Screening of Strongyloides infection using an ELISA test in transplant candidates

OBJECTIVES: Hyperinfection or disseminated strongyloidiasis has been frequently reported after transplants and is related to high mortality. This study aimed to screen for strongyloidiasis using serological diagnoses in transplant candidates. METHODS: An ELISA test was performed with filariform larvae of Strongyloides venezuelensis as a source of antigen. RESULTS: In the serum from transplant candidates, anti-Strongyloides IgG antibodies were detected in 35/150 (23.3%) samples by soluble fractions in phosphate buffered saline (PBS), 31/150 (20.7%) samples by soluble fractions in Tris-HCl, 27/150 (18.0%) samples by membrane fractions in PBS and 22/150 (14.7%) samples by membrane fractions in Tris-HCl. CONCLUSIONS: The present results suggest the ELISA test, ideally using soluble fractions of filariform larvae S. venezuelensis in PBS, as an additional strategy for the diagnosis of strongyloidiasis in transplant candidates.

Ascaris lumbricoides coinfection reduces tissue damage by decreasing IL-6 levels without altering clinical evolution of pulmonary tuberculosis or Th1/Th2/Th17 cytokine profile

Abstract INTRODUCTION: Immunological control of Mycobacterium tuberculosis infection is dependent on the cellular immune response, mediated predominantly by Th1 type CD4+ T cells. Polarization of the immune response to Th2 can inhibit the host immune protection against pathogens. Patients with tuberculosis coinfected with helminths demonstrate more severe pulmonary symptoms, a deficiency in the immune response against tuberculosis, and an impaired response to anti-tuberculosis therapy. METHODS: We evaluated the cellular immune response and the impact of the presence of Ascaris lumbricoides on the immune and clinical response in pulmonary tuberculosis patients. Ninety-one individuals were included in the study: 38 tuberculosis patients, 11 tuberculosis patients coinfected with Ascaris lumbricoides and other helminths, 10 Ascaris lumbricoides patients, and 34 non-infected control individuals. Clinical evolution of pulmonary tuberculosis was studied on 0, 30, 60, and 90 days post-diagnosis of Mycobacterium tuberculosis and Ascaris lumbricoides. Furthermore, immune cells and plasma cytokine profiles were examined in mono/coinfection by Mycobacterium tuberculosis and Ascaris lumbricoides using flow cytometry. RESULTS: There were no statistical differences in any of the evaluated parameters and the results indicated that Ascaris lumbricoides infection does not lead to significant clinical repercussions in the presentation and evolution of pulmonary tuberculosis. CONCLUSIONS: The association with Ascaris lumbricoides did not influence the Th1, Th2, and Th17 type responses, or the proportions of T lymphocyte subpopulations. However, higher serum levels of IL-6 in tuberculosis patients may explain the pulmonary parenchymal damage.

Seroepidemiological aspects of human infection by Strongyloides stercoralis in Alfenas, southern Minas Gerais, Brazil

Abstract INTRODUCTION: In most Strongyloides stercoralis infected individuals, nematoidosis occurs asymptomatically, but in immunocompromised patients, it can cause hyperinfection. Serological techniques seem to be a good alternative for detecting this parasite. METHODS The frequency of seropositivity for strongyloidiasis in Alfenas, MG, was estimated using the enzyme linked immunosorbent assay on blood samples, between May and August of 2015. RESULTS: Out of 258 samples tested, 53.9% were positive, and the frequency of seropositive individuals was higher in the peripheral districts of the municipality. CONCLUSIONS: The results indicate high seropositivity rates for strongyloidiasis among the residents of Alfenas city.

Frequency of anti-Toxocara antibodies in broiler chickens in southern Brazil / Frequência de anticorpos anti-Toxocara em frangos de corte no Sul do Brasil

Abstract The aim of this study was to evaluate the presence of anti-Toxocara antibodies in naturally infected broiler chickens (n = 189) from the state of Paraná, southern Brazil. The chickens were reared in a semi-intensive system by small family farmers (n = 7). An enzyme-linked immunosorbent assay (ELISA) was performed to detect the presence of anti- Toxocara spp. IgY after serum adsorption with Ascaridia galli antigens. An overall seroprevalence of 67.7% (128/189; 95% CI = 61.1-74.4) was observed. The frequency of positive animals by farm ranged from 29.6% to 100%. The optical density and reactivity index values observed in ELISA test indicated the possible chronicity of infection of the evaluated chickens. Associations between the presence of antibodies and the area where the chickens were reared (p = 0.382) or the population density of dogs on the farm (p = 0.785) were not observed. This study shows a high prevalence of Toxocara spp. antibodies in broiler chickens reared in semi-intensive systems and provides evidence that chickens are a good indicator of environmental contamination by larva migrans agents. Further studies are necessary to assess the risk factors associated with poultry infection and the likelihood of toxocariasis transmission to humans via the ingestion of free-range chicken meat.

