Autochthonous Chagas' disease in Santa Catarina State, Brazil: report of the first case of digestive tract involvement.

We report the first case of digestive tract pathology (megaesophagus) determined by Trypanosoma cruzi infection in Santa Catarina State, southern Brazil. A 63-year-old female had presumptive clinical diagnosis of Chagas' disease, which was confirmed by imaging (endoscopy and esophagogram) and immunological methods. Further molecular diagnosis was carried out with esophagus and blood samples collected during corrective surgery. Polymerase chain reaction tested positive for Trypanosoma cruzi in both esophagus and buffy coat samples.

Autochthonous Chagas' disease in Santa Catarina State, Brazil: report of the first case of digestive tract involvement

We report the first case of digestive tract pathology (megaesophagus) determined by Trypanosoma cruzi infection in Santa Catarina State, southern Brazil. A 63-year- old female had presumptive clinical diagnosis of Chagas' disease, which was confirmed by imaging (endoscopy and esophagogram) and immunological methods. Further molecular diagnosis was carried out with esophagus and blood samples collected during corrective surgery. Polymerase chain reaction tested positive for Trypanosoma cruzi in both esophagus and buffy coat samples

Biology of Triatoma klugi Carcavallo, Jurberg, Lent & Galvão 2001 (Heteroptera: Reduviidae) under laboratory conditions: effects of distinct blood sources and susceptibility to Trypanosoma cruzi and Trypanosoma rangeli.

The life cycle of Triatoma klugi Carcavallo, Jurberg, Lent & Galvão 2001 was compared under laboratory conditions using two groups of the F1 generation obtained from field-collected bugs. Among the 100 nymphs weekly fed on mice (Group A) or chicken (Group B), 77% of Group A and 67% of Group B reached the adult stage, and the mean time from the first nymphal stage to adult was 190.08 +/- 28.31 days and 221.23 +/- 40.50, respectively. The average span in days for each stage per group and the number of blood meals required for each stage were also evaluated. The overall mortality rate was 23% and 33% for Groups A and B, respectively. The mean number of eggs laid per month in a three-month period was of 56.20, 51.70 and 73.20 for Group A, and 64.50, 53.50 and 38.71 for Group B. Despite the blood source, comparative analysis revealed no statistically significant differences in the life cycle of T. klugi under laboratory conditions. Infection rates over 60% were observed for both Trypanosoma cruzi strains tested. Even revealing high infection rates of the hemolymph by T. rangeli strains, T. klugi revealed no salivary gland infections and was not able to transmit the parasite.

Biology of Triatoma klugi Carcavallo, Jurberg, Lent & Galväo 2001 (Heteroptera: Reduviidae) under laboratory conditions: effects of eistinct blood sources and susceptibility to Trypanosoma cruzi and Trypanosoma rangeli

The life cycle of Triatoma klugi Carcavallo, Jurberg, Lent & Galväo 2001 was compared under laboratory conditions using two groups of the F1 generation obtained from field-collected bugs. Among the 100 nymphs weekly fed on mice (Group A) or chicken (Group B), 77 percent of Group A and 67 percent of Group B reached the adult stage, and the mean time from the first nymphal stage to adult was 190.08 ± 28.31 days and 221.23 ± 40.50, respectively. The average span in days for each stage per group and the number of blood meals required for each stage were also evaluated. The overall mortality rate was 23 percent and 33 percent for Groups A and B, respectively. The mean number of eggs laid per month in a three-month period was of 56.20, 51.70 and 73.20 for Group A, and 64.50, 53.50 and 38.71 for Group B. Despite the blood source, comparative analysis revealed no statistically significant differences in the life cycle of T. klugi under laboratory conditions. Infection rates over 60 percent were observed for both Trypanosoma cruzi strains tested. Even revealing high infection rates of the hemolymph by T. rangeli strains, T. klugi revealed no salivary gland infections and was not able to transmit the parasite

Differentiation of Trypanosoma rangeli: high production of infective Trypomastigote forms in vitro.

In the present study, we report a simple method to induce high Trypanosoma rangeli differentiation in vitro, producing a large number of infective trypomastigote forms. Parasites from SC-58 (Brazil) and Choachi (Colombia) strains were cultivated at 27 degrees C in TC-100, Grace and DMEM media, each supplemented with 5% fetal bovine serum and prepared at three distinct pHs (6.0, 7.0, 8.0). Differentiation was microscopically evaluated at 0, 3 and 6 days after cultivation in each medium by determining the percentage of trypomastigotes in Giemsa-stained smears. Our data revealed similar results for both T. rangeli strains, showing (after 6 days of cultivation in DMEM medium, pH 8.0) the presence of about 80% of trypomastigotes. These culture-derived trypomastigotes proved to be infective to both Balb-C mice and Rhodnius spp, reaching the triatomine's salivary glands. Our results describe a new and easy method to induce high T. rangeli differentiation in vitro, allowing further studies on the antigenic constitution of trypomastigotes.