BACILLUS TETANI 245 



to result from infection with B. tetani. In tetanus neonatorum 

 the organisms gain entrance through the umbilical wound; in 

 puerperal cases through the inner surface of the uterus. Contam- 

 ination of vaccine and sera used in human therapy have unfor- 

 tunately occurred. In St. Louis in 1901 diphtheria antitoxin 

 taken from a horse during the period of incubation of tetanus 

 was administered to seven children, all of whom died of tetanus. 

 Bacteriological examination showed the serum to be sterile, but 

 it contained large amounts of tetanus toxin. A law has since been 

 passed requiring all sera and vaccines sold in interstate traffic to 

 be controlled by animal tests. 



Tetanus is a local infection resulting in general toxemia. Clini- 

 cally it is characterized by a gradually increasing stiffness and 

 spasmodic contractions of the voluntary muscles, commencing 

 with those of the jaw and the back of the neck. The spasms 

 are tonic in character, and as the disease progresses succeed each 

 other with only a slight intermission. The bacilli never gain ac- 

 cess to the blood and consequently are never distributed to the 

 internal organs but remain localized at the site of infection, where 

 they produce one of the most powerful toxins known, which when 

 absorbed gives rise to the main symptoms and lesions of the in- 

 fection. Therefore while the blood of a tetanus patient contains 

 no bacilli it is laden with the toxin which is responsible for the 

 disease. 



The most important feature of tetanus toxin is its strong affinity 

 for nerve tissue. It is rapidly absorbed from the local site of 

 infection into the blood and lymph streams, is distributed to the 

 muscles, and it is thought by many investigators reaches the 

 spinal cord and brain indirectly through absorption by the end 

 plates of the motor nerves. 



Regardless of the amount of infection there is always an incuba- 

 tion period during which the bacilli multiply and produce the toxin. 

 Generally speaking, the severer the infection the shorter will be 

 the period of incubation and the greater the probability that the 

 case will have a fatal ending. The toxin is produced and may be 

 absorbed during or soon after the first twenty-four hours follow- 



