104 TRYPANOSOMES AND SLEEPING SICKNESS 



come they generally are worse in the evening, unlike malarial f evers. 

 After a variable time the victim becomes weak and anemic, probably 

 due to toxins secreted by the parasites, his pulse becomes rapid, 

 and various lymph glands, especially those of the neck, tend to 

 swell up and become tender. Often an irritating rash breaks out 

 on the skin during the early stages of the disease. Loss of am- 

 bition and vitality usually figure prominently, and childbirth 

 is seriously interfered with. It is possible that after weeks or 

 months or years of irregular fever and debility the disease may 

 spontaneously disappear, and never become more than trypano- 

 some fever. Usually, however, the parasites ultimately succeed in 

 penetrating to the cerebrospinal fluid in the cavity of the brain 

 and spinal cord, and " sleeping sickness " results. In some cases 

 the onset of this horrible disease has been known to be delayed 

 for seven years after the beginning of the disease, but usually it 

 comes in the course of a few months. 



Sleeping sickness is ushered in by an increase in the general 

 physical and mental depression, the symptoms being not unlike 

 those of hookworm disease but more pronounced. The victim 

 wants to sleep constantly and lies in a stupor; his mind works 

 very slowly, and even the slightest physical exertion is obnoxious. 

 Eventually the sleepiness gets such a hold on him that he is 

 likely to lose consciousness at any time and even neglects to swal- 

 low his food. After weeks of this increasing drowsiness, his 

 body becomes emaciated, a trembling of the hands and other 

 parts of the body develops, with occasional muscular convulsions 

 and sometimes maniacal attacks. He finally passes into a state 

 of total loss of consciousness ending in death, or death may end 

 the unhappy condition earlier during an unusually intense con- 

 vulsion or fever, or through the agency of some complicating 

 disease. Death, so far as is known at present, is the inevitable 

 outcome. A large per cent of infections occur among people 

 of middle age. Old people are significantly few in number in" 

 sleeping sickness districts. The presence of these few may be 

 due to a natural or acquired immunity. In Nigeria the disease 

 predominates in young people, possibly because they are water- 

 carriers and are therefore more exposed to the bites of testse flies. 



Treatment. In the early stages of the Gambian disease, a 

 cure can sometimes be effected by the administration of certain 

 drugs. Various arsenic and antimony compounds act as spe- 



