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.

Trypanosoma cruzi parasitemia observed in immunocompromised patients: the importance of the artificial xenodiagnosis.

Trypanosoma cruzi parasitemia observed in immunocompromised patients (transplant or positive HIV) occurred more frequently by the artificial xenodiagnosis method (10/38) compared with hemoculture (2/38), given the same quantity of blood. Other ways of diagnosis, like mice inoculation (5/38), QBC and buffy coat (2/38), were evaluated also. This result showed the importance of the artificial xenodiagnosis. The other techniques increased only one more patient positive.

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.

[Detection of Cyclospora sp oocysts in the feces of stray dogs in Greater São Paulo (São Paulo State, Brazil)]. / Pesquisa de oocistos de Cyclospora sp em fezes de cães da Grande São Paulo, Estado de São Paulo, Brasil.

Fecal samples from 140 adult stray dogs of Greater São Paulo (São Paulo State, Brazil) were examined for Cyclospora sp oocysts. No cases of infection by this coccidium were detected.

[Evaluation of antiparasitic activity of allopurinol, against Trypanosoma cruzi, in experimental system using infected triatomines]. / Avaliação da atividade antiparasitária do alopurinol, referente ao Trypanosoma cruzi, em sistema experimental que utiliza triatomíneos infectados.

The antiparasitic activity of allopurinol, against Trypanosoma cruzi, was evaluated by a procedure using infected triatomines. This methodology indicated that the drug was unable to eliminate the protozoa in the digestive tract of the insects. Therefore, further knowledge to improve our understanding of allopurinol in the context of the etiologic treatment of infection by T. cruzi was not acquired. Despite this finding the drug continues to be used, even though its performance appears to be full of divergences and contradictions.

A survey of congenital Chagas' disease, carried out at three health institutions in São Paulo City, Brazil.

The congenital transmission of Chagas' disease was evaluated in 57 pregnant women with Chagas' disease and their 58 offspring. The patients were selected from three Health Institutions in São Paulo City. The maternal clinical forms of Chagas' disease were: indeterminate (47.4%), cardiac (43.8%) and digestive (8.8%); 55 were born in endemic areas and two in São Paulo City. The transmission of Chagas' disease at fetal level was confirmed in three (5.17%) of the 58 cases studied and one probably case of congenital Chagas' disease. Two infected infants were born to chagasic women with HIV infection and were diagnosed by parasitological assays (microhematocrit, quantitative buffy coat-QBC or artificial xenodiagnosis). In both cases the placenta revealed T. cruzi and HIV p24 antigens detected by immunohistochemistry. In one case, a 14-week old abortus, the diagnosis of congenital T. cruzi infection was confirmed by immunohistochemistry. The other probable infection, a 30-week old stillborn, the parasites were found in the placenta and umbilical cord. The Western blot method using trypomastigote excreted/secreted antigens of T. cruzi (TESA) was positive for IgG antibodies in 54/55 newborns and for IgM in 1/55 newborns. One of the two newborns with circulating parasites had no detectable IgG or IgM antibodies. The assessment of IgG antibodies in the sera of pregnant women and their newborns was performed by ELISA using two different T. cruzi antigens: an alkaline extract of epimastigotes (EAE) and trypomastigote excreted/secreted antigens (TESA). The analysis showed a linear correlation between maternal and newborn IgG antibody titers at birth.

[The evaluation of the efficacy of azithromycin and pyrimethamine used alone or in combination in the treatment of an experimental infection in mice by Toxoplasma gondii]. / Avaliação da eficácia da azitromicina e da pirimetamina, usadas isolada ou associadamente, no tratamento de infecção experimental de camundongos pelo Toxoplasma gondii.

The efficacy of azithromycin and pyrimethamine in experimental infection of mice with Toxoplasma gondii was tested. Daily dosages of 200 mg/kg and 12.5 mg/kg, respectively, were given orally over a period of ten days. The medications were administered in combination or separately. The combined use of the drugs yielded better results, and a similar investigation using a cystogenic strain of the parasite will be conducted in a future study.

[Utility of gamma rays in prophylaxis of transmissible malaria by blood transfusion]. / Estudo sobre a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue.

