The Epizootiology of Bovine Ephemeral Fever in Australia and Papua‐new Guinea

Bovine ephemeral fever is an important viral disease of cattle in Australia. The disease occurred each year, principally in summer and autumn, between 1981 and 1985. Queensland and the northern half of New South Wales were areas of greatest activity with only sporadic cases being reported from the Northern Territory and the northern third of Western Australia. Since 1981, the disease has been endemic in an extensive area of eastern Australia and has tended to occur in widely scattered outbreaks rather than the north-south advancing wave form of the epidemics of 1936-37, 1967-68, 1970-71 and 1972-74. The southernmost outbreaks between 1981 and 1985 were well within the limits of these earlier epidemics. The pattern of disease appears to have become seasonally endemic rather than periodically endemic in the northern two-thirds of eastern Australia. Ephemeral fever was not recorded in Victoria, Tasmania, South Australia or the southern part of Western Australia between 1981 and 1985

Section: Discussionmentioning

confidence: 96%

“…The maps which illustrate the epidemics of 1936-37 by (Seddon 1938;Murray 1970;St George et at. 1977), and to a lesser extent by Uren et at.…”

Section: Discussionmentioning

confidence: 99%

Section: Virus Isolationmentioning

confidence: 99%

See 1 more Smart Citation

Epidemiology of Bovine Ephemeral Fever in Australia 1981?1985

Uren¹,

George²,

Kirkland³

et al. 1987

“…The method used was the intracerebral inoculation of suckling mice as described by St George et al (1977).…”

Section: Laboratory Proceduresmentioning

confidence: 99%

Serological and Biochemical Factors in Bovine Ephemeral Fever

George¹,

Cybinski²,

Murphy³

et al. 1984

Clinical signs of ephemeral fever, which were observed in individual cattle during two successive epidemics in 1973 and 1976, were related to biochemical, cellular and serological changes in the blood. The rise in peripheral blood neutrophil counts in sampies collected from 12 sentinel cattle on a daily basis before, during and after natural disease in the two epidemics to mean peaks of 9 . 6-12 . 5 X 10 9 per litre, and fall in counts of lymphocytes to a trough of 5-7 X 10 9 per litre was found to occur on the same day as the fever peak. A fall in serum calcium levels from a normal mean of 2·55 mmol/l to 2·0 mmol/I occurred on the day clinical signs were most pronounced. Serum magnesium levels were affected to only a minor degree. Plasma fibrinogen rose from a normal mean of 5·0 g/I to a peak of 18 g/I on the second day of disease and fell towards normal in the week after recovery. Neutralizing antibodies to bovine ephemeral fever virus were detected up to 63 days prior to clinical disease, and the rise of antibody after recovery was secondary in pattern. Serological evidence of a prior infection with an antigenically related virus, Kimberley virus, was found in these animals. In more severe clinical cases of ephemeral fever serum calcium levels were as low as 1·95 mmol/l. Treatment of cattle showing clinical signs of the disease with phenylbutazone and calcium borogluconate was favourable.

“…Consequently the procedure of carrying out insect collections only where and when an epidemic occurred was revised to that of collecting continuously 0004-9417/84/050351 $02.00 in an area where there was a high probability that infection of cattle with bovine ephemeral fever would occur. Beatrice Hill in the Northern Territory was selected because sentinel herd serology (St George et al 1977) indicated that bovine ephemeral fever would be encountered if collections were made to cover two wet seasons. Laboratory facilities were available on site, and importantly, access by road was possible throughout the year.…”

Section: Introductionmentioning

confidence: 99%

Isolation of Arboviruses from Insects Collected at Beatrice Hill, Northern Territory of Australia, 1974?1976

Ha¹,

Al²,

Td³

et al. 1984

Between October 1974 and May 1976, 57596 mosquitoes, 169957 Culicoides, 5923 Lasiohelea and 1043 phlebotomines were collected for virus isolation at Beatrice Hill (lat. 12�39'S.,long. 131�20'E.) in the Northern Territory of Australia. A total of 94 viruses belonging to 22 different serological groupings was isolated. The following species of insect yielded viruses which were identified and those viruses marked with an asterisk represent a new record of insect host: