84 BACTERIOLOGY. 



New Orleans, and San Francisco, to quarantine all 

 suspects among the immigrants. 



Infection always takes place by way of the ali- 

 mentary tract, from infected water and food. While 

 infected water is the most common cause, the infection 

 may be carried on vegetables that have been washed 

 in infected water, particularly those used as salads. 

 Flies can deposit the infection on bread, butter, meat, 

 and other foodstuffs. Direct infection from handling 

 soiled bed-linen is not uncommon, as is shown by the 

 greater frequency of the disease among washerwomen 

 during epidemics. The onset of cholera, following an 

 incubation period of two to five days, is sudden, with 

 frequent watery stools, high fever, and great prostra- 

 tion. In the severe cases death may occur in eight to 

 twelve hours. The infection localizes itself in the 

 intestine. The spirilla are never found in the cir- 

 culating blood, consequently the stools alone are in- 

 fectious and may continue to be for months after re- 

 covery. People who carry the spirilla of cholera in 

 the intestine after recovery are called cholera carriers. 

 Prevention To prevent the disease during epidemics all 



drinking-water and milk must be boiled, and no meat 

 or vegetables eaten unless cooked. Great care must be 

 taken to exclude flies from contact with foods. Bed- 

 linen, clothing, and utensils used by patients should be 

 soaked in 5 per cent, carbolic solution, and subse- 

 quently boiled in the laundry. Attendants upon 

 cholera patients should be careful to disinfect the hands 

 after handling the patients. The stools are best dis- 



