive cattle sera ... | 1983 | 6306901 |
| phylogenetic characterisation of bluetongue viruses from naturally-infected insects, cattle and sheep in australia. | the polymerase chain reaction was used to detect the presence of bluetongue virus (btv) in a number of clinical and insect samples collected in the northern territory of australia. sequence analyses of the amplified btv genes differentiated endemic australian and exotic viruses. two potential exotic btv were detected as a result of pcr analyses of blood from sentinel animals and of the insect vector, culicoides wadai. the detection of btv in c wadai was the first direct demonstration of the pres ... | 1994 | 8048903 |
| climatic factors associated with the infection of herds of cattle with bluetongue viruses. | the incidence of bluetongue virus infection of 15 cattle herds in queensland, australia, was determined by a serum neutralization test. the maximum temperature (degree c), minimum temperature (degree c) and rainfall (mm) data were obtained from the meteorological recording stations closest to each herd. using unweighted least-squares regression analysis, the best statistical model explaining the most variability in the herd incidence rate included the ratio between the maximum and minimum temper ... | 1996 | 8739526 |
| evaluation of a competitive enzyme-linked immunosorbent assay to detect infection of cattle in sentinel herds in queensland, australia with bluetongue viruses. | a competitive enzyme-linked immunosorbent assay (elisa) was used to detect serogroup specific antibodies to bluetongue viruses. this test is commercially available and was evaluated with serially collected sera from 10 sentinel herds of cattle maintained in queensland, australia during 1994. determination of an infection during the period of observation was based on the development of a serum neutralisation (sn) test titre > or = 1:8 to any one of 8 bluetongue virus serotypes known to exist in a ... | 1996 | 8861648 |
| spatial analysis of seroconversion of sentinel cattle to bluetongue viruses in queensland. | to assess quantitatively the spatial distribution of seroconversion of queensland cattle to bluetongue viruses. | 1996 | 8894018 |
| simulation analysis of the effect of herd immunity and age structure on infection of a cattle herd with bluetongue viruses in queensland, australia. | a state-transition model based on leslie matrix formulation was used to investigate the effects of herd immunity and age structure on the infection of a simulated cattle herd with bluetongue viruses under australian climatic conditions. increasing duration of immunity decreased the prevalence of infection. a duration of immunity of 33 months was consistent with prevalence estimates made from previous serological studies of bluetongue virus. herd prevalence displayed slowly dampening cyclical var ... | 1997 | 9234438 |
| association between risk of seroconversion of sentinel cattle to bluetongue viruses and culicoides species (diptera: ceratopogonidae) in queensland, australia. | the association between risk of seroconversion of sentinel cattle to bluetongue viruses and the number of culicoides brevitarsis kieffer and c. wadai kitaoka caught by light traps was investigated using survival analysis. eight sentinel herds that seroconverted to bluetongue viruses between 1990 and 1994, and for which insect-trapping data were available, were selected for inclusion in the study. these herds were located at six sites along the eastern coast of queensland, australia, from approxi ... | 1997 | 9443333 |
| models for the dispersal in australia of the arbovirus vector, culicoides brevitarsis kieffer (diptera: ceratopogonidae). | culicoides brevitarsis is the main biting midge responsible for the transmission of bluetongue and akabane viruses to livestock in australia. models are given for its dispersal after winter from endemic areas at the southern limit of its distribution in new south wales (nsw); the models might also be applicable elsewhere. model 1 shows that dispersal can be explained by distance from a key point just outside the endemic area in mid-northern/northern coastal nsw. the model provides probability da ... | 2000 | 11087955 |