The investigation of congenital infection by Trypanosoma cruzi in an endemic area of Chile: three protocols explored in a pilot project.

Given the increasing travel of pregnant women from areas were Trypanosoma cruzi is endemic, the congenital transmission of the parasite has become a global public-health problem. In a recent pilot study, which ran in Chile from 2006 to 2010, three strategies for exploring and managing T. cruzi-infected mothers and their infected or uninfected neonates were investigated. Any protocols applied to the investigation of such mother-and-child pairs need to include the detection of infection in pregnant women, the detection of infection, if any, in the children born to the women, the appropriate treatment of the infected neonates, and the serological-parasitological follow-up of all of the neonates until their medical discharge.

Monitoring the efficacy of specific treatment in chronic Chagas disease by polymerase chain reaction and flow cytometry analysis.

PCR and FC-ALTA were used to monitor parasite clearance in 54 chronic chagasic patients who had completed therapy with allopurinol (ALLO, n = 31) or itraconazole (ITRA, n = 23) ten years earlier. All patients maintained positive conventional serology. 25 of them showed positive XD (ALLO, n = 11 and ITRA, n = 14) and 29 negative XD (ALLO, n = 20 and ITRA, n = 9). 43 patients were positive by both techniques (ALLO, n = 23 and ITRA, n = 20). Seven of 54 patients were negative by PCR and positive by FC-ALTA and three of 54 were positive by PCR and negative by FC-ALTA. Only one case with both tests negative should be considered cured. Of 29 patients with negative XD, 14 treated ALLO (70 %) and nine with ITRA (77.8 %) showed positive PCR and FC-ALTA. These results do not show differences of efficacy among the drugs, and reinforce the relevance of using sensitive tools such as PCR and FC-ALTA for the follow-up of patients with chronic Chagas disease.

Cystic echinococcosis of the tongue leading to diagnosis of multiple localizations.

The tongue is a rare site of localization of cystic echinococcosis. We report a 3-year-old patient with cystic echinococcosis of the tongue demonstrated by histopathology. The cyst of the tongue was surgically removed. The tongue lesion led us to find additional liver and lung cystic lesions that were successfully treated with albendazole therapy.

Lytic antibodies in Trypanosoma cruzi-infected persons with low parasitemia.

An antibody-dependent, complement-mediated lysis test performed with three Chilean trypomastigote strains used as target cells revealed strain dependence in the detection of lytic antibodies in chronic chagasic sera. The highest percentage of lytic sera was observed when MF or V115 strains were used as target cells (90% and 71%, respectively) in the chronic chagasic group with negative xenodiagnosis results. No significant statistical association was observed between lytic activity in chronic chagasic sera and the presence or absence of cardiopathy (P > 0.01). Western blot analysis showed that lytic sera recognize different antigens depending on the strain used and nonlytic sera had a weaker capacity to detect them.

Efficient diagnosis of giardiasis among nursery and primary school children in Santiago, Chile by capture ELISA for the detection of fecal Giardia antigens.

Fecal samples were obtained from 722 of 820 children attending 7 nursery schools and 1 primary school in the city of Santiago, Chile. Microscopy of formol-ether concentrates showed that 33% of the children were infected with Giardia lamblia. Prevalences among primary school students (5-10 years of age) of G. lamblia (38%), Endolimax nana (43%), and Entamoeba coli (25%) were overall higher than among nursery school students (3 months-5 years of age; prevalences 29%, 21%, and 16%, respectively). There was no apparent association between socio-economic intake and levels of G. lamblia infection: the private nursery school had the highest recorded level of infection (40%). One hundred sixty-two triplicate stool specimens were used to compare microscopy with an enzyme-linked immunosorbent assay (ELISA) for the detection of Giardia fecal antigens. The ELISA was highly sensitive and specific either visually (95% and 97%, respectively) or by optical density determination (99% and 96%, respectively). Incorporation of non-immune rabbit immunoglobulin-coated control wells did not enhance sensitivity and specificity. The antigen detection ELISA is an extremely effective tool for the epidemiological investigation of giardiasis.

