. Animal parasites and human disease. Parasites; Medical parasitology; Insects as carriers of disease. CHAGAS' DISEASE — PARASITE IN MAN 109 bugs of the genus Triatoma serve as intermediate hosts; bugs of a number of species infected with trypanosomes morphologically indistinguishable from T. cruzi have been found all the way from Central America to Argentina, but the disease in man has been recognized only in a small part of this extensive area, though it is sus- pected of existing in northern Argen- tina and may oc- cur in many more places than is now known. Human Cycle.— The tryp
. Animal parasites and human disease. Parasites; Medical parasitology; Insects as carriers of disease. CHAGAS' DISEASE — PARASITE IN MAN 109 bugs of the genus Triatoma serve as intermediate hosts; bugs of a number of species infected with trypanosomes morphologically indistinguishable from T. cruzi have been found all the way from Central America to Argentina, but the disease in man has been recognized only in a small part of this extensive area, though it is sus- pected of existing in northern Argen- tina and may oc- cur in many more places than is now known. Human Cycle.— The trypanosome causing this disease very closely resem- bles the sleeping sickness trypano- somes in form but it is quite different in its life history. In the human body, Chagas recognized two distinct types which he believed to be male and fe- male forms, but Subsequent Work FlG" f' Trypanosoma cruzi A, cyst containing Leish- ^ mama forms in muscle fiber of guinea-pig, cross section; indicates that these n., nucleus of muscle fiber. B, older cyst, containing f w 0 fvnes are tryPanosome forms, in neuroglia cell in gray matter of W U lyp cerebrum; n., nucleus of parasitized cell; bl. cap., blood merely young and capillary; unpar. a, unparasit-zed cells. X 1000. (After adult forms of the Vianna0 parasite. Unlike other trypanosomes this species as found in the blood never exhibits stages in division, and this fact led Chagas to search for some other form of multiplication. He found in the lungs of infected animals what he thought to be a process of division of the trypanosomes into eight parts, but this later was found to be a stage in the life history of an entirely. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Chandler, Asa C. (Asa Crawford), 1891-1958. New York, J. Wiley
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Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1922
