MICROBIAL DISEASES OF MAN AND ANIMALS. 665 



TYPHUS FEVER.* 



Typhus fever (ship fever, jail fever) has been known to exist for 

 centuries but until very recently we have been without precise knowl- 

 edge concerning its cause. Typhus is found in all parts of the world; 

 it affects man only and is characterized by a high fever and an erup- 

 tion on the skin. The course of the disease is limited and lasts for 

 only about twelve days. In the years 1909 and 1910 Nicolle, working 

 in Tunis, and Anderson and Goldberger, and Ricketts and Wilder 

 working in Mexico, showed that typhus is communicated from man 

 to man by means of the body louse (Pediculus vestimenti), and that 

 the disease is not contagious in the ordinary sense of the word. Nicolle 

 states that after biting a typhus fever patient the louse cannot convey 

 the infection until the fourth day thereafter and that it loses this power 

 after the seventh day. This indicates a similarity between the micro- 

 organisms causing yellow fever, malaria and typhus. The disease may 

 be communicated to monkeys by subcutaneous inoculations of blood 

 from a typhus fever patient. The virus may be transferred from one 

 monkey to another indefinitely. In monkeys recovery from severe attack 

 produces a firm immunity. No microorganism has been discovered which 

 can be regarded as the cause of the disease. Attempts to pass the virus 

 through filters have been unsuccessful with the possible exception of 

 certain experiments by Nicolle. The virus is destroyed by heating from 

 50 to 55. 



WHOOPING COUGH, f 



Whooping cough accounted for the death of 4856 children in the United 

 States in 1907. The causative agent, according to Bordet and Gengou, 

 is an influenza-like bacillus. 



It is a non-motile coccoid bacillus, stained faintly by aniline dyes and 

 Gram-negative. It is distinguished from the influenza bacillus by agglu- 

 tination and complement deviation tests and by the fact that it can be 

 gradually adapted to ordinary media. 



The production of pertussis in young animals has been claimed. The 

 organism has an endotoxin which produces local necrosis after subcu- 

 taneous injection. 



Immune sera developed against the bacillus in animals with agglutinins 



* Prepared by M. Dorset, 

 f Prepaerd by Edward Fidlar. 