Resumo A finalidade do presente estudo foi avaliar a presença de anticorpos anti- Toxocara, em frangos de corte naturalmente infectados (n = 189), no Norte do Paraná, Sul do Brasil. Os frangos foram criados em sistema semi-intensivo, em pequenas propriedades rurais (n = 7). Os testes sorológicos foram realizados pela técnica de ELISA, para detecção de anticorpos IgY (IgG), com pré-adsorção do soro com antígenos de Ascaridia galli. Foi observada uma prevalência de 67,7% (128/189; IC 95% = 61,1-74,4). A frequência de animais soropositivos por propriedade variou de 29,6% a 100%. Os valores da Densidade Ótica e do Índice de Reatividade observados no teste de ELISA indicaram uma possível cronicidade de infecção dos frangos avaliados. Não foi observada correlação entre a positividade dos animais, quando comparada a área (p = 0,382) e a densidade populacional de cães por propriedade (p = 0,785). O presente estudo verificou uma alta prevalência de anticorpos anti-Toxocara em frangos de corte criados em sistema semi-intensivo e oferece dados que apontam esses animais como bons indicadores de contaminação ambiental por agentes de larva migrans . Estudos futuros são necessários para avaliar os fatores de risco associados e a possibilidade da transmissão de toxocaríase ao ser humano pela ingestão de carne de frango.

Negative serology of Fasciola hepatica infection in patients with liver cancer in Peru: a preliminary report

Abstract INTRODUCTION: The etiology of several hepatocellular carcinoma (HCC) cases remains largely unknown. Although Fasciola hepatica has been associated with liver fibrosis in Latin America, it has not yet been associated with HCC. This study aimed to determine the existence of specific IgG antibodies against F. hepatica in the serum samples of HCC patients. METHODS In total, 13 serum samples from 13 HCC patients were screened using Fas2-ELISA. RESULTS Fas2-ELISA demonstrated negative results in all HCC patients included in this study. CONCLUSIONS The pre-existence of F. hepatica infection in HCC patients needs to be further investigated in epidemiological and experimental studies.

Seroprevalence of human cysticercosis in Jataí, Goiás state, Brazil

ABSTRACT The Taenia solium cysticercosis affects millions of people worldwide and is considered a public health problem, especially in developing countries. The diagnosis of neurocysticercosis is complex and involves the analysis of epidemiological, clinical, neuroimaging, and immunological host data. Neurocysticercosis is endemic in Brazil, and is related to the cause of death mainly in the Southeast, South, and Central-West regions. The objective of this study was to determine the seroprevalence of cysticercosis in inhabitants of the city of Jataí, Goiás, in the Central-West region of Brazil from April to August 2012. A total of 529 serum samples were analyzed by enzyme-linked immunosorbent assay for detecting IgG antibodies against T. solium larvae, and Western blotting was used for confirming the diagnosis through the recognition of at least two specific peptides from their serum antibodies. The 351/529 (66.3%) reactive samples were analyzed by enzyme-linked immunosorbent assay and Western blotting confirmed the diagnosis in 73 samples that recognized at least two of the following peptides specific IgG antibodies for cysticercosis: 18, 24, 28-32, 39-42, 47-52, 64-68, and 70 kDa. The seroprevalence of cysticercosis was 13.8% (95% CI 5.9-21.7), demonstrating that the studied area is endemic to this disease.

