BOVINE DIPHTHERIA 339 



tion, and that before the end of five days after inoculation, was 

 finally excreted in the cow's milk. " The presence of the 

 diphtheria bacillus," he wrote, " could with certainty, by microscopic 

 and culture observations, be demonstrated in the milk of the cow 

 collected under all precautions ; the number of bacilli present on 

 that day in the milk amounted to 32 per c.c." Scrapings from 

 vesicles on the sixth day were inoculated into two calves, which 

 then suffered from a like disease.^ 



During 1890 and 1891, Dr Klein repeated these experiments 

 on milch cows, and in two further instances, out of six cows, an 

 eruption was produced on the udder and teats, and in one of these 

 positive cases the B. diphtheric^ was found in the milk about a 

 week after inoculation. 



It must be admitted that positive results did not always follow 

 these experimental researches ; there was not always eruption, nor 

 was the bacillus uniformly isolated from the milk. Loffler, Abbott, 

 Ritter, and others, including many veterinarians, have criticised the 

 experiment, and hold that there is no evidence at present that 

 diphtheria is a bovine disease. Since the time of the York Town 

 epidemic, some twenty milk-diphtheria outbreaks have been in- 

 vestigated, with the result that, with one or two exceptions, the infec- 

 tivity of the milk was certainly derived from human sources and not 

 from bovine. In the Croydon outbreak in 1890, an udder eruption 

 was discovered on the cows yielding the suspected milk, and Klein 

 reported that this eruption was similar to those met with in 

 diphtheria outbreaks traced to milk of diseased cows. hX. 

 Worcester in the following year, and at Glasgow in 1892, similar 

 evidence was obtained. 



Up to the present, however, it may be said that the evidence 

 forthcoming points in the direction of human rather than bovine 

 infection as the origin of the diphtheria bacillus in milk. 



An interesting investigation has recently been made by Dean 

 and Todd, Respecting a small outbreak of diphtheria occurring 

 in 1 90 1.- In this outbreak several individuals suffered from 

 diphtheria, and several others in the same households suffered from 

 sore throat, probably diphtheritic. These individuals obtained their 



^ See A Treatise on Hygiene and Public Health (Stevenson & Murphy), 

 vol. ii., pp. 1 61 -1 64 (Klein). Also Local Government Board Report, 1889, 

 p. 167 et seq. 



2 Jour, of Hygiene, April 1902 (vol. ii., No. 2, p. 194). Experiments on tJie 

 relation of the Cow to Milk Diphtheria, by George Dean, M.B., and Charles 

 Todd, M.D. 



