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SCIENCE 



[N. S. Vol. XLVII. No. 1204 



those in which the pathogenic organisms 

 are present in the food at its origin, with- 

 out human intervention; and those in 

 which the food has become contaminated 

 from human sources during the process of 

 preparation, transportation or serving. 



The contamination of food with disease 

 germs on its way from source to consumer 

 may occur through direct contact either 

 with a person suffering from disease or a 

 convalescent or a healthy carrier. From 

 such an individual the specific pathogens 

 may he conveyed to the food by mouth- 

 spray or by contaminated fingers. 



It proba;bly does not often happen that 

 such contamraation is brought about by a 

 person seriously ill with a specific infection 

 except in the initial or later stages of the 

 malady. The incapacitating effects of most 

 infectious diseases tend to prevent the 

 active participation of the patient in mar- 

 keting or serving food. Mild or atypical 

 cases, however, of such diseases as typhoid 

 fever are a source of danger, and instances 

 are on record where food-borne infections 

 have originated from definitely affected 

 persons. From the public-health stand- 

 point infection from this source is im- 

 portant and must be guarded against with 

 great vigilance. 



In a variety of human infections con- 

 valescents constitute an important source 

 of food contamination. As is well kno^^Ti, 

 pathogenic organisms may be present in 

 the nose or throat, in the intestines or in 

 other organs, for some time after clinical 

 recovery has taken place. It is possible 

 in diphtheria and some other infections 

 to determine with a high degree of cer- 

 tainty when the specific germs finally dis- 

 appear from the body, but unfortunately 

 this knowledge is not always taken advan- 

 tage of in actual practise. There is reason 

 to believe that in typhoid fever, for in- 

 stance, patients frequently are released 



from ihe hospital while they are still dis- 

 charging typhoid bacilli from the bowels 

 or bladder. The hospital authorities often 

 do not inform their clients or themselves 

 on this point, and the germ-bearing con- 

 valescent is not warned of the danger to 

 family and associates which his condition 

 involves. In some infections the length of 

 persistence of the specific germs can not 

 be determined by present methods, and 

 consequently only rule-of -thumb methods of 

 quarantine are practicable. As matters 

 stand, it is plain that food-handling by 

 those recently convalescent from any in- 

 fectious disease is always to be avoided; 

 knowledge of this fact shoiild be spread as 

 widely as possible. 



It is not necessary to dwell at length 

 on the significance of the true "carrier" 

 in food-borne infections, since in recent 

 years the nature of the disease-carrier 

 problem has been given wide publicity. 

 The term disease carrier is commonly ap- 

 plied to those in whom the specific germ 

 persists far beyond the usual period of 

 convalescence and also to those who harbor 

 a disease-producing microbe, although they 

 have apparently never suffered from a 

 clinical attack. It is evident that this latter 

 group constitutes a peculiarly insidious 

 source of infection, since the possession of 

 disease-conveying power is often entirely 

 unsuspected by the persons affected, and is 

 only revealed by investigations following 

 an actual outbreak.^ The majority of the 



3 A remarlvable instance of a typhoid carrier has 

 been reported by Jundell (Sygiea, Festband, 1908 ; 

 editorial, Jour. Amer. Med. Assoc, 1909, 52, p. 

 388). The grandmother, 79 years old, of a large 

 family was found in 1908 to harbor typhoid ba- 

 cilli and had apparently been responsible in her 

 lifetime for some thirty-two eases of typhoid fever 

 in members of her family and in servants and other 

 persons in the household. The period during 

 which this carrier was capable of conveying infec- 

 tion apparently extended over fifty-four years, 



