Serologic Studies of Myxovirus Para-Influenza 3 in Cattle and the Prevalence of Antibodies in Bovines

Summary The relative sensitivities of the hemagglutination inhibition (HI), neutralization (N) and complement fixation (CF) tests to detect parainfluenza 3 antibodies in bovine sera were compared. The HI and N tests were essentially similar in sensitivity; the CF test was less sensitive but appeared to be useful in detecting recent infections. The temporal appearance and persistence of each type of antibody was studied. A serologic survey of market cattle bled at slaughter showed that at least 70% had parainfluenza 3 antibodies and that infection had a wide geographic distribution. The data suggest that greater numbers of new infections occur during the fall than during other periods of the year.