The co-evolution of parasites and insects has promoted the development of a powerful and sophisticated strategy based on both physiological and biochemical vector and/or parasite mechanisms, which act to facilitate parasite development or its disruption in the invertebrate host. The debate concerning the Trypanosoma cruzi and T. rangeli- triatomine vector interactions results from their complexity and modes of parasite transmission (Garcia and Azambuja 1991, Kollien and Schaub 2000). Like T. cruzi, T. rangeli infects humans and a wide range of other mammals and has a similar geographic distribution (Guhl and Vallejo 1998).
Many factors are believed to contribute to the establishment of trypanosomes in the gut of the invertebrate host. However, differences in the biological cycles between both parasites exist: T. rangeli, but not T. cruzi, invades the hemocoel and physico-chemical barriers such as the gut membranes, which are important to T. cruzi development, but not to T. rangeli in the digestive tract (Gonzalez et al. 1999, Azambuja and Garcia, personal observation).
This review outlines research on the developmental aspects of Trypanosoma cruzi and Trypanosoma rangeli in the insect vector, which may reveal new perspectives for the control of Chagas disease.