Mathematical Biosciences and Engineering (MBE)

Alternative transmission modes for Trypanosoma cruzi

Pages: 657 - 673, Volume 7, Issue 3, July 2010      doi:10.3934/mbe.2010.7.657

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Christopher M. Kribs-Zaleta - Mathematics Department, University of Texas at Arlington, Box 19408, Arlington, TX 76019-0408, United States (email)

Abstract: The parasite Trypanosoma cruzi, which causes Chagas' disease, is typically transmitted through a cycle in which vectors become infected through bloodmeals on infected hosts and then infect other hosts through defecation at the sites of subsequent feedings. The vectors native to the southeastern United States, however, are inefficient at transmitting T. cruzi in this way, which suggests that alternative transmission modes may be responsible for maintaining the established sylvatic infection cycle. Vertical and oral transmission of sylvatic hosts, as well as differential behavior of infected vectors, have been observed anecdotally. This study develops a model which accounts for these alternative modes of transmission, and applies it to transmission between raccoons and the vector Triatoma sanguisuga. Analysis of the system of nonlinear differential equations focuses on endemic prevalence levels and on the infection's basic reproductive number, whose form may account for how a combination of traditionally secondary infection routes can maintain the transmission cycle when the usual primary route becomes ineffective.

Keywords:  Trypanosoma cruzi, Chagas, oral infection, vertical infection, vector infection.
Mathematics Subject Classification:  Primary: 92D30, 92D40; Secondary: 92D25.

Received: July 2009;      Accepted: April 2010;      Available Online: June 2010.