Table 1. -Complement fixation titers of deer experimentally infected with Bluetongue or Epizootic Hemorrhagic 



disease 



Scrum no. 



History 



CI'" titer 



Classification 



1 Pool (0 scrums) Pre. lnoc 



2 Pool (6 scrums) Post lnoc, 3-4 Weeks Hluetongue 



3 Scrum. 3-4 Months Post lnoc. Bluetongue 



4 (1 serum), 3-4 Months, Post lnoc, Bluetongue . . 



5 (1 serum). Pre. lnoc 



6 (1 serum). Pre. lnoc 



7 ( 1 serum), Pre. lnoc 



8 (1 scrum), Post lnoc, 1 Month. EHD 



9 (1 scrum). Post lnoc. 1 Month. EHD 



10 (1 scrum), Post Contact, 1 Month. EHD 



Less than 50 percent fix at 1-5 dilution. 

 20 percent fix at 1-5 dilution. 



N 1 



Negative 



20 



Positive 



20 



Do. 



20 



Do. 



N 



Negative 



N 



Do. 



N 



Do. 



N 2 



Do. 



N 2 



Do. 



N 2 



Do. 



Discussion 



The intensit) and duration of the complement fixing antibody response was marked in both sheep and cattle 

 and may have been related to the virulence of the BT8 strain of the virus. However, the presence of a viremia was 

 not detected during or at the termination of the experiment. The sensitivity of the CF test in detecting cattle and 

 sheep previously infected with BT was demonstrated. 



The failure of the serums from EHD infected deer to fix complement with BT antigen except at a barely 

 detectable level was of great significance. The EHD virus is similar in physical and chemical characteristics to BT and 

 some degree of cross reaction might have been expected. All strains of BT virus will fix complement with a mouse 

 brain antigen prepared from any strain of the virus. If the EHD virus was just another strain of BT virus, a strong 

 reaction would have been detected between the BT mouse brain antigen and the serums from the EHD infected deer. 

 This serological data is evidence for the uniqueness of EHD as a distinct and separate agent from BT virus. 



3. 



4. 



REFERENCES 



Boulanger, P. Technique of a Modified Direct Complement Eixation Test for Viral Antibodies in 

 Heat-Inactivated Cattle Serum. Can. J. Comp. Med. 24 (I960): 262-269. 



, Ruckerbauer, G. M., Bannister, G. L., Cray, D. P. and Girard, A. Studies on Bluetongue. 



III. Comparison of Two Complement-Fixation Methods. Can. J. Comp. Med. Vet. Sci. 31 (July 1967): 



166-170. 



Robertson, A., Appel, M., Bannister. G. L., Ruckerbauer, G. M. and Boulanger, P. Studies on Bluetongue. II. 



Complement-Fixing Activity of Ovine and Bovine Sera. Can. J. Comp. Med. 29 (1963): 113-117. 



Thomas, F. C. and Miller, Janice. A Comparison of Bluetongue Virus and EHD Virus: Electromicroscopy and 



Serology. Can. J. Comp. Med. 35 (Jan. 1971): 22-27. 



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