Analysis of over 1500 triatomine vectors from across the US, predominantly Texas, for Trypanosoma cruzi infection and discrete typing units.

Across the Americas, triatomine insects harbor diverse strains of Trypanosoma cruzi (T. cruzi), agent of Chagas disease. Geographic patterns of vector infection and parasite strain associations, especially in vectors encountered by the public, may be useful in assessing entomological risk, but are largely unknown across the US. We collected Triatoma spp. from across the US (mainly Texas), in part using a citizen science initiative, and amplified T. cruzi DNA to determine infection prevalence and parasite discrete typing units (DTUs). We found 54.4% infection prevalence in 1510 triatomines of 6 species; prevalence in adult T. gerstaeckeri (63.3%; n=897) and T. lecticularia (66.7%; n=66) was greater than in T. sanguisuga (47.6%; n=315), T. indictiva (47.8% n=67), T. rubida (14.1%; n=64), and T. protracta (10.5%; n=19). The odds of infection in adults were 9.73 times higher than in nymphs (95% CI 4.46-25.83). PCR of the spliced leader intergenic region (SL-IR) and/or the putative lathosterol/episterol oxidase TcSC5D gene revealed exclusively T. cruzi DTUs TcI and TcIV; 5.5% of T. cruzi-positive samples were not successfully typed. T. gerstaeckeri (n=548) were more frequently infected with TcI (53.9%) than TcIV (34.4%), and 11.9% showed mixed TcI/TcIV infections. In contrast, T. sanguisuga (n=135) were more frequently infected with TcIV (79.3%) than TcI (15.6%), and 5.2% showed mixed infections. Relative abundance of parasite DTUs varied spatially, with both TcI and TcIV co-circulating in vectors in central Texas, while TcIV predominated in northern Texas. Given prior findings implicating TcI in human disease and TcI and TcIV in animal disease in the US, knowledge of spatial distribution of T. cruzi infection and DTUs in vectors is important to understanding public and veterinary health risk of T. cruzi infection.

Curtis-Robles R ，Auckland LD ，Snowden KF ，Hamer GL ，Hamer SA ... -  《-》

Abundant triatomines in Texas dog kennel environments: Triatomine collections, infection with Trypanosoma cruzi, and blood feeding hosts.

Busselman RE ，Curtis-Robles R ，Meyers AC ，Zecca IB ，Auckland LD ，Hodo CL ，Christopher D ，Saunders AB ，Hamer SA ... -  《-》

Epidemiology and Molecular Typing of Trypanosoma cruzi in Naturally-Infected Hound Dogs and Associated Triatomine Vectors in Texas, USA.

Curtis-Robles R ，Snowden KF ，Dominguez B ，Dinges L ，Rodgers S ，Mays G ，Hamer SA ... -  《PLoS Neglected Tropical Diseases》

The Biology of the Triatomine Bugs Native to South Central Texas and Assessment of the Risk They Pose for Autochthonous Chagas Disease Exposure.

Wozniak EJ ，Lawrence G ，Gorchakov R ，Alamgir H ，Dotson E ，Sissel B ，Sarkar S ，Murray KO ... -  《-》

Trypanosoma cruzi Infection Prevalence and Bloodmeal Analysis in Triatomine Vectors of Chagas Disease From Rural Peridomestic Locations in Texas, 2013-2014.

Protozoan pathogen Trypanosoma cruzi (Chagas, 1909) is the etiologic agent of Chagas disease, which affects millions of people in Latin America. Recently, the disease has been gaining attention in Texas and the southern United States. Transmission cycle of the parasite involves alternating infection between insect vectors and vertebrate hosts (including humans, wildlife, and domestic animals). To evaluate vector T. cruzi parasite burden and feeding patterns, we tested triatomine vectors from 23 central, southern, and northeastern counties of Texas. Out of the 68 submitted specimens, the majority were genetically identified as Triatoma gerstaeckeri (Stal, 1859), with a few samples of Triatoma sanguisuga (LeConte, 1855), Triatoma lecticularia (Stal, 1859), Triatoma rubida (Uhler, 1894), and Triatoma protracta woodi (Usinger, 1939). We found almost two-thirds of the submitted insects were polymerase chain reaction-positive for T. cruzi Bloodmeal sources were determined for most of the insects, and 16 different species of mammals were identified as hosts. The most prevalent type of bloodmeal was human, with over half of these insects found to be positive for T. cruzi High infection rate of the triatomine vectors combined with high incidence of feeding on humans highlight the importance of Chagas disease surveillance in Texas. With our previous findings of autochthonous transmission of Chagas disease, urgent measures are needed to increase public awareness, vector control in and around homes, and Chagas screening of residents who present with a history of a triatomine exposure.

Gorchakov R ，Trosclair LP ，Wozniak EJ ，Feria PT ，Garcia MN ，Gunter SM ，Murray KO ... -  《-》