Effect of acetylsalicylic acid on total myenteric neurons in mice experimentally infected with Trypanosoma cruzi.

We investigated the effects of acetylsalicylic acid (ASA) on the total myenteric neuronal population in the descending colon in Trypanosoma cruzi-infected mice. Thirty-five male Swiss mice, 60 days old, were divided into a control group (C group), control group treated with ASA (CA group), infected group (I group), and infected group treated with ASA (IA group). A total of 1300 trypomastigotes of the Y strain of T. cruzi were intraperitoneally inoculated in the IA and I groups. The CA and IA groups were treated with ASA intraperitoneally. At 75 days post-infection (dpi), all of the animals were sacrificed. Neurons in the colon were stained with Giemsa, quantified, and measured. No difference in the course of infection was observed between the IA and I groups, reflected by the parasitemia curve. Acetylsalicylic acid treatment in the CA and IA groups did not alter the total number of myenteric neurons compared with the C and I groups. The CA and IA groups exhibited an increase in the nuclear area, cytoplasmic area, and neuronal body area compared with the C and I groups. Future studies should elucidate the mechanism of action of ASA against Chagas' disease in the chronic phase.

Impact of benznidazole on infection course in mice experimentally infected with Trypanosoma cruzi I, II, and IV.

American trypanosomiasis is an emerging zoonosis in the Brazilian Amazon. Studies on benznidazole (BZ) chemotherapy with Trypanosoma cruzi from this region have great relevance, given the different discrete typing units (DTUs) that infect humans in the Amazon and other regions of Brazil. We performed a parasitological, histopathological, and molecular analysis of mice inoculated with strains of T. cruzi I, II, and IV that were BZ-treated during the acute phase of infection. Groups of Swiss mice were inoculated; 13 received oral BZ, whereas the other 13 comprised the untreated controls. Unlike parasitemia, the infectivity and mortality did not vary among the DTUs. Trypanosoma cruzi DNA was detected in all tissues analyzed and the proportion of organs parasitized varied with the parasite DTU. The BZ treatment reduced the most parasitological parameters, tissue parasitism and the inflammatory processes at all infection stages and for all DTUs. However, the number of significant reductions varied according to the DTU and infection phase.

Moderate physical exercise reduces parasitaemia and protects colonic myenteric neurons in mice infected with Trypanosoma cruzi.

This study evaluated the influence of moderate physical exercise on the myenteric neurons in the colonic intestinal wall of mice that had been infected with Trypanosoma cruzi. Parasitology and immunological aspects of the mice were considered. Forty-day-old male Swiss mice were divided into four groups: Trained Infected (TI), Sedentary Infected (SI), Trained Control (TC), and Sedentary Control (SC). The TC and TI were subjected to a moderate physical exercise program on a treadmill for 8 weeks. Three days after finishing exercise, the TI and SI groups were inoculated with 1,300 blood trypomastigotes of the Y strain-T. cruzi. After 75 days of infection results were obtained. Kruskal-Wallis or Analyze of variance (Tukey post hoc test) at 5% level of significance was performed. Moderate physical exercise reduced both the parasite peak (day 8 of infection) and total parasitemia compared with the sedentary groups (P < 0.05). This activity also contributed to neuronal survival (P < 0.05). Exercise caused neuronal hypertrophy (P < 0.05) and an increase in the total thickness of the intestinal wall (P < 0.05). The TI group exhibited an increase in the number of intraepithelial lymphocytes (P > 0.05). In trained animals, the number of goblet cells was reduced compared with sedentary animals (P < 0.05). Physical exercise prevented the formation of inflammatory foci in the TI group (P < 0.05) and increased the synthesis of TNF-α (P < 0.05) and TGF-ß (P > 0.05). The present results demonstrated the benefits of moderate physical exercise, and reaffirmed the possibility of that it may contribute to improving clinical treatment in Chagas' disease patients.

Toxocariasis in children attending a Public Health Service Pneumology Unit in Paraná State, Brazil.