Evaluation of the recombinant antigens Wb14 and WbT for the capture antibody diagnosis of lymphatic filariasis

BACKGROUND Lymphatic filariasis (LF) is a parasitic disease caused mainly by the Wuchereria bancrofti worm and that affects up to 120 million people worldwide. LF is the second cause of chronic global deformity, responsible for 15 million people with lymphedema (elephantiasis) and 25 million men with scrotal hydrocele. Its diagnosis is still associated with numerous difficulties, such as the sample collection periods (microfilaria nocturnal periodicity) and limited diagnostic kits. OBJECTIVES The aim of this work was to evaluate two recombinant antigens (Wb14 and WbT) as part of an enzyme-linked immunosorbent assay (ELISA) based antibody capture tests for LF. METHODS The recombinant antigens rWb14 and rWbT were expressed in Escherichia coli BL21 and an antibody capture ELISA was performed. For this, sera were used from microfilaremic individuals with W. bancrofti (MF), chronic pathology (CP), individuals infected with Strongyloides (SP) and healthy controls from endemic (EN) and non-endemic (NE) areas. FINDINGS Both tests showed similar results, with 90% sensitivity and 96.6% specificity. In comparison with the BM14 ELISA commercial test, the Wb14 and WbT antigens performed with identical sensitivity but greater specificity. Reduced positivity with the CP suggested a potential to monitor cure. This was not confirmed, however, when sera from individuals up to seven years after treatment were assayed. MAIN CONCLUSIONS The Wb14 and WbT ELISAs were considered efficient and promising diagnostic tests. Due to the importance of antibody capture analysis to evaluate the Global Program to Eliminate Lymphatic Filariasis (GPELF), the tests proposed here appear as great alternatives to the available commercial system.

Validity of a commercial kit for detection of antibodies in bovine serum in an endemic area for fasciolosis / Validade de um kit comercial para detecção de anticorpos no soro bovino em área endêmica de fasciolose

Abstract Fasciolosis is caused by Fasciola hepatica that affects the bile ducts and liver parenchyma of ruminants, which can result in economic loss. This study aimed to carry out the validity of the commercial kit ELISA® indirect front of the simple fecal sedimentation test used as the standard. 143 samples were collected blood and feces of cattle from Jerome, south of the Espírito Santo. Serum samples were left at -80 °C and used to perform the ELISA kit IDEXX®. All animals to stool examinations were also positive to the ELISA (22) and negative samples to test stool (121), 52 animals reacted positively against the antibody research. The frequency of fasciolosis was 15.4% in the stool examinations and 51.8% by ELISA. The validity was calculated by sensitivity (100%), specificity (57%), positive predictive value (29%) and negative predictive value (100%), and the correlation between the tests calculated using the kappa index of 0.35. The better sensitivity of the ELISA commercial kit should not be a separately evaluated, since the cost benefit and the technical facility must be considered.

Resumo Fasciolose é causada pela Fasciola hepatica, parasito que acomete os ductos biliares e o parênquima hepático dos ruminantes e pode resultar em perdas econômicas. Objetivou-se realizar a validade do kit comercial ELISA® indireto frente ao teste de sedimentação fecal simples utilizado como padrão. Foram coletadas 143 amostras de sangue e fezes de vacas provenientes do Sul do Espírito Santo. As amostras de sangue foram centrifugadas para separação do soro. As amostras de soro foram congeladas a -80ºC e utilizadas para análise com o kit de ELISA IDEXX®. Todos os 22 animais positivos ao exame coproparasitológico também foram positivos ao ELISA e, das 121 amostras negativas ao exame de fezes, 52 reagiram positivamente frente à pesquisa de anticorpos. A frequência de fasciolose foi de 15,4% no exame coproparasitológico e 51,8% pelo ELISA. A validade foi calculada pela sensibilidade (100%), especificidade (57%), valor preditivo positivo (29%) e valor preditivo negativo (100%), sendo considerada medíocre a concordância entre os testes, calculada pelo índice kappa (0,35). A maior sensibilidade obtida para o kit comercial ELISA não deve ser avaliada isoladamente, uma vez que o custo benefício e a facilidade da técnica devem ser considerados.

