Seven third stage nymphs of Triatoma infestans were infected with Trypanosoma cruzi of mice during the acute phase. After a time of being positives, the triatomids became a microscopical negative in feces examination. The feces of these negative triatomids were inoculated to eight mice and controled from 16 to 44 days. Three mice (37,5%) showed infection of the blood. These results suggest the necessity to induce an infection in a mouse upon which, from the fifteenth day on, tests should be conducted in order to check for trypomastigotes.

Seven third stage nymphs of Triatoma infestans were infected with Trypanosoma cruzi of mice during the acute phase. After a time of being positives, the triatomids became a microscopical negative in feces examination. The feces of these negative triatomids were inoculated to eight mice and controled from 16 to 44 days. Three mice (37,5%) showed infection of the blood. These results suggest the necessity to induce an infection in a mouse upon which, from the fifteenth day on, tests should be conducted in order to check for trypomastigotes.