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.

[Experimental infection in mice by Plasmodium berghei: an evidence of antiparasitic action of azithromycin]. / Evidência da ação antiparasitária da azitromicina na infecção experimental de camundongos pelo Plasmodium berghei.

Infections of Plasmodium berghei in mice was stopped by azithromycin which was administered orally in dosages of 100mg/kg, for 28 days. This antibiotic was given since the same day that the animals were infected. The outcome suggests the necessity of more investigations on this antiparasitic activity.

Evidência da ação antiparasitária da azitromicina na infecção experimental de camundongos pelo Plasmodium berghei / Experimental infection in mice by Plasmodium berghei: an evidence of antiparasitic action of azithromycin

Infections of Plasmodium berghei in mice was stopped by azithromycin which was administered orally in dosages of 100mg/kg, for 28 days. This antibiotic was given since the same day that the animals were infected. The outcome suggests the necessity of more investigations on this antiparasitic activity.

A azitromicina debelou a infecção experimental de camundongos pelo Plasmodium berghei quando administrada, pela via oral e durante 28 dias, na dose de 100mg/kg, iniciada no mesmo dia em que os animais foram infectados. Mediante uso de 10mg/kg houve insucesso. Os resultados obtidos suscitam investigações complementares sobre a referida atividade antiparasitária desse medicamento.

Identification of Cryptosporidium spp. oocysts in fecal smears stained with Heidenhain's iron hematoxylin.

There is no paucity of methods for diagnosing Cryptosporidium spp. infection. The merits of immunoassays notwithstanding, microscopic identification of Cryptosporidium spp. oocysts in fecal samples remains an important diagnostic procedure. It owes the persistence of its use to such characteristics as dispensing with expensive equipment and kits, requiring only basic laboratory facilities, and having a low probability of false positive results when permanent slides are prepared, which can be re-examined in case of doubt. Cryptosporidium spp. oocysts can be readily identified in fecal smears prepared according to a regressive iron hematoxylin staining technique. The number of steps and their duration, as well as costs, were reduced to a minimum without loss of image quality and permanence of the preparations.