Survival of Trypanosoma cruzi in Dead Triatoma gerstaeckeri Under Laboratory Conditions

Trypanosoma cruzi (T. cruzi) is primarily transmitted through infectious triatomine feces, with ingestion of infected triatomines being an alternative transmission route. Viable T. cruzi inside dead triatomines presents a potential veterinary health concern to animals that may eat insects, especially if insecticides create an abundance of dead insects in the immediate proximity of a host species. In the present study, Triatoma gerstaeckeri were experimentally infected with T. cruzi and then decapitated; subsequently, their carcasses were subjected to ambient laboratory conditions for intervals of up to 14 days, with feces and gut contents inoculated into culture. Viable parasites were detected throughout a period of 10 days but not thereafter, and the proportion of culture-positive dead triatomines decreased after 6 days (P <0.001) compared to 0 days. The odds of parasite viability decreased with the presence of bacterial or fungal growth (P <0.001) and at higher cycle threshold values of fecal spots (P = 0.008). Dead triatomines may pose a T. cruzi transmission risk if ingested by animals.