Suitability of a rapid DNA isolation and amplification for detection of Trypanosoma cruzi in Triatoma infestans dry fecal spots collected on filter paper.

A rapid DNA extraction was used for T. cruzi detection in triatomines dry fecal spots collected on filter paper and analyzed by PCR. Fifty T. infestans were fed on experimentally infected Balb/C mice with high T. cruzi parasitemia and divided into five groups of ten triatomines, and 100 triatomines were infected with lower parasitemia and divided into five groups of 20 triatomines. One dry fecal spot was analyzed per group on days 1, 2, 3, 4 and 5 post feeding. Amplification targeted T. cruzi TCZ sequence and resulted positive from day 4 after bugs feeding in the two models (high and lower parasitemial. The rapid DNA isolation and PCR proposed are suitable for detection of T. cruzi DNA in filter paper and should be considered in field research.

Manifestations of Chagas disease (American trypanosomiasis) in patients with HIV/AIDS.

Between June 1989 and December 2005, an observational study of adults co-infected with HIV and Trypanosoma cruzi was conducted, to investigate the spectrum of manifestations of chronic Chagas disease (American trypanosomiasis) in the HIV-positive. The 31 men and 22 women investigated were aged 23-59 years. Each subject was investigated by ambulatory (Holter) and non-ambulatory electrocardiography, chest X-ray, oesophagography and echocardiography (to determine the clinical form of trypanosomiasis), by xenodiagnosis, blood culture and the microscopical examination of blood (to explore their T. cruzi parasitaemia), and by counting their CD4 T cells (to stage their HIV infection). The subjects were followed-up for 1-190 months (median = 58 months) and checked for re-activation of their Chagas disease, which was usually defined by the occurrence of unusual clinical manifestations and/or the detection, by microscopical examination, of trypanosomes in the blood or cerebrospinal fluid. Eleven (20.8%) of the subjects showed re-activation, another nine (17.0%) were found to have developed high T. cruzi parasitaemias but these were only detected by xenodiagnosis or culture, and 15 (28.3%) had illnesses typical of chronic Chagas disease in HIV-negative individuals, with low parasitaemias. Anti-T. cruzi therapy (benznidazole), recommended for 17 patients, resulted in the sustained reduction of parasitaemia in 11 of the 12 subjects who completed treatment. Chagas disease was the cause of death of eight of the 14 subjects who died during the study. Four of the women investigated gave birth, each to a single child, during follow-up, and three of the four babies showed evidence of the congenital transmission of T. cruzi.

Novo processo para triagem de medicamentos na infeccao experimental pelo Trypanosoma cruzi / New process for screening of drugs in experimental infection with Trypanosoma cruzi

E proposto processo para triagem da capacidade terapeutica de medicamentos na infeccao experimental pelo Trypanosoma cruzi. O metodo tem base no emprego de triatomineos parasitados que se alimentam, decorridos periodos diferentes para haver compatibilizacao com niveis sanguineos, em camundongos aos quais foi administrado o farmaco sob apreciacao; assim, o tubo digestivo do hemiptero participara como estrutura propicia a avaliacao. Em observacao inicial, ocorreu utilizacao do benzonidazol, que se mostrou apenas parcialmente ativo, pelo menos de acordo com a maneira de execucao do novo procedimento.

Tentativas de criacao de triatomineos em laboratorio por meio de alimentacao "in vitro" / Attempts for cultivation of triatominae in laboratory through \"in vitro\" feeding

Para simplificar a criacao de triatomineos em laboratorio, necessaria, por exemplo, a execucao do xenodiagnostico e em estudos de carater biologico, foi tentada alimentacao "in vitro", mediante emprego de sangue, citratado ou desfibrinado, de galinhas abatidas em matadouro avicola. Para avaliacao da eficacia desse proposito, observacoes de duas naturezas, com Triatoma infestans, tiveram lugar, atraves das seguintes medidas; a) analise do encadeamento de estadios nifais sucessivos e da exequibilidade de satisfatorios acasalamentos, oviposicao fertil e adequada reproducao; b) apreciacao da infectividade e da viabilidade do Trypanosoma cruzi nos insetos. Como conclusao, ficou evidente que, a despeito da facilitacao operacional, o intuito nao conduziu ao exito desejado, ja que o procedimento classico, usado como controle, mostrou-se sempre superior.