Trypanosoma Cruzi-Infected Panstrongylus Geniculatus And

Rojas-Cortez et al. Parasites & Vectors (2016) 9:158 DOI 10.1186/s13071-016-1445-1 SHORT REPORT Open Access Trypanosoma cruzi-infected Panstrongylus geniculatus and Rhodnius robustus adults invade households in the Tropics of Cochabamba region of Bolivia Mirko Rojas-Cortez1*, Maria-Jesus Pinazo2, Lineth Garcia3, Mery Arteaga1,2, Liliana Uriona1, Seyla Gamboa1, Carolina Mejía1, Daniel Lozano1, Joaquim Gascon2, Faustino Torrico1 and Fernando A. Monteiro4 Abstract Background: There are hardly any data available on the relationships between the parasite and the vector or regarding potential reservoirs involved in the natural transmission cycle of Trypanosoma cruzi in the Tropics of Cochabamba, Bolivia. Local families from communities were responsible for the capture of triatomine specimens, following a strategic methodology based on entomological surveillance with community participation developed by the National Chagas Programme of the Ministry of Health of Bolivia. Findings: We describe the collection of adult Panstrongylus geniculatus and Rhodnius robustus naturally infected with Trypanosoma cruzi from houses and from the hospital of Villa Tunari municipality. The flagellates found in the digestive tract of P. geniculatus belong to genetic lineages or DTUs TcI and TcIII, whereas only lineage DTU TcI was found in R. robustus. The detection of these vectors infected with T. cruzi reveals the vulnerability of local communities. Conclusion: The results presented here highlight the risk of Chagas disease transmission in a region previously thought not to be endemic, indicating that the Tropics of Cochabamba should be placed under permanent entomological and epidemiological surveillance. Keywords: Panstrongylus geniculatus, Rhodnius robustus, Trypanosoma cruzi, Tropics of Cochabamba, Bolivia Background Other native vectors are also often reported in Bolivia, Chagas disease transmission to humans occurs when they including Triatoma sordida and Panstrongylus megistus come in contact with Trypanosoma cruzi-infected feces of in the valleys, and Rhodnius stali, R. robustus, Panstron- hematophagous insects of the subfamily Triatominae gylus rufotuberculatus and P. geniculatus in the Amazon (Hemiptera: Reduviidae) [1]. Epidemiologically important region and Yungas [3–5]. Light-attracted and in search triatomine species are those with the ability to efficiently of food sources, these vectors occasionally invade human colonize rural habitations where they may transmit the T. dwellings, thus presenting the possibility of T. cruzi cruzi to local inhabitants. Of the 17 currently recognized transmission to humans [4]. triatomine species that occur in Bolivia, only Triatoma TheAmazonregionandtheYungashavenotbeencon- infestans fulfills the above definition, being responsible for sidered endemic for Chagas disease. However, several stud- 80 % of vector-borne Chagas disease transmission in en- ies have documented the presence of Rhodnius specimens demic areas such as the mesothermal valleys and the in palm trees close to rural households both in the Yungas Chaco [2]. region, La Paz Department, and in the Cochabamba Tropic region [4, 5]. The Rhodnius robustus species complex is distributed * Correspondence: [email protected] throughout the Amazon region [6]. These taxa utilise 1Fundación CEADES, Cochabamba, Bolivia several Amazonian palm tree species as natural habitats, Full list of author information is available at the end of the article © 2016 Rojas-Cortez et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Rojas-Cortez et al. Parasites & Vectors (2016) 9:158 Page 2 of 6 and might show high percentages of natural infection flows were stronger in the 50s due to the Bolivian with T. cruzi [7]. Agrarian Reform and in the 80s due to a combination A preferred habitat of Rhodnius spp. are non-cultivated of economic hardship and adverse weather conditions palm trees with dense foliage as they provide shelter for a caused by climate change [19]. wide variety of mammals and birds, which serve as food The main goal of this study was to identify, based on a sources for the insects [8, 9]. community-oriented surveillance program, the sylvatic Panstrongylus geniculatus, on the other hand, has a Chagas disease vectors that most often invade house- very wide geographical distribution, from Southern holds in the Tropic of Cochabamba region, in Bolivia, Mexico to Northern Argentina [10]. In Bolivia, this vec- and determine their natural infection rates and identify tor has been