102 STUDY AND IDENTIFICATION OF BACTERIA 



As the bacilli do not multiply to any extent in the blood itself the disease cannot 

 be considered as a typical septicaemia but as a bacteriaemia. 



Typhoid bacilli can be isolated from the blood during the latter 

 period of incubation and rarely after the tenth day of the disease. 

 It is a practical point that the time to isolate the bacteria from the 

 blood is in the first days of the attack. The diagnosis by agglutina- 

 tion is only expected after the seventh to tenth day. Agglutination 

 may not appear until during convalescence, and in about 5% of the 

 cases it is absent. It, as a rule, disappears within a }tear. 



Very little success has ben obtained with curative sera. Chantamesse, by 

 treating horses with a nitrate from cultures of typhoid bacilli on splenic pulp and 

 human defibrinated blood, claimed to have obtained a curative serum possessing 

 antitoxic power. Wright's method of prophylactic inoculation is now being em- 

 ployed in the British army with apparent success. In this, twenty-four- to forty- 

 eight-hour-old cultures are killed at 53 C.; 1/4% of lysol is then added. An injec- 

 tion of 500 million bacteria is made at the first inoculation, and ten days later an 

 injection of one billion. The British prefer to inject subcutaneously in the infra- 

 clavicular region and at the insertion of the deltoid. The Germans consider three 

 injections as conferring greater immunity. 



Russell has obtained splendid results in the U. S. Army with his method of 

 vaccination. In this three injections are given at intervals of ten days, the dosage 

 being 500,000,000, for the first and 1,000,000,000 for each of the two succeeding 

 injections. 



Typhoid vaccines sterilized with 0.5% of phenol appear to keep much longer and 

 to have a higher immunizing power than those prepared by sterilization with heat 

 and subsequent addition of the antiseptic. 



Typhoid bacilli may be found not only in the blood, urine and faeces but as well 

 in the sputum of cases showing pulmonary involvement. They have also been found 

 in the cerebrospinal fluid of cases showing meningeal symptoms. At the autopsy 

 they may be found in the spleen, Pyer's patches, mesenteric glands and liver. 



A very important discovery is that certain persons, who may have 

 had only a slight febrile attack, may eliminate typhoid bacilli for years 

 in their faeces (typhoid carriers). The bacilli are also eliminated for 

 considerable periods in the urine. Distinction is now being made 

 between acute carriers (convalescents) and chronic carriers. 



The most satisfactory method of detecting carriers is by examina- 

 tion of faeces or urine plated out on Endo's medium. While carriers 

 usually give a Widal reaction this is by no means constant. Typhoid 

 carriers are said to maintain a high opsonic index. 



The urine and faeces of typhoid convalescents should be proven negative by cul- 

 tural procedure before discharging J;hej3atients. 