Enzyme-linked immunosorbent assay for diagnosis of Amphimerus spp. liver fluke infection in Humans

BACKGROUND Amphimerus spp. is a liver fluke that infects humans and domestic animals. It is highly prevalent in some Ecuadorian communities. Currently, diagnosis is based on the microscopic observation of eggs in faeces, but this has variable sensitivity. More sensitive methods are needed for diagnostic testing. OBJECTIVE The main objective of this work was to develop an enzyme-linked immunosorbent assay (ELISA) using crude antigens from Amphimerus spp. adult worms to detect anti-Amphimerus IgG in human sera. METHODS Crude somatic antigens were obtained from adult Amphimerus spp. worms. Human sera from 119 patients were tested: 48 from individuals with a confirmed Amphimerus spp. infection, 78 from non-infected Ecuadorians living in the endemic region, 60 from persons living in non-endemic areas (20 Ecuadorians, 20 Europeans, and 20 Africans), and 33 who had other parasitic and non-parasitic infections. PRINCIPAL FINDINGS Results were analysed using the receiver-operator characteristic (ROC) curve analysis with an area under curve (AUC) value of 0.967. The accuracy of the ELISA was high. The sensitivity was 85.0% [95% confidence interval (CI): 80.3-89.7%] and the specificity was 71.0% (95% CI: 65.2-76.8%). Some cross reactivity was detected against Paragonimus mexicanus, Fasciola hepatica, Schistosomiasis, Taenia solium, Strongyloides stercoralis, Mansonella spp., and Vampirolepis nana. MAIN CONCLUSIONS We have developed the first ELISA technique that detects anti-Amphimerus IgG in human sera with good sensitivity, repeatability and reproducibility. However, more specific antigens are needed to further enhance performance of this assay. Regardless, this ELISA test could be useful for early diagnosis and prompt treatment of human Amphimerus spp. infections.

Validez de tres métodos de inmuno-diagnóstico de neurocisticercosis: revisión sistemática de la literatura con meta-análisis 1960-2014 / Validity of three methods for inmuno-diagnostic of neurocysticercosis: systematic review of the literature with meta-analysis 1960-2014

Introduction: The screening of neurocysticercosis is complex and immunological methods have varying validity. Objective: To evaluate the validity of ELISA for antigen and antibody, and EITB for antibody in the screening of neurocysticercosis. Methods: Meta-analysis of diagnostic tests with an ex-ante protocol implemented in five databases with 15 search strategies, ensuring reproducibility in the selection and extraction of information. Sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratio and ROC curve were estimated in MetaDiSc, and predictive values, and Youden index were estimated in Epidat. Results: EITB presented sensitivity of 85.7% (95% CI 83.5-87.7), specificity 93.9% (95% CI = 92.7-95.0), PLR 19.6 (95% CI = 8,6-44.6), NLR 0.16 (95% CI = 0.12-0.21), OR diagnostic 136.2 (95% CI = 54.7-342.6) and area under the curve 0.926. In ELISA for antibody sensitivity was 87.5% (95% CI = 86.1-88.8), specificity 92.2% (95% CI = 91.4-93.0), PLR 11.3 (95% CI = 8.45-15.11), NLR 0.15 (95% CI = 0.13-0.18), diagnostic OR 87.4 (95% CI = 60.1-127.1) and area under the curve 0.950. ELISA for antigen showed low diagnostic validity. No differences were found in these parameters by sample, antigen or antibody type. Conclusion: ELISA for antibodies and EITB have a similar diagnostic value, detection of serum and CSF showed a similar validity.

Introducción: La tamización de neurocisticercosis es compleja y los métodos inmunológicos presentan validez variable y generalmente bajos tamaños de muestra. Objetivo: Evaluar la validez de ELISA para detección de antígeno y anticuerpo, y EITB para detección de anticuerpo en la tamización de neurocisticercosis. Métodos: Meta-análisis de pruebas diagnósticas con un protocolo ex-ante aplicado en cinco bases de datos con 15 estrategias de búsqueda, garantizando reproducibilidad en la selección y extracción de la información. Se estimó sensibilidad, especificidad, cocientes de probabilidad (CP), razón de odds diagnósticas y curva ROC en MetaDiSC, y valores predictores, índice de Youden y exactitud en Epidat. Resultados: EITB presentó sensibilidad de 85,7% (IC 95% = 83,5-87,7), especificidad 93,9% (IC9 5% = 92,7-95,0), CPP 19,6 (IC 95% = 8,6-44,6), CPN 0,16 (IC 95% = 0,12-0,21), OR diagnóstica 136,2 (IC 95% = 54,7-342,6) y área bajo la curva 0,926. En ELISA para anticuerpos la sensibilidad fue 87,5% (IC 95% = 86,1-88,8), especificidad 92,2% (IC 95% = 91,4-93,0), CPP 11,3 (IC 95% = 8,45-15,11), CPN 0,15 (IC 95% = 0,13-0,18), OR diagnóstica 87,4 (IC 95% = 60,1-127,1) y área bajo la curva 0,950. ELISA para antígeno presentó baja validez diagnóstica. No se hallaron diferencias en estos parámetros según tipo de muestra, antígeno o anticuerpo. Conclusión: ELISA para anticuerpos y EITB presentan una utilidad diagnóstica similar, la detección de suero presentó una validez similar al líquido cefalorraquídeo.

