Epidemiologia e controle da esquistossomose mansônica em área onde o hospedeiro intermediário é Biomphalaria tenagophila

The epidemiology and control of schistosomiasis mansoni in the Municipality of Pedro de Toledo (State of S. Paulo, Brazil) since 1980, has been studied. In 1980 the prevalence evaluated by stool exams (Kato-Katz method) was 22.8% and no statistical difference at 5.0% level was observed between rural and urban zones. The intensity of infection was low (58.5 eggs/g of faeces); the highest prevalence and intensity of infection rates were observed within the group of from 5 to 29 years of age, respectively. The transmission of schistosomiasis usually occurred during leisure time. The majority of the carriers of the parasite were asymptomatic. Of the B. tenagophila examined only 0.4% were found to be infected. The control programme has been intensified from 1981 on resulting in a sharp decrease in the prevalence from 22.8% in 1980 to 6% at the present time. This result shows that, in spite of the control programme there is a residual human prevalence. A beginning has been made on the investigation into the possible causes of this residual prevalence (6.0% was maintained through out 1987).Desde 1980, está-se estudando a epidemiologia e o controle da esquistossomose mansônica no Município de Pedro de Toledo (Estado de São Paulo, Brasil). Em 1980 a prevalência avaliada por exame de fezes (método de Kato-Katz) foi de 22,8%. Estatisticamente, ao nível de 5%, não houve diferença nas prêvalencias observadas nas zonas rural e urbana. A intensidade de infecção foi baixa (média geométrica de 58,5 ovos por grama de fezes). As maiores prevalências e intensidades de infecção foram registradas na faixa etária de 5 a 29 anos. Geralmente a transmissão da endemia verificou-se durante o lazer. Apenas 0,4% de B. tenagophila mostraram-se positivos para cercárias de S. mansoni. A maioria dos portadores era assintomático. O programa de controle foi intensificado após avaliação dos dados de 1980, resultando em diminuição acentuada da prevalência de 22,8% em 1980 para 6%. Esta prevalência residual vem se mantendo até 1987. Agora iniciamos estudos para investigar as possíveis causas dessa prevalência residual

Efficacy of an enzyme-linked immunosorbent assay as a diagnostic tool for schistosomiasis mansoni in individuals with low worm burden

IgM-ELISA is an immunoenzymatic method useful for detection of IgM antibodies against a fraction of Schistosoma mansoni adult worm antigen (AWA) that is soluble in trichloroacetic acid (AWA-TCA). This method was applied to three groups of individuals with different clinical and epidemiological characteristics, and the results compared with those obtained by other diagnostic methods: immunofluorescence test for detection of IgM antibodies (IgM-IFT) or IgG antibodies (IgG-IFT), ELISA for detection of IgG antibodies (IgG-ELