DETECTION OF BACTEREMIA IN CATTLE INOCULATED WITH BOVINE VIRAL DIARRHEA VIRUS

Abstract

Bovine viral diarrhea virus infection of cattle interfered with normal blood clearance mechanisms, as evidenced by the detection of an endogenous bacteremia in up to 85% of infected calves during the first 5 days after infection. Detectable bacteremia occurrence correlated with the period of leukopenia and depression of lymphocyte mitogen [phytohemagglutinin] response. Noninoculated control animals, reinoculated immune calves, or calves, or calves inoculated with infectious bovine rhinotracheitis virus yielded consistently negative cultures. Bacillus spp. were isolated in almost all calves. Similar organisms were isolated occasionally from the blood of normal calves when medium containing sodium polyanetholesulfonate was used for culture. Evidently bovine viral diarrhea virus infection depressed the normal defense mechanisms, presumably humoral factors or phagocytic function, resulting in uninhibited blood circulation of bacteria during infection.