The enzyme-linked immunosorbent assay (ELISA) is the most widely used tool to detect anti-Toxocara IgG antibodies for both serodiagnostic and seroepidemiological surveys on human toxocariasis. In the last eight years a high prevalence of toxocariasis (32.2-56.0%) has been reported in children attending public health units from municipalities in the state of Paraná, Brazil. Therefore, the aim of this work was to compare the frequency found among the general child population with that of children attending a public pneumology service in Maringá, Paraná, Brazil and describe the laboratorial, clinical and epidemiological findings. The research was conducted at the Consórcio Público Intermunicipal de Saúde do Setentrião Paranaense (CISAMUSEP) from July 2009 to July 2010 among children aged between one and 15 years. From a total of 167 children studied, only 4.2% (7/167) tested positive for anti-Toxocara spp. IgG antibodies and presented mild eosinophilia (2/7), increased serum IgE levels (6/7) and a positive allergy test for mites (5/7). The presence of pets (dogs or cats) at home did not correlate with the seroprevalence. In conclusion, cases of toxocariasis involving the respiratory tract are rare in children attending a public health pneumology unit in the northwestern region of Paraná State, despite the high prevalence of this type of toxocariasis among the infantile population attending Basic Health Units in the same geographical area.

Toxocariasis in children attending a Public Health Service Pneumology Unit in Paraná State, Brazil / Toxocaríase em crianças atendidas em Unidade de Pneumologia do Serviço de Saúde Pública, Paraná, Brasil

The enzyme-linked immunosorbent assay (ELISA) is the most widely used tool to detect anti-Toxocara IgG antibodies for both serodiagnostic and seroepidemiological surveys on human toxocariasis. In the last eight years a high prevalence of toxocariasis (32.2-56.0%) has been reported in children attending public health units from municipalities in the state of Paraná, Brazil. Therefore, the aim of this work was to compare the frequency found among the general child population with that of children attending a public pneumology service in Maringá, Paraná, Brazil and describe the laboratorial, clinical and epidemiological findings. The research was conducted at the Consórcio Público Intermunicipal de Saúde do Setentrião Paranaense (CISAMUSEP) from July 2009 to July 2010 among children aged between one and 15 years. From a total of 167 children studied, only 4.2% (7/167) tested positive for anti-Toxocara spp. IgG antibodies and presented mild eosinophilia (2/7), increased serum IgE levels (6/7) and a positive allergy test for mites (5/7). The presence of pets (dogs or cats) at home did not correlate with the seroprevalence. In conclusion, cases of toxocariasis involving the respiratory tract are rare in children attending a public health pneumology unit in the northwestern region of Paraná State, despite the high prevalence of this type of toxocariasis among the infantile population attending Basic Health Units in the same geographical area.

O teste imunoenzimático (ELISA) constitui a ferramenta mais utilizada no diagnóstico individual da toxocaríase humana e/ou em inquéritos soroepidemiológicos para pesquisa de anticorpos IgG anti-Toxocara spp. Tendo em vista a elevada freqüência da toxocaríase (32,2% e 56,0%) observada em crianças atendidas em Unidades Básicas de Saúde de municípios do noroeste do Paraná, durante pesquisas realizadas ao longo dos últimos oito anos, o objetivo deste trabalho foi comparar estas frequências em crianças encaminhadas a uma unidade de Pneumologia do serviço de saúde pública da cidade de Maringá, noroeste do Estado do Paraná, Brasil e descrever os achados laboratoriais, clínicos e epidemiológicos das crianças soropositivas. A pesquisa foi realizada no Centro de Especialidades Regional - CISAMUSEP - entre julho de 2009 a julho de 2010, em crianças com idade entre um e 15 anos. De 167 crianças investigadas, sete (4,2%) apresentaram anticorpos IgG anti-Toxocara spp. Entre elas, duas (1,2%) crianças soropositivas apresentaram eosinofilia (baixos níveis), seis mostraram níveis elevados de IgE e cinco, teste alérgico positivo, principalmente para ácaros. Concluindo, no noroeste do estado do Paraná foram observados raros casos de crianças com toxocaríase envolvendo o trato respiratório e que foram atendidas por serviços públicos de Pneumologia ainda que na região estudada tenha sido observada elevada prevalência de toxocaríase em crianças assistidas pelas Unidades Básicas de Saúde (BHU).

Association between seropositivity for Toxoplasma gondii, scholastic development of children and risk factors for T. gondii infection.

BACKGROUND: We evaluated the possible association of seropositivity for Toxoplasma gondii and certain risk factors for T. gondii infection with the scholastic development of children. METHOD: One hundred children aged 6-13 years attending the Hospital Municipal de Maringá Paranáa, Brazil, participated in the study. Serologic tests for IgG and IgM anti-T. gondii (indirect immunofluorescence (capture ELISA) were performed. The Scholastic Performance Test (SPT) for writing, mathematics and reading was applied to each child, and the result was classified as high, average or poor. The guardian of each child responded to a questionnaire about certain aspects of the child's living situation and diet. RESULTS: The prevalence of seropositivity for T. gondii was 8%. An association between seropositivity for T. gondii and scholastic development in the mathematics subtest and also consumption of fresh cheese were observed. Children with exposed soil, sand or grass lawn in their peridomicile were 9.116 times more likely to be infected by T. gondii. CONCLUSION: The findings showed the need to test school-age children for this parasite, educate families with T. gondii-positive children, provide training to educators, monitor recreation areas, and raise awareness of the need for care in handling food.

