Abdominal ultrasound in the evaluation of fibrosis and portal hypertension in an area of schistosomiasis low endemicity.

This study was undertaken in the municipality of Bananal, São Paulo, an endemic area for schistosomiasis with a prevalence under 10% and low parasite load among infected individuals. Our objective was to identify the clinical forms of schistosomiasis among 109 patients in whom the disease had been diagnosed through direct fecal analysis and who had been medicated with oxamniquine at the time of the Plan for the Intensification of Schistosomiasis Control Actions (1998-2000). These patients were submitted to an abdominal ultrasonography and fecal analysis by Kato-Katz method, four years, on average, after the end of the Plan. Five patients, whose abdominal ultrasound images were compatible with either peripheral or central periportal fibrosis and portal hypertension, were identified. None of the 109 patients presented Schistosoma mansoni eggs at fecal analysis. Ultrasonography is a sensitive, noninvasive diagnostic method that allows a better identification of the extent of liver involvement in schistosomiasis cases.

[Observations on Blastocystis hominis and Cyclospora cayetanensis in routine parasitological examinations]. / Observações sobre Blastocystis hominis e Cyclospora cayetanensis em exames parasitológicos efetuados rotineiramente.

We report some observations made from routine parasitological examinations on feces. The methods of Faust et al. and of spontaneous sedimentation in water are not enough to identify Blastocystis hominis. Significant percentage presence of this protozoan was found, especially when staining with iron hematoxylin was performed. Cyclospora cayetanensis was found in 0.7% of the cases, which suggests that this parasite should also routinely be investigated by appropriate techniques.

[An evaluation of the efficacy of the CSF method for diagnosing intestinal helminthiases]. / Uma avaliação sobre a eficácia do método CSF no diagnóstico de helmintíases intestinais.

The recently proposed CSF method for diagnosing intestinal helminthiases was compared with the other methods (direct; Faust et al.; spontaneous sedimentation in water; and Kato-Katz) that are routinely for this purpose. The CSF method performed satisfactorily, thus showing that this technique can be adopted for use in diagnoses or epidemiological analyses.

[Behavior of the chemiluminescent ELISA method in relation to results considered discordant via three conventional techniques for diagnosing Chagas disease]. / Comportamento do método quimioluminescente-ELISA em relação a resultados considerados discordantes por meio de três técnicas convencionais para diagnóstico da doença de Chagas.

When indirect hemagglutination, indirect immunofluorescence and enzyme-linked immunosorbent assay are used together for serologically diagnosing Chagas disease, results that are considered discordant sometimes occur because there is disagreement between what these tests indicate. The availability of the chemiluminescent ELISA method enabled tests on 200 serum samples that had previously produced discordant results from the three above-mentioned methods. CL-ELISA revealed that 193 of these samples were negative and seven were positive. The use of this new procedure provides further support for understanding this subject, but more concrete advances will depend on documentation with blood analyses from people previously demonstrated to be unquestionably infected or uninfected with Trypanosoma cruzi.

Survival of Trypanosoma cruzi in sugar cane used to prepare juice.

Chagas disease can be transmitted to man by many different means, including contact with infected triatomine feces, blood transfusion, laboratory accidents, organ transplants, and congenital or oral routes. The latter mode has received considerable attention recently. In this assay, we evaluate the survival of Trypanosoma cruzi contaminating sugar cane used to prepare juice, as well as the viability and capacity for infection by the parasite after recovery. Thirty triatomines were contaminated with T. cruzi Y strain and 45 days later pieces of sugar cane were contaminated with the intestinal contents of the insects. The pieces were ground at different intervals after contamination (time=0, 1, 4, 6, 12 and 24 hours) and the juice extracted and analyzed. Different methods were used to show T. cruzi in the juice: direct analysis, hematocrit tube centrifugation and QBC, and experimental inoculation in 47 female BALB/c mice (five control mice and seven mice for each interval examined (five inoculated orally and two intraperitoneally). Positive results were found using the direct analysis and QBC methods for juice prepared up to 12 hours after initial contamination. However, by the centrifugation technique, positivity was found only up to four hours after contamination of the sugar cane. Inoculated animals showed parasitemia during a 14 day observation period, demonstrating the high survival rate of T. cruzi in sugar cane.

[Observations on the use of TESA blot for the serological diagnosis of Chagas' disease]. / Observações sobre o TESA blot no diagnóstico sorológico da doença de Chagas.

TESA blot was compared with indirect hemagglutination, indirect immunofluorescence and ELISA tests. In sera from 30 participants infected with Trypanosoma cruzi, and in 30 non infected the four techniques produced entirely equivalent results, all positive and all negative, respectively. In cases admitted to be inconclusive or in visceral leishmaniasis, frequent false positives were detected. However, TESA blot contributed with the least proportion of them.

Short report: persistence of tumor necrosis factor-alpha in situ after lesion healing in mucosal leishmaniasis.

Mucosal leishmaniasis (ML) is a disease characterized by intense activation of inflammatory cells and extensive tissue destruction. Among the cytokines involved in the immune response to ML, tumor necrosis factor-alpha (TNF-alpha) has attracted strong interest because of its roles in the modulation of the immune response. We studied 20 patients with ML who provided biopsy specimens before treatment and after lesion healing obtained by specific therapy. The biopsy specimens were subjected to immunohistochemical analysis for in situ quantification of cellular and extracellular TNF-alpha. The amount of TNF-alpha was significantly lower in the healed lesions compared with pretreatment biopsy specimens, although TNF-alpha persisted at the tissue level even after lesion healing. This relevant finding demonstrates for the first time an in situ tissue reduction of TNF-alpha after treatment and shows persistence of TNF-alpha in healed lesions may be related to the maintenance of an immunopathologic background for relapses observed in ML.

Microwave treatment of human milk to prevent transmission of Chagas disease.

It is recognized that breast feeding is an alternative means of transmission of Chagas disease. However, thermal treatment of milk can prevent this occurrence. As domestic microwave ovens are becoming commonplace, the efficacy of microwave thermal treatment in inactivating Trypanosoma cruzi trypomastigotes in human milk was tested. Human milk samples infected with T. cruzi trypomastigotes (Y strain) from laboratory-infected mice, were heated to 63 degrees C in a domestic microwave oven (2,450 MHz, 700 W). Microscopical and serological examinations demonstrated that none of the animals inoculated orally or intraperitoneally with infected milk which had been treated, got the infection, while those inoculated with untreated, infected milk, became infected. It was concluded that the simple treatment prescribed, which can easily be done at home, was effective in inactivating T. cruzi trypomastigotes contained in human milk.

[Evaluation of the sensitivity of the indirect immunofluorescence test at the 1:20 dilution in the diagnosis of Chagas disease]. / Avaliação da sensibilidade da diluição 1 / 20 pela reação de imunofluorescência indireta, no diagnóstico sorológico da doença de Chagas.

Sera from people in the chronic stage of Chagas disease, whose infection had been parasitologically validated, were assayed by using the indirect immunofluorescence test to evaluated its performance at the 1:20 dilution. All tests were consistently positive at 1:20 and higher dilutions, even in the presence of concomitant infection with the human immunodeficiency virus (HIV). It is thus valid, into the light of this experiment, to take into account the remarkable sensitivity of such serological test at the above mentioned dilution.

[Preservation of Cryptosporidium oocystis in fecal specimens for parasitological examination]. / Conservação de oocistos de Cryptosporidium em fezes para exame parasitológico.

By using a simple and easily available device which contains a 10% buffered formaldehyde solution, fecal samples are rendered odorless and can be stored at room temperature with no biosafety hazards. Cryptosporidium oocysts contained in such fecal samples can be identified without difficulty by using the Kinyoun method. This system permits an adequate preservation of the material, which facilitates the execution of tasks related to assistance and epidemiology.

[Blastocystosis: a high proportion of cases found in schoolchildren of São Paulo, State of São Paulo, Brazil]. / Elevada porcentagem de blastocistose em escolares de São Paulo, SP.

As a part of medical assistance activities, parasitological examination of fecal samples from 227 school children from a public institution of São Paulo (SP) revealed a rather high proportion of results positive for Blastocystis hominis. Other protozoan and worm species were markedly scarcer, a peculiar situation according to our judgement. It is acknowledged that blastocystosis is still largely an indefinite and controversial subject, which deserves adequate analysis to avoid drawbacks in the sphere of action of public health and general medical assistance.

[Blastocystosis: controversy and indefinedness]. / Blastocistose: controvérsias e indefinições.

Blastocystosis is the infection caused by Blastocystis hominis. It is associated with frequent and unquestionably very important controversy and lack of definition, above all due to its implications for general assistance and medical care. In that connection, there is considerable disagreement on the subject of the pathogenicity of this protozoan, which should be categorically defined. Other aspects besides the above, require clarification through results from well conducted studies aiming at attributing Blastocystis hominis a proper role within the context of public health. Another matter worthy of attention is the diagnostic value of the parasitological stool examination, with the proviso that it is adequate, as are fecal smears suspended in saline solution or permanent mounts stained with iron hematoxylin or thionine. The use of inadequate techniques tends to produce false negative results, thereby impeding investigation into the real importance of this microorganism.

[Evaluation of the efficacy of azithromycin and pyrimethamine, for treatment of experimental infection of mice with Toxoplasma gondii cystogenic strain]. / Avaliação da eficácia da azitromicina e pirimetamina em camundongos infectados por cepa cistogênica de Toxoplasma gondii.

The efficacy of prolonged administration of azithromycin and pyrimethamine was evaluated in mice experimentally infected with cystogenic strain of Toxoplasma gondii. The animals were intraperitoneally inoculated with one cyst of T. gondii and after 20 days were allocated into four groups: GI, infected without treatment; GII, infected and treated with the association of pyrimethamine (12.5 mg/kg/day) and azithromycin (100 mg/kg/day); GIII, infected and treated with the same dose of pyrimethamine; and GIV, infected and treated in the same way with azithromycin. The oral treatment lasted 120 days, after this period all the animals were sacrificed and the count of cysts in the brain was done. The association of both drugs provided the best results, by diminishing the cyst count in the brain of the animals treated in this way.

[A retrospective search for maternal transmission of Chagas infection from patients in the chronic phase]. / Busca retrospectiva da transmissão maternal da infecção chagásica em pacientes na fase crônica.

Maternal transmission of Trypanosoma cruzi from 278 children of 145 mothers, chronically infected with this protozoan, to their offspring was investigated. This study was based upon serological tests. In only two cases (2/278 = 0.70%), such mode of transmission was demonstrated to have occurred. However, as according to extant records both patients had also been breast-fed, and the contribution of this factor could not be ruled out. In any case, maternal transmission, an alternative mode of acquiring the infection with Trypanosoma cruzi, was demonstrated. The methodology used is a further contribution to the evaluation of the prevalence of this propagating mechanism of T. cruzi; in addition to those aimed at the main objective of the investigation, records were kept about pregnancy, parturition, puerperium, abortion, prematurity, perinatal deaths and breast-feeding, which might contribute to a better interpretation of the subject.

[Treatment of chronic Chagas' disease with an association of nifurtimox and corticoid]. / Tratamento da fase crônica da doença de Chagas com nifurtimox associado a corticóide.

Ten patients with chronic Chagas' disease were treated with nifurtimox (8-9 mg/kg/day) associated with betamethasone (9 mg/day initially and then gradually reduced) during 60 days, with one exception. It was intended to combine the respective anti-parasitic and anti-inflammatory actions of these drugs. The expected stimulating effect of betamethasone on the infection could possibly enhance the anti-Trypanosoma cruzi action of nifurtimox. Long term persistence of negative xenodiagnosis, used to control the results, was observed in only one of the cases. Regaridng the other patients, post-treatment positivity of xenodiagnosis and serological testes attested the failure of this therapy. As this study has demonstrated, adequate and long term follow-up of treated cases is necessary to ensure correct conclusions.

[Antischistosomal activity of artemether in experimental Schistosomiasis mansoni]. / Atividade antiparasit ria do artemether na esquistossomose mans nica experimental.

OBJECTIVE: To evaluate the effect of intramuscular injection of artemether in mice experimentally infected with Schistosoma mansoni, at the time of infection, during schistosomula maturation and after the beginning of egg-laying. METHODS: Eighty adult females Balb/c mice were divided into 8 groups with 10 animals each. Seven groups were infected with S. mansoni using 60 cercariae for each animal, inoculated subcutaneously, and the remaining group was maintained without infection. Among the seven infected groups, six were treated with artemether, according to the following schedule: three groups received doses of 100 mg/kg on days 0, 20 or 60 after inoculation of the cercariae; the other three received 50 mg/kg of artemether, also on days 0, 20 or 60. At the end of the 9th, 10th and 11th weeks after infection all the mice infected with S. mansoni were submitted to fecal examination using the Kato-Katz technique. On the 80th day of the experiment, the surviving animals were sacrificed and submitted to perfusion of the portal system in order to recover the worms. Body, liver and spleen weights of each animal were determined at that time. RESULTS: A reduction in egg-laying and the number of worms recovered was observed in mice treated with artemether (50 or 100 mg/kg) on the 20th day after infection. The decrease in the number of worms was more notable among S. mansoni females. A significant decrease in liver and spleen weights was also seen on the 20th day among animals treated with 50 or 100 mg/kg of artemether and also among those that received the drug at a dose of 50 mg/kg 60 days after infection. CONCLUSIONS: Evidence of the antischistosomal activity of artemether was shown, even at a dose of 50 mg/kg, when the drug was administered during the schistosomula maturation period in the portal system of the vertebrate host.