336 TYPHOID FEVER 



the case is likely to be paratyphoid fever. With regard to the 

 effects of other sera on the paratyphoid bacillus, it may be said 

 that usually a typhoid serum will require to be used in greater 

 concentrations to clump this bacillus than are necessary to obtain 

 an effect with the typhoid bacillus itself. Similar effects are 

 observed when the sera of animals immunised against Gaertner's 

 bacillus or the bacillus of psittacosis are used. In all serum 

 tests the essential point is that deductions should alone be based 

 on comparative observations of the highest dilutions in which 

 a clumping effect is produced with any series of organisms 

 compared. 



As has been indicated, a disease resembling typhoid fever is 

 not the only condition originated by the paratyphoid bacillus. 

 The organism has been isolated from cases of bone abscess, from 

 orchitis, and in Widal's case from a thyroid abscess, and in such 

 cases the history of a previous typhoid-like illness may not be 

 elicited. It has also been found in ordinary faeces. In animal 

 experiments it produces in rabbits and guinea-pigs a fatal ill- 

 ness of a septicsemic type with serous inflammations. 



Bacillus Enteritidis (Gaertner). In 1888 Gaertner, in 

 investigating a number of cases of illness resulting from eating 

 the flesh of a diseased cow, isolated, from the meat and from the 

 spleen of a man who died, a bacillus closely resembling the 

 typhoid bacillus. Since then a great number of outbreaks of 

 gastro-enteritis due to eating diseased meat have been inquired 

 into, and very frequently similar bacilli have been found both in 

 the stools and in the organs. These bacilli closely resemble the 

 paratyphoid organism, indol is not produced, and generally 

 speaking the fermentations of sugars also correspond. With 

 regard to the latter it may, however, be said that, according to 

 some, lactose is fermented, while other observers have found this 

 not to be the case. No doubt different strains differ somewhat 

 from one another. Here again much information may be 

 obtained from the agglutinating properties of the serum and also 

 from the effects on suspicious bacilli of the sera of animals 

 immunised against other strains and other members of the coli 

 group. It has also been found that the serum of persons suffer- 

 ing from meat poisoning sometimes clumps the typhoid bacillus, 

 though a higher concentration is required than in the case of 

 Gaertner's bacillus. The Gaertner group of organisms is very 

 pathogenic for laboratory animals. Often, whatever the channel 

 of infection, there is intense haemorrhagic enteritis, and very 

 usually there is a septicaemia with the occurrence of serous inflam- 

 mations ; the bacilli are recoverable from the solid organs and 



