AMERICAN TRYPANOSOMIASIS: TRANSMISSION AND VECTOR EFFECTIVENESS STUDIES.
Final rept. 1 Jan 65-31 Mar 68,
USAF EPIDEMIOLOGICAL LAB LACKLAND AFB TEX
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A laboratory study was made of the vector capability of two Texas species of Triatoma T.S. texana and T. gerstaeckeri. A comparison as then made with Rhodnius prolixus, a South American vector or Trypanosoma cruzi Chagas. A Brazilian and local strain of T. cruzi was maintained and determination made of their infectivity to experimental animals. The feeding and defecation habits of R. prolixus makes it a better contaminative transmitter of T. cruzi than the other two species. Direct oral contamination and ingestion of infected bugs produced the greatest number of infections among those routes of inoculation that might occur in nature. A rat could become infected by feeding on one infected bug. It was concluded that wood rats became infected at an early age, primarily by ingesting infected bugs. Parasites were observed in the peripheral blood, 5 to 14 days following inoculation and persisted up to 47 days. Infection rates were higher in bugs that fed on rats with a high parasitemia than in those with a low parasitemia. It is concluded that xenodiagnosis would be affected by the degree of parasitemia in the host and by the sex of the bugs. Due to the habits of the Texas vectors, it is not considered likely that American trypanosomiasis will become endemic in humans in this area. Author
- Medicine and Medical Research