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Publication The etiological and epidemiological studies on the Ibaraki disease i...  

Update Date: [2013-11-13]

NO.: 32

AHRI report No.32


The etiological and epidemiological studies on the Ibaraki disease in Taiwan



Taiwan Animal Health Reseaxch Institue

Author Yung-Kung Liao, Yong-Siu LA1J, Shin-Tse Huang and Sliu-Hwei Lee

Nonsuppurative eneephaltils has l:een deeeed spcndically in Taiwan since 1985. However, the exact causative agent was not recognized intil July of 19), when Ibaxald disease virus was first isolaed from cerebollum of a cattle with nonsuppuxative encephalitis in (lia-Yi district in Taiwan. During the pevailing jrncd of the discase, epidamilolgical survey was conduced on 72 young calves aged under 1 year, from 8 farms lccaed in Chia-Yi District. Result showerl that 10 calves (14 %) suffered from the disease. Nine sick calves culled or died within a few days after the onset of clinical signs. Virus isolation was further rerformed on 73 blocd samples from epimotic farms, and results showed that 28 plasma samples and 11 bkxxl ecU samples coninerl the Orbivirus, respectively. During the ericd of Sepemter to Octoirer, virus were isolated from the nasal discharge and blood of infected cattle, with the symptoms mainly in the respiratory not, of two farms in Pinguth. Furthermore, Orbivirus was
iUfl1flZ7 also isolated from a newboirn calf with nurvous signs in Kaohsiung district in Decemker of 1991.

The viruses isolated from field cases were ethogenic to suckling mice, Exrerimental infection of isolated virus to cattle also induced clinical sign in respiratory not. Furthermore, virus could ire recovered from blocd of the infected cattle even 54 days past incculation. A four consecutive years of serological survey on antibodies against Ibarald diseease in cattle in Taiwan was conduced from 1987 to 19). The antibody-positive rae of dairy cattle in Taiwan increased from 25% in 1987 to85 % in 19%. The result indicaed that the disease was epitic in cattle opulation inTaiwan. This is theffistreportofthecxxunenceoflbaxa]ddiseaseinTaiwan. [*Liao YK, Lu YS, Huang ST and L SH. The etiological and epiclerriiological sedies on the IbaraiddiseaseinTaiwan. J ChinScxoVetSci22(3):183-19l, 1996. *ppe]ip1g author TEL:C12-621 2111, FAX:02-622 5345]


Raraki disease, Orbivixus, Nonsuppurative encephalitis