Are dead Triatoma infestans a competent vector of Trypanosoma cruzi?

Abstract

After Triatoma infestans death, Trypanosoma cruzi survived several days, maintaining the ability to infect a vertebrate host. Dead bugs from an endemic area collected during an official spraying campaign showed mobile rectal trypanosomes up to 14 days after vector death. Two days after vector death 2,760 trypomastigotes were found alive in its rectal material. However, the number of mobile trypomastigotes decreased significantly from the 5th day after death. Laboratory proofs with third and fifth nymphal stage showed similar results. Living trypanosomes were found in their rectal material at 10 days in third stage and even at 30 days in fifth nymphal stage. The mean number of trypomastigotes had no changes up to 10 days in third nymphal stage and increased significantly from 1 to 10 days in the fifth stage. Conjunctival instillation as well as intraperitoneal inoculation to mice, of metacyclic forms from dead T. infestans produced infection in the vertebrate host. Present results show that human contact with dead vector is highly probable in summer and living and infective T. cruzi are available for transmission in the vector.

Chagas Disease in the Amazon Basin: Association of Panstrongylus geniculatus (Hemiptera: Reduviidae) with Domestic Pigs

“…Many mammal species in Amazonian forests are reservoir hosts of T. cruzi, including marsupiaIs such Ali proçedures used in the collection and examination of animais, and in the collection ofhuman blood samples, were in accord with the approved methods specified by relevant staff of the Instituto Evandro Chagas, Fundação Nacional de Saude, Brazil. infective metacyclic forms of T. cruzi equivalent to those in the vector may occur (Deane et al 1986, Asin and Catala, 1991, Shikanai-Yasuda et al 1991, Calvo-Méndez et al 1994. In addition, one bug species, R. brethesi, may transmit T. cruzi to forest workers who harvest fronds from bug-infested palm trees (Leopoldinia piacaba) (Coura et al 1994a).…”

Validation of Trypanosoma cruzi inactivation techniques for laboratory use

“…Although we have not assessed parasite viability beyond 2 h it is interesting to note that in a separate study T . cruzi trypomastigotes were still infective 14 days after Triatoma infestans vector death [ 23 ] highlighting the need for validation for specific inactivation methods. T .…”