This study was carried out to evaluate the fortuitons advantage of using gamma irradiation in the prophylaxis of transmissible malaria by blood transfusion, with mice as the experimental model. In the first step, when the infected blood with Plasmodium berghei was submitted to 2,500 rad and 5,000 rad, with or without metronidazol, there was no success, because the animals presented parasitaemia and died after inoculation of irradiated blood. However, there was partial success in the second step, when the infected blood received 10,000 and 15,000 rad, and was inoculated in mice, which showed infection, and presented a survival rate of 20% and 40%, respectively, with later negativation of blood infected by P. berghei.

Estudo sobre a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue / Utility of gamma rays in prophylaxis of transmissible malaria by blood transfusion

This study was carried out to evaluate the fortuitons advantage of using gamma irradiation in the prophylaxis of transmissible malaria by blood transfusion, with mice as the experimental model. In the first step, when the infected blood with Plasmodium berghei was submitted to 2,500 rad and 5,000 rad, with or without metronidazol, there was no success, because the animals presented parasitaemia and died after inoculation of irradiated blood. However, there was partial success in the second step, when the infected blood received 10,000 and 15,000 rad, and was inoculated in mice, which showed infection, and presented a survival rate of 20% and 40%, respectively, with later negativation of blood infected by P. berghei.

O estudo foi realizado com o objetivo de avaliar a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue, tendo sido, para isso, usados camundongos infectados pelo Plasmodium berghei. Na primeira fase, quando submetemos sangue deles retirado a 2.500 e 5.000rad, com associação ou não de metronidazol, não obtivemos sucesso, já que todos os animais antes sem a parasitose apresentaram parasitemia e morreram após inoculação do sangue irradiado. Porém, ocorreu êxito parcial na segunda fase, ao serem empregados 10.000 e 15.000rad, porquanto 20% e 40% dos roedores, respectivamente, embora tenham ficado infectados, sobreviveram, com posterior negativação quanto à presença do P. berghei.

Human cyclosporiasis diagnosis: report of a case in São Paulo, SP, Brazil.

Diagnosis of the human cyclosporiasis is reported in São Paulo, SP, Brasil. Cyclospora cayetanensis has been identified in the feces of a patient by a modified Kinyoun staining method, with later sporulation in a solution of 2.5% potassium dichromate. The probability that this parasite is the eventual cause of gastrointestinal disturbances in the country was stimulated by this finding, which was arrived at by a simple technique. It had been kept in mind that the disease was expressing itself mainly among immunocompromised patients, whose number is increasing; especially in those with acquired immunodeficiency syndrome (AIDS), which is caused by the human immunodeficiency virus (HIV).

[Determination of HIV protein 24 in feces of Triatoma infestans fed with blood from AIDS patients]. / Pesquisa da proteína 24 do vírus da imunodeficiência humana (HIV) nas fezes de triatomíneos alimentados em pacientes com AIDS.

OBJECTIVE: To verify any possibility of the elimination of p24 in feces of Triatoma infestans, p24 being an antigen and one of the markers of HIV infection. The purpose of the study was the evaluation of any risk of contamination by laboratory staff who work with activities related to this particular insect, and also investigate any mechanism that might thus lead to the dissemination of HIV. METHOD: Triatoma infestans were fed with p24-marked blood from 23 AIDS patients. Twenty-four and 48 hours later, their feces were examined in order to verify the presence of the antigen. The search for p24 was performed by means of the immunoenzymatic technique. RESULT AND CONCLUSION: No protein 24 was detected in any of the samples. In accordance with the applied methodology, the purpose of showing that the elimination of p24 does not occur, was obtained. Were this question approached in other ways different results might reveal new information in terms of risks of HIV dissemination.

Tratamento de ratos, experimentalmente infectados pelo Strongyloides venezuelensis, através da ivermectina administrada por via oral / The treatment of rats experimentally infected with Strongyloides venezuelensis by orally administered ivermectin

Em modelo experimental, baseado na infecção de ratos pelo Strongyloides venezuelensis, foi avaliada a atividade terapêutica de duas preparações de ivermectina, para usos veterinário e humano. Houve interesse em verificar a efetividade em relação a vermes adultos e formas larvárias. A administração dos fármacos ocorreu sempre por via oral e a posologia correspondeu à dose única de 0,2mg/kg. Considerados os vermes adultos e as formas larvárias, o produto para emprego veterinário propiciou eliminações expressas pelas porcentagens de 98,0% e 84,2%; quanto à outra preparação, as taxas situaram-se em 59,3% e 73,0%, respectivamente. O estudo revelou, então, utilidade do anti-helmíntico quando usada a via oral e, também, mostrou significativa ação sobre as formas larvárias, certamente valiosa quando vigente a modalidade disseminada da estrongiloidíase.

