MEASLES. 283 



Measles. 



Measles is a contagious disease peculiar to man. It lasts for 

 one or two weeks, and produces fever, catarrh of the respiratory 

 mucous membrane, and a characteristic rash. It is highly contagious, 

 especially before the nature of the disease is revealed; there is 

 consequently great difficulty in preventing its spread in schools 

 and households. The contagium appears to be given off from the 

 body, principally if not entirely, by the breath. One attack is pro- 

 tective against future attacks. ~"The whole population of a, country 

 may acquire a certain degree of immunity. Measles introduced into 

 countries where it was previously unknown assumes a most malig- 

 nant form. There are no characteristic post-mortem appearances. 



Bacteria in Measles. — Micrococci have been found in the 

 blood, catarrhal exudation, and skin, by Keating, Babfes, and others, 

 but they are accidental epiphytes of no importance, or associated 

 with secondary complications, as in scarlet fever. 



Canon and Pielicke have found in the blood small bacilh varying 

 in form. They do not grow on nutrient agar or blood serum, but 

 cultures were obtained by pricking the finger of a patient suffering 

 from measles, and allowing the blood to drop into sterilised broth. 

 After a few days the broth became cloudy, and later, a flocculent 

 deposit formed. The bacilli were also obtained from the nasal and 

 conjunctival secretions. The nature of the contagium of measles 

 is unknown. 



Stamping-out System Measles is not easily controlled by the 



stamping-out system ; it is, in fact, extremely difficult, almost impos- 

 sible, to prevent its spread, as it is especially infectious during the 

 period of incubation. Notification, isolation, and disinfection assist in 

 controlling an epidemic, but the value of the system does not apply 

 to the-same extent in measles as in other infectious diseases. 



