National Institute of Animal Health (NIAH)

Topics in Animal Health Research 1996

21. An outbreak of Bluetongue disease in cattle and sheep in Japan

Japanese

An outbreak of a disease like Ibaraki disease of cattle and sheep swept over the eastern parts of Japan during the months from August through October in 1994. The clinical and pathological findings were very reminiscent of Ibaraki disease.
The pathologic findings of the disease are mainly confined to the mucous membrans of digestive tract and the musculature and lesions essentially consist of hyperemia. The most conspicuous change was observed in esophagus larynx pharynxis degeneration of the striated muscles.
An attempt failed to isolate virus directly in HmLu-1 cells or BHK21 cells from the cattle. But bluetongue virus was isolated in embryonating chicken eggs from the sheep. Subsequently, BTV isolated from these infected embryos was passaged once in Vero cell and twice in BHK21 cell cultures.
At that time, PCR tests were carried out by the method of MoColl et al. Using the PCR bluetongue viral RNA was detected in blood samples from affected cattle.
Antibody for bluetongue virus was detected in all affected cattle and sheep serum samples, but were negative against Chuzan virus whereas a few of their method had antibodis for Ibaraki virus.
In the epizootic area AGID antibody for bluetongue virus was detected in high rates of the serum samples tested. Whereas it was found in a few or none of the serum samples from the non-epizootic areas.
In the present study, correlation of bluetongue infection and deglutitive difficulty symptom in cattle and sheep were revealed. All these findings strongly suggest that bluetongue virus is the etiological agent of the outbreaks.
(Lab. of Virological Products, Department of Biological Product)

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