Molecular detection of Trypanosoma cruzi and other potential pathogens in triatomine bugs from jungle and highland regions of Perú

The risk of Chagas disease and other Triatomine-borne infections to service members deployed in the Americas is unknown.  Herein, we used more sensitive methods for pathogen detection in triatomines from Amazonian (Amazonas, Ucayali) and highland (Arequipa) regions of Peru. Triatomines were collected manually from peri-domestic resting sites in urban and rural areas. DNA was extracted from the digestive tract of non-engorged specimens, and the anterior midgut and posterior midgut/hindgut of engorged ones. PCR targeting the small subunit ribosomal RNA (SSUrRNA) was employed for Trypanosomatid detection (~500bp). A nested-PCR targeting the 24S α-ribosomal DNA gene was used for confirmation of Trypanosomatids (∼280bp)and Trypanosoma cruzi (∼110–130bp) detection. ITS-PCR (~600 bp) was used for preliminary Bartonella detection.  Triatomines collected (48) included Pastrongylus herreri (10) and Rhodnius robustus (11) in Amazonian states, and Triatoma infestans (29) in the highland region.  SSUrRNA-PCR detected Trypanosomatid DNA in three non-engorged and four engorged R. robustus, and three engorged T. infestans.  24S α-ribosomal-PCR detected Trypanosomatid DNA in four non-engorged and four engorged R. robustus, and one engorged T. infestans. Trypanosoma cruzi was detected only in five non-engorged and four engorged R. robustus. Two engorged T. infestans and one engorged P. herreri were ITS-PCR positive suggesting possible infection with Bartonella. Our findings suggest that 24S α-ribosomal-PCR was more sensitive for Trypanosomatids/T. cruzi detection and samples positive only by SSurRNA-PCR may harbor other Trypanosomatids. Bartonella infection will be confirmed by other molecular markers and sequencing. Peri-domestic T. cruzi transmission appears to occur in the Amazonian region.