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Prevalence and Diversity of Trypanosoma cruzi in Triatomine Vectors and Their Blood Meal Sources from South Central Texas, USA
by
,
Rebecca J. Kilgore
1,
Trina Guerra
2,
Heather Beck
2,
Andrea Villamizar Gomez
2,
Michael R. J. Forstner
2,* and
Dittmar Hahn
2 1
The Tick-Borne Disease Research Laboratory, Department of Microbiology, Immunology, and Genetics, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
2
Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
*
Author to whom correspondence should be addressed.
Biology 2024, 13(7), 489; https://doi.org/10.3390/biology13070489 (registering DOI)
Submission received: 21 April 2024
/
Revised: 24 June 2024
/
Accepted: 29 June 2024
/
Published: 30 June 2024
(This article belongs to the Special Issue Advances in Leishmaniasis and Chagas Disease: Biology, Epidemiology, Treatment and Control)
Simple Summary
Chagas disease is endemic to the state of Texas in the United States but does not have consistent surveillance or reporting. We utilized multiple sampling sites and different species of triatomine to gain data on the blood meal sources found by DNA testing for the host and vector species identities. From domestic, peridomestic, and rural sites, we found a breadth of blood meal origins including mammals, chickens, and reptiles. Unique non-native taxa utilized for blood meals enabled us to also report on extensive foraging distances for the vectors. Understanding the diversity of blood meal sources and the distances the vectors travel between meals and daytime refuges are both important aspects for understanding the spread of this disease.
Abstract
The prevalence of Trypanosoma cruzi was assessed in 117 triatomine insects from central Texas. The qPCR-based results revealed T. cruzi in 59% of the insects (62 adults and eight nymphs), with overall prevalences of T. cruzi of 0% (0/9), 64% (11/17), 58% (10/17), 73% (30/41), and 57% (19/33) for the Bastrop, Caldwell, Gonzales, Guadalupe, and Hays counties, respectively. Analyses of 18S rRNA fragments confirmed T. cuzi in 81% of these samples. Vectors were identified as Triatoma gerstaeckeri (35% of which 65% were positive for T. cruzi), T. sanguisuga (21%, 43% positive), and Paratriatoma leticularia (0.3%, 100% positive). Food sources were recovered from 29% of the insects. Raccoons were 53% of the blood meals (83% positive for T. cruzi), while the remainder came from a variety of sources, including humans (33% positive), house geckos, Eastern woodrats, plain-bellied water snakes (50% positive), hispid cotton rats (0% positive), chickens (100% positive); Asian forest turtles, bison, and pigs (0% positive). The serendipitous detection of blood meal sources at known minimum distances from the collection of the vector insect enabled us to provide several instances where the insect foraging distance was greater than 400 m. These vector foraging distances are novel information that can assist in our understanding of the landscape dynamics for the spread of the pathogen.
Keywords:
triatomine; blood meal sources; Trypanosoma cruzi