Prevalence of Trypanosoma cruzi infection among Bolivian immigrants in the city of São Paulo, Brazil

With the urbanisation of the population in developing countries and the process of globalisation, Chagas has become an emerging disease in the urban areas of endemic and non-endemic countries. In 2006, it was estimated that the prevalence of Chagas disease among the general Bolivian population was 6.8%. The aim of the present study was to determine the prevalence of Trypanosoma cruzi infection among Bolivian immigrants living in São Paulo, Brazil. This study had a sample of 633 volunteers who were randomly selected from the clientele of primary care units located in the central districts of São Paulo, Brazil. Infection was detected by two different ELISA assays with epimastigote antigens, followed by an immunoblot with trypomastigote antigens as a confirmatory test. The prevalence of the infection was 4.4%. Risk factors independently associated with the infection were: a history of rural jobs in Bolivia, knowledge of the vector involved in transmission, and having relatives with Chagas disease. Brazil has successfully eliminated household vector transmission of T. cruzi, as well as its transmission by blood transfusion. The arrival of infected immigrants represents an additional challenge to primary care clinics to manage chronic Chagas disease, its vertical transmission, and the blood derivatives and organ transplant programs.

Efficacy of nitazoxanide against toxocara canis: larval recovery and humoral immune response in experimentally infected mice / Eficácia da nitazoxanida contra Toxocara canis: recuperação larvária e resposta imune humoral em camundongos experimentalmente infectados

SUMMARYThe efficacy of nitazoxanide (NTZ) against toxocariasis was investigated in an experimental murine model and results were compared to those obtained using mebendazole. Sixty male BALB/c mice, aged six to eight weeks-old, were divided into groups of 10 each; fifty were orally infected with 300 larvaed eggs of T. canisand grouped as follows, G I: infected untreated mice; G II: infected mice treated with MBZ (15 mg/kg/day) 10 days postinfection (dpi); G III: infected mice treated with NTZ (20 mg/kg/day) 10 dpi; G IV: infected mice treated with MBZ 60 dpi; G V: infected mice treated with NTZ 60 dpi; GVI: control group comprising uninfected mice. Mice were bled via retro-orbital plexus on four occasions between 30 and 120 dpi. Sera were processed using the ELISA technique to detect IgG anti- Toxocaraantibodies. At 120 dpi, mice were sacrificed for larval recovery in the CNS, liver, lungs, kidneys, eyes and carcass. Results showed similar levels of anti- ToxocaraIgG antibodies among mice infected but not submitted to treatment and groups treated with MBZ or NTZ, 10 and 60 dpi. Larval recovery showed similar values in groups treated with NTZ and MBZ 10 dpi. MBZ showed better efficacy 60 dpi, with a 72.6% reduction in the parasite load compared with NTZ, which showed only 46.5% reduction. We conclude that administration of these anthelmintics did not modify the humoral response in experimental infection by T. canis. No parasitological cure was observed with either drug; however, a greater reduction in parasite load was achieved following treatment with MBZ.

