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|Title:||Epidemiology of Swine Influenza Virus in Cattle (Respiratory Diseases)|
|Author(s):||Lopez, Jorge W.|
|Department / Program:||Veterinary Medical Science|
|Discipline:||Veterinary Medical Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Biology, Veterinary Science|
|Abstract:||Various strains of influenza viruses have been isolated from ruminants and antibody responses detected by serological tests. The widespread occurrence of swine influenza virus (SIV) justifies studies to assess the importance of other animals that cohabitate with swine as potential reservoirs.
The objectives were: (a) to determine in calves infected with SIV clinical signs, hematologic, and pathologic alterations; viral activity by fluorescent antibody technique and virus isolation from selected tissues of calves; duration of virus shedding and antibody response, and whether SIV can be transferred to uninoculated calves; (b) Compare the hemagglutination inhibition (HI) test with the single radial hemolysis (SRH) test in screening cattle sera; (c) Determine prevalence of antibodies to SIV in feeder calves; and (d) Compare cell culture susceptibility to SIV.
Five calves were infected with an aerosol of SIV strains A/Sw/IL/75 (H1N1) containing 1,700 EID50. Two calves were given the same amount of killed virus. Two uninoculated calves were housed together with one inoculated calf each. Four calves were used as controls.
A complete randomized design was used and the following traits were measured daily on each treatment: rectal temperature, white blood cell count, and level of antibody to SIV. In addition nasal secretions were collected for virus isolation.
Clinical signs included cough, nasal and eye discharge. A significant increase in antibody titer in inoculated calves was detected by SRH, and HI tests (P 0.05). Virus was isolated for 7 days. Necropsy and histologic findings were limited to the respiratory tract. Histopathology of the lungs showed inflammatory cells in the peribronchial area, alveolar collapse, and increase in alveolar macrophages. The trachea and turbinates had infiltration of mononuclear cells in the subepithelial layer. Fluorescence was present in the epithelial cells of the turbinate, trachea, and bronchi.
A survey of 177 paired cattle sera showed that 3.4% had prior experience with SIV.
It is concluded that SIV can cause natural infection in cattle and that the virus can be transferred to uninoculated calves.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.
|Date Available in IDEALS:||2014-12-16|
This item appears in the following Collection(s)
Dissertations and Theses - Veterinary Clinical Medicine
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois