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.

A prospective clinical study of the mononucleosis syndrome in a developing country.

A prospective aetiologic analysis made of 70 children and adults with the clinical and haematologic features of infectious mononucleosis (IM) in Sao Paulo, Brazil, revealed 65.7% due to EBV (31 heterophile antibody positive (HA+), 15 HA negative (HA-) cases), 8.6% due to T. gondii and 4.3% due to CMV. One case was related to viral hepatitis and one to drug hypersensitivity. The other 18.6% were of unknown cause. In the 46 IM cases positive tests were found for EBV/IgM in 93.5%, for heterophile by the absorbed horse Rbc test in 64.2% and by sheep Rbc in 37%. The immune-adherence haemagglutination test was slightly more sensitive than the horse Rbc test in 39 IM sera tested. In 41 EBV/IgM positive sera, EBV/IgA was present in 17/25 containing heterophile antibody and in 2/16 lacking heterophile antibody; anti-EA was present in 85%. The average age of HA+ IM cases was 13.2 years and of HA- cases 4.7 years. Three HA+ and 5 HA- IM cases occurred in the 0-2 year old age group. Few clinical features differentiated between aetiological agents. Exudative tonsillitis was the most helpful one and occurred in 67.7% of HA+ IM cases, 26.7% of HA- cases, in 1 of 3 CMV cases, and not at all in 6 T. gondii infections.

Efficacy of various drugs for treatment of giardiasis. A comparative study.

A total of 172 patients with giardiasis were treated with four of the drugs most commonly used for this infection. All drugs were used in their usual posologic schedules. The cure rates achieved with furazolidone, nimorazole, metronidazole, and tinidazole were; respectively, 72%, 94%, 87%, and 97%, while in a control group given no medication stools of only 35% of the patients became negative. Side effects were of minor importance in patients treated with nimorazole and metronidazole, and were somewhat more frequent and severe in those treated with furazolidone. Tinidazole produced no side effects.

Ultrastructure of the lung in falciparum malaria.

We describe a case of fatal falciparum malaria, with severe pulmonary insufficiency in the absence of fluid overload or cardiac failure. At autopsy the most striking change was a marked pulmonary interstitial edema. The endothelial cell was the most altered structure, showing marked cytoplasmic swelling which narrowed the capillary lumen. Monocytes were also found occupying the capillary lumen. The edematous interstitium also showed macrophages with endocytes and malarial pigment. There was no disseminated intravascular coagulation or other terminal complications. The patient's respiratory insufficiency seems not to have derived from the complications usually associated with the fatal malaria but from malaria-induced alveolar septal changes.

Antibody response to the 43 kDa glycoprotein of Paracoccidioides brasiliensis as a marker for the evaluation of patients under treatment.

Sera of patients with paracoccidioidomycosis contained IgG-, IgA-, and IgM-specific antibodies to a 43 kDa antigen contained in the filtrate of a culture of Paracoccidioides brasiliensis. IgG- and IgA-specific antibodies were present in all observed patients. The IgM response was more frequent in acute cases, and the mean titers of IgG- and IgM-specific antibodies were higher in the acute forms. By the fourth month of chemotherapy, there was a decay of IgG, IgA, and IgM antibody titers to this antigen in acute cases, correlating with clinical improvement. The detection of IgG and IgA antibodies and the sequential determination of antibodies to the 43 kDa glycoprotein may be useful tools for serodiagnosis and evaluation of therapeutic efficacy.

Heart transplantation for chronic Chagas' heart disease.

BACKGROUND: Chagas' disease has been considered a contraindication to heart transplantation as Trypanosoma cruzi infection could recur after immunosuppression. METHODS: We report the follow-up of 22 patients who underwent orthotopic heart transplantation for treatment of end-stage chronic Chagas' heart disease, divided in two groups. Group 1 consisted of 9 patients operated on from September 1985 to June 1991, and group 2 patients underwent transplantation from July 1991 to June 1995. After our early experience with group 1, we attempted to use a lower cyclosporine dosage in group 2. RESULTS: Total actuarial survival at 24 months was 60%, and it was better for group 2 (33% for group 1, 80% for group 2, p = 0.008). Parasitemia occurred similarly in both groups, but Chagas' disease reactivation was seen in 5 group 1 patients and in 1 group 2 member (p < 0.002). Neoplasia developed in 5 group 1 patients and 1 group 2 patient, and contributed to death in 3 of them. CONCLUSIONS: These data demonstrate satisfactory outcome of cardiac transplantation in patients with end-stage Chagas' heart disease in the second phase of our experience. Further progress is necessary to improve the results and evaluate its proper role in the management of this disease.

Interstitial nephritis in human kala-azar.

Little is known about renal alterations in kala-azar. The renal histopathology of 21 patients admitted to hospital in São Paulo, Brazil, during the period 1960 through 1981 who either died or had a renal biopsy (two cases) is presented. All the specimens showed oedema and diffuse interstitial inflammatory infiltrate of lymphocytes and plasma cells with more compact foci of cells in some areas. In general, glomeruli did not show any important alterations. These aspects were interpreted as acute interstitial nephritis aetiologically related to later phase kala-azar. This interstitial alteration does not usually seem to determine any clinical manifestations. However, it seems that moderate and severe cortical intersitial damage contribute to the onset of renal insufficiency when severe clinical complications occur. The precise mechanisms of this lesion need further investigation since the aetiological agents have not been seen causing the damage locally.

[Hematologic changes in leptospirosis]. / Alterações hematológicas na leptospirose.

30 cases of leptospirosis admitted to the Clinica de Doenças Infecciosas e Parasitárias do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo were studied for blood count alterations. 16 patients (53.3%) had a normal white blood cell count at the moment of admission. 12 patients (40%) presented a high white blood cell count and 2 (6.6%) had a low count. 29 patients (96.6%) had a high proportion of neutrophils and 25 patients (83.3%) presented a high number of immature forms. 24 patients had anemia. Thrombocytopenia was present in 26 patients (86.6%). The most characteristic changes found in bone marrow aspirate were the alterations of M:E ratio (myeloid-erythroid ratio) due to relative and/or absolute hyperplasia of the myeloid series, and/or relative and/or absolute hypoplasia of the erythroid series; erythropoiesis was predominantly micro-erythroblastic in many patients; mild to moderate plasmocytosis was found; and, regarding the interstitial series, increased macrophagic activity was noted. There was no direct correlation between the number of megakaryocytes and the blood platelet count, but there was a direct correlation between the bone marrow platelet production and blood platelet count. We believe that it is very difficult to have a good idea of the dynamic mechanisms that lead to medullar platelet production in the presence of platelet consumption, through a random test of the bone marrow.

[The early diagnosis of leptospirosis by demonstrating antigens via an immunohistochemical exam of the hamstring muscle]. / Diagnóstico precoce da leptospirose por demonstração de antígenos através de exame imuno-histoquímico em músculo da panturrilha.

Establishing an early and certain diagnosis of leptospirosis has been a difficult task. So, we analysed the histopathological alterations of the gastrocnemius muscle, and studied, for the first time, the usefulness of the immune histochemical method of peroxidase-antiperoxidase for the demonstration of the spirochete and of its products in this tissue. Histopathological observations have shown a picture of myositis, characterized by interstitial inflammatory infiltrate and necrotic-degenerative abnormalities of muscle fibers. The lesions were considered minimal in 69.45% of the patients, moderate in 19.45%, severe in 5.55% and absent in the remaining. On the other hand, the immune histochemical method identified the etiology in 94.45% what was considered very expressive.

Thrombocytopenia and leptospirosis.

The present study has intended to contribute to the elucidation of the pathogenic mechanisms, involved in the thrombocytopenia and in the bleeding diathesis seen in the course of Leptospirosis. The group of cases included in the present prospective study consisted of 30 patients with Leptospirosis, admitted to the Infectious and Parasitic Diseases Ward, Hospital das Clínicas, Faculty of Medicine, University of São Paulo. The following possible mechanisms of thrombocytopenia have been considered and therefore investigated: platelet consumption, due to disseminated intravascular coagulation; immune-mediated platelet destruction, due to platelet-associated antibodies and an inhibited platelet production in the bone marrow. Thrombocytopenia occurred in 86.6% of 30 patients and did not seem to be immune-mediated by platelet-associated antibodies. Furthermore it did not seem to be due to a disseminated intravascular coagulation consumption. Although there was a statistically-significant correlation between bone marrow platelet production and platelet counts we think that the static microscopic examination of a bone marrow aspirate cannot accurately depict the dynamic mechanisms of platelet production when these cells are being consumed in peripheral blood. Vasculitis should be considered as the most important factor for the pathogenesis of the bleeding disturbances in Leptospirosis. However, we believe that thrombocytopenia, uremia and coagulation disorders, individually or as a group, should be included among the contributing factors that lead to and worsen bleeding episodes, which represent the leading cause of death in this disease.

