706 BACTERIA IN AIR, SOIL, WATER, AND MILK 



(formerly spoken of as Bacillus acidi lactici [Kruse]), with other strep- 

 tococci, has shown that, essentially, this streptococcus does not differ 

 from streptococci from other sources, and is practically indistinguish- 

 able by cultural methods from Streptococcus pyogenes. Similar com- 

 parisons made by Schottmiiller,' Miiller,^ and others have led to like re- 

 sults. Since streptococci may be found in milk from perfectly normal 

 cows and are almost regularly associated with lactic-acid fermenta- 

 tion, it is unlikely that these microorganisms hold ordinarily any 

 specific relationship to disease. 



Recently, however, a number of epidemics of sore throat caused by 

 streptococci have been traced to milk upon reasonably reliable evidence. 

 Accounts of such epidemics in Chicago and in Baltimore have been 

 published by Capps and Miller ' and by Hamburger.* 



The presence of pus cells and leucocytes in milk, together with 

 streptococci, was also formerly regarded as of great importance. 

 -Enumerations of leucocytes in milk were first made by Stokes and 

 Weggefarth.^ Their method of enimieration consisted in centrifugaliz- 

 ing a definite voliune of milk, spreading the entire sediment over a 

 definite area on a slide, and counting the leucocytes found in a nmnber of 

 fields. Calculations from this may then be made as to the number of 

 leucocytes per cubic centimeter. This method, and modifications of it, 

 have been used by a large number of observers, but the value of the con- 

 clusions drawn from them has been much exaggerated. Normal milk 

 may contain leucocytes in moderate numbers, and importance may be 

 attached to such leucocyte counts only when their number largely ex- 

 ceeds that present in other specimens of perfectly normal milk. When- 

 ever such high leucocyte counts are found, of course, a careful veteri- 

 nary inspection and examination for pyogenic disease should be made. 



Foot-and-mouth disease, an infectious condition prevailing among 

 cattle, characterized by a vesicular rash on the mouth and about the 

 hoofs, has, in a number of cases, been definitely shown to be transmitted 

 to man through the agency of milk. Notter and Firth* reported an 

 epidemic occurring among persons supplied with milk from a single dairy 

 in which foot-and-mouth disease prevailed among the cows. In this 



1 Schottmuller, Munch, med. Woch., 1903. 



2 Midler, Arch. f. Hyg., Ivi, 1906. 



' Capps and Miller, Jour. A. M. A., June, 1912, p. 1848. 



' Hamburger, Bull, of the Johns Hopk. Hosp., xxiv, Jan., 1913. 



5 Stokes and Weggefarth, Med. News, 91, 1897. 



^ Notter and Firth, quoted from Harrington, "Theory and Practice of Hygiene." 



