Clinical conditions associated withintestinal strongyloidiasis in Rio de Janeiro, Brazil

INTRODUCTION: Strongyloides stercoralis is a soil-transmitted helminth that produces an infection that can persist for decades. The relationships between certain clinical conditions and strongyloidiasis remains controversial. This study aims to identify the clinical conditions associated with intestinal strongyloidiasis at a reference center for infectious diseases in Rio de Janeiro, Brazil. METHODS: The clinical conditions that were assessed included HIV/AIDS, HTLV infection, cardiovascular diseases, diabetes, obstructive respiratory diseases, viral hepatitis, tuberculosis, cancer, chronic renal disease, nutritional/metabolic disorders, psychiatric conditions, rheumatic diseases and dermatologic diseases. We compared 167 S. stercoralis-positive and 133 S. stercoralis-negative patients. RESULTS: After controlling for sex (male/female OR = 2.29; 95% (CI): (1.42 - 3.70), rheumatic diseases remained significantly associated with intestinal strongyloidiasis (OR: 4.96; 95% CI: 1.34-18.37) in a multiple logistic regression model. With respect to leukocyte counts, patients with strongyloidiasis presented with significantly higher relative eosinophil (10.32% ± 7.2 vs. 4.23% ± 2.92) and monocyte (8.49% ± 7.25 vs. 5.39% ± 4.31) counts and lower segmented neutrophil (52.85% ± 15.31 vs. 61.32% ± 11.4) and lymphocyte counts (28.11% ± 9.72 vs. 30.90% ± 9.51) than S. stercoralis-negative patients. CONCLUSIONS: Strongyloidiasis should be routinely investigated in hospitalized patients with complex conditions facilitate the treatment of patients who will undergo immunosuppressive therapy. Diagnoses should be determined through the use of appropriate parasitological methods, such as the Baermann-Moraes technique. .

Prevalência de parasitoses intestinais em comunidade quilombola no município de Bias Fortes, estado de Minas Gerais, Brasil, 2008 / Prevalence of parasitic intestinal diseases in a quilombola community, in the Municipality of Bias Fortes, State of Minas Gerais, Brazil, 2008

Objetivo: investigar a prevalência e os fatores associados às parasitoses intestinais na população de Colônia do Paiol, comunidade quilombola na Zona da Mata de Minas Gerais, Brasil. Metodologia: procedeu-se um estudo de corte transversal por censo, sendo que dos 425 moradores, 391 (92 por cento) foram avaliados mediante resposta a questionário estruturado e exame coproparasitológico. Resultados: a positividade para pelo menos uma espécie parasitária foi de 63,8 por cento, sendo as espécies patogênicas mais frequentes Ascaris lumbricoides (22,4 por cento) e Trichuris trichiura (17,9 por cento); o poliparasitismo ocorreu em 36,5 por cento dos investigados; predominaram casos no sexo feminino e na faixa etária de escolares de seis a 14 anos de idade. Conclusão: observou-se associação entre a presença de parasitos intestinais e determinadas condições ambientais, confirmando a necessidade de melhoria das condições de saneamento básico e de acesso ao serviço de saúde, de utilização de medicações de fácil administração no tratamento das enteroparasitoses e de educação em saúde para os membros da comunidade.

Objective: the study aims to investigate prevalence and factors associated to intestinal parasitic diseases in the population of Colônia do Paiol, a quilombola community in the municipality of Bias Fortes, located in the Zona da Mata region of the State of Minas Gerais, Brazil. Methodology: cross-sectional census study was conducted, and 391 (92 per cent) of the 425 inhabitants were interviewed through a questionnaire and evaluated by means of a coproparasitologic test. Results: the test positivity rate for at least one parasite specie was of 63.8 per cent, and the pathogenic species more often found were Ascaris lumbricoides (22.4 per cent) and Trichuris trichiura (17.9 per cent); multiparasitism was diagnosed in 36.5 per cent of those who took part in the study; prevalence was higher for females compared to males, also for school children aged from 6 to 14 years old. Conclusion: a significant association was observed between the presence of intestine parasites and a number of environment conditions such as sewage collection and disposal, access to basic health services, use of easily administered medicines for treatment of enteroparasitosis, and education policies on basic health knowledgeamong population members.

Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis

The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB.

Primer caso humano parasitado por Paramphistomidae (Trematoda: Digenea) en Venezuela / First human case parasitized by Paramphistomidae (Trematoda: Digenea) in Venezuela

Se presenta el primer caso humano en Venezuela de infección por Paramphistomidae (Fischoeder, 1901) perteneciente a una familia primitiva de trematodos descrita en mamíferos, reptiles y peces; en mamíferos se ha señalado en el rumen y la redecilla de rumiantes, cerdos, equinos, caprinos y bovinos. El caso clínico corresponde a una paciente de diez años procedente del estado Portuguesa. Quien presentó, durante un año de evolución, dolor abdominal difuso, náuseas con vómitos que coinciden con la expulsión con las heces de estructuras parasitarias adultas. Fueron colectados huevos del interior de los parásitos adultos (poro genital), mientras que de las heces de la paciente se evidenciaron iguales estructuras ovígeras. Por medio de análisis morfológicos y morfométricos se definió el parásito como de la familia Paramphistomidae. La niña proviene de un grupo familiar numeroso con deficiente nutrición calórico-proteica que refería alimentarse de productos del río próximo a la vivienda, la cual se encuentra en un área rural dispersa, con malas condiciones socio-sanitarias y está circundada por cultivos de arroz, con amplias zonas que están anegadizas durante todo el año. El presente parásito no está descrito en Venezuela por lo que se realizarán estudios para identificar la especie y señalar los hospedadores que intervienen en su ciclo.

It is reported the first human case of Paramphistomatidae infection (Fischoeder, 1901) in Venezuela, belonging to a primitive family of trematodes which are described in mammals, reptiles and fish, in mammals have been identified in the rumen and reticulum of ruminants, pigs, horses, goats and cattle. The clinical case belongs to a ten-year-old girl from Portuguesa State, who had a year of evolution: Diffuse abdominal pain, nausea with vomiting that match the stool expulsion of adult parasitic structures. Eggs were collected inside the genital pore of adult parasites while the patient’s stool showed the same ovigerous structures. The parasite is defined as Paramphistomatidae family by means of its morphological and morphometric analysis. The girl comes from a large family group with protein-calorie deficient nutrition who eats products coming from the river near her home, which is located in a dispersed rural area with poor socio-sanitary conditions and is surrounded by rice fields, with large areas that are subject to flooding during the year. This parasite is not described in Venezuela so studies will be undertaken to identify it accurately and to identify the hosts involved in the cycle.

Intestinal parasitic infections in renal transplant recipients

The impact of intestinal parasitic infection in renal transplant recipients requires careful consideration in the developing world. However, there have been very few studies addressing this issue in Iran. This study was conducted to determine the prevalence of intestinal parasitic infections in renal transplant recipients in Iran. Stool specimens from renal transplant recipients and control groups were obtained between June 2006 and January 2007. The samples screened for intestinal parasitic infections using direct smear, formalin-ether sedimentation, Sheather's flotation and modified Ziehl-Neelsen staining methods. Out of 150 renal transplant recipients, 33.3 percent (50), and out of 225 control group, 20 percent (45) were infected with one or more type of intestinal parasites. The parasites detected among patients included Entamoeba coli (10.6 percent), Endolimax nana (8.7 percent), Giardia lamblia (7.4 percent), Blastocystis spp. (4.7 percent), Iodamoeba butschlii (0.7 percent), Chilomastix mesnili (0.7 percent) and Ascaris lumbricoides (0.7 percent). Multiple infections were more common among renal transplant recipients group (p < 0.05). This study highlights the importance of testing for intestinal parasites among Iranian renal transplant recipients. Routine examinations of stool samples for parasites would significantly benefit the renal transplant recipients by contributing to reduce severe infections.

