Wide distribution of Trypanosoma cruzi-infected triatomines in the State of Bahia, Brazil

• Main Authors: Gilmar Ribeiro, Carlos G. S. dos Santos, Fernanda Lanza, Jamylle Reis, Fernanda Vaccarezza, Camila Diniz, Diego Lopes Paim Miranda, Renato Freitas de Araújo, Gabriel Muricy Cunha, Cristiane Medeiros Moraes de Carvalho, Eduardo Oyama Lins Fonseca, Roberto Fonseca dos Santos, Orlando Marcos Farias de Sousa, Renato Barbosa Reis, Wildo Navegantes de Araújo, Rodrigo Gurgel-Gonçalves, Mitermayer G. dos Reis
• Format: Article
• Language: English
• Published: BMC 2019-12-01
• Series: Parasites & Vectors
• Subjects: Chagas disease; Entomological surveillance; Trypanosoma cruzi; Blood meal; PCR
• Online Access: https://doi.org/10.1186/s13071-019-3849-1

Abstract Background The identification of Trypanosoma cruzi and blood-meal sources in synanthropic triatomines is important to assess the potential risk of Chagas disease transmission. We identified T. cruzi infection and blood-meal sources of triatomines caught in and around houses in the state of Bahia, northeastern Brazil, and mapped the occurrence of infected triatomines that fed on humans and domestic animals. Methods Triatominae bugs were manually captured by trained agents from the Epidemiologic Surveillance team of Bahia State Health Service between 2013 and 2014. We applied conventional PCR to detect T. cruzi and blood-meal sources (dog, cat, human and bird) in a randomized sample of triatomines. We mapped triatomine distribution and analyzed vector hotspots with kernel density spatial analysis. Results In total, 5906 triatomines comprising 15 species were collected from 127 out of 417 municipalities in Bahia. The molecular analyses of 695 triatomines revealed a ~10% T. cruzi infection rate, which was highest in the T. brasiliensis species complex. Most bugs were found to have fed on birds (74.2%), and other blood-meal sources included dogs (6%), cats (0.6%) and humans (1%). Trypanosoma cruzi-infected triatomines that fed on humans were detected inside houses. Spatial analysis showed a wide distribution of T. cruzi-infected triatomines throughout Bahia; triatomines that fed on dogs, humans, and cats were observed mainly in the northeast region. Conclusions Synanthropic triatomines have a wide distribution and maintain the potential risk of T. cruzi transmission to humans and domestic animals in Bahia. Ten species were recorded inside houses, mainly Triatoma sordida, T. pseudomaculata, and the T. brasiliensis species complex. Molecular and spatial analysis are useful to reveal T. cruzi infection and blood-meal sources in synanthropic triatomines, identifying areas with ongoing threat for parasite transmission and improving entomological surveillance strategies.