RESUMOFoi investigada a eficácia da nitazoxanida (NTZ) na toxocaríase murina experimental e os resultados comparados com os obtidos usando mebendazol (MBZ). Sessenta camundongos BALB/c machos, com idade entre seis e oito semanas foram divididos em grupos de 10 cada, 50 foram infectados oralmente com 300 ovos larvados de T. canise agrupados a seguir: GI: camundongos infectados não tratados; GII: camundongos infectados tratados com MBZ (15 mg/kg/dia) 10 dias pós-infecção (dpi); GIII: camundongos infectados tratados com NTZ (20 mg/kg/dia) 10 dpi, GIV: camundongos infectados tratados com MBZ 60 dpi; GV: camundongos infectados tratados com NTZ 60 dpi; GVI: controle não infectado. Os camundongos foram sangrados via plexo retro orbitário em quatro ocasiões entre o 30º e 120º dpi. Os soros foram processados pela técnica de ELISA para detecção de anticorpos IgG anti- Toxocara.Aos 120 dpi, os animais foram sacrificados para a recuperação larvária do SNC, fígado, pulmões, rins, olhos e carcaça. Os resultados mostraram níveis similares de anticorpos IgG anti- Toxocaraentre os camundongos infectados mas não submetidos a tratamento e os grupos infectados e tratados com MBZ ou NTZ, aos 10 e 60 dpi. Os valores da recuperação larval foram similares nos grupos tratados com NTZ e MBZ 10 dpi. MBZ mostrou melhor eficácia aos 60 dpi, com redução de 72,6% da carga parasitária comparada com NTZ, que mostrou redução somente de 46,5%. Concluímos que a administração destes anti-helmínticos não modificou a resposta humoral na infecção experimental por T. canis. Não foi observada cura parasitológica com nenhuma das drogas; porém maior redução na carga parasitária foi obtida após o tratamento com MBZ.

Seropositivity for ascariosis and toxocariosis nd cytokine expression among the indigenous people in the Venezuelan delta region / Seropositividad para ascariosis y toxocariosis y expresión de citocinas entre la población indígena de la región del delta Venezolano

The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.

El objetivo del presente estudio fue determinar la seropositividad de infección por Ascaris suum y Toxocara canis, utilizando antígenos de excreción/secreción (E/S) de Ascaris suum (AES) y Toxocara canis (TES) en una población indígena. Adicionalmente, se cuantificó la expresión de citocinas a partir de células de sangre periférica. Un total de 50 indígenas Warao se incluyeron en el estudio; 43 fueron adultos y 7 niños. Entre los adultos, 44,1% fueron seropositivos para ambos parásitos; mientras que los niños sólo mostraron seropositividad a uno u otro de los helmintos. Para ascariosis, el porcentaje de seropositividad para los antígenos AES fue alto tanto en adultos como en niños; 23,3% y 57,1%, respectivamente. Para toxocariosis, el porcentaje de seropositividad para los antígenos TES fue bajo en adultos así como en niños; 9,3% y 14,3%, respectivamente. El porcentaje de seronegatividad fue similar tanto para los antígenos AES como para TES en adultos (27,9%) y niños (28,6%). Cuando la seropositividad fue analizada a través de la técnica de Western blotting utilizando los antígenos AES; 3 bandas de 97,2, 193,6 y 200,2 kDas fueron principalmente reconocidas. Para los antígenos TES, 9 bandas fueron mayormente identificadas; 47,4, 52,2, 84,9, 98,2, 119,1, 131,3, 175,6, 184,4 y 193,6 kDas. Los análisis coproparasitológicos mostraron que los parásitos Blastocystis hominis, Hymenolepis nana y Entamoeba coli fueron los parásitos intestinales más comúnmente observados. La cuantificación de la expresión de las citocinas IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 e IL-4 mostró que hubo un significante incremento de la expresión de IL-4 entre los indígenas con seropositividad para los antígenos TES (p < 0.002). La seropositividad para Ascaris y Toxocara fue prevalente entre los indígenas Warao.

Membrane fractions from Strongyloides venezuelensis in the immunodiagnosis of human strongyloidiasis / Frações de membrana de Strongyloides venezuelensis para o imunodiagnóstico da estrongiloidíase humana

Strongyloides venezuelensis is a parasitic nematode of rodents frequently used to obtain heterologous antigens for the immunological diagnosis of human strongyloidiasis. The aim of this study was to evaluate membrane fractions from S. venezuelensis for human strongyloidiasis immunodiagnosis. Soluble and membrane fractions were obtained in phosphate saline (SS and SM) and Tris-HCl (TS and TM) from filariform larvae of S. venezuelensis. Ninety-two serum samples (n = 92) were obtained from 20 strongyloidiasis patients (Group I), 32 from patients with other parasitic diseases (Group II), and 40 from healthy individuals (Group III), and were analyzed by enzyme-linked immunosorbent assay (ELISA). Soluble fractions (SS and TS) showed 90.0% sensitivity and 88.9% specificity, whereas the membrane fractions (SM and TM) showed 95.0% sensitivity and 94.4% specificity. The present results suggest the possible use of membrane fractions of S. venezuelensis as an alternative antigen for human strongyloidiasis immunodiagnosis.

