Brill's disease has been defined as a typhus-like illness occurring chiefly among the immigrant populations of the Northeastern coastal cities of the United States.1 In this paper and one which is to follow2 attention is directed to recent clinical and laboratory studies of Brill's disease which emphasize that: (1) the present diagnosistic criteria must be revised; (2) the reported incidence of Brill's disease may be expected to increase; (3) Brill's disease may indeed be important in initiating new epidemics of louse-borne typhus, and (4) the etiologic agent, isolated from 7 patients, is indistinguishable from that of classic epidemic typhus.
HISTORY
During an epidemic of typhoid in Mount Sinai Hospital, New York, in 1896 Nathan Brill became convinced of the specificity of the Widal test, which had just been described. Brill's curiosity was aroused when he observed sporadic cases of an atypical typhoid-like disease in which the Widal reactions