Treatment of human chronic fascioliasis with triclabendazole: drug efficacy and serologic response.

Between November 1990 and March 1992, 24 asymptomatic individuals in Chile with chronic hepatic fascioliasis confirmed by the presence of Fasciola hepatica eggs in feces were treated with a single oral dose of triclabendazole (10 mg/kg of body weight) after an overnight fast. Nineteen (79.2%) of 24 patients were egg-negative two months after treatment. Three of five cases with F. hepatica in feces after the first treatment were retreated and parasitologic cure was achieved. Tolerance to the drug was excellent; none of the patients had either secondary symptoms or important alterations in levels of aspartate and amino transferases, alkaline phosphatase, or bilirubin during or after treatment. Mild eosinophilia, present in 70% of the cases, persisted at least until 60 days after treatment. An enzyme-linked immunosorbent assay (ELISA) was highly effective in diagnosis and post-treatment monitoring. Before treatment, 20 (83.3%) of 24 confirmed cases had positive test results. The test results became negative by the second month of treatment in 40% of the cured cases. This percentage increased progressively, reaching 91.3% at 12 months after therapy. In the five cases in which treatment failed, the ELISA results remained positive until the end of the follow-up period (six months). In three of these cases who accepted a second round of therapy with triclabendazole six months after the first treatment, the ELISA results became negative in all three six months after parasitologic cure and remained negative until the end of the period. Due to its efficacy, excellent tolerance, and ease of administration (a single oral dose), triclabendazole appears to be the drug of choice for chronic human fascioliasis.

Treatment of chronic Chagas' disease with itraconazole and allopurinol.

Four hundred four patients with chronic Chagas' disease were treated with itraconazole (6 mg/kg of body weight/day for 120 days), allopurinol (8.5 mg/kg of body weight/day for 60 days), or with a placebo of pure starch. Patients were monitored over a period of four years by clinical examination, serology, xenodiagnosis, hemoculture, and electrocardiogram. Drug tolerance was good, with only four treatments discontinued due to side effects that subsided after suspension of treatment. Parasitologic cure was evident in 44% of the those treated with allopurinol and 53% of those treated with itraconazole, and the electrocardiographic evaluation showed normalization in 36.5% and 48.2%, respectively, of patients with chronic or recent cardiopathy.

Isolation and partial characterization of three DNA polymerases from Trypanosoma cruzi.

Three distinct DNA polymerase fractions (A, B and C), were isolated from Trypanosoma cruzi epimastigote forms. Fraction A is a low molecular mass enzyme corresponding to beta-like DNA polymerase of T. cruzi. Fraction B co-purified along several purification steps with fraction A, but in the last step it was clearly separated by a phosphocellulose chromatography. Fraction C was separated from fractions A and B by binding to DEAE-cellulose column, since the other two fractions were eluted in the flowthrough. This enzyme has an apparent native molecular mass of 100 kDa and showed a high preference for poly(dC)-oligo(dG) among different template-primers tested as substrate. Western-blot and biochemical analysis strongly suggest that the three DNA polymerase fractions correspond to different molecular entities. These results are in agreement with the idea that fraction C is a new DNA polymerase of T. cruzi, not described before.

Effect of itraconazole on lytic antibodies levels in chronic Chagas disease.