In vivo susceptibility to benznidazole of Trypanosoma cruzi strains from the western Brazilian Amazon.

OBJECTIVE: To assess the susceptibility of Trypanosoma cruzi strains from Amazon to benznidazole. METHODS: We studied 23 strains of T. cruzi obtained from humans in the acute phase of Chagas disease, triatomines and marsupials in the state of Amazonas and from chronic patients and triatomines in the state of Paraná, Brazil. The strains were classified as TcI (6), TcII (4) and TcIV (13). For each strain, 20 Swiss mice were inoculated: 10 were treated orally with benznidazole 100 mg/kg/day (TBZ group) for 20 consecutive days and 10 comprised the untreated control group (NT). Fresh blood examination, haemoculture (HC), PCR, and ELISA were used to monitor the cure. RESULTS: The overall cure rate was 60.5% (109/180 mice) and varied widely among strains. The strains were classified as resistant, partially resistant or susceptible to benznidazole, irrespective of discrete typing units (DTUs), geographical origin or host. However, the TcI strains from Amazonas were significantly (P = 0.028) more sensitive to benznidazole than the TcI strains from Paraná. The number of parasitological, molecular and serological parameters that were significantly reduced by benznidazole treatment also varied among the DTUs; the TBZ group of mice inoculated with TcIV strains showed more reductions (8/9) than those with TcI and TcII strains. CONCLUSIONS: Benznidazole resistance was observed among natural populations of the parasite in the Amazon, even in those never exposed to the drug.

Neuronal changes caused by Trypanosoma cruzi: an experimental model.

Define an experimental model by evaluating quantitative and morphometric changes in myenteric neurons of the colon of mice infected with Trypanosoma cruzi. Twenty-eight Swiss male mice were distributed into groups: control (CG, n=9) and inoculated with 100 (IG(100), n=9) and 1000 (IG(1000), n=10) blood trypomastigotes, Y strain-T. cruzi II. Parasitemia was evaluated from 3-25 days post inoculation (dpi) with parasites peak of 7.7 × 10(6) and 8.4 × 10(6) trypomastigotes/mL at 8(th) dpi (p>0.05) in IG(100) and IG(1000), respectively. Chronic phase of the infection was obtained with two doses of 100mg/Kg/weight and one dose of 250mg/Kg/weight of Benznidazole on 11, 16 and 18 dpi. Three animals from each group were euthanized at 18, 30 and 75 dpi. The colon was stained with Giemsa. The quantitative and morphometric analysis of neurons revealed that the infection caused a decrease of neuronal density on 30(th) dpi (p<0.05) and 75 dpi (p<0.05) in IG(100) and IG(1000). Infection caused death and neuronal hypertrophy in the 75(th) dpi in IG(100) and IG(1000) (p<0.05, p<0.01). The changes observed in myenteric neurons were directly related to the inoculate and the time of infection.

Neuronal changes caused by Trypanosoma cruzi: an experimental model

Define an experimental model by evaluating quantitative and morphometric changes in myenteric neurons of the colon of mice infected with Trypanosoma cruzi. Twenty-eight Swiss male mice were distributed into groups: control (CG, n=9) and inoculated with 100 (IG100, n=9) and 1000 (IG1000, n=10) blood trypomastigotes, Y strain-T. cruzi II. Parasitemia was evaluated from 3-25 days post inoculation (dpi) with parasites peak of 7.7 × 10(6) and 8.4 × 10(6) trypomastigotes/mL at 8th dpi (p>0.05) in IG100 and IG1000, respectively. Chronic phase of the infection was obtained with two doses of 100mg/Kg/weight and one dose of 250mg/Kg/weight of Benznidazole on 11, 16 and 18 dpi. Three animals from each group were euthanized at 18, 30 and 75 dpi. The colon was stained with Giemsa. The quantitative and morphometric analysis of neurons revealed that the infection caused a decrease of neuronal density on 30th dpi (p<0.05) and 75 dpi (p<0.05) in IG100 and IG1000. Infection caused death and neuronal hypertrophy in the 75th dpi in IG100 and IG1000 (p<0.05, p<0.01). The changes observed in myenteric neurons were directly related to the inoculate and the time of infection.

Definir um modelo experimental de avaliação de alterações quantitativas e morfométricas nos neurônios mientéricos do cólon de camundongos infectados pelo Trypanosoma cruzi. Vinte e oito camundongos Swiss machos foram distribuídos nos grupos: controle (GC, n=9) e infectados com 100 (IG100, n=9) e 1000 (IG1000, n=10) tripomastigotas sanguíneos, cepa Y-T. cruzi II. A parasitemia foi avaliada 3-25 dias pós inoculação (dpi), com pico de parasitos de 7,7 × 10(6) e 8,4 × 10(6) tripomastigotas/mL no 8º dpi (p>0,05) em IG100 e IG1000, respectivamente. A fase crônica da infecção foi obtida com duas doses de 100mg/Kg/weight e uma dose de 250mg/Kg/ weight do benznidazol, em 11, 16 e 18 dpi. Três animais de cada grupo foram sacrificados aos 18, 30 e 75 dpi. O cólon foi corado com Giemsa. A análise quantitativa e morfométrica de neurônios revelou que a infecção causou uma diminuição da densidade neuronal no 30º dpi (p<0,05) e 75 dpi (p<0,05) em IG100 e IG1000. A infecção causou morte e hipertrofia neuronal no 75º dpi em IG100 e IG1000 (p<0,05, p<0,01). As alterações observadas nos neurônios mientéricos foram diretamente relacionadas ao inóculo e tempo de infecção.

Serological, clinical and epidemiological evaluation of toxocariasis in urban areas of south Brazil.

Toxocariasis is a worldwide public-health problem that poses major risks to children who may accidentally ingest embryonated eggs of Toxocara. The objectives of this study were to investigate the occurrence of anti-Toxocara spp. antibodies in children and adolescents and the variables that may be involved, as well as environmental contamination by Toxocara spp. eggs, in urban recreation areas of north central mesoregion, Paraná State, Brazil. From June 2005 to March 2007. a total of 376 blood samples were collected by the Public Health Service from children and adolescents one to 12 years old, of both genders. Samples were analyzed by the indirect ELISA method for detection of anti-Toxocara antibodies. Serum samples were previously absorbed with Ascaris suum antigens, and considered positive with a reagent reactivity index >1. Soil samples from all of the public squares and schools located in the four evaluated municipalities that had sand surfaces (n = 19) or lawns (n = 15) were analyzed. Of the 376 serum samples, 194 (51.6%) were positive. The seroprevalence rate was substantially higher among children aging one to five years (p = 0.001) and six to eight years (p = 0.022). The clinical signs and symptoms investigated did not show a statistical difference between seropositive and seronegative individuals (p > 0.05). In 76.5% of the investigated recreation places, eggs of Toxocara were detected in at least one of the five collected samples. Recreation areas from public schools were 2.8 times more contaminated than from public squares. It is important to institute educational programs to inform families and educators, as well as to improve sanitary control of animals and cleaning of the areas intended for recreation in order to prevent toxocariasis.

Serological, clinical and epidemiological evaluation of toxocariasis in urban areas of south Brazil / Avaliação sorológica, clínica e epidemiológica da toxocaríase em áreas urbanas do sul do Brasil

Toxocariasis is a worldwide public-health problem that poses major risks to children who may accidentally ingest embryonated eggs of Toxocara. The objectives of this study were to investigate the occurrence of anti-Toxocara spp. antibodies in children and adolescents and the variables that may be involved, as well as environmental contamination by Toxocara spp. eggs, in urban recreation areas of north central mesoregion, Paraná State, Brazil. From June 2005 to March 2007. a total of 376 blood samples were collected by the Public Health Service from children and adolescents one to 12 years old, of both genders. Samples were analyzed by the indirect ELISA method for detection of anti-Toxocara antibodies. Serum samples were previously absorbed with Ascaris suum antigens, and considered positive with a reagent reactivity index >1. Soil samples from all of the public squares and schools located in the four evaluated municipalities that had sand surfaces (n = 19) or lawns (n = 15) were analyzed. Of the 376 serum samples, 194 (51.6 percent) were positive. The seroprevalence rate was substantially higher among children aging one to five years (p = 0.001) and six to eight years (p = 0.022). The clinical signs and symptoms investigated did not show a statistical difference between seropositive and seronegative individuals (p > 0.05). In 76.5 percent of the investigated recreation places, eggs of Toxocara were detected in at least one of the five collected samples. Recreation areas from public schools were 2.8 times more contaminated than from public squares. It is important to institute educational programs to inform families and educators, as well as to improve sanitary control of animals and cleaning of the areas intended for recreation in order to prevent toxocariasis.

