Trypanosoma cruzi: two genetic groups in Paraná state, Southern Brazil.

This paper presents the genetic characterization of Trypanosoma cruzi strains isolated from chronic chagasic patients, triatomines, and sylvatic reservoirs from Paraná state, Southern Brazil, using the RAPD and SSR-PCR techniques. It has shown the presence of both phylogenetic groups of T. cruzi (I and II), describing for the first time the existence of T. cruzi II in Paraná state.

Secondary triatomine species in dwellings and other nearby structures in municipalities under epidemiological surveillance in the state of Paraná, Brazil.

OBJECTIVE: Since data are scarce regarding secondary triatomine species in the Brazilian state of Paraná, this study investigated infestations in inhabited and abandoned houses and in various other nearby structures in rural areas of that state. METHODS: Triatomines were manually captured in inhabited and uninhabited houses and other nearby structures in nine areas (eight municipalities and one district) of Paraná from June 1996 to February 2000. Testing for Trypanosoma cruzi infection was performed, as were also precipitin tests to determine the triatomines' food sources. RESULTS: While Triatoma infestans was not found in any of the nine areas of Paraná that were studied, three secondary triatomine species were detected: Triatoma sordida, Panstrongylus megistus, and Rhodnius neglectus. T. sordida was the most common species found, comprising 575 of the 658 triatomines captured (87.4%). The second-most common was P. megistus, with 82 specimens (12.5%). Of the various categories of structures investigated, uninhabited houses was the most frequently infested category (19/62, or 30.6%), followed by chicken coops (24/350, or 6.9%). The primary food source of the triatomines was the blood of birds. Nevertheless, in the municipality with the highest density of triatomines, the food sources included domestic animals and even humans. We found that 13.4% of the T. sordida and 13.5% of the P. megistus were infected with Trypanosoma cruzi. CONCLUSIONS: These results demonstrate the need to maintain entomological surveillance measures in the studied areas. This is especially important since Brazil and other countries of Latin America have affirmed the need to interrupt the vector-borne transmission of Chagas' disease.

[The ACHEI Program: Chagas' disease awareness through comprehensive education in the municipality of Maringá, Northwest Paraná, Brazil]. / Programa ACHEI: Atenção ao chagásico com educaçao integral no município de Maringá e região noroeste do Paraná, Brasil.

This study analyzes 131 chagasic patients from different endemic areas that came to the Chagas' disease laboratory at the Maringa State University. The subjects discovered they were infected principally because they presented symptoms (58%) or donated blood (29.4%). During etiologic treatment for Trypanosoma cruzi, 45.2% of benznidazole users complained of side effects. Based on these data, the ACHEI program (Chagas' Disease Awareness through Comprehensive Education) was developed, which is a multiprofessional/interdisciplinary extension project. Monthly meetings are held that are divided into two parts: The first half of the meetings provide specific information, including the distribution of brochures explaining Chagas' disease transmission, symptoms and treatment. The second half of the meetings focuses on psycho-social assistance and includes topics such as self-esteem and personal responsibility. The meetings provide an environment for chagasic patients to share their concerns regarding post-diagnosis quality of life, fear, anxiety, stigma and family and social group relationships. In short, the meetings offer an opportunity for patients to reflect on their situation and to discover ways to deal with their disease.

[Endoparasite prevalence in truck farmers and in the vegetables of Feira do Produtor de Maringá, Paraná]. / Prevalência de enteroparasitas em horticultores e hortaliças da Feira do Produtor de Maringá, Paraná.

Few studies have assessed the contamination of vegetables at Brazilian production sites. From April 1996 to December of 1997, the sanitary conditions of raw consumed vegetables sold in the Feira do Produtor de Maringá were investigated. We based the analyses on the contamination of vegetables, of the producers (stool samples and material under the fingernails) and of the water used for irrigation. It was observed that 16.6% of 144 samples of five different types of vegetables were contaminated with intestinal parasites. Forty three of 163 individuals (26%) were infected with one or more parasites. Only three of the 49 samples of material under the fingernails analyzed were positive for intestinal parasites. Analysis of samples of the water used for vegetable irrigation showed that the water did not satisfy bacteriological standards of potability. We conclude that in the investigated area the contamination of vegetables occurred during the production phase and that a sanitary education campaign directed at the producers is needed.