We report the chemotherapeutic effect of itraconazole in chronic chagasic patients. The efficacy of treatment was analyzed by xenodiagnosis (XD), conventional serology (CS) and antibody dependent-complement mediated lysis test (CoML). Twenty chronic chagasic persons from endemic areas of Chile were grouped according to the results of xenodiagnosis (XD) performed before therapy. The follow-up of patients was performed at an average time of 42 months after treatment. No significative statistical differences were observed in the result of ELISA and Indirect Immunofluorescence test performed on serq before and after therapy with itraconazole. In the group of patients with positive XD before therapy, sera from six of them displayed lytic activity against Trypanosoma cruzi. The lytic activity of only one of these sera became negative after therapy. In relation to XD, five of those patients showed a positive tests at least once during the follow-up period. In the group of ten patients with negative XD before therapy, sera from eight of them displayed lytic activity. At the end of the follow-up period seven of them became negative. Nine of the ten patients maintained their original condition with respect to XD. These results suggests that parasitaemia level before therapy condition could be an important parameter to consider in the chemotherapy of chronic Chagas disease.

The PCR-based detection of Trypanosoma cruzi in the faeces of Triatoma infestans fed on patients with chronic American trypanosomiasis gives higher sensitivity and a quicker result than routine xenodiagnosis.

In the xenodiagnosis (XD) of American trypanosomiasis (Chagas disease), Trypanosoma cruzi in the triatomine bugs fed on the patient can now be detected using PCR (XD-PCR) as well as by microscopy (XD-M). In a study to compare XD-PCR with XD-M, triatomine bugs were fed on 50 cases of chronic American trypanosomiasis, of whom only 25 were ever found positive by XD-M. Overall, the bugs fed on 34 of the patients (all 25 cases found positive by XD-M and nine of the other patients) were found PCR-positive, giving a 330-bp fragment corresponding to part of the hyper variable region of the kinetoplast DNA of T. cruzi. Of the 25 patients who were ever found positive by XD-M, 20 gave bugs that were smear-positive on day 90 and a similar number (24; P=0.125) gave bugs that were PCR-positive at this time. On day 30, however, the bugs fed on only 11 of these 25 patients were found positive by microscopy, whereas 23 of these patients were found positive by XD-PCR (P=0.0016). Thus, not only was XD-PCR more sensitive than XD-M but it was also quicker, revealing more cases within 30 days than detected using XD-M over a period of 90 days.

Itraconazole or allopurinol in the treatment of chronic American trypanosomiasis: the results of clinical and parasitological examinations 11 years post-treatment.

Eleven years after they had been given itraconazole or allopurinol for the treatment of chronic American trypanosomiasis, 109 adult patients were checked for electrocardiographic abnormalities and evidence of Trypanosoma cruzi infection. The parasitological investigations included xenodiagnosis, in which the faeces of Triatoma infestans that had fed on the patients were checked under the microscope for flagellates. In addition, a PCR-based assay and a hybridization assay were used to test blood samples from the patients, and faeces from the Tri. infestans that had fed on the patients, for Try. cruzi DNA. For the data analysis, the patients were divided into four groups known as normal/normal, abnormal/normal, normal/abnormal and abnormal/abnormal, according to whether the patients had been found to have normal or abnormal electrocardiograms (ECG) shortly before the first treatment and to have normal or abnormal ECG when checked at the 11-year follow-up. The 51 normal/normal and 24 normal/abnormal patients were assumed to have been in the 'indeterminate' phase of the disease when they were treated, whereas the 16 abnormal/normal and 18 abnormal/abnormal patients all had evidence of chagasic cardiopathy at that time. When checked 11 years post-treatment, 40 (78.4%), 17 (70.8%), 14 (87.5%) and 17 (94.4%) of these patients, respectively, were each found positive for Try. cruzi in at least one of the parasitological tests. The hybridization assay, whether applied to human blood or bug faeces, appeared a significantly more sensitive test than the PCR-based assays or microscopically assessed xenodiagnosis (P<0.05). Only the 21 patients who appeared to be negative for Try. cruzi could be considered parasitologically cured (although all still appeared to have anti-Try. cruzi antibodies in their blood). Only 13 of these parasitologically cured patients (seven of those treated with itraconazole and six of those given allopurinol) had normal ECG at the 11-year follow-up. In Chile at least, itraconazole, which caused fewer adverse effects than the allopurinol while being no less effective at preventing cardiopathy, appears to be the drug of choice to treat chronic American trypanosomiasis in adults.

