PSITTACOSIS BACILLUS 337 



often from the blood. In man, as the name of the bacillus 

 indicates, the symptoms are centred in the intestine, where there 

 is usually marked inflammation of the mucous membrane, some- 

 times attended with haemorrhage into it ; evidence of a septicaemic 

 condition may also exist. Infection may take place by the 

 bacillus itself where meat has been insufficiently cooked or 

 merely pickled, and here the illness usually appears within 

 twenty-four hours of the food being partaken of, but symptoms 

 may appear almost at once, in which case they are no doubt due 

 to the action of toxins ; here it is important to note that the 

 poisons formed by this group of organisms are relatively heat- 

 resisting, so that boiling for a time does not destroy the toxicity. 

 In cases of Gaertner bacillus poisoning, the animal whose 

 carcase is suspected has usually been found to have been itself 

 suffering from the action of the bacillus, but cases of meat 

 poisoning also occur where the meat of a healthy animal becomes 

 infected subsequently to slaughter with organisms pathogenic to 

 man. In such cases these organisms are often varieties of the 

 b. coli group, and indeed the b. coli itself may be the cause of 

 meat poisoning. 



The Psittacosis Bacillus. When parrots are imported from the 

 tropics in large numbers many die of a septicsemie condition in which an 

 enteritis, it may be hsemorrhagic, is a marked feature. There is intense 

 congestion of all the organs and peritoneal ecchymoses. From the 

 spleen, bone marrow, and blood there has been isolated a short, 

 actively, motile bacillus with rounded ends which does not stain by 

 Gram's method. It groivs on all ordinary media, and on potato resembles 

 b. coli. It does not liquefy gelatin, does not ferment lactose, does not 

 curdle milk, and gives no indol reaction. Culturally the organism is 

 practically indistinguishable from the two bacilli last described. The 

 parrot is most susceptible to its action, but it also causes a fatal 

 hsemorrhagic septicaemia in guinea-pigs, rabbits, mice, pigeons, and 

 fowls, the bacilli after death being chiefly in the solid organs. From 

 affected parrots the disease appears to be readily communicable to man, 

 chiefly, it is probable, from the feathers being soiled by infective 

 excrement. Several small epidemics have been recognised and in- 

 vestigated in Paris. After about ten days' incubation, headache, 

 fever, and anorexia occur, followed by great restlessness, delirium, vomit- 

 ing, often diarrhoea, and albuminuria. Frequently broncho-pneumonia 

 supervenes, and a fatal result has followed in about a third of the cases 

 observed. The organism has been isolated from the blood of the heart. 

 The psittacosis bacillus is evidently one of the typhoid group, a fact 

 which is further borne out by the observation that it is clumped by a 

 typhoid serum 1 : 10 (normal serum having no result). The clumping 

 is, however, said to be incomplete, as the bacilli between the clumps may 

 retain their motility. It differs from the typhoid bacillus in its growth 

 on potatoes and in its pathogenicity. 



The Serum Diagnosis of Typhoid Fever. This method of 



22 