identified in the Yungas region, the eastern the strain of T. cruzi. plains, and the Bolivian Chaco [4]. Despite its occasional entry into homes attracted by light, this species does not Methods colonize human dwellings, which is an important factor Triatomine specimens were obtained from local residents limiting its potential as an efficient vector of Chagas of communities in the Tropics of Cochabamba between disease [11]. August 2012 and January 2014, in the framework of action In the natural habitats, P. geniculatus can be found in of the Villa Tunari Center for Comprehensive Chagas caves which provide shelter to armadillos, anteaters, Disease Care (VTCCCDC), a collaborative project between marsupials, bats and rodents. They can also be found in the Colectivo de Estudios Aplicados y Desarrollo Social of palm trees, under trunks and bark and in bromeliad Bolivia (CEADES) and the Institute for Global Health plants [12, 13]. (ISGlobal), Barcelona, Spain. Residents carried out the An increasing number of food-borne Chagas disease capture of triatomine species according to a strategic meth- outbreaks have been caused by different sylvatic vectors odology based on entomological surveillance with commu- [14]. Most cases of Chagas disease transmission per os nity participation developed by the National Chagas have occurred in Brazil, but they have also been reported Program (Ministry of Health, Bolivia). Members of each less frequently in countries such as Colombia, Argentina, household received an educational folder with instructions Venezuela, Ecuador and Bolivia [15]. on how to search for triatomines in their homes (Additional More than 180 domestic, synanthropic and wild species file 1: Fig. S1). After notification by the residents, house in- of mammals, especially nest-building rodents, opossums spection for insects was carried out by the man-hour and primates, are likely to be infected with T. cruzi. method. Trypanosoma cruzi is now classified into seven The entomological surveillance folder was designed to be discrete typing units (DTUs): T. cruzi I (TcI) to T. cruzi used in tropical non-endemic regions where triatomines VI (TcVI) and Tcbat. TcI has the widest distribution ran- are not known to colonize houses. It provides basic infor- ging from southern USA to northern Argentina and mation on Chagas disease, a schematic representation of all Chile; TcII is found predominantly in the southern and community players that take part in the initiative, and an central regions of South America; TcIII and TcIV have entry for family data. Inside there are two figures illustrat- both been detected from western Venezuela to the ing both the peridomestic and intradomestic areas with di- Argentinian Chaco; TcV and TcVI occur in southern and rections on how to clean and maintain each area in order central South America; and Tcbat is reported from the to prevent triatomine colonization. Earlier studies had iden- Amazonian rainforest to urban areas of the central, tified the presence of Rhodnius robustus in palm trees of northeast and southeast Brazil [16–18]. the Tropics of Cochabamba region [MR-C, personal com- The Tropics of Cochabamba region is technically munication]. Thus, the developmental cycle for this referred to as a bosque de uso múltiple.Itspopulation species was included in the folder to facilitate vector belongs predominantly to the Quechua ethnic group identification by the participants. Information on and the economy relies basically on the harvesting of how to avoid oral Chagas disease transmission is coca leaves and tropical fruits, with fish farming and also provided (Additional file 1: Fig. S1). tourism playing secondary roles. This geographical Collected triatomines were delivered to the VTCCCDC, area is not considered epidemiologically important be- where they were morphologically identified according to cause it is located outside the endemic region (i.e. the taxonomic keys of Lent & Wygodzinsky [3], and where T. infestans occurs). stored in the laboratory for further use. The Chagas disease epidemiological scenario in the For the microscopic observation, drops of feces extracted region has gone through important changes. This re- from triatomines were mixed with phosphate-buffered sa- gion has experienced intense migration of people com- line solution and viewed at a magnification of 400×. A sam- ing from highly endemic Andean regions, leading to the ple was considered positive whenever flagellate parasites development of many new settlements.

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