THE EPIDEMIOLOGY OF TYPHOID FEVER

It is but little more than half a century since typhoid fever became first recognized as a disease different from other "slow" or "continued" fevers or even distinct from typhus fever. And yet in few other diseases has greater progress been made toward definite conceptions of cause, mode of spread and manner of prevention.

The realization of the part played by contaminated drinking-water came very early in the study of modes of dissemination of this infection. It is natural that this should have been the case in view of the explosive character and frequent striking localization of water-borne outbreaks. Epidemics like those at Plymouth, Ithaca and Butler in this country tend to focus attention on drinking-water as a primary source of infection. The practice of distributing to the inhabitants of cities raw drinking-water mixed with sewage is, however, steadily receding. It is not necessary to recapitulate here the various procedures