A toxocaríase é um problema de saúde pública mundial, com maior risco para crianças que podem, acidentalmente, ingerir ovos embrionados de Toxocara spp.. Os objetivos deste estudo foram avaliar a ocorrência de anticorpos anti-Toxocara spp. em crianças e adolecentes e as variáveis que podem estar envolvidas, bem como a contaminação ambiental por ovos de Toxocara spp., em locais de recreação, em áreas urbanas da mesorregião norte central, Paraná, Brasil. De junho de 2005 a março de 2007 foram coletadas 376 amostras de sangue de crianças e adolescentes de um a doze anos, de ambos os sexos, atendidas pelo Sistema Único de Saúde. As amostras foram analisadas pelo método de ELISA indireto para detecção de IgG anti-Toxocara e previamente absorvidas com antígeno de Ascaris suum. Foram consideradas reagentes as amostras com índice de reatividade > 1. A análise das amostras de areias (n = 19) e gramados (n = 15) de cada município foi realizada em todas as praças e escolas públicas. Das 376 amostras de soro, 194 (51,6 por cento) foram positivas. A taxa de soroprevalência foi substancialmente mais elevada entre as crianças na faixa etária de até um a cinco (p = 0.001) e de seis a oito anos de idade (p = 0,022). Os sinais e sintomas clínicos investigados não mostraram diferenças estatísticas entre soropositivos e soronegativos (p > 0,05). Em 76,5 por cento dos locais de recreação investigados, ovos de Toxocara foram detectados em pelo menos uma das cinco amostras. Os locais de recreação das escolas públicas estavam 2,8 vezes mais contaminados do que as praças. É importante a realização de programas educativos junto às famílias e educadores, o controle sanitário de animais e a higienização dos locais destinados à recreação para prevenção da toxocaríase.

A prospective study of Toxoplasma-positive pregnant women in southern Brazil: a health alert.

We evaluated anti-Toxoplasma gondii IgM-reactive pregnant women seen at a high-risk pregnancy outpatient clinic. From March 2005 to January 2008 in Paraná, Brazil, pregnant women seen by the Brazilian Public Health System, in any gestational period, who were anti-T. gondii IgM-positive, were followed. Clinical symptoms were noted, and tests performed including IgA, IgG avidity, ultrasonogram, and amniocentesis (PCR/inoculation in mice). Of 75 patients, 8 showed low, 3 intermediate and 31 high IgG avidity. Of those who underwent the avidity test, 31 (70.5%) were in the second trimester of pregnancy. Thirty-two (42.7%) pregnant women received specific treatment. Six received triple combination treatment; in three, tachyzoites were isolated, although only one was PCR-positive, showing changes in the cerebral sonogram, borderline IgA, and the Sabin tetrad. One fetus died, and one non-reactive IgM pregnant woman showed ocular recurrence. The municipality of residence, contact with cats during adulthood, and ingestion of unpasteurized milk were shown to be important risk factors. Congenital toxoplasmosis was observed in a pregnancy referred late for treatment. Follow-up of children born to mothers with diagnosed or suspected acute toxoplasmosis is crucial in the management of the changes that toxoplasmosis may cause.

Reação em cadeia da polimerase (PCR) no diagnóstico da infecção pelo Trypanosoma cruzi em camundongos / Polymerase chain reaction (PCR) for Trypanosoma cruzi infection diagnosis in mice

O objetivo do estudo foi avaliar o desempenho da reação em cadeia da polimerase (PCR) para detectar o DNA de Trypanosoma cruzi no sangue de camundongos infectados com clones do protozoário pertencentes aos genótipos 19, 20 (T. cruzi I), 39 e 32 (T. cruzi II), comparando-o com o exame de sangue a fresco (ESF), a hemocultura (HC) e o teste imunoenzimático (ELISA). Foram analisadasamostras de sangue de camundongos BALB/c experimentalmente infectados com 20 clones. A positividade da PCR foi significativamente superior à das demais técnicas estudadas e a seguinte ordem de positividade foi observada: PCR (100,00) > ELISA(94,44) > HC (78,86) > ESF (73,28). Ao contrário da ELISA, HC e ESF, a positividade da PCR não variou de acordo com o genótipo. Esses dados mostram o potencial da técnica da PCR para o diagnóstico da doença de Chagas.