Shayla Johnson

Learn More
A cell culture attenuated Australian bluetongue virus serotype 23 (BLU23) prototype vaccine was assessed for its effects on pregnant Merino sheep. Seventy-six ewes were vaccinated at 5 different stages of gestation, and the failure to lamb at term was as follows: 35 to 43 days of gestation, 20/36 (56%); 57 to 64 days of gestation, 3/10 (30%); 81 to 88 days(More)
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(More)
AIMS This was a pilot study of the use of a clinical pharmacist as a therapeutics adviser (academic detailer) to modify antibiotic prescribing by general practitioners. METHODS Following a visit by the adviser (March-May), 112 general practitioners were recruited and randomised to control or active groups. A panel of experts prepared a best practice chart(More)
OBJECTIVE Evaluate noninvasive prenatal testing (NIPT) with cell-free DNA as a screening method for trisomies 21, 18, and 13 in an obstetrical clinical practice setting. METHODS Observational study of pregnant women who underwent prenatal screening for fetal trisomy from 30 July 2012 to 1 December 2012. NIPT was offered to all patients in addition to(More)
Trials were conducted in three regions of Australia to investigate the potential for improvised shelters and chemical treatments to reduce feeding by Culicoides on cattle and thereby minimise the risk of bluetongue transmission during transport of cattle to ports. Various designs and combinations of roofs and walls were placed around penned cattle. Chemical(More)
Field collected Culicoides brevitarsis Kieffer and C. wadai Kitaoka were fed on sheep that had been artificially infected with a field-isolate of either bluetongue virus serotype 3 (BLU3), BLU9, BLU16, or BLU23. Feeding rates averaged 11.9% but were variable. Survival of midges during incubation tended to be enhanced by the addition of antibiotics and(More)
OBJECTIVE To describe the distribution and prevalence of cattle herds with detectable antibody to bovine pestivirus in Queensland in 1994/95. MATERIALS AND METHODS The study used 7,838 serum samples collected from 250 herds in Queensland, as part of a structured animal health surveillance program conducted in 1994 and 1995. Samples were collected from(More)
OBJECTIVE To assess quantitatively the spatial distribution of seroconversion of Queensland cattle to bluetongue viruses. DESIGN A sentinel herd study. SAMPLE POPULATION Sixty-nine sentinel herds at 30 locations. PROCEDURE Spatial clustering of seroconversion to bluetongue viruses was investigated during the period from 1990 to 1994. RESULTS(More)
The authors have characterised the genetic diversity of the bluetongue virus (BTV) RNA segments 3 and 10 from Indonesia, Malaysia and Australia. Analysis of RNA segment 3, which codes for the core protein VP3, showed conserved sequences in the previously defined Australasian topotype, but which further divided into four distinct clades or genotypes. Certain(More)