HUMAN TRYPANOSOMIASIS 149 



G. palpalis is plentiful. The houses should be fly-proof, 

 and as far as possible from native settlements. 



When travelling fly-proof clothing should be worn and 

 boots after the style of mosquito boots ; veils also should 

 be worn and loose gloves. 



Prophylaxis for natives is very difficult, (i) Segregation 

 of the infected ; (2) deportation of the non-infected to 

 a fly-free area ; (3) destruction of the fly along ordinary 

 routes of travel ; (4) treatment of infected persons to 

 reduce the number of trypanosomes where it is impossible 

 to isolate them in a fly- free country, are the most 

 promising measures. 



(1) Segregation of the infected is not likely to be 

 thorough, as the symptoms are for a long time indefinite 

 and the prolonged search of the blood necessary to find 

 trypanosomes is impracticable for a large collection of 

 persons. 



Examination for enlarged glands is not conclusive, as 

 glandular enlargement is so common from other causes. 

 A combination, however, of the examination for enlarged 

 glands and microscopic examination of the fluid obtained 

 by gland puncture is of value in preventing the introduc- 

 tion of diseased persons into a community. The segre- 

 gation camps must be in a district free from the fly or 

 they may form a focus for the spread of infection. 



(2) Deportation of the whole of the uninfecied popula- 

 tion to a fly-free area is the most satisfactory of the present 

 methods. The old station must be burnt, the gardens 

 destroyed, and patrols established, or some of the people 

 will return and may become infected. 



(3) Destruction of the fly along known trade routes 

 is important. The points of special danger are ferries, 

 fords and watering-places, as at such places many 

 travellers pass and the fly is often present. 



Extensive clearing of the jungle along the banks of 

 the rivers for 100 yards from the edge of the water and 

 on each side of the path in the vicinity of water will 

 greatly reduce the number of flies present. 



