954 DISEASES CAUSED BY FILTKABLE VIRUS 



the most favorable temperature for hatching is at 35 C., when the 

 hatching time is very much speeded up and may be less than eight 

 days. It is important to know that louse eggs are destroyed by 

 temperatures slightly above 60 C. But it is not safe to rely upon 

 such low temperatures for disinfestation. While the nits are quite 

 susceptible to temperature, they are much harder to destroy by 

 insecticides than are the adult lice. It is important to remember 

 that many of the insecticide substances which are applied to the 

 body and clothing for the prevention of lousiness may keep lice 

 away but will not kill them when once present. 



It is also important to remember that, although the adult louse 

 must feed with some regularity in order to thrive and lay its eggs, 

 the eggs may remain alive on clothing, underwear, etc., for a month 

 at least, away from the human body, and may be hatched out when 

 this clothing is put on. Thus, clothing, underwear, blankets, etc., 

 of louse infested dugouts, huts, ships, etc., must be taken care of 

 even if it has not been worn for some time. 



Although the louse, like the bed bug in the song, has no wings * ' at 

 all," and is not a wanderer, it is astonishing how easily it can pass 

 from one individual to another. Lice may be easily acquired during the 

 examination of a case, in passing through a crowd, or in handling 

 underwear and clothing in laundry work or disinfesting operations. 



The adult louse feeds about twice a day, and the louse bites, 

 while they may be quite annoying to some individuals, may cause 

 practically no reaction or annoyance in habitually lousy persons. 

 They are apt to leave the body of the sick and usually do leave 

 the body of the dead as soon as possible. When removed from 

 human sources of food, they may die in anywhere from one or two 

 days to a week. Nine or ten days is stated as the probable limit 

 to which the adult may live in clothing that has been hung up or 

 put away. 



Delousing depends upon early discovery of lousiness in a com- 

 munity, regiment or other unit, personal cleanliness, disinfestation 

 of those who are lousy and disinfestation of clothing, blankets, etc., 

 and quarters. 



In armies and in communities during the existence of louse-borne 

 diseases, inspection for lousiness of bodies, underclothing, etc., 

 should be carried out at frequent intervals. The individual who 

 attempts to protect himself should inspect his own body and under- 

 clothing on going to bed at night. 