IgA1 levels in milk and serum samples from intestinal parasite-infected or normal puerperae

In this study, IgA1 levels in the milk and serum of puerperae were compared and a correlation was established between the levels of this immunoglobulin and the occurrence of parasitism. Eighty-three paired milk and serum samples were obtained from puerperal and IgA1 levels were analyzed. In addition, the presence of intestinal parasites in stool samples from these puerperae was determined. Twelve puerperae tested positive for intestinal parasites and all their samples presented an IgA1 ELISA Index > 1. There was a correlation between serum and milk IgA1 levels and puerperae with any parasite in their stool (r = 0.6723; p = 0.0166). This finding may reinforce the importance of breast-feeding for the protection of neonates.

Intestinal helminthes and/or Toxocara infection are unrelated to anti-HBs titers in seven-year-old children vaccinated at birth with recombinant hepatitis B vaccine

The aim of this investigation was to evaluate the possible effect of nematode infection on anti-HBs antibody levels in the serum of seven-year-old schoolchildren vaccinated at birth with the recombinant hepatitis B vaccine. Anti-HBs and anti HBc antibodies were evaluated in the sera of 100 schoolchildren with at least one intestinal nematode and/or a positive serological reaction for anti-Toxocara antibodies and in 95 schoolchildren without intestinal helminthiasis or serum anti-Toxocara antibodies. Both groups were from public elementary schools located on the urban periphery of Vitória, ES, Brazil. Among these 195 children, the median anti-HBs antibody titer was 31.3IU/ml and the frequency of titers less than 10IU/ml was 33.8 percent (95 percent CI: 27.1-40.4 percent). There were no significant differences between the medians of anti-HBs titers or the frequency of titers less than 10IU/ml between the groups with or without helminthes (29.5 and 32.9IU/ml and 33 and 34.7 percent, respectively; p>0.05). Even when the children with intestinal nematodes and/or anti-Toxocara antibodies and with blood eosinophil counts over 600/mm³ were compared with children without infection from intestinal nematodes and without anti-Toxocara antibodies, with blood eosinophil counts less than 400 eosinophils/mm³, these differences were not significant. None of the children presented anti-HBc antibodies. In conclusion, infections with intestinal nematodes and/or the presence of anti-Toxocara antibodies did not interfere with the anti-HBs antibody titers in seven-year-old children vaccinated at birth with the recombinant hepatitis B vaccine.

O objetivo dessa investigação foi avaliar um possível efeito de infecções por nematóides sobre os níveis de anticorpos anti-HBs no soro de escolares de sete anos de idade, vacinados ao nascer com a vacina recombinante para hepatite B. Anticorpos anti-HBs e anti-HBc foram avaliados no soro de 100 escolares portadores de pelo menos um nematóide intestinal e/ou uma reação sorológica positiva para anticorpos anti-Toxocara e em 95 escolares sem helmintíases intestinais e sem anticorpos séricos anti-Toxocara, todos matriculados em escolas primárias públicas situadas na periferia urbana de Vitória, ES, Brasil. Nas 195 crianças, a mediana dos títulos dos anticorpos anti-HBs foi 31,3UI/ml, e a freqüência de títulos inferiores a 10UI/ml foi de 33,8 por cento (IC a 95 por cento:27,1- 40,4 por cento). Não houve diferença significativa entre as medianas dos títulos de anti-HBs ou da freqüência de títulos inferiores a 10 UI/ml entre as crianças com ou sem helmintos (29,5 e 32,9 UI/ml e 33 e 34,7 por cento, respectivamente; p >0.05). Mesmo quando comparadas crianças com nematóides intestinais e/ou anticorpos anti-Toxocara com eosinófilos circulantes acima de 600/mm³, com crianças sem infecção com nematóides intestinais e sem anticorpos anti-Toxocara, com menos de 400 eosinófilos/mm³, aquelas diferenças não foram significativas. Nenhuma das crianças apresentou anticorpos anti-HBc. Em conclusão, infecções com nematóides intestinais e/ou presença de anticorpos anti-Toxocara não interferem nos títulos de anticorpos anti-HBs em crianças de sete anos de idade, vacinadas ao nascer com a vacina recombinante para hepatite B.

