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Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060 EISSN: 1678-8060
Vol. 94, No. 3, 1999, pp. 413-419
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Bioline Code: oc99077
Full paper language: English
Document type: Research Article
Document available free of charge
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Memórias do Instituto Oswaldo Cruz, Vol. 94, No. 3, 1999, pp. 413-419
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Effects of Non-Susceptible Hosts on the Infection with Trypanosoma cruzi of the Vector Triatoma infestans: an Experimental Model
Diego P Vázquez; Delmi Canale & Ricardo E Gürtler
Abstract
We tested experimentally the effects of the presence of non-susceptible hosts on the infection with Trypanosoma cruzi of the vector Triatoma infestans. The experiment consisted in two treatments: with chickens, including two chickens (non-susceptible hosts) and two infected guinea pigs (susceptible
hosts), and without chickens, including only two infected guinea pigs. The hosts were held unrestrained in individual metal cages inside a closed tulle chamber. A total of 200 uninfected T. infestans third instar nymphs were liberated in each replica, collected on day 14, and examined for infection and blood meal sources on day 32-36. The additional presence of chickens relative to infected guinea pigs: (a) significantly modified the spatial distribution of bugs; (b) increased significantly the likelihoods
of having a detectable blood meal on any host and molting to the next instar; (c) did not affect the bugs' probability of death by predation; and (d) decreased significantly the overall percentage
of T. infestans infected with T. cruzi. The bugs collected from inside or close to the guinea pigs' cages showed a higher infection rate (71-88%) than those collected from the chickens' cages (22-32%). Mixed blood meals on chickens and guinea pigs were detected in 12-21% of bugs. Although the presence of chickens would decrease the overall percentage of infected bugs in
short term experiments, the high rate of host change of T.infestans would make this difference fade out if longer exposure times had been provided.
Keywords
Trypanosoma cruzi - Triatoma infestans - Triatominae - Chagas disease - infection - transmission - zooprophylaxis - host-feeding patterns
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© Copyright 1999 Fundacao Oswaldo Cruz - Fiocruz Alternative site location: http://memorias.ioc.fiocruz.br
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