Strongyloides venezuelensis é um nematódeo parasita de roedores, frequentemente usado como antígeno heterólogo para o diagnóstico imunológico da estrongiloidíase humana. O objetivo deste estudo foi avaliar frações de membrana de S. venezuelensis para o imunodiagnóstico da estrongiloidíase humana. Para tanto, frações solúveis e de membrana foram obtidas em solução salina fosfato (SS e MS) e Tris-HCl (ST e MT) de larvas filarioides de S. venezuelensis. Amostras de soro de 92 indivíduos, sendo 20 com estrongiloidíase (Grupo I); 32 com outras parasitoses (Grupo II), e 40 indivíduos saudáveis (Grupo III), foram analisadas pelo teste Imunoenzimático (ELISA). As frações solúveis (SS e ST) apresentaram 90,0% e 88,9%, enquanto que as frações de membrana (MS e MT) demonstraram 95,0% e 94,4%, de sensibilidade e especificidade, respectivamente. Os resultados obtidos permitem indicar as frações de membranas como antígeno alternativo para o diagnóstico da estrongiloidíase humana.

An Outbreak of Trichinellosis by Consumption of Raw Soft-Shelled Turtle Meat in Korea

Trichinellosis transmission to humans via the consumption of reptile meat is rare worldwide. In Korea, however, 2 such outbreaks, possibly via consumption of soft-shelled turtle meat, have occurred in 2 successive years. In 17 August 2014, 6 patients were admitted to Wonju Severance Christian Hospital complaining of myalgia, fever, and headache. Eosinophilia was the indication of the initial laboratory results, and they were eventually diagnosed as trichinellosis by ELISA. All of the patients worked at the same company and had eaten raw soft-shelled turtle meat at a company dinner 10 days prior to their admission. They were treated with albendazole for 2 weeks, upon which all of their symptoms disappeared. This is the 8th report on human trichinellosis in Korea, and the second implicating raw soft-shelled turtle meat.

Seroprevalence of Trichinella sp. in Wild Boars (Sus scrofa) from Yanggu-gun, Gangwon-do, Korea

A total 7 outbreaks of trichinellosis have occurred in Korea, mostly as a result of consumption of raw wild boar (Sus scrofa) meat. Since only 1 serological survey on wild boars had yet been performed in Korea, the present study aimed to estimate the prevalence of trichinellosis in wild boars and some species of rodents by artificial digestion and serological examinations in Yanggu-gun, Gangwon-do, the endemic area of trichinellosis. Both the wild boar and rodent muscle samples revealed no Trichinella larvae by direct examination and artificial digestion method. However, serological examinations revealed that 4 wild boar sera samples out of 118 (3.4%) were positive to Trichinella antigen. Although the recovery of Trichinella larvae ended in a failure, it is proved for the first time that the sylvatic cycle of Trichinella has been maintained in wild boars of Gangwon-do, Korea.

Prevalence of Serum IgG Antibodies to Cystic Echinococcus Antigen among Patients in an Uzbekistan Emergency Hospital

Cystic echinococcosis (CE) is one of the most widespread zoonotic helminthiases, which can last an asymptomatic infection for several years. The purpose of this study was to demonstrate serum antibody prevalence of CE among asymptomatic people in Uzbekistan using ELISA. A total of 2,547 serum samples were collected, 66 from confirmed CE patients and 2,481 of patients with other diseases than CE at a hospital in Tashkent, Uzbekistan. The serum samples were screened for CE specific IgG antibodies by ELISA using cystic fluid antigen obtained from sheep. The serum antibody positive rate was 89.4% (59/66) in CE and 3.6% (89/2,481) in other disease patients. The present ELISA recognized 89.4% sensitivity and 96.4% specificity. The ELISA absorbance of positive samples was distributed 0.271-0.971 for CE and 0.273-0.887 for other disease patients. The other disease patients with high absorbance over 0.3 were 50 (2.0%) who were presumed to be active CE patients. The patients in their 40s showed the highest positive rate of 5.2% (P=0.181), and women were 4.4% while men were 3.1% positive (P=0.136). The data confirmed that there are many asymptomatic patients of CE in Tashkent. It is indicated that CE is an endemic disease of public health importance in Uzbekistan.

Cross-reactivity of Toxocariasis with Crude Antigen of Toxascaris leonina Larvae by ELISA

Roundworms of Toxocara canis and Toxascaris leonina are common gastrointestinal helminths of canids over the world. Humans are infected with T. canis larvae through ingestion of infective eggs in contaminated environments or larvae by consumption of raw or uncooked meat or livers. Recently, patients of clinically diagnosed toxocariasis are increasing and require correct diagnosis in Korea. The present study investigated serological cross-reactivity between crude antigens of T. canis (TCLA) and T. leonina (TLLA) larvae. We collected serum specimens from 177 toxocariasis patients who were clinically suspected in the Seoul National University Hospital and 115 healthy controls. An ELISA method for toxocariasis was used to evaluate diagnostic efficacy of TLLA for serodiagnosis of human toxocariasis. The IgG ELISA using TLLA gave 14 (14.3%) positives of 98 TCLA positive specimens among 177 suspected toxocariasis patients. Most of them showed high absorbances with TCLA. In conclusion, there is a partial cross reaction between serum specimens of toxocariasis and TLLA.

Association between allergic responses and Schistosoma mansoni infection in residents in a low-endemic setting in Brazil

Introduction Schistosomiasis is endemic in 76 countries and territories. Several studies have found an inverse correlation between parasitic disease and the development of allergies. The purpose of the present study was to determine whether infection with Schistosoma mansoni in subjects with a low parasite load is protective against allergy. The final sample consisted of 39 S. mansoni-positive and 52 S. mansoni-negative residents of a small community in northeastern Brazil. Methods All subjects were submitted to the Kato-Katz test, anti-S. mansoni IgG measurement, the prick test for aeroallergens, eosinophil counts and serum IgE measurement. Results Subjects who reacted to one or more antigens in the prick test were considered allergic. Only 7 S. mansoni-positive subjects (17.9%) reacted to one or more antigens, whereas 20 S. mansoni-negative subjects (38.5%) tested positive for allergy. Conclusions Our findings suggest that, in areas of low endemicity, infection with S. mansoni significantly reduces the risk of the development of allergy in subjects with a low parasite load. .

Determination of IgG avidity in BALB/c mice experimentally infected with Toxocara canis / Determinação da avidez de IgG em camundongos BALB/c experimentalmente infectados com Toxocara canis

Toxocariasis is a zoonotic disease in that IgM titers can remain high for long periods making difficult to determine the stage of the disease. The aim of this study is to investigate the applicability of indirect ELISA, associated with urea, to discriminate between the acute and chronic toxocariasis. IgG avidity was evaluated in 25 BALB/c mice experimentally infected with 1000 Toxocara canis eggs. Blood samples were collected, and sera treated with 6 M urea and assayed by ELISA every two weeks. The percent IgG avidity was determined using the mean absorbance of sera treated with urea, divided by the mean absorbance of untreated sera. In the first 15 days post-inoculation, was observed a low percentage, between 7.25 and 27.5%, IgG avidity, characteristic of an acute infection. After 60 days of infection, all the mice showed between 31.4 and 58% IgG avidity, indicating a chronic infection.

A toxocaríase é uma zoonose na qual os títulos de IgM podem permanecer elevados por longos períodos, tornando difícil a determinação do estágio em que a doença se encontra. O objetivo deste estudo foi investigar a aplicabilidade de um teste indireto de ELISA, associado com ureia, para fazer a discriminação entre as fases aguda e crônica da toxocaríase. A avidez de IgG foi avaliada em 25 camundongos BALB/c experimentalmente infectados com 1000 ovos embrionados de Toxocara canis. A cada duas semanas, amostras de sangue foram coletadas, o soro tratado com ureia 6M e realizado o ensaio pela técnica de ELISA. O percentual de avidez de IgG foi determinado, usando-se a média das absorbâncias dos soros tratados com ureia dividida pela média das absorbâncias dos soros não tratados. Nos primeiros 15 dias pós-inoculação, foi observado um baixo percentual de avidez de IgG, entre 7,25 e 27,5%, característico da fase aguda da infecção. Após 60 dias de infecção, todos apresentaram avidez de IgG entre 31,4 e 58%, indicando a fase crônica da infecção.