Total IgE level in respiratory allergy: study of patients at high risk for helminthic infection

OBJETIVO: Eosinofilia e elevação de IgE sérica são expressões de atopia, contudo há fatores intervenientes como, por exemplo, as parasitoses intestinais. Esta pesquisa verifica a relação entre IgE sérica total, eosinófilos e IgE específica anti-áscaris em indivíduos portadores de asma e/ou rinite alérgica. MÉTODOS: Estudo do tipo transversal em adolescentes portadores de asma e/ou rinite alérgica que foram examinados quanto ao nível sérico de IgE total, de IgE anti-áscaris e de contagem dos eosinófilos sangüíneos. RESULTADOS: Foram analisados 101 pacientes com idade entre 12 e 21 anos. A mediana da IgE foi 660 UI/mL (P25-75 243,5-1500), e a dos eosinófilos foi 510 células/mm³ (P25-75 284-811). A IgE anti-áscaris foi positiva em 73 por cento (74/101) da amostra, mas houve apenas 33,7 por cento (34/101) de positividade ao parasitológico de fezes. Os coeficientes de correlação encontrados foram: 0,34 (p = 0,001) entre IgE total e eosinófilos, 0,52 (p < 0,001) entre IgE total e IgE anti-áscaris e 0,26 (p = 0,01) entre eosinófilos e IgE anti-áscaris. O modelo de regressão linear múltipla final encontrou que IgE anti-áscaris foi fator contribuinte para IgE sérica total com coeficiente de determinação (r2 ajustado) de 0,25 (F = 12,35; p < 0,001), e esse efeito foi independente de contagem de eosinófilos séricos e de parasitose intestinal por helmintos. CONCLUSÃO: Em pacientes com alergia respiratória e IgE sérica total bastante elevada, oriundos de áreas com alto risco de infecção por helmintos, a pesquisa de IgE anti-áscaris como possível fator explicativo pode ser de maior ajuda que a realização do parasitológico de fezes.

OBJECTIVE: Eosinophilia and increased serum IgE levels are indicators of atopy; however, other factors can also play a key role, such as intestinal parasitic infections. This study assesses the relationship between total serum IgE, eosinophil count, and anti-Ascaris IgE in individuals with asthma and/or allergic rhinitis. METHODS: A cross-sectional study was carried out in adolescents with asthma and/or allergic rhinitis. The patients had their total serum IgE, anti-Ascaris IgE and eosinophil count measured. RESULTS: A total of 101 patients aged 12 to 21 years were assessed. Median IgE level was 660 IU/mL (P25-75 243.5-1500), and the eosinophil count corresponded to 510 cells/mm³ (P25-75 284-811). Anti-Ascaris IgE was positive in 73 percent (74/101) of the individuals, but parasitological stool examination yielded positive results in only 33.7 percent (34/101). The correlation coefficients were the following: 0.34 (p = 0.001) between total IgE level and eosinophil count, 0.52 (p < 0.001) between total IgE level and anti-Ascaris IgE, and 0.26 (p = 0.01) between eosinophil count and anti-Ascaris IgE. The final multiple linear regression model pointed out that anti-Ascaris IgE contributed to a total serum IgE level with a coefficient of determination (adjusted R²) of 0.25 (F = 12.35; p < 0.001). This effect occurred regardless of eosinophil count and of the presence of intestinal helminthic infection. CONCLUSION: In patients with respiratory allergy and increased total serum IgE levels living in areas where there is a high risk for helminthic infections, the quantification of anti-Ascaris IgE can be more useful and more insightful than the parasitological stool examination.