Strongyloides venezuelensis experimental infection in rats was treated by two different oral preparations of ivermectin, 0.2 mg/kg. One was a human formula used by WHO in the treatment of onchocerciasis; the other was a veterinary preparation. Adult worms and larvae were evaluated. The human formulation cleared both forms in 59.3% (adult worms) and 73.0% (larvae), whereas the veterinary one cleared 98.0% and 84.2%, respectively. The antilarval action is very useful when treating systemic strongyloidiasis.

[The treatment of rats experimentally infected with Strongyloides venezuelensis by orally administered ivermectin]. / Tratamento de ratos, experimentalmente infectados pelo Strongyloides venezuelensis, através da ivermectina administrada por via oral.

Strongyloides venezuelensis experimental infection in rats was treated by two different oral preparations of ivermectin, 0.2 mg/kg. One was a human formula used by WHO in the treatment of onchocerciasis; the other was a veterinary preparation. Adult worms and larvae were evaluated. The human formulation cleared both forms in 59.3% (adult worms) and 73.0% (larvae), whereas the veterinary one cleared 98.0% and 84.2%, respectively. The antilarval action is very useful when treating systemic strongyloidiasis.

[Oocysts of Cryptosporidium sp in feces: comparison of the modified Kinyoun and Heine methods]. / Pesquisa de oocistos de Cryptosporidium sp em fezes: comparação entre os métodos de Kinyoun modificado e de Heine.

The diagnosis of intestinal infection by Cryptosporidium sp is crucial today; with the progression of the AIDS epidemic, many cases of cryptosporidiosis have appeared in this setting and in other immunodeficiency diseases. We compared the advantages and disadvantages of Heine's method and modified Kinyoun's method in the following parameters: morphology of the parasite, quantitation of cysts, stability of the staining characteristics timewise on the slides and time spend at staining. All positive fecal smears were obtained from patients with AIDS. The sensitivity of these two techniques was the same. The choice should be made by the best aspects of each method. Heine's was better for quantitation of the cysts and was faster. Kinyoun's was better for conserving the stained smear.

Human cryptosporidiosis: detection of specific antibodies in the serum by an indirect immunofluorescence.

Cryptosporidium sp., a coccidian parasite usually found in the faeces of cattle, has been recently implicated as an agent of human intestinal disease, mainly in immunocompromised patients. In the study realized, by an indirect immunofluorescence technique, specific immunoglobulins (IgG and IgM) have been demonstrated in human serum against Cryptosporidium oocysts. Purified oocysts were used as antigens in the indirect immunofluorescence assay. After analyzing this test in sera from selected groups of patients, the frequency of both specific IgG and IgM of immunocompetent children who were excreting oocysts in their faeces was 62% and in children with negative excretion of oocytes was 20% and 40%, respectively. In adults infected with the human immunodeficiency virus (HIV) and who were excreting Cryptosporidium in their stools, the frequency was 57% for IgG but only 2% for IgM. Twenty three percent of immunocompromised adults with not determined excretion of oocysts in their stools had anti-Cryptosporidium IgG in their sera. Children infected with human immunodeficiency virus had no IgM and only 14% had IgG detectable in their sera. The indirect immunofluorescence assay, when used with other parasitological techniques appears to be useful for retrospective population studies and for diagnosis of acute infection. The humoral immune response of HIV positive patients to this protozoan agent needs clarification.

[The treatment of cryptosporidiosis in AIDS patients using paromomycin]. / Tratamento da criptosporidíase em pacientes com AIDS, por meio da paromomicina.

The authors treated with paromomycin 25 patients, with AIDS and cryptosporidiosis. The drug was given orally in a doses of 500 mg qid, for a period of 14 days. Tolerance was good, with just two cases of mild side-effects. Clinical improvement was obtained in 19 (76%) patients. Parasitological cure, however, occurred only in a low percentage (25%). In some cases where initial success was observed, recrudescence occurred after some weeks or few months, but with retreatment again clinical improvement was obtained. Even if it does not lead to frequent parasite eradication, the good clinical results and tolerance permit us to consider paromomycin one of the few drugs effective for the treatment of cryptosporidial diarrhea in AIDS patients. Studies with maintainance therapy are indicated.