The Parasite Load of Trypanosoma cruzi Modulates Feeding and Defecation Patterns of the Chagas Disease Vector Triatoma infestans

Abstract

Trypanosoma cruzi is the causal agent of Chagas disease, a parasitic zoonosis transmitted mainly through the feces of triatomine insects. Triatoma infestans is the main triatomine vector of this disease in South America. Previous research has shown that T. cruzi infection modifies the behavior of triatomines. We evaluated, for the first time, the effect of parasite load on feeding and defecation behavior, which we quantified by using real-time PCR. The detection time of the host was shorter in infected individuals, and the number of bites increased, while the dejection time was reduced when compared with the non-infected group. A significant correlation between the parasite load and the behavioral changes registered in the infected triatomines was found. These results would indicate that the intensity of T. cruzi infection modulates the feeding and defecation behavior of T. infestans, increasing the vector competence of this triatomine vector.

The interplay between temperature, Trypanosoma cruzi parasite load, and nutrition: Their effects on the development and life-cycle of the Chagas disease vector Rhodnius prolixus

“…Previous studies have shown that T . cruzi -infected triatomines start excreting urine sooner, and at a faster rate, than uninfected control triatomines [ 57 , 73 ]. However, in our study, we did not observe any effect of infection status (i.e., uninfected versus infected treatment groups) on urine excretion, possibly because urine was collected for a relatively long period of time (such that any differences in the speed of onset and/or rate of urinary excretion would have been masked).…”

Does Trypanosoma cruzi (Chagas, 1909) (Kinetoplastida: Trypanosomatidae) modify the antennal phenotype of Triatoma dimidiata (Latreille, 1811) (Hemiptera: Triatominae)?

“…On the other hand, Depickere et al [ 55 ] determined the effect of T. cruzi on the aggregation behavior of Triatoma infestans (Klug, 1834) captured in the field and naturally infected. Recent studies with T. infestans have shown that infected insects after 45 days present changes in their circadian locomotor activity and feeding and defecation patterns [ 68 , 73 ].…”

“…While several works have analyzed the mechanisms associated with T. cruzi-vector dynamics (e.g., biotic and abiotic factors) to understand the T. cruzi-triatomine interactions, under a co-evolutionary scenario [54], literature about how the parasites may influence the insects is more limited, and the studies have mainly been focused on the parasite's effects on four patterns of the vector behavior: life-history traits, feeding, defecation, and dispersion/ locomotion [55]. Different studies have found negative effects of T. cruzi infection on vector survival [56][57][58][59], fecundity [59,60], post-embryonic development [59,61,62], behavior [55,[63][64][65][66][67][68], and physiological processes [55,60,[69][70][71], while other studies have not identified these effects on patterns of alimentation/defecation [56,72,73], development, and reproduction [74][75][76]. Overall, most of these studies determined that the effects of T. cruzi are species-dependent, age-dependent, sex-dependent, and even environment/physiology-dependent.…”

Does Trypanosoma cruzi modify the antennal phenotype of Triatoma dimidiata (Hemiptera: Reduviidae)?

“…On the other side, Depickere et al [55] determined the effect of T. cruzi on the aggregation behavior of T. infestans captured in the eld and naturally infected. Recent studies with T. infestans, have shown that infected insects after 45 days present changes in their circadian locomotor activity and feeding and defecation patterns [68,73].…”

“…While several works have analyzed the mechanisms associated with T. cruzi-vector dynamics (e.g., biotic and abiotic factors) to understand the T. cruzi-triatomine interactions, under a co-evolutionary scenario [54], literature about how the parasites may in uence the insects is more limited, and the studies have mainly been focused on the parasite's effects on four patterns of the vector's behavior: life-history traits, feeding, defecation, and dispersion/locomotion [55]. Different studies have found negative effects of T. cruzi infection on vector's survival [56][57][58][59], fecundity [59,60], post-embryonic development [59,61,62], behavior [55,[63][64][65][66][67][68], and physiological processes [55,60,[69][70][71], while other studies have not identi ed these effects on patterns of alimentation/defecation [56, 72,73], development and reproduction [74][75][76]. Overall, most of these studies determined that the effects of T. cruzi are species-dependent, age-dependent, sex-dependent, and even environment/physiology-dependent.…”