| experimental infection of culicoides brevitarsis from south-east queensland with three serotypes of bluetongue virus. | laboratory-reared c. brevitarsis (biting midges) were fed on sheep which had been experimentally infected with bluetongue serotype 1 (csiro 156), bluetongue serotype 20 (csiro 19) or bluetongue serotype 21 (csiro 154), or on cattle experimentally infected with bluetongue serotype 20 (csiro 19). approximately 77 000 c. brevitarsis were exposed to sheep and 9000 to cattle. the average percentage feeding on sheep was 54% and on cattle 47%. in attempts to transmit virus by bite 3360 c. brevitarsis w ... | 1985 | 2998313 |
| climatic factors associated with the prevalence of bluetongue virus infection of cattle herds in queensland, australia. | the prevalence of bluetongue virus in 410 cattle herds in queensland, australia, was estimated by using the bluetongue virus agar gel immunodiffusion test, and 18 climatic variables were estimated for the location of each herd. temperature and rainfall were the factors most closely associated with the prevalence of bluetongue virus in the herds, and the simplest relationship which explained the most variability in the prevalence included the average daily maximum temperature and the average annu ... | 1994 | 8036770 |
| antibodies to bluetongue and related orbiviruses in sheep and goats in bluetongue virus-endemic areas of northern and central queensland. | | 1995 | 8787524 |
| infection of cattle in queensland with bluetongue viruses: 1. prevalence of antibodies. | a survey of nearly 20,000 cattle in queensland was conducted to describe the prevalence and distribution of infection by serotypes of bluetongue virus. the overall prevalence of serum antibodies to one or more bluetongue viruses was 8.7% (95% confidence interval 8.3 to 9.1). sera from cattle contained neutralising activity against 2 serotypes, 1 and 21. no evidence was found of infection with other serotypes previously isolated in australia. the overall prevalence of serotype 1 antibodies was 7. ... | 1995 | 7661819 |
| 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 |
| action taken in queensland to prevent a possible introduction of bluetongue virus in cattle semen. | | 1967 | 6067735 |
| vectors of bluetongue virus in australia. | two of the 5 serotypes of bluetongue virus (btv) known from australia have been isolated from field collected insects. serotype 20 was isolated in 1975 from a mixed pool of 214 insects containing several culicoides species. serotype 1 has been isolated from c. (avaritia) fulvus sen & das gupta collected at beatrice hill in the northern territory and from c. (avaritia) brevitarsis kieffer collected at peachester in southeast queensland. all other isolates of bluetongue (bt) group viruses have bee ... | 1985 | 2989850 |
| congenital bovine epizootic arthrogryposis and hydranencephaly in australia. distribution of antibodies to akabane virus in australian cattle after the 1974 epizootic. | at the end of the 1974 epizootic of bovine congenital arthrogryposis and hydranencephaly in south-eastern new south wales, an australia-wide serological survey (about 4,000 serums) was made to determine the ditribution of cattle possessing serum neutralising antibodies against akabane virus. eighty per cent of the serums from cattle in northern australia (western australia, northern territory, and queensland) were positive. a detailed study in the epizootic area in new south wales (particularly ... | 1976 | 1016149 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| infection of cattle in queensland with bluetongue viruses: i. prevalence of antibodies. ii. distribution of antibodies. | | 1995 | 8585855 |
| infection of cattle in queensland with bluetongue viruses: ii. distribution of antibodies. | a survey of the distribution of serum antibodies to bluetongue viruses in queensland cattle herds was conducted in 1989. a total of 410 herds were selected in which sera from 20 or more cattle had been tested with the agar gel immunodiffusion (agid) test. estimates of prevalence were standardised for age of cattle and adjusted using results from serum neutralisation (sn) tests. spatial statistical methods were used to investigate the distribution of these selected herds with respect to the preva ... | 1995 | 8526815 |
| the use of discriminant analysis in predicting the distribution of bluetongue virus in queensland, australia. | the climatic variables that were most useful in classifying the infection status of queensland cattle herds with bluetongue virus were assessed using stepwise linear discriminant analysis. a discriminant function that included average annual rainfall and average daily maximum temperature was found to correctly classify 82.6% of uninfected herds and 72.4% of infected herds. overall, the infection status of 74.1% of herds was correctly classified. the spatial distribution of infected herds was fou ... | 1994 | 8091641 |
| 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 |
| infection of cattle with bluetongue viruses in queensland, australia: results of a sentinel herd study, 1990-1992. | between 1990 and 1992, 47 sentinel herds of 10-20 cattle each were established throughout queensland, australia to monitor bluetongue virus infection. sixteen herds at 12 locations seroconverted to bluetongue viruses during the study. herd incidence rates ranged from 0.0 to 3.45 seroconversions per cattle-year at risk. the mean incidence rate was 0.29 seroconversions per cattle-year at risk (95% confidence interval 0.23-0.36), and the median incidence rate was 0.32 seroconversions per cattle-yea ... | 1995 | 7653027 |
| evaluation of an agar gel immunodiffusion test to detect infection of cattle with bluetongue viruses in queensland, australia. | an agar gel immunodiffusion (agid) test to detect group-specific antibodies to infection of cattle by bluetongue viruses was evaluated using field collected sera in queensland, australia. the agid test was compared to the serum neutralisation (sn) test used to detect serotype-specific bluetongue virus antibodies. the agid test was found to be highly sensitive (95% confidence interval, 80.7-100%) but to have moderate specificity (95% confidence interval, 59.3-79.6%), relative to the sn test. the ... | 1995 | 7653026 |