Browsing by Autor "Roxana Carrasco"

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Prevalence of anti-R-13 antibodies in human<i>Trypanosoma cruzi</i>infection
(Oxford University Press, 1995) Christine Aznar; Pablo Lopez‐Bergami; Silvia Brandariz; Christine Mariette; Pascale Liégeard; Maria do Carmo de Deus Alves; Erika Luna Barreiro; Roxana Carrasco; Sonia Lafon; Dan Kaplan
Infection with Trypanosoma cruzi develops in three phases: acute, indeterminate or asymptomatic, and chronic phase (with cardiac or digestive manifestations). Moreover, transmission may occur from infected mothers to newborn, the so-called congenital form. In the present study, humoral responses against T. cruzi total extract and against the 13 amino acid peptide named R-13 derived from the parasite ribosomal P protein, previously described as a possible marker of chronic Chagas heart disease, were determined pateints and in blood bank donors from endemic areas. While in sera from acute phase, only IgM anti-T.cruzi response was observed, both IgM and IgG anti-T. cruzi antibodies were detected in sera from congenitally infected newborns. The percentage of positive response in sera from blood bank donors was relatively high in endemic regions. Antibodies against the R-13 peptide were present in a large proportion of cardiac chagasic patients but were totally lacking in patients with digestive form of Chagas disease. Furthermore, anti-R-13 positive responses were detected in congenitally infected newborns.
Prevalence of Trypanosoma cruzi infection in blood banks of seven departments of Bolivia
(Instituto Oswaldo Cruz, Ministério da Saúde, 1990) Roxana Carrasco; Hortensia Miguez; Clara Camacho; Lourdes Echalar; Suzana Revollo; Tania Ampuero; Jean-Pierre Dedet
Trypanosoma cruzi infection was studied in 1,298 sera samples of blood banks from 7 capital departments of Bolivia, using the immunofluorescence test (IFI) and Enzyme Linked Immunosorbent Assay (ELISA). The percentages of positivity in these 7 departments have an average of 28% and are distributed as follows: Sta. Cruz 51%, Tarija 45%, Cochabamba 28%, Sucre 39%, La Paz 4.9%, Oruro 6% and Potosi 24%. The prevalence is related with the altitude levels of the different departments. However in Potosi (3,945 m) we found a 24% of prevalence, probably due to the proximity of endemic valleys to the city. The authors suggest a strict control in blood donors since there exists a great risk of infection.
Seroprevalencia y factores de riesgo para Tenia solium (teniasis y cisticercosis) en humanos de zonas rurales en provincias de 8 departamentos de Bolivia
(1999) Roxana Carrasco; Hortencia Miguez; Clara Camacho
Specific immunodiagnosis of Chagas disease: immunodiffusion test using a specific serum anti-Trypanosoma cruzi component 5.
(National Institutes of Health, 1987) Simone Frédérique Brénière; Yves Carlier; Roxana Carrasco; S Molinedo; Jean-Loup Lemesre; P. Desjeux; D. Afchain
A micro double diffusion test (MD), allowing the identification of precipitation brand 5 by identity reaction, using a rabbit specific anti-component 5 serum, was evaluated for the immunological diagnosis of Chagas' disease. The previous studies on the Trypanosoma cruzi specificity of component 5[g] were completed, showing it to be absent in Leishmania brazilienis, but present in different strains of T. cruzi. 200 sera from Bolivian patients were studied. (88 with a positive xenodiagnosis, 45 with mucocutaneous leishmaniasis but without Chagas' disease, and 67 controls). Band 5 was found in 74 (84.1%) of the sera with positive xenodiagnosis but was never found either in the leishmaniasis or in the control groups. MD, allowing an easy detection of T. cruzi specific band 5, cheap and simple to perform, can be recommended in association with other serological tests, when highly specific immunodiagnosis of Chagas' disease is required.
Sylvatic Triatomines (Hemiptera: Reduviidae) in Bolivia: Trends Toward Domesticity and Possible Infection with Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae)
(Oxford University Press, 1995) François Noireau; Marie-France Bosseno; Roxana Carrasco; Jenny Telleria; Fernando Regla Vargas; Clara Camacho; Nina Yaksic; Simone Frédérique Brénière
The risk of domestic transmission of Trypanosoma cruzi (Chagas) by sylvatic triatomines was assessed in an isolated area of the subandean region of Bolivia. None of the 390 residents examined had serological evidence of infection. Two sylvatic triatomine species, Eratyrus mucronatus (Stål) and Triatoma sordida (Stål), were found in houses and in peridomestic structures. The collection of nymphal instars of both species from some houses indicated possible domesticity. Microscopic examination of feces from 92 insects showed no parasites, and cultures from the guts of 30 insects were negative. Nevertheless, a polymerase chain reaction (PCR) test performed on the same fecal samples showed the presence of T. cruzi DNA in 19.1 and 12.5% of E. mucronatus and T. sordida, respectively. These 16 PCR-positive samples were hybridized with 2 T. cruzi-specific probes known from the domestic cycle in Bolivia (clones 20 and 39). At least 1 of these clones was identified in 7 bugs (5 E. mucronatus and 2 T. sordida). Moreover, no hybridization was observed with these probes in S E. mucronatus and 1 T. sordida samples that showed an amplified band by PCR. These data indicated that T. cruzi clones, genetically unrelated to clones 20 and 39, also were circulating in this area. Based on these results, the 2 sylvatic triatomine species encountered in Apolo should not be overlooked as possible local vectors of T. cruzi.