Feeding patterns of Triatoma infestans (Hemiptera: Reduviidae) in relation to transmission of American trypanosomiasis in Argentina.

Abstract

Agar double diffusion tests were used to analyze the origin of blood meals from 720 Triatoma infestans bugs collected from bedrooms and peridomestic structures of 9 households near Guanaco Muerto in the Province of Cordoba, Argentina. The intestinal contents of 332 (46.1%) of the bugs reacted to 1 or more of 11 antisera tested. Dog was the most frequently identified host in bugs collected from bedrooms (48.9%), followed by chicken (34.8%) and man (11.9%). A significantly higher number of blood meals from dogs were identified in nymphs than in adults. A predominance of identified feedings from goat (43.8%) and chicken (33.3%) were found in bugs from peridomestic structures. Movement of T. infestans between domestic and peridomestic structures is apparently minimal, since identified blood meals in bugs from bedrooms included only 1.8% from wild cavies, 0.4% from goats and 0.4% from horses, while only 3.3% of the total identified feedings from peridomestically collected bugs were from man. Since only a small number of bugs collected from goat pens and chicken houses contained blood meals from opossum (1.9%) and rodents (4.5%), these animals were considered to be of little importance in the maintenance of domestic populations of T. infestans . The highest rates of infection with Trypanosoma cruzi were found in bugs from bedrooms (63.6%). Peridomestically collected bugs from storerooms, chicken houses and goat pens showed significantly lower rates of infection (25, 2.4 and 1.4%, respectively). In bugs collected from bedrooms, a high correlation occurred between identified feedings from dogs and the rate of infection with T. cruzi . Dogs were considered the most important host, both as a reservoir source of T. cruzi and in the maintenance of domiciliary T. infestans in the study area.