Handbook of medical entomology . the tick,just as nagana of cattle was attributed to the direct effect of the biteof the tsetse-fly. The disease is commonly known as tick-feveror by the various native names of the tick. In 1904, Ross and Milne, in Uganda, and Button and Todd on theCongo, discovered that the cause of the disease is a spirochsete whichis transmitted by the tick. This organism has been designated byNovy and Knapp as Spirochceta duttoni. Ornithodoros moubata (fig. 142), the carrier of African relapsingfever, or tick-fever, is widely distributed in tropical Africa, andoccurs in gre
Handbook of medical entomology . the tick,just as nagana of cattle was attributed to the direct effect of the biteof the tsetse-fly. The disease is commonly known as tick-feveror by the various native names of the tick. In 1904, Ross and Milne, in Uganda, and Button and Todd on theCongo, discovered that the cause of the disease is a spirochsete whichis transmitted by the tick. This organism has been designated byNovy and Knapp as Spirochceta duttoni. Ornithodoros moubata (fig. 142), the carrier of African relapsingfever, or tick-fever, is widely distributed in tropical Africa, andoccurs in great numbers in the huts of natives, in the dust, cracksand crevices of the dirt floors, or the walls. It feeds voraciouslyon man as well as upon birds and mammals. Like others of theArgasid<2, it resembles the bed-bug in its habit of feeding primarilyat night. Button and Todd observed that the larval stage is under-gone in the egg and that the first free stage is that of the octopodnymph. 230 African Relapsing Fever of Man 231. 142. Ornithodoros moubata. (a) Anterior part of venter; (6) second stagenymph; (c) capitulum; {d) dorsal and (e) ventral aspect of female;(/) ventral aspect of nymph; (g) capitulum of nymph. After Nuttalland Warburton. 232 Arthropods as Essential Hosts of Pathogenic Protozoa The evidence that the fever is transmitted by this tick is con-clusive. Koch found that from five per cent to fifteen per cent, andin some places, fifty per cent of the ticks captured, harbored thespirochaste. The disease is readily transmitted to monkeys, rats,mice and other animals and the earlier experiments along: these lineshave been confirmed by many workers. Not only are the ticks which have fed on infected individualscapable of conveying the disease to healthy animals but they trans-mit the causative organism to their progeny. Thus Mollers (1907),working in Berlin, repeatedly infected monkeys through the bitesof nymphs which had been bred in the laboratory from infected tic
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