The occurrence of numerous epidemics of infectious mononucleosis, in foundling homes, children's hospitals, schools and colleges, has been reported.1 The persons involved in these outbreaks all had symptoms or physical manifestations of some kind. The number of cases in these epidemics rapidly reached a peak and then declined. The blood of most of the patients showed a marked increase in the mononuclear elements. In some instances the abnormal type of lymphocyte considered characteristic of infectious mononucleosis was present; in others an increase in the number of small lymphocytes occurred without the presence of abnormal cells. The results of the Paul-Bunnell test, which was used in only three of the epidemics reported on in the literature, were given as positive in two reports (Nolan1g and York and Eckley1k) and negative in the third (Rosenbaum1f).
In view of the fact that the patients in these epidemics of infectious