[Triatomids and forest reservoirs of Trypanosoma cruzi in the state of Paraná, southern Brazil. Preliminary results]. / Estudo sobre triatomíneos e reservatórios silvestres de Trypanosoma cruzi no Estado do Paraná, Sul do Brasil. Resultados preliminares.

In the rural area of five municipalities of the Northeast of the State of Paraná, Brazil, 154 adults or nymphs of Triatoma sordida and 2 Panstrongylus megistus were captured in 21 (41.2%) of 51 dwellings at the peridomestic sites. Trypanosoma cruzi-like organisms were found in 58 out of the 135 (43.0%) triatomids. Moreover, it was also found in the blood of 4/7 opossum (Didelphis sp). The triatomine infestation was more prevalent in the peridomicile than inside house. The forsaken wooden house presented the highest level of infestation (53.8%). Although the rural area of the Northeast of the State of Paraná is considered under epidemiologic surveillance it still presents a high level of peridomestic infestation by triatomids highly infected with T. cruzi-like organisms.

Trypanosoma cruzi: chemotherapy with benznidazole in mice inoculated with strains from Paraná state and from different endemic areas of Brazil.

Strains of Trypanosoma cruzi from different geographical areas have shown different levels of susceptibility to trypanosomicidal drugs. The susceptibility in vivo to benznidazole was investigated in eighteen strains of T. cruzi. Twelve were isolated from chronic chagasic patients from different Chagas' disease endemic areas. The other six strains were isolated from the northwestern region of Paraná state; two of them from patients, three from triatomines (Triatoma sordida) and one from wild reservoir (Didelphis sp.). To test drug the infected mice were divided into two groups of twenty. One group was treated with benznidazole for twenty consecutive days and the other group was used as untreated control. The treatment began after detection of the infection by direct blood examination or haemoculture. The control of cure was done through haemoculture and indirect immunofluorescence test. The drug eliminated the inflammatory lesions of the skeletal muscle of mice considered cured and from the heart of most of them. Moreover, the inflammatory lesions were reduced in treated but not cured animals. The T. cruzi strains studied showed a gradient of drug susceptibility that varied from 0% to 100%. Ten strains were considered sensitive to the treatment (61 to 100% of cure), one strain was partially sensitive (50% of cure) and seven strains were considered resistant to the treatment (0 to 40% of cure). This variation was observed both in strains of T. cruzi isolated from domestic and sylvatic cycles.

Trypanosoma cruzi infection in offspring born to chagasic C3H/He mice.

This study reports the effects of Trypanosoma cruzi infection induced in C3H/He male and female mice born to chagasic mice. An experimental model was established infecting female C3H/He mice with a low virulent T. cruzi clone. In this model, mating, fertilization, pregnancy evolution and delivery was carried out successfully. The offspring was infected at four, six and eighth weeks of age. The results showed that the offspring born to chagasic mothers present decreased resistance to acquired T. cruzi infection. This decreased resistance was expressed by higher levels of parasitaemia and higher mortality rates in offspring born to chagasic mothers than in controls. Age and sex were shown to be important factors of this phenomenon. The results suggest that maternal immune system products can modulate the immune response of the offspring.

[Biological characterization of clones of the Y, CL and MR strains of Trypanosoma cruzi in inbred C3H mice]. / Caracterização biológica de clones das cepas Y, CL e MR de Trypanosoma cruzi em camundongos C3 H isogênicos.

Ten clones of Trypanosoma cruzi isolated from Y, CL and MR strains were studied. The infectivity of culture forms, parasitemia pattern, polymorphism and mortality were studied in C3H inbred mice. Significant intra-group differences among Y and CL clones were found. MR clones showed higher homogeneity. These data indicate that T. cruzi strains can show different degrees of heterogeneity. It is suggested that conditions used to maintain T. cruzi strains may result in a selective advantage for some subpopulations (clones) after many years of laboratory maintenance.