Dinamica de la transmision de Trypanosoma Cruzi en una zona rural de la Argentina: II dos Relacion entre la infeccion domestica en ninos y perros y la densidad de Triatoma infestants infectados / Dynamics of transmission of Trypanosoma Cruzi in a rural área of Argentina: II. Household infection patterns among children and dogs relative to the density of infected Triatoma infestans

RESUMEN

cross-sectional survey of 20 households was conducted at Amama (Santiago del Estero Province, Argentina), an área where active Trypanosoma cruzi transmission was occurring and where no official insecticide applications agains Chagas' disease vector had been made. The survey sought to collect data on the numbers of Triatoma infestans vectors present, the intensity of T. cruzi transmission to dogs and children, and relationships between the presence of infected household dogs and T. cruzi infection among children. Bugs were collected with forceps and flashlights by two-man teams and later by spraying the walls and roofs of the study houses with a synthetic pyrethrin solution. Blood samples, obtained from all members of each study household and from household pets, were tested serologically for T. cruzi; in addition, study subjects were tested for T. Cruzi by xenodiagnosis. The bug collection effort found relatively few Tr. infectans (less than 15 per house) in about a quarter of the study households, and relatively high densities (over 50 bugs) in all but one of the rest. Similarly, less than 16 T. cruzi infected vectors were found in six study homes, while most of the rest yielded at least 40. Statistically significant differences were found between the T, cruzi infection rates of both children and dogs in low-risk and high-risk settings. Examination of the collected information also suggests