Presentación atípica de toxocariasis infantil: a propósito de un caso / Atypical presentation of infant toxocariasis: about a case

Resumen Se presenta el caso de una niña de 8 años, procedente de la Amazonia peruana, con una presentación atípica de una toxocariasis. El cuadro clínico, de un mes de evolución, fue caracterizado por dolor abdominal crónico, palidez y geofagia, asociado a una masa abdominal y linfoadenopatías generalizadas. No hubo sintomatología respiratoria, dérmica, ocular o neurológica. En el hemograma se encontró una anemia y eosinofilia periférica acentuada y una eosinofilia moderada en el aspirado medular. El diagnóstico fUe confirmado por serología por el método de enzimoinmunoanálisis (ELISA), que mostró la presencia de anticuerpos anti-Toxocara de tipo IgG e IgM. Se administró tratamiento con albendazol 400 mg al día, durante cinco días, con una evolución favorable.

Abstract We present the case of an 8-year-old girl with an atypical presentation of toxocariasis, from the Peruvian Amazon. A month ago, the clinical presentation was characterized by the presence of abdominal pain, paleness and geophagia, associated with an abdominal mass and generalized lymphadenopathy. There were no respiratory, dermal, ocular or neurological symptoms. Marked peripheral eosinophilia was found in the blood count, and moderate eosinophilia in the spinal cord aspírate. The diagnosis was confirmed by serology with the enzyme-linked immunosorbent assay (ELISA), which showed the presence of IgG and IgM anti- Toxocara antibodies. Treatment with albendazole 400 mg once daily was administered for five days with favorable evolution.

Innovative approaches to improve serodiagnosis of Strongyloides stercoralis infection

ABSTRACT Strongyloidiasis is a helminthiasis of neglected condition that has no gold standard parasitological diagnosis due to the intermittent release of larvae in feces. This study aimed to use an scFv (single chain variable fragment) obtained by Phage Display, previously validated to detect immune complexes in serum samples from individuals infected with Strongyloides stercoralis by enzyme-linked immunosorbent assay (ELISA). Now the ability of scFv to detect the immune complexes was verified by immunofluorescence, flow cytometry using magnetic beads and surface plasmon resonance (SPR). As ELISA, the SPR, immunofluorescence and flow cytometry demonstrated the ability of scFv to detect immune complexes in sera from individuals with strongyloidiasis and discriminate them from sera of individuals with other parasitic diseases and healthy individuals. Besides de conventional ELISA, the novel approaches can also be promptly applied as auxiliary diagnostic tools to the existing parasitological method for accurate diagnosis of human strongyloidiasis.

Frequency of enteroparasitic infections and serum positivity for Toxocara spp. in children from a public day care center in Southern Brazil / Frequência de enteroparasitos e de soropositividade para Toxocara spp. em crianças de uma creche pública do Sul do Brasil

Abstract Introduction Day care centers play an important social role in children's early education and development. The objective of this study was to investigate the frequency of intestinal parasitic infections and infection with Toxocara spp. in children from a day care center in the city of Rio Grande, Rio Grande do Sul, Brazil. Methods: The study was conducted using fecal samples from 50 children, ages three to six years, using Ritchie, Faust, Rugai, and Kinyoun's techniques. A closed and structured epidemiological questionnaire was used to collect data from the parents/guardians of the children. Serological studies for detection of antibodies to Toxocara spp. by immunoenzymatic assays using Toxocara excretion and secretion antigen (TES) were conducted on sera collected from 41 children. Results: The frequency of enteroparasites was 18%, with 43.9% of the children testing seropositive for Toxocara spp. Low family income and low literacy levels of parents/guardians were common factors between the families of the parasite-positive children. For the children who tested positive for Toxocara spp., most of the parents/guardians reported using only water for sanitizing raw vegetables and fruits. Conclusions: The high seropositivity rates for Toxocara spp. indicate that children were exposed to this parasite, and it is important to reduce the risk of infection. In addition, the seropositivity for enteroparasites and the interviews with the parents/guardians indicate the need to educate the studied population regarding the modes of intestinal parasite transmission and the prophylactic measures needed to prevent their dissemination.

