During the five and one-third years between January 1936 and May 1, 1941 there were admitted to the Queensboro Contagious Pavilion 29 patients with encephalitis which followed acute contagious diseases of childhood. In the greatest number of these, 20 (69 per cent), the infection followed measles; in 4 (14 per cent), pertussis; in 4 (14 per cent), mumps, and in 1 (3 per cent), chickenpox. Of the 20 patients with encephalitis complicating measles, 16 (80 per cent) were admitted to the hospital within the period of less than three and one-half months from Jan. 29, 1941 through May 1, 1941. This period corresponded to one of increased incidence of measles.
ETIOLOGY
Inasmuch as an appreciable number of instances of measles are not reported, one can only speculate on the incidence of encephalitis as a complication of this disease. Neal1 has stated that before epidemic encephalitis made its appearance in