Preliminary study of the presence of antibodies against excretory-secretory antigens from protoscoleces of Echinococcus granulosus in dogs with intestinal echinococcosis

The aim of the present study was to analyze the antibody response against excretory-secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, using sera from dogs infected with E. granulosus and other helminths. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. Immunochemical characterization was performed by immunoblotting with sera from dogs naturally infected with E. granulosus (n = 12), sera from dogs infected with helminths other than E. granulosus (n = 30), and helminth-free dog sera (n = 20). These findings were compared to those obtained from a somatic extract of protoscoleces (S-Ag). ES-Ag only showed four cross-reacting proteins of 65, 61, 54, and 45-46 kDa. Antigens with apparent masses of 89 and 50 kDa in ES-Ag and of 130 and 67 kDa in S-Ag were identified by sera of dogs infected with E. granulosus only, whereas a protein of 41-43 kDa was recognised by the majority of the sera from dogs with non-echinococcal infection. Employing ELISA to study the same sera, S-Ag revealed higher immunoreactivity than ES-Ag, but also showed higher cross-reactivity levels when sera from dogs with non-echinococcal infection were assayed in immunoblotting.

Mucosal mast cell-derived chondroitin sulphate levels in and worm expulsion from FcRgamma-knockout mice following oral challenge with Strongyloides venezuelensis

Mucosal mast cell-derived chondroitin sulphates (sulphated proteoglycans) were assayed in gut washings and homogenate of FcRgamma-knockout (KO) and wild-type (WT) C57BL/6 mice challenged with Strongyloides venezuelensis in order to assess their possible role in secondary immunity against enteric nematodes. Groups of immune KO and WT mice were challenged by oral gavage with 300 infective larvae (L3). Establishment of infection was assessed by daily faecal analysis to determine the number of eggs per gram of faeces (EPG) and by adult worm recovery on days 5 and 13 post challenge. Mucosal mast cell (MMC) counts were done on days 5 and 13 post challenge while MMC-derived chondroitin sulphates in gut washings (days 1 and 5) and homogenate (day 8) were assayed by high performance liquid chromatography (HPLC). Results showed that patent infection occurred in challenged KO but not WT mice despite significantly higher mastocytosis in jejunal sections of KO than WT mice (p<0.001). Similarly but against prediction, significantly higher concentration of MMC-derived chondroitin sulphates was observed in gut homogenate of KO than WT mice (p<0.05). In contrast, significantly higher concentration of chondroitin sulphates was observed in gut washings of WT than KO mice (p<0.05). These results suggest that MMC in KO mice failed to release sufficient amount of sulphated proteoglycans into the gut lumen as did the WT mice, which may have been part of the hostile environment that prevented the establishment in and eventual expulsion of adult S. venezuelensis from the gut of WT mice following challenge.

Significance of schistosomal granuloma modulation

Hepatic Schistosoma mansoni periovular granulomas undergo changes in size, cellular composition and appearance with time. This phenomenom, known as "immunological modulation", has been thought to reflect host immunological status. However, as modulation has not been observed outside the liver, participation of local factors, hitherto little considered, seems crucial. Components of the extracellular matrix of periovular granulomas of the mouse were particularly studied in three different organs (liver, lung and intestine) and during three periods of infection time (acute, intermediate and chronic) by means of histological, biochemical and imunofluorescence techniques, while quantitative data were evaluated by computerized morphometry, in order to investigate participation of local factors in granuloma modulation. Results confirmed modulation as a exclusively hepatic phenomenom, since pulmonary and intestinal granulomas, formed around mature eggs, did not change size and appearance with time. The matricial components which were investigated (Type I, III and IV collagens, fibronectin, laminin, proteoglycans and elastin) were found in all granulomas and in all organs examined. However, their presence was much more prominent in the liver. Elastin was only found in hepatic granulomas of chronic infection. The large amount of extracellular matrix components found in hepatic granulomas was the main change responsible for the morphological aspects of modulation. Therefore, the peculiar environment of the liver ultimately determines the changes identified in schistosomal granuloma as "modulation".