Resumo Introdução As creches desempenham um importante papel social na educação e desenvolvimento inicial das crianças. O objetivo deste estudo foi investigar a frequência de infecções parasitárias intestinais, além de infecção por Toxocara spp. em crianças de uma creche na cidade do Rio Grande, Rio Grande do Sul, Brasil. Métodos: Para o estudo, foram coletadas amostras fecais de 50 crianças de três a seis anos, analisadas pelas técnicas de Ritchie, Faust, Rugai e Kinyoun, sendo aplicado um questionário epidemiológico fechado e estruturado aos pais/responsáveis ​​das crianças. Também foi realizada uma pesquisa sorológica de anticorpos para Toxocara spp. em 41 crianças, pelo ensaio imunoenzimático, associado ao antígeno de excreção e secreção (ES), com soros pré-adsorvidos com antígeno somático de Ascaris lumbricoides. Resultados: A frequência de enteroparasitos foi de 18%, enquanto que 43.9% das crianças foram soropositivas para Toxocara spp.. Baixa renda familiar e baixo nível de alfabetização dos pais/responsáveis ​​foram fatores comuns entre as famílias das crianças parasitadas. A maioria dos pais ou responsáveis das crianças, com diagnóstico positivo para enteroparasitos ou para Toxocara spp., relatou utilizar apenas água para a higienização de verduras e frutas. Conclusões: As altas taxas de soropositividade para Toxocara spp. indicam que as crianças foram expostas a esse parasito, sendo importante minimizar o risco de infecção. Além disso, a positividade de 18% para enteroparasitos e os dados obtidos com as entrevistas realizadas com os pais ou responsáveis demonstram a necessidade da realização de trabalhos com a população estudada que visem a divulgação sobre as parasitoses intestinais, especialmente sobre medidas profiláticas especificas.

Schistosomiasis: an epidemiological update on Brazils southernmost low endemic area in Esteio

Abstract INTRODUCTION: Brazil's southernmost state, Rio Grande do Sul (RGS), was considered schistosomiasis-free until 1998 when a low endemic focus was identified in Esteio, a city located next to the capital of RGS. In the last two decades, the control interventions applied in the region have been apparently successful, and the absence of new cases indicated the possibility of interrupted schistosomiasis transmission. The objective of this study was to update the clinical and epidemiological data of schistosomiasis in Esteio. METHODS: We reviewed all 28 individuals diagnosed with the infection since 1997 and a survey was applied to a group of 29 school-aged children residing in Vila Pedreira, one of the most affected neighborhoods. RESULTS No eggs were detected in fecal samples using the Helmintex method, and all samples were negative for serum antibodies on examination by the western blot technique using the Schistosoma mansoni microsomal antigen (MAMA- WB). In contrast, 23 individuals (79%) tested positive for the cathodic circulating antigen with the point-of-care immunochromatographic test (POC-CCA) on urine samples. Of the 28 formerly infected individuals, only eight were located, of which four tested positive, and four tested negative for serum antibodies using the MAMA-WB technique. CONCLUSIONS: Current adverse conditions for S. mansoni transmission in Esteio and the absence of a confirmed diagnosis suggests that there is (i) a lack of specificity of the POC-CCA test in low endemic settings, and (ii) a high probability that interruption of schistosomiasis has been achieved in Esteio.

Infection by Angiostrongylus cantonensis in both humans and the snail Achatina (Lissachatina) fulica in the city of Macapá, in the Amazon Region of Brazil

In January and February 2019, a malacological survey was conducted in the area surrounding the residence of a 12-year-old child that had contracted cerebral angiostrongyliasis in the municipality of Macapá, capital of the Amapá State, northern Brazil. The serological examination was positive for Angiostrongylus cantonensis infection, the principal etiological agent of this parasitosis. A sample of 54 molluscs was artificially and individually digested for parasitological analysis, containing 38 specimens of Achatina fulica, nine specimens of Bulimulus tenuissimus and seven specimens of Sarasinula linguaeformis. A. fulica was the most abundant mollusc, and the only species infected with A. cantonensis, as well as presenting co-infections with other nematodes. This is the first report of cerebral angiostrongyliasis in the Amazon Region, and the first record of A. fulica infected with A. cantonensis in Amapá. These findings highlight the potential risks of human angiostrongyliasis, and the need to implement public health measures to control the spread of the disease.

Extract of Ascaris suum induces TGF-ß and early production of IgG1 in experimental autoimmune hepatitis / Extrato de Ascaris suum induz TGF-ß e produção precoce de IgG1 na hepatite autoimune experimental

Abstract In experimental autoimmune hepatitis (EAH) of Th1 profile, an extract of adult Ascaris suum worms (ASC) was previously found to deviate the immune response to a Th2/IL-10 pattern. Here, the effects of treatment with ASC on production of TGF-β and the anti-Ascaris isotypes IgG1 and IgG2a in EAH were evaluated. EAH was induced in BALB/c mice, intravenously with concanavalin A. Two hours later, these animals received ASC (EAH+ASC group) or PBS vehicle (EAH group). IgG1 and IgG2a were evaluated 8 h, 24 h and 7 d after induction. TGF-β was measured in a splenocyte culture at this last time. The isotype levels in the EAH group were low throughout the kinetics. In the EAH+ASC group, there was significant production of IgG1 at 24 h and 7 d, but of IgG2a only at 7 d. There was statistically greater production of TGF-β in the EAH+ASC group. The higher levels of IgG1 and TGF-β in this group suggest that an additional Th1 response control route exists in EAH, which needs to be investigated.

Resumo Na hepatite autoimune experimental (HAE) de perfil Th1, o extrato de vermes adultos Ascaris suum (ASC) desviou a resposta imune para um padrão Th2/IL-10. Neste trabalho, foram avaliados os efeitos do tratamento com ASC na produção TGF-β e dos isótipos de IgG1 e IgG2a anti-Ascaris na HAE. Esta foi induzida em camundongos BALB/c intravenosamente com Concanavalina A. Após duas horas, os animais receberam ASC (grupo HAE+ASC) ou veículo PBS (grupo HAE). IgG1 e IgG2a foram avaliados em 8 horas, 24 horas e 7 dias após indução. TGF-β foi mensurado em cultura de esplenócitos nesse último tempo. Os níveis dos isótipos no grupo HAE foram baixos durante toda a cinética. No grupo HAE+ASC, houve produção significativa de IgG1 em 24 horas e 7 dias, mas somente em 7 dias para IgG2a. A produção de TGF-β foi estatisticamente maior no grupo HAE+ASC. Níveis mais altos de IgG1 e TGF-β nesse grupo sugerem uma via adicional de controle da resposta Th1 na HAE que precisa ser investigada.

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.

IgE antibodies from schistosomiasis patients to recognize epitopes in potato apyrase

Abstract INTRODUCTION: High percentages of structural identity and cross-immunoreactivity have been reported between potato apyrase and Schistosoma mansoni ATP diphosphohydrolase (SmATPDases) isoforms, showing the existence of particular epitopes shared between these proteins. METHODS: Potato apyrase was employed using ELISA, western blot, and mouse immunization methods to verify IgE reactivity. RESULTS: Most of the schistosomiasis patient's (75%) serum was seropositive for potato apyrase and this protein was recognized using western blotting, suggesting that parasite and plant proteins share IgE-binding epitopes. C57BL/6 mice immunized with potato apyrase showed increased IgE antibody production. CONCLUSIONS: Potato apyrase and SmATPDases have IgE-binding epitopes.

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.

Maternal schistosomiasis: IL-2, IL-10 and regulatory T lymphocytes to unrelated antigen in adult offspring mice

Abstract INTRODUCTION: We evaluated IL-10, IL-2 and regulatory T cells (Treg), in response to ovalbumin (OA), in offspring from schistosomotic mouse mothers. METHODS: We used animals born (BIM) or suckled (SIM) from infected mothers; and mice born/suckled from infected (BSIM) or non-infected mothers (CONTROL). After OA+adjuvant immunization, spleen cells were cultured, with or without OA, and doubly marked for cytometry. RESULTS: BIM showed fewer CD4+/IL-2+ and more B220+/IL-10+ cells, whereas the SIM group showed increased Treg frequency. BSIM had fewer B220+/IL-10+ and Treg cells. CONCLUSIONS: Separately, gestation or nursing induced immunosuppressive cells in infected mothers, but improved anti-OA immunity when combined.

Sheep polyclonal antibody to map Haemonchus contortus mimotopes using phage display library / Anticorpo policlonal de ovinos para mapear mimetopos de Haemonchus contortus usando a biblioteca de Phage display

Abstract The aim of this study was to evaluate phage display technology for mapping Haemonchus contortus mimotopes. We screened the PhD-7 Phage Display Peptide Library Kit with a sheep polyclonal antibody against H. contortus. After four rounds of selection, 50 phage peptide clones were selected by biopanning and sequenced. Two clones displaying peptide mimotopes of H. contortus proteins were chosen for sheep immunization: clone 6 - mimotope of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and clone 17 - mimotope of a disorganized muscle family member (Dim 1). Twelve sheep were allocated into 3 groups of 4 animals as follow: G1: control group; G2/GAPDH: immunized with clone 6; and G3/Dim1: immunized with clone 17. Four immunizations were performed at intervals of seven days (0, 7, 14, and 21 days). On day 28 post initial vaccination, all groups were orally challenged with 2500 H. contortus infective larvae. The mimotope peptides selected by phage display were recognized by IgG from sheep naturaly infected with H. contortus. The immunization protocol showed an increasein IgG anti-M13 phage titers, but no effect was observed in IgG-specific for the anti-mimotope peptides. This is the first report of successful use of a phage display library for the identification of mimotopes of H. contortus proteins.

Resumo O objetivo deste estudo foi avaliar a tecnologia de phage display no mapeamento de mimetopos de Haemonchus contortus. Anticorpo policlonal de ovinos anti-H. contortus foi usado para seleção a partir da biblioteca PhD-7 Phage Display Peptide Library Kit (New England BioLabs). Após quatro rodadas, 50 clones de fagos expressando peptídeos foram selecionados e sequenciados. Dois clones que exibiram mimetopos de H. contortus foram escolhidos para imunização de ovinos: clone 6 - mimetopo de gliceraldeído-3-fosfato desidrogenase (GAPDH) e clone 17 - mimetopo da família do músculo desorganizado (Dim 1). Doze ovinos foram alocados em 3 grupos de 4 animais, da seguinte forma: G1: grupo controle, G2/GAPDH: imunizado com o clone 6 e G3/Dim1: imunizado com o clone 17. Quatro imunizações foram realizadas (0, 7, 14 e 21 dias). No dia 28 após a primeira imunização, todos os grupos foram desafiados oralmente com 2500 larvas infectantes de H. contortus . Os peptídeos mimetopos selecionados foram reconhecidos por IgG de ovinos naturalmente infectados por H. contortus. O ensaio de imunização revelou um aument dos títulos de IgG anti-fago M13, mas não ocorreu aumento de IgG anti-peptídeos mimetopos. Este é o primeiro relato de uso bem sucedido da biblioteca de Phage display para a identificação de mimetopos de H. contortus.

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.