TRYPANOSOMIASIS IN THE ABSENCE OF TSETSES. 237 



could work properly, and those present laughed at my putting such a question to him. 

 One man, the one shown in the photograph, I spoke of as " elder," and was told that he 

 looked like an elder because of the disease, but was really only a " warrior." 



Poor sight, or even bhndness, is stated by the Lumbwa to be caused by the 

 disease occasionally, but two people with the skin affection who had bad sight looked 

 to me to be suffering from cataract. 



The youngest person with the skin affection that I saw was a boy perhaps sixteen 

 years old, but I was told that quite small children sometimes had it. Young people 

 maj^ recover from the disease, and I met three people who said they had done so ; 

 one of them, now an elder, said he had been ill for five years, and recovered ten years 

 ago. With old people, I gathered, the condition always persists until death. Some 

 people told me that they had had the disease for thirty years or more. It seems 

 imlikely that the disease is the cause of death. 



WTiile the Lumbwa are convinced that this disease is caused by the bites of Simu- 

 lium, they do not believe that it can be caused by a single bite or by only a few bites. 

 I was told repeatedly that a person living a short time, say a fortnight, in badly 

 infested country, would not get the disease, and people that I met have lived there 

 much longer than that without contracting it. Again, I was told that while the 

 disease could be contracted by herding animals in infested country day after day, 

 it would be safe for a person to herd them there occasionally. The Lumbwa have no 

 hesitation in going into infested country now and again to hunt, pick vegetables, or 

 search for honey, and a very well-marked track runs right through the forest between 

 the well-inhabited districts to the north and to the south of the infested forest on 

 both sides of the Chemosit. And further, just away from the edge of infested forest, 

 and in country where I took Siniulium in small numbers, many Lumbwa were living, 

 and considered themselves to be running only very slight risk of getting the disease. 

 Simulium, the Lumbwa told me, does not enter houses. 



Part of this slightly infested area adjacent to badly infested forest, the Lumbwa 

 told me, they had cleared of thick forest, thus, they said, themselves converting it 

 from unsafe into reasonably safe country. Another obvious way of avoiding the 

 bites of the fly is the wearing of European clothes. I was scarcely bitten at all 

 myself while moving in infested country for three weeks. 



The total number of people that I saw who were said to have the disease at the 

 time of my visit, not counting one Kisii, who possibly had the disease and who will be 

 mentioned again shortly, was twenty-three. Seven other cases I heard of, but did 

 not see, and probably some others exist. Of these twenty- three people, twelve were 

 male and eleven female. Roughly speaking, eleven were young and twelve old. Of 

 the twenty-three, eight were living in the forest at the time of my visit and at least 

 six had lived there previously, making their homes elsewhere after getting the disease. 

 The remainder had lived near to infested forest and had often gone into the forest. 

 I was told that cases of this disease were not to be found in country away from the 

 vicinity of infested forest. It was said that if a person with the disease attempted 

 to settle in country other than adjacent to the infested forest, he would not be allowed 

 to do so by the other inhabitants. 



The one apparent exception which I came across, to the coincidence of distribution 

 of the disease and Simulium, was a Kisii elder whose skin showed both folds and spots, 

 but who was stated never to have Uved in infested country. 



Special reference must be made to two settlements in clear spaces in the infested 

 forest, areas in which the fly could be found in fair numbers, and both surrounded 

 by heavily infested forest, where I inquired, as far as I was able, after the health of 

 those who were living there. There may have been other people that I did not see 

 or hear about, but eight adults that I saw who had lived there for more than two years 

 all had the disease, though one other old resident, a man that I did not succeed in 

 (4183) S 



