MICROBIAL DISEASES OF MAN AND DOMESTIC ANIMALS 867 



be increased." This finding of the Illinois Commission has been 

 confirmed by subsequent investigators. Thus the Thompson-Mc- 

 Fadden Pellagra Commission found, in 1913, that the individuals in 

 Southern cotton-mill villages, in whose families milk was an article of 

 daily use, were distinctly less subject to pellagra than their neighbors 

 who did not use milk. More recently the dietary studies of the U. S. 

 Public Health Service have confirmed these findings, especially in 

 respect to the value of milk. However, the study of actual dietaries 

 of pellagrins and their comparison with dietaries of other people in the 

 same district has pointed clearly to the conclusion that there is no 

 single element in these diets nor any group of elements, the inclusion 

 or exclusion of which can be regarded either as the cause or as a certain 

 preventive of pellagra. 



The Illinois Commission, in 1911, placed as its first conclusion 

 " According to the weight of evidence pellagra is a disease due to infec- 

 tion with a living microorganism of unknown nature." The Thomp- 

 son-McFadden Commission in 1913 found that "new cases of pellagra 

 originated almost exclusively in a house in which a preexisting pellagrin 

 was living, or next door to such a house, suggesting that the disease 

 has spread from old cases as centers." Such spread was most rapid 

 where insanitary methods of sewage disposal were in use. In a later 

 report, 1917, this commission confirmed these conclusions and pre- 

 sented the details of an extensive experiment conducted in the com- 

 munity of Spartan Mills, Spartanburg, S. C., where, by replacing the 

 insanitary surface privies with an efficient water carrier sewer system, 

 one of the worst pellagra foci was transformed into a community in 

 which the disease no longer spread. These observations have, in all 

 essentials, been confirmed by Jobling, Petersen and their co-workers, 

 (1916, 1917) at Nashville, Tenn., who found pellagra to be "practically 

 a disease of the unsewered city areas, a family disease or almost as 

 frequently a disease of the house next door." 



These investigations have, therefore, not only shown that endemic 

 pellagra may be alleviated by improvement in dietary and that its 

 further spread can be effectively checked by sanitary measures directed 

 to the proper disposal of sewage, but also have pointed to the intestinal 

 tract as the location in which the parasitic cause of pellagra is to be 

 sought. 



