January 25, 191S] 



SCIENCE 



83 



"liealthy carriers," however, are known 

 to have been recently in contact with pa- 

 tients or convalescents. 



Efforts to keep down the number of 

 food-borne infections due to the contamina- 

 tion of food by sick persons, convalescents 

 or carriers are therefore mainly directed to 

 placing the ordinary food manipulations 

 in the hands of healthy persons and of 

 those who have not been recently in con- 

 tact with the sick. This task is somewhat 

 simplified by the rather limited number 

 of diseases likely to be conveyed through 

 such agencies. The chief food-borne in- 

 fections hitherto traced to human con- 

 tamination are typhoid fever and the var- 

 ious paratj-phoid infections. To these must 

 be added certain infections transmitted in 

 milk which are rarely, if ever, conveyed 

 in other food-stuffs. Outbreaks of diph- 

 theria, scarlet fever and streptococcus sore 

 throat due to milk have been reported in 

 considerable numbers, but foods other than 

 milk probably seldom serve as the vehicle 

 of these diseases. In the majority, if not 

 in all, of these cases, the specific germ en- 

 ters the milk directly from human sources. 

 It is probable, however, that in some in- 

 stances a secondarily infected cow must be 

 held responsible. It is theoretically pos- 

 sible for the bacillus of human tuberculosis 

 to be transmitted by food, but evidence 

 of the frequency of such transmission is 

 not readily forthcoming. Even the con- 

 tamination of milk by a tuberculous milker 

 is not easy to prove. Since it is almost 

 impossible to trace most cases of tuber- 

 culosis to their origin, any precise evalua- 

 tion of source of infection in this disease 

 is at present out of the question. Tech- 

 nical difficulties, however, should not be 

 allowed to override the application of ana- 



1854-1908. The disease was confined strictly to 

 this one family, and the neighborhood was free 

 from typhoid fever during all these years. 



logics drawn from other diseases. It seems 

 entirely reasonable to suppose that milk 

 and other foods can become contaminated 

 in the course of their collection or hand- 

 ling by a person discharging human tu- 

 bercle bacilli. In the recent examination 

 in New York City of 1980 food-handlers, 

 10 cases of active tuberculosis were found. 

 The agency of flies in bringing about the 

 contamination of food both with tubercle 

 and typhoid bacilli must also be taken into 

 consideration. 



It can not be forgotten that there is a 

 possibility of the multiplication of patho- 

 genic bacteria in food. In general, micro- 

 organisms pathogenic for man do not in- 

 crease freely outside the human bodj^, 

 and when discharged into the air, water 

 or soil, quickly perish. But in many foods 

 conditions obtain very much like those in 

 the artificial culture media used in lab- 

 oratories. If such foods become contami- 

 nated with pathogenic bacteria, a consider- 

 able increase in bacterial numbers may oc- 

 cur. In point of fact, it has been observed 

 that multiplication of this sort does take 

 place. There are many instances where 

 the incriminated food, when fresh, gave 

 rise to little or no injury, but after stand- 

 ing 24 hours or less without visible signs 

 of decomposition produced numerous cases 

 of illness. Especially significant is the 

 large number of outbreaks in which such 

 foods as meat jellies, meat pies, salads and 

 made dishes generally have been incul- 

 pated. A very large proportion of the re- 

 corded outbreaks has been traced to foods 

 that have been prepared for the table and 

 then allowed to stand before being eaten, 

 or that have kept over to a second or third 

 day as remnants after the first serving. 

 Cooking, so far from surely destroying all 

 bacteria, may in some cases provide a 

 favorable temperature for bacterial multi- 

 plication, as in the celebrated California 



