STUDIES ON ARBOVIRUS INFECTIONS IN EQUINES
Annual progress rept. 1 July 1962-30 June 1963
ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND FORT DETRICK MD
Pagination or Media Count:
A series of experiments were conducted in which burros were subjected to multiple exposures to Group A arboviruses. Production of broadly re active CF antibodies was found to depend on the sequence of different viruses injected. The highest broad spectrum CF reactions appeared in EEE immune burros after challenge with virulent VEE virus. Primary inoculation with EEE, WEE, and VEE gave good specific CF and HAI antibody response. In WEE immune burros, challenged with Sindbis virus, antibody response was insignificant. The immune response of domestic chickens of various ages to inoculation with EEE virus is in progress. Blood virus levels in younger birds were of a higher order and persist longer than in older birds inoculated with the same quantity of virus. Guaroa virus was cultivated on 6 different tissue culture lines. The virus is being characterized and the immunologic response is being measured in mice, rabbits, and chickens. Unsuccessful attempts were made to produce a hemagglutinin to Cache Valley-like virus recently isolated. Of 156 non- vaccinated ponies, neutralizing antibodies to EEE were detected in 40 with HA antibodies to EEE detectable in 19. A serologic survey indicates that a Cache Valley-like virus is rather widely disseminated in domestic animals in the tidewater areas of Maryland and Virginia.