[Parasitic infections in renal transplantation patients]. / Infecciones parasitarias en trasplantados renales.

We performed indirect hemagglutination tests for toxoplasmosis and Chagas disease, complement fixation test for toxoplasmosis, stool examination for parasites and Graham test for enteroparasites in 51 patients before and after renal transplant. Post transplant surveys were performed at 3, 6, 9, 12 and 18 months. 18 patients who were positive for toxoplasmosis remained so and 5 new asymptomatic cases were detected in the post transplant period (15%). Two patients who were positive for Chagas disease remained positive and asymptomatic. One patient receiving a kidney from a Chagas positive donor remains negative. Asymptomatic enteric infection was detected in 45% of patients at some time during follow up: amebic infection (25%), giardiasis (14%) and oxyuriasis (24%). Two patients showed asymptomatic cryptosporidiasis.

Itraconazole or allopurinol in the treatment of chronic American trypanosomiasis: the regression and prevention of electrocardiographic abnormalities during 9 years of follow-up.

Several drugs are now known to have useful activity against Trypanosoma cruzi, the causative agent of human American trypanosomiasis (Chagas disease). However, the long-term effects of chemotherapy on the electrocardiographic (ECG) abnormalities associated with this disease have only been assessed for benznidiazole. In the present study, the ECG changes in 299 cases of chronic Chagas disease were followed for 9 years after treatment with itraconazole (N = 136) or allopurinol (N = 163). Among the 97 cases who were found to have ECG abnormalities immediately prior to their treatment, the two drugs appeared equally effective, such abnormalities being corrected in 23 (50%) of the 46 cardiopathy cases given itraconazole and 25 (49%) of the 51 given allopurinol (P > 0.05). Both of these 'cure rates' are much higher than the 8.1% frequency of abnormal-normal conversion observed among 198 'historical controls' (i.e. cases of chronic Chagas disease who had been left untreated; P < 0.05). Itraconazole appeared better than allopurinol at preventing the development of cardiopathy in the cases who appeared electrocardiographically normal at baseline. Among 202 such cases, only two (2.2%) of the 90 treated with itraconazole but 28 (25.0%) of the 112 given allopurinol were found to have developed ECG abnormalities during follow-up (P < 0.05). Therefore, although itraconazole and allopurinol are equally effective at reversing ECG alterations, itraconazole offers better protection against the development of new ECG abnormalities among those with chronic Chagas disease.

[Serologic evaluation of treatment of chronic Chagas disease with allopurinol and itraconazole]. / Evaluación serológica del tratamiento de la enfermedad de Chagas crónica con alopurinol e itraconazol.

BACKGROUND: Chagas disease is endemic in Chile. Allopurinol and itraconazole have activity against Trypanosoma cruzi and are recommended for the treatment of chronic disease in adults. AIM: To evaluate the chemotherapeutic effects of allopurinol and itraconazole using conventional and non conventional serologic tests. PATIENTS AND METHODS: Sera of 90 patients with chronic Chagas disease were studied before and after 9 to 11 months of treatment with allopurinol or itraconazole and after two months of treatment with placebo. Indirect immunofluorescence, ELISA and Western Blot analysis were the conventional serologic tests used and antibody dependent complement mediated lysis (CoML) the non conventional test. RESULTS: There were no differences in ELISA and indirect immunofluorescence tests before and after therapy. Antigenic recognition profiles by Western Blot showed qualitative and quantitative differences in a small number of cases. CoML showed that the greater negativity was achieved in the Chagasic group treated with allopurinol or itraconazole that had a negative xenodiagnosis before drug treatment (35.8 and 61.6%, respectively). CONCLUSIONS: There is a reversion of lytic activity in sera of patients with negative xenodiagnosis before treatment, suggesting the parasitemia could be an important parameter to be considered in the chemotherapy of Chagas disease.

