678 PATHOGENIC MICROORGANISMS 



upon tnc fact that bacteriological water examinations of this kind must 

 always be associated with careful sanitary survey of the water shed and 

 engineering examination of the purification plant, if there is one avail- 

 able. It is important for the sanitarian to remember that, while water 

 epidemics are constantly diminishing as large scale water purification 

 becomes more and more universal, there are still occasional epidemics 

 in which accidents have occurred to ordinarily properly functioning 

 purification plants. ' Such an epidemic was recently reported from 

 Salem, Ohio, 108 where in September and October of 1920, following a 

 rainy period, enteritis of unknown origin afflicted about one-half the 

 population. Subsequent investigation showed that 3 cases of typhoid 

 fever had occurred in early September; and typhoid fever reports began 

 in late October and early November. Investigation of the water supply 

 revealed pollution probably due to the contamination of one of the 

 gravity lines connecting a group of wells with the reservoir. Aside 

 from the earliest cases mentioned above, the first cases appeared about 

 October 1st, and reached a peak of 54 new cases on November 1st, 

 which was the highest daily number of the epidemic. Up to November 

 20th, a total number of 785 cases, with 12 deaths occurred. Recently, 

 we have heard of another epidemic which occurred in a California town, 

 where a small explosive outbreak of typhoid fever occurred owing to 

 accident to the water supply followed by direct pumping from the 

 river, for one day, necessitated by repairs. The considerable and 

 unexceptional diminution of typhoid fever in all cities where water 

 supply purification plants have been installed, may be found tabulated 

 in such books as Rosenau's Hygiene, Mason's book on water supply, 

 and others. 



Milk may act as a distributor of typhoid fever either by direct infec- 

 tion of the milk from milk handlers who are carriers, or from bottles 

 that are returned from houses where typhoid fever or typhoid carriers 

 exist. A considerable number of milk epidemics have been traced 

 beyond doubt, and have usually been characterized by an explosive 

 onset and by the fact that the majority of the patients were women and 

 children. Milk is an excellent culture media for the typhoid bacillus, 

 and an enormous increase of the organisms in the milk between contam- 

 ination and consumption may occur without visible changes in the milk. 

 Uncooked vegetables, salad, radishes, etc., may be responsible for typhoid 

 infection, and of recent years it has also been shown that oysters may 



108 Jour, of the A. M. A., 75, 1920, 1498. 



