Abstract
Since the discovery of myxovirus parainfluenzae 3 from acute respiratory illness by Chanock et al. (1958), this virus has attracted attention as one of the most important etiological agents causing acute respiratory disease syndromes (Chanock et al, 1959; Hilleman et al, 1962) . Generally speaking, parainfluenzal syndromes were at first considered to be mostly diseases of children, but recently it has been reported that adults are also liable to be infected with parainfluenza viruses (Dick et al. 1961; Bloom et al. 1961) ; thus the parainfluenza 3 infection seems to play a considerably important role in common cold syndromes. On the other hand, there is a virus causing“shipping fever”among cattle, which is antigenically very similar to human parainfluenza 3 virus (Abinanti et al., 1960; Abinanti et al., 1961; Ketler et al., 1961), and Ketler et al. (1961) point out that in the epidemiologic sense, shipping fever bears an analogy to epidemic acute respiratory illness of military recruits, in which human parainfluenza 3 infection seems also to be involved (Bloom et al., 1961) . In this respect, human parainfluenza 3 infection presents also an important problem from the epidemiological point of view.
In the spring of 1960, more than ten cases of parainflenza 3 infection were experienced in Tozuka, Yokohama and Komagome, Tokyo. The present paper will describe these experiences.