Ciclosporosis: infección por Cyclospora cayetanensis / Cyclosporosis: Cyclospora cayetanensis infection

Cyclospora cayetanensis es un protozo descrito a inicios de siglo, pero detectado como causante de enfermedad humana sólo desde hace 20 años, por lo cual se le considera una infección emergente. Produce una diarrea prolongada pérdida de peso, dolor abdominal y decaimiento en pacientes previamente sanos y en inmunodeprimidos. Se le ha descrito en todo el mundo en personas de todas las edades. Se diagnostica mediante el examen coproparasitoscópico seriado con tinción especial para organismos ácido-alcohol-resistentes de manera específica por no ser de uso rutinario en los laboratorios. Se trata con la combinación de TMP-SMZ, los inmunodeprimidos requieren de profilaxis posterior

Enteroparasitosis en pacientes con sida / Enteric infection in patients with aids

Varios agentes infecciosos pueden producir enfermedad gastrointestinal y en particular diarrea en los pacientes con enfermedad por VIH.Las parasitosis entéricas son comunes dentro de esta población,adoptando características especiales respecto de la población respecto de población en general,no sólo en los aspectos clínicos de las mismas sino tambien en su etiología.Agentes inocuos en la mayoría de los casos para el hospedero inmunocompetente plantean un verdadero desafío diagnóstico y terapéutico en estos pacientes.Estudios de prevalencia en exámenes de materia fecal realizados en el Hospital de Enfermedades Infecciosas Francisco J. Muñiz determinaron que Blastocystis hominis.Criptosporidium sp.,Giardia lamblia,Endolimax nana,Entamoeba coli,Isospora beli y Strongyloides stercoralis corresponden a más del 90 por ciento del total de enteroparasitosis en los pacientes con SIDA.Los clásicos exámemes en fresco y seriado de materia fecal procesados con técnicas de concentración adecuadas ,permiten a través de la observación directa y técnicas de concentraciones especiales llegar al diagnóstico etiológico en la mayoría de los casos.El tratamiento de estas parasitosis en este grupo poblacional permance todavía como un punto a resolver.La maroría de los autores coinciden que las fallas de tratamiento y el alto índice de recaídas son el denominador común en estos pacientes.Dado el alto impacto de estas parasitosis en los pacientes con SIDA realizamos esta revisión con el objeto de recorrer los aspectos fisiopatológicos y clínicos de las mismas complementando la misma con el valioso aporte de los profesionales de nuestro Hospital Escuela experimentados en el tema

Different T-lymphocyte subset responses dictate organ involvement in schistosomiasis

In this study, 2 color flow cytometric immunophenotyping analysis of lymphocytes and their subsets estimated in fresh peripheral venous blood sample of 15 patients with bilharzial hepatic fibrosis as a result of Schistosoma mansoni infection. 15 patients with active intestinal bilharziasis only without hepatic fibrosis or splenomegaly as well as 15 healthy volunteers. Bilharzial hepatic fibrosis was confirmed by histopathological examination of liver biopsy specimens. HBsAg and HCV Ab positive patients were excluded from the study. Results showed that CD4+% in the group of patients with bilharzial hepatic fibrosis was significantly higher than that of the group with active intestinal bilharziasis. While no significant difference was observed between the two groups of patients with bilharziasis when compared with the control group. CD8+% decreased significantly in patients with bilharzial hepatic fibrosis compared with both control and patients with active intestinal bilharziasis. While CD8+% increased significantly in the group of active intestinal bilharziasis compared with control. CD4/CD8 ratio increased significantly in patients with bilharzial hepatic fibrosis compared with the group of active intestinal bilharziasis and control group. NK% decreased significantly in patients with bilharziasis while NK% increased significantly in the group of active intestinal bilharziasis compared to control. No significant difference was present among the studied groups as regards total leucocytic count, absolute lymphocytic count, CD3%, CD19% and activated T-lymphocyte percentages

