An entomological and serological survey was performed in three localities of the Department of Concepción, Province of Corrientes, Argentina in 1998 and1999, to
Key words: Triatoma infestans -Triatoma sordida -infestation -infection -seroprevalence -ArgentinaIn rural areas of Corrientes Province, Triatoma infestans (Klug 1834) is mainly found indoors and is also present in peridomestic premises (Bar et al. 1992(Bar et al. , 1996b(Bar et al. , 1997.T. sordida (Stål 1859) colonizes wild biotopes (Bar et al. 1996a) as well as artificial ecotopes in peridomestic areas, sometimes coexisting with T. infestans and even established inside a rural house (Bar et al. 1992(Bar et al. , 1996b. In Corrientes city it frequently invades houses and a large colony was captured in an urban ecotope (Bar et al. 1993).Although intradomestic colonies of T. infestans have been eliminated from some areas of Corrientes province, T. sordida may replace it as a domestic vector. Integration of extradomestic triatomines to domestic transmission cycles has been occasionally reported in Minas Gerais, Brazil (Diotaiuti et al. 1993).Anthropic environmental modification, mainly the replacement of natural forest by cultivated land, harvesting of wood and uncontrolled grazing may produce a concentration of wild mammals and triatomines in the peridomicile, generating local transmission cycles of Trypanosoma cruzi. Those foci can provide invading vectors to the domicile that can eventually carry trypanosomes (Wisnivesky-Colli et al. 1993). The peridomicile may represent a transition environment for triatomines coming from the wild and facilitate their domiciliation process (Gajate et al. 1996).An important flood affected Corrientes Province in 1998, as a consequence of the El Niño phenomenon, which made the owners of the dwellings leave them temporarily. Most of the houses were rebuilt afterwards. This entire situation contributed to the increase of the environmental disturbance.In order to increase our knowledge on the ecology of domestic and wild triatomines, an entomological and serological survey was carried out in rural settlements of the Department of Concepción, Corrientes.
MATERIALS AND METHODSStudy area -The study area was situated in the localities of Santa Rosa, Colonia Tabay and Colonia Tata Cuá of the Department of Concepción, Corrientes, Argentina (27º to 28ºS and 57º to 58ºW). Biogeographically the area belongs to the oriental district of the Chaco region (Cabrera & Willink 1973).Socioeconomic characteristics -Most of the houses were built with materials obtained from the environment. Wood walls and sheet metal or cardboard roofs were observed in 62.5% of the households, the remainder had mud stick walls and thatched roofs. Similar materials were used to built the storerooms and kitchens.Domestic animals were present in 97% of the households, of which 80.5% were dogs, 55% cats and 53% hens.Peridomestic ecotopes were open structures made with sticks or wood, partially covered or not by a roof, 5-20 m far from the domiciles.The main act...