176 APPLIED BACTERIOLOGY FOR NURSES 



slightly curved. Coccoid forms occur. The bacilli are 

 most abundant in the blood on the fourth or fifth day 

 preceding the crisis. 



Plotz has prepared a vaccine from this organism, but the 

 experience with this is still too short to determine its value 

 in combating typhus fever. Infection is carried from 



Fig. 60. Bacillus typhi exanthematici. Gram's stain. X 1000. 

 (Plotz, Olitsky, and Baehr, in Journal of Infectious Diseases.) 



man to man through the bite of infected body lice, and 

 perhaps also other vermin. Prophylaxis: Cleanliness; dis- 

 infection of infected clothing; measures directed against 

 vermin. 



Leprosy Bacillus. Small, acid-fast rods, resembling 

 tubercle .bacilli, found in large numbers, especially in the 

 cutaneous lesions. It is not yet established just how the 

 disease is communicated, 