Antibody response to Salmonella typhi in human schistosomiasis mansoni

Antibody response to Salmonella typhi O and H antigens was evaluated in 24 individuals with either hepatointestinal or hepatosplenic schistosomiasis mansoni before and after typhoid vaccination, and compared with that of non-infected controls. Before vaccination, Schistosoma-infected patients showed a higher frequency of positive antibody to O antigen and the same frequency to H antigen when compared with that of healthy individuals. However, those with hepatosplenic schistosomiasis showed higher titres of antibody to H antigen than those with hepatointestinal disease or healthy individuals. Infected subjects, particularly those with hepatointestinal disease, showed a decreased response after typhoid vaccine. This diminished ability to mount an immune response towards typhoid antigens during schistosomiasis may interfere with the clearance of the bacteria from blood stream and, therefore, play a role in the prolonged survival of salmonella as observed in some patients with chronic salmonellosis associated with schistosomiasis.

A microcalorimetric assay to measure the reactivity of antigen-stimulated mononuclear cells from Schistosoma mansoni infected patients

The reactivity of mononuclear cells (2 x 10**6/ml minimum Eagle's medium, MEM) from normal subjects and from Schistosoma mansoni-infected patients was evaluated by microcalorimetry. The results which are reported as heat production (mcal for 2 x 10**6 cells in 3600s), were 2,087 ñ 21.2 and 2,497.0 ñ 21.3 for mononuclear cells from infected patients (N = 8) under stimulation with S. mansoni soluble egg antigen (SEA) and soluble adult worm antigenic preparation (SWAP), respectively. The values for cells from normal subjects (N = 8) were 13.7 ñ 1.1 and 29.3 ñ 3.2 in the presence of the same antigens. Pre-treatment of mononuclear cells from patients with 1 mM aminophylline (a cAMP phospphodiesterase inhibitor) totally abolished heat production. Cell viability (> 95%) was not changed after the measurement. The microcalorimetric assay described here measures the cellular metabolic activity and we feed justified in suggesting this techinique as an auxiliary diagnosis of schistosomiasis. Given the sensitivity, precision and accuracy of this microcalorimetric assay, we feel it can be used for the diagnosis of disease conditions for which a reliable diagnostic method is required

Etiología de diarrea con sangre en niños de una comunidad rural / Etiology of bloody diarrhea in children of a rural village

Se investigó la etiología de diarrea con sangre en una cohorte de 75 niños rurales seguidos longitudinalmente durante los primeros dos años de vida. De un total de 636 episodios de diarrea, 71 (11%) mostraron la presencia de sangre. Se aisló un patógeno en 59 (83%) de los 71 casos; 35%mostraron la presencia de Escherichia coli enteroagregativa (EAEC), 11%de E. coli productora de toxinas tipo Shiga (SLT) I y/o II; 13%de Shigella, 7%de Campylobacter jejuni, o de E. coli enterotoxigénica (ETEC); y en 4%de E. coli enteropatógena (EPEC), E. coli enteroinvasora, Salmonella, Giardia lamblia, o Hymenolepis nana. Se encontraron cultivos mixtos en 16%de casos durante el primer año y en 18%durante el segundo. Estas mezclas fueron principalmente combinaciones de C. jejuni o ETEC con EAEC. el 78%de los niños con diarrea con sangre cursaron con un solo evento diarreico durante los primeros dos años de vida con duración promedio de siete días. Epidemiológicamente, la incidencia de diarrea con sangre se incrementó progresivamente durante los primeros dos años de vida, con un descenso significativo después de los diez meses de edad. La prevalenia de patógenos estuvo afectada por la estacionalidad, excepto para EAEC cuya prevalencia fué endémica. En el caso de Shigella y E. coli productora de SLT, la agrupación de casos en tiempo y el aislamiento de especies serológicamente idénticas indicaron que las infecciones fueron resultado de brotes de una fuente común