Short communication Risk of transmission of Trypanosoma cruzi by wild Triatoma infestans (Hemiptera: Reduviidae) in Bolivia supported by the detection of human blood meals Nelly Lilian Rosio Buitrago a,⇑ , Marie France Bosseno a,b , Etienne Waleckx a,b , Philippe Brémond a , Pablo Vidaurre c , Faustine Zoveda a , Simone Frédérique Brenière a,b a MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le développement (IRD), Représentation in Bolivia, Av. Hernando Siles N°5290, Esq Calle 7 Obrajes, CP 9214, La Paz, Bolivia b Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, Rafael Zubieta #1889, Miraflores, Casilla M-10019, La Paz, Bolivia c Servicio Departamental de Salud (SEDES), Departamento de La Paz, Bolivia article info Article history: Received 23 February 2013 Received in revised form 29 June 2013 Accepted 2 July 2013 Available online 13 July 2013 Keywords: Wild Triatoma infestans Human blood meals Bolivia abstract We analyzed the food sources of Bolivian wild Triatoma infestans (the main vector of Chagas disease in this country), to assess the role of these populations in the epidemiological context of Chagas disease. Ninety-eight blood meals were identified by heteroduplex assay and sequencing. Most of them were from wild mammals but surprisingly 27 were from humans. This brings to light the occurrence of human–vec- tor contacts at risk of Trypanosoma cruzi transmission in the wild environment by highly infected insects. Ó 2013 Elsevier B.V. All rights reserved. Trypanosoma cruzi, the causative agent of Chagas disease, has sylvatic and domestic cycles maintained mainly by triatomine vec- tors (Hemiptera: Reduviidae) in both environments. The vectorial transmission of the parasite occurs (i) when triatomines ingest blood from an infected mammalian host and (ii) when the trypo- mastigote forms of the parasite, present in the feces left near the site of the bite lesion, invade mammalian cells. The cycles may be independent or connected by the movement of domestic, wild, and synanthropic infected animals (Barreto, 1972) and infected tri- atomines between human and natural habitats. Also, humans can be a link between the two environments because of their activities such as collecting firewood that can be infested by triatomines and bringing it to their domicile. American trypanosomiasis is primar- ily a wild enzootic disease, dating from when prehistoric humans lived in the forest before becoming sedentary (Fernandes et al., 2008). Then the vectorial transmission of T. cruzi was mainly con- sidered to occur indoors because some triatomine species had suc- cessfully adapted to dwellings and more recently other species were found to sporadically enter dwellings attracted by light (Car- bajal de la Fuente et al., 2007). However, outdoor vectorial trans- mission to humans has been described in the tropical rainforest, related to camping and human activities such as hunting, gathering plants, and tourist activities (Coura, 1988, 2006). Triatoma infestans (the main vector of Chagas disease in the Southern Cone Countries of South America) has long been regarded as almost exclusively domestic, although a few wild populations have been reported in the Cochabamba valley in Bolivia (Torrico, 1946; Dujardin et al., 1987; Bermudez et al., 1993); therefore, transmission was consid- ered to take place exclusively indoors. At present, many more pop- ulations of wild T. infestans have been discovered in Bolivia, near human habitats in the ecoregion of the Inter-Andean Dry Forest, (Cortez et al., 2007; Buitrago et al., 2010) and in the neighboring countries of Argentina, Chile and Paraguay (Bacigalupo et al., 2010; Ceballos et al., 2011; Rolón et al., 2011) but the existence of outdoor-dwelling vector-borne transmission by T. infestans is virtually undocumented in the overall T. infestans endemic area. Hematophagy is an obligatory habit of Triatominae and the analysis of blood meals (i) identifies the animals used as blood sources, thus maintaining the triatomine populations in different environments, (ii) identifies the mammal species that are potential reservoirs of the parasite, (iii) detects the movement of triatomines between domestic and wild environments, and (iv) evaluates the rate of anthropophilia of triatomines. In this paper we report the finding of animal and human blood meals of wild T. infestans collected from eight previously reported 1567-1348/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.meegid.2013.07.002 ⇑ Corresponding author. Address: Institut de Recherche pour le Développement (IRD), Representation in Bolivia, Av. Hernando Siles N°5290, Esq. Calle 7 Obrajes, CP 9214 La Paz, Bolivia. Tel.: +591 (2) 278 29 69; fax: +591 (2) 278 29 44. E-mail address: rosiob8@gmail.com (N.L.R. Buitrago). Infection, Genetics and Evolution 19 (2013) 141–144 Contents lists available at SciVerse ScienceDirect Infection, Genetics and Evolution journal homepage: www.elsevier.com/locate/meegid