252 BACTERIA PATHOGENIC TO MAN 



understanding of the disease. It may be prevented by thoroughly 

 cooking the meat and by refusing to accept from the butcher meat 

 that is the least tainted. 



True Meat Poisoning. This form of meat poisoning is due to bacillus 

 enteritidis, and in every instance the animal is diseased at the time of 

 the slaughter. It may be contracted by eating sausage, since the meat 

 of diseased animals is sometimes surreptitiously put on the market 

 in the form of sausage. 



Dunham makes bacillus enteritidis the chief type of the intermediates 

 and proposes the name "the enteritidis group." Buxton classes the 

 bacillus with the paracolons. It does not ferment lactose ; milk becomes 

 more alkaline; it ferments dextrose with a production of gas containing 

 about one-third CO 2 , two-thirds H, and it also ferments mannite, 

 maltose, and dextrin. 



Bacillus enteritidis is pathogenic for cows, horses, pigs, goats, mice,, 

 and guinea-pigs, but not for dogs and cats. 



The Injected Meat. In many epidemics bacillus enteritidis has been 

 isolated, not only from the organs of fatal cases, but from the suspected 

 meat. The meat does not differ in appearance or taste from that of 

 healthy animals. It has already been stated that it may be made into 

 sausages, and one epidemic at least has been caused by eating "dried 

 meat" consisting of large pieces of the flesh of sheep and goats nearly 

 dried in the sun and eaten cooked or merely softened by soaking. 

 Cooking does not always destroy the bacilli, as the thermal death 

 point may not be reached in the interior of the meat. Infected meat 

 which is not eaten immediately after it has been cooked is especially 

 dangerous. 



The meat has always come from animals sick at the time of slaugh- 

 ter. The meat of cows and calves have most often caused the epi- 

 demics, though that of horses, pigs, and goats have also been respon- 

 sible. Dunham says that no known case has come from mutton, and 

 that the pig has .been implicated in only one outbreak which has been 

 studied bacteriologically. In this connection it is interesting to recall 

 that Theobald Smith has insisted on the similarity between the hog- 

 cholera bacillus and bacillus enteritidis. 



The animals from which the infected meat has come have suffered 

 during life from puerperal fever aixd uterine inflammations, navel 

 infection in calves, septicaemia, septicopysemia, diarrhoea, and local 

 suppurations, and have not infrequently been killed because of their 

 unsound condition. How animals become infected is not known. 



Dunham thinks milk may be a source of infection in man, but 

 states that bacteriological evidence of it is incomplete. Bacillus 

 enteritidis has been found, however, in the milk of infected guinea-pigs 

 (Basenau). 



Transmission to Man. The disease may be transmitted to* man in 

 two ways: (1) by eating the infected meat, and this is by far the most 

 common means, and (2) from man to man according to Gartner, Van 

 Erminghem, and Fischer. Dunham found inconclusive evidence of this- 