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.

[Human pulmonary dirofilariasis acquired in Brazil: report of a case]. / Dirofilariose pulmonar humana, adquirida no Brasil: comunicação de um caso.

We report the second published case of human dirofilariasis acquired in Brazil. The patient had two pulmonary coin lesions seen in conventional chest roentgenogram and confirmed as solid round nodules by computerized X-ray chest scan. Diagnosis was done by surgical removal of one of the lesions and anatomopathological study of tissue removed.

Etiological drug treatment of human infection by Trypanosoma cruzi.

Forty-nine American Trypanosomiasis (Chagas' disease) patients, with xenodiagnosis proven parasitemia were treated by the authors. Forty-one of these patients were given benznidazole, at dosages ranging from 5mg/kg/day to 8mg/kg/day, during a pre-established period of 60 days. In this group, 17 patients had an undetermined form of the disease, whereas 22 had cardiologic disease and 4 had digestive disease (two patients had a mixed form of the disease). Side effects were frequent, and led to the discontinuation of treatment in 17 patients. The follow-up period ranged from 1 to 20 years (mean follow-up period of 6 yrs. 7 mo). 26 (63.4%) of the patients became parasitemia-negative. The other eight patients were treated with nifurtimox, during 120 days, following a variable dose regime of 5mg/kg/day (initial dose) to 17 mg/kg/day (final dose). Six of them had severe side effects, and only one patient remained parasitemia-negative throughout the observation period (ranging from 1 to 18 years). Benznidazole proved to be better tolerated and more effective in the management of parasitemia when compared to nifurtimox, although more effective and less toxic drugs are still desirable.

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).

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.

[Frequency of malaria relapse due to Plasmodium vivax in a non-endemic region (São Paulo, Brazil)]. / Análise da freqüência de recaídas de malária por Plasmodium vivax em região não endêmica (São Paulo, Brasil).

Very few well-established information is available about the frequency and timeliness of relapses in cases of Plasmodium vivax malaria acquired in Brazil. So, we analysed a series of correctly treated patients observed out of endemic areas. The rate of relapses seen in São Paulo, which may represent that of the parasitosis in the whole country, was high, ranging from 7.5% to 24.5%, and early in most cases, i.e. appearing by three months, what anticipates a high endemicity.

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

We propose a screening process for detection of therapeutic activity of drugs against experimental infection with Trypanosoma cruzi. It is based on the use of infected triatominae that are fed on mice which have received the study drug. Blood meals are made at different time schedule in order to adapt with serum drug levels. The digestive tube of the hemiptera will, thus, work as a suitable structure for examination. In a initial observation, benzonidazole was used, and was shown to be only partially active at least in the conditions of this new procedure.

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.

Pasteurization of human milk to prevent transmission of Chagas disease.

Although admittedly transmission of Trypanosoma cruzi infection through breastfeeding is a rare event, it involves serious risks. To test the effectiveness of pasteurization in preventing this mode of infection, three sets of samples of human milk were tested: a - contaminated with T. cruzi and pasteurized; b - contaminated with T. cruzi and non-pasteurized; c - non-contaminated and pasteurized. Samples from all sets were orally and intraperitoneally administered to 90 BALB/c mice. The animals inoculated with contaminated, non-pasteurized samples, got the infection. Controls and the animals inoculated with contaminated and pasteurized milk were not infected. The hypothesis was accepted that pasteurization inactivates T. cruzi trypomastigotes.

[Attempts to culturing triatominae in the laboratory using "in vitro" feeding]. / Tentativas de criação de triatomíneos em laboratório por meio de alimentação "in vitro".

In order to simplify breeding of triatominae in the laboratory, for performing xenodiagnosis and other biologic studies, we tried to feed the insects "in vitro" with citrated or defibrinated blood from commercially abated chicken. Two types of efficacy observations were carried out with Triatoma infestans: a) analysis of the chaining of successive nymphal stages, viability of satisfactory matching, fertile oviposition and adequate reproduction; b) assessment of viability and infectivity of Trypanosoma cruzi in the insects. As a conclusion, it became evident that, despite operational easiness, the objectives were not achieved, since the classical procedure used as the control, was always superior.