The triatomines of northern Peru, with emphasis on the ecology and infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae)

Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35 percent of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Marañón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4 percent of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus), whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended

Biogeography of Triatominae (Hemiptera: Reduviidae) in Ecuador: implications for the design of control strategies

Chagas disease control strategies strongly depend on the triatomine vector species involved in Trypanosoma cruzi transmission within each area. Here we report the results of the identification of specimens belonging to various species of Triatominae captured in Ecuador (15 species from 17 provinces) and deposited in the entomological collections of the Catholic University of Ecuador (Quito), Instituto Oswaldo Cruz (Brazil), the Natural History Museum London (UK), the London School of Hygiene and Tropical Medicine (UK), the National Institute of Hygiene (Quito), and the Vozandes Hospital (Quito). A critical review of published information and new field records are presented. We analysed these data in relation to the life zones where triatomines occur (11 life zones, excluding those over 2,200 m altitude), and provide biogeographical maps for each species. These records are discussed in terms of epidemiological significance and design of control strategies. Findings relevant to the control of the main vector species are emphasised. Different lines of evidence suggest that Triatoma dimidiata is not native to Ecuador-Peru, and that synanthropic populations of Rhodnius ecuadoriensis in southern Ecuador-northern Peru might be isolated from their sylvatic conspecifics. Local eradication of T. dimidiata and these R. ecuadoriensis populations might therefore be attainable. However, the presence of a wide variety of native species indicates the necessity for a strong longitudinal surveillance system

Ultrastructural observations on trypanosoma herpetosoma rangeli in the salivary glands of rhodnius ecuadoriensis, hemiptera, reduvidae

Fue realizado un estudio ultraestructural de las glándulas salivares del triatomino rhodnius ecuadoriensis experimentalmente infectado por el tripanosomatídeo, trypanosoma (herpetosoma) rangeli, con la finalidad de documentar los aspectos básicos de la infección glandular por este flagelado. Gran número de formas epimastigotes fueron encontradas en la hemolinfa que baña la parte externa de las glándulas en el hemoceloma. Algunos flagelados parecían intimamente asociados a la membrana basal del epitelio glandular y varios de ellos parecían estar iniciando el proceso de su invasión, rompiendo la lámina basal con el flagelo. En el interior de las células glandulares observamos que, T. rangeli se presentaba en la forma de esteromastigotes, células redondeadas rodeadas externamente por un flagelo, que envolvía apretadamente el parásito. En la luz glandular también observamos gran número de epimastigotes mezclados con los productos de la secreción glandular, el material presentó apenas pocas formas paramastigotes y trypomastigotes identificadas de manera inquívoca. El significado de los paramastigotes en el ciclo evolutivo del T. rangeli aguarda futuros estudios

Leishmania mexicana: aspectos taxonomicos y rareza de la infeccion humana en Tres Bracos, Bahia, Brasil. / Leishmania mexicana: taxonomic aspects and rarity of human infection in Tres Bracos, Bahia, Brazil

Del estudio de 51 stocks de Leishmania aislados de pacientes humanos de leishmaniasis cutaneomucosa en Tres Bracos, Bahia, Brasil, los autores describen, en detalle, el analisis de los dos unicos stocks de L. mexicana, identificando uno de ellos como L. mexicana amazonensis. El otro aislado permanece en posicion taxonomica no definida pues considerandosele como un miembro de L. mexicana, encuentranse dificultades para su identificacion subespecifica. Evaluan tambien los parametros biologicos e isoenzimaticos y discutem el papel de los anticuerpos monoclonales en la tipificacion de estos stocks. Los autores remarcan la rareza de la transmision de parasitos del complejo L. mexicana en esta region, aun cuando estudien epidemiologicamente por mais de 8 anos la infeccion humana