[Evaluation of ELISA and counterimmunoelectrophoresis in diagnosis of human neurocysticercosis in Chile]. / Evaluación de ELISA y contrainmunoelectroforesis en el diagnóstico de la neurocisticercosis humana en Chile.

The aim of this work was to assess the diagnostic accuracy for neurocysticercosis, of ELISA and counterimmunoelectrophoresis techniques, in sera and cerebrospinal fluid. Two hundred eight serum samples (47 coming from patients with confirmed cysticercosis) and 87 cerebrospinal fluid samples (27 coming from patients with confirmed cysticercosis) were analyzed. A crude and standardized extract of swine muscle cysticercus cellulose was used as antigen. ELISA and counter immunoelectrophoresis had a 100% specificity in cerebrospinal fluid. In sera, counterimmunoelectrophoresis had a 94.1% specificity. In sera and cerebrospinal fluid, ELISA had a 85.1% sensitivity. Cross reactions were observed in sera of patients with confirmed hydatidosis. Thus, the high specificity of both techniques in cerebrospinal fluid is probably due to the low incidence of cerebral hydatidosis in Chile. It is concluded that for the diagnosis of neurocysticercosis, antibodies against cysticercus cellulosae must be sought paralelly in serum and cerebrospinal fluid using ELISA and counterimmunoelectrophoresis.

[Fascioliasis in populations of rural areas with high prevalence of animal infection]. / Fascioliasis en población rural de áreas con alta prevalencia de infección animal.

Between January 1986 and December 1990 the prevalence of F. hepatica infection was studied in 5861 rural inhabitants of the provinces of Curico, Talca and Linares, VII Region, an hyperendemic zone of animal fascioliasis. Every one was screened by intradermal (IDR), complement fixation (CF), double diffusion (DD) counterelectrophoresis (CIEF), immunoelectrophoresis (IEP) and enzyme-linked immunoabsorbent assay (ELISA) tests. 366/1881 (9.3%) had positive IDR; 61 (1.04%) positive CF; 14 (0.24%) positive DD and 105/3838 (2.73%) positive ELISA and thus considered under suspicion to be infected. F. hepatica eggs were searched in stool in 241 of these persons. 37 cases were thus confirmed. Another 4 individuals with positive immunobiological tests and absence of the parasite eggs in stools were confirmed by duodenal intubation. 21 of the confirmed cases (51.2%) had less than 15 years of age. Women were more frequently infected than men (73.2% vs 26.8%). The 41 cases represent 0.7% of the surveyed population predicting 2000 cases among the total rural population of these provinces (300,000 persons). These results indicate that human fascioliasis is an important problem in the zone, perhaps much higher if family contacts of the index cases and symptomatic persons are included.

[Tungiasis. A clinical case]. / Tungiasis. Caso clinico.

A 22 year old Chilean male presented with necrotic lesions of the 5 toes of the right foot and the heal of the left foot. He had spent 7 months traveling in the Amazona region of Brazil. Surgery was performed to clean the areas where eggs of Tunga penetrans were identified.

[Efficacy of Chagas' disease vector control demonstrated through human infection]. / Eficacia del control del vector de la enfermedad de Chagas demonstrada a través de la infección humana.

The aim of this study was to assess the efficacy of Chagas disease vector control in Chile, using human disease as an index. After a twelve years control program using insecticides, dwelling infection in the IV region fell from 49 to 4%. In Combarbalá (a community of the IV region) the infection rate, detected by indirect hemagglutination, immunofluorescence and ELISA tests, decreased from 21.8% in 1986 to 8.2% in 1992 in primary school students (p < 0.001) and from 7.5 to 5% in high school students. Besides the vector control program, no other important epidemiological changes occurred in this period, excepting some ecological changes.