Freqüência de infecção por Toxocara em crianças atendidas em serviço público de Maringá, sul do Brasil

The lack of specific laboratorial diagnosis methods and precise symptoms makes the toxocariasis a neglected disease in Public Health Services. This study aims to determine the frequency of Toxocara spp. infection in children attended by the Health Public Service of Hospital Municipal de Maringá, South Brazil. To evaluate the association of epidemiological and clinical data, an observational and cross-section study was carried out. From 14,690 attended children/year aged from seven month to 12 years old, 450 serum samples were randomly collected from September/2004 to September/2005. A questionnaire was used to evaluate epidemiological, clinical and hematological data. An ELISA using Toxocara canis larval excretory-secretory products as antigen detected 130 (28.8%) positive sera, mainly between children from seven month to five years old (p = 0.0016). Significant correlation was observed between positive serology for Toxocara, and frequent playing in sandbox at school or daycare center (p = 0.011) and the presence of a cat at home (p = 0.056). From the families, 50% were dog owners which exposed soil backyards. Eosinophilia (p = 0.776), and signs and symptoms analyzed (fever p = 0.992, pneumonia p = 0.289, cold-like symptoms p = 0.277, cough p = 0.783, gastrointestinal problems p = 0.877, migraine p = 0.979, abdominal pain p = 0.965, joint pain p = 0.686 and skin rash p = 0.105) could not be related to the presence of anti-Toxocara antibodies. Therefore, two asthmatics children showed titles of 1:10,240 and accentuated eosinophilia (p = 0.0001). The authors emphasize the needs of prevention activities.A falta de métodos de diagnóstico laboratorial específico e sintomas específicos fazem da toxocaríase uma doença negligenciada nos serviços públicos de saúde. Este estudo teve por objetivo determinar a freqüência de infecção por Toxocara spp. em crianças atendidas no serviço público do Hospital Municipal de Maringá, sul do Brasil, e avaliar a associação com dados epidemiológicos e clínicos, em estudo observacional e transversal. De 14.690 crianças/ano atendidas, com idade entre sete meses a 12 anos, foram coletados 450 soros de setembro/2004 a setembro/2005. Um questionário foi utilizado para avaliar dados epidemiológicos, clínicos e hematológicos. Pelo teste ELISA, com antígeno de excreção/secreção de larvas de Toxocara canis, detectou-se 130 (28,8%) soros positivos, principalmente em crianças entre sete meses e cinco anos (p = 0,0016). Houve significante correlação entre sorologia positiva para Toxocara e freqüente recreação das crianças em caixas de areia da escola ou pré escola (p = 0,011) e presença do gato no domicilio (p = 0,056). Das famílias dessas crianças, 50% possuíam cachorros e o quintal com solo exposto. Eosinofilia (p = 0,776), sinais e sintomas (febre p = 0,992, pneumonia p = 0,289, resfriado p = 0,277, tosse p = 0,783, problema gastrointestinal p = 0877, dor de cabeça p = 0,979, dor abdominal p = 0,965, dores articulares p = 0,686, urticária p = 0,105) não se correlacionaram com a soropositividade. Todavia, duas crianças asmáticas apresentaram títulos de 1:10.240 (>; 1:320) e acentuada eosinofilia (p = 0.0001). Os autores enfatizam a necessidade de atividades preventivas

Human toxocariasis: contribution by Brazilian researchers

In the present paper the main aspects of the natural history of human infection by Toxocara larvae that occasionally result in the occurrence of visceral and/or ocular larva migrans syndrome were reviewed. The contribution by Brazilian researchers was emphasized, especially the staff of the Tropical Medicine Institute of São Paulo (IMT)

Standardization of dot-ELISA for the serological diagnosis of toxocariasis and comparision of the assay with ELISA Padronização do teste dot-ELISA para o diagnóstico da toxocaríase, estudo comparativo com o teste imunoenzimático ELISA

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.<br>Padronizou-se o teste imunoenzimático dot-ELISA, empregando-se os antígenos somático (S) e excretor-secretor (ES) de Toxocara canis, para pesquisa de anticorpos específicos em 22 soros de pacientes com idades entre 5 a 15 anos, com dados clínicos de toxocaríase. Como grupo controle, foram estudados 14 soros de indivíduos supostamente normais e 28 soros de pacientes com outras patologias. Todas as amostras em estudo foram empregadas antes e após absorção com extrato de Ascaris suum. Os resultados obtidos foram avaliados comparativamente com o teste ELISA evidenciando, nos dois testes estudados, comportamento semelhante quanto à sensibilidade e maior especificidade para o dot-ELISA, com qualquer dos dois antígenos estudados. O teste dot-ELISA mostrou-se eficiente para o diagnóstico da toxocaríase humana, apresentando vantagens quanto ao rendimento, estabilidade, tempo e facilidade de execução e baixo custo

Toxocara seroprevalence in children from a subtropical city in Argentina Prevalencia de anticuerpos anti Toxocara en niños de una ciudad subtropical de Argentina

Most studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73% of the children had one or more dogs living at home, 57% reported geophagia and 37.9% were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls.<br>La mayoría de los estudios realizados en Argentina, han enfocado a la Toxocariosis como un problema medioambiental propio de las grandes ciudades y no existen datos acerca de esta infección entre los niños de ciudades medianas o pequeñas. A fin de determinar la prevalencia de anticuerpos anti-Toxocara en la población infantil de la ciudad de Resistencia, se estudiaron 206 niños de ambos sexos, con edades comprendidas entre los 1-14 años, mediante el test de Elisa, empleando antígenos E/S de larva L2 de Toxocara canis. También se evaluaron los niveles de inmunoglobulinas séricas y los parámetros hematológicos; se efectuaron análisis coproparasitológico seriados en heces de 5 días y se recolectó información epidemiológica mediante cuestionario a los padres. Los resultados obtenidos señalan que el 73% de los niños tenían uno o mas perros viviendo en la casa, que el 57% tenían antecedentes de geofagia y que el 37.9% tenían serología positiva para Toxocara, aunque no hubo diferencias estadísticamente significativas entre varones y mujeres ni con la edad. Un mayor riesgo de contraer la infección se observó entre los grupos etarios 5-6 y 7-8 de varones y 3-4 y 5-6 de mujeres

An alternate technique for isolation of Toxocara canis excretory-secretory antigens

The aim of the present study was to test the effectiveness of a sausage-casing membrane for dialysis of Toxocara excretory-secretory antigens (TES). The protein concentrated by the tested membrane was compared with that obtained using a Sigma commercial membrane, as were the protein fractions found by polyacrylamide gel electrophoresis. Standard positive and negative serum samples were evaluated in an ELISA immunoassay, and equivalent data were obtained in all steps, indicating that the sausage-casing membrane is efficient, besides being less expensive to process.<br>O objetivo do presente estudo foi testar a eficácia de uma membrana utilizada para o preparo de embutidos, na obtenção do antígeno de excreção e secreção de Toxocara (TES). A concentração protéica foi comparada com a obtida com a membrana Sigma tanto quanto as frações protéicas separadas por eletroforese em gel de poliacrilamida. Amostras de soros padrão positivo e negativo foram avaliadas no teste imunoenzimático ELISA. Dados equivalentes foram observados em todas as etapas, sugerindo que a membrana possa ser utilizada para diálise por ser eficiente e de menor custo no preparo do antígeno

Occupational and domiciliary contact with dogs as factors of risk to human infection with Toxocara larvae

The contact with dogs at home or place of work has been investigated as factors of risk in the occurrence of the visceral larva migrans syndrome caused by Toxocara, in man. Through the E.L.I.S.A. (enzyme-linked immunosorbent assay) technique, the presence of antibodies to Toxocara was searched in the sera of 79 women who have been raising or had raised dogs at home in the last two years and 123 men, who were municipal public employees in charge of the capture and keeping of stray dogs. The control groups were constituted by 205 sera from women who denied domiciliary contact with dogs, at least in the last two years, and 139 sera from men whose occupation did not urge them to contact with dogs. A significant more elevated frequency of antibodies to Toxocara was observed among women with domiciliary contact with dogs; nevertheless, there was not a significant difference in the positive rates in the case of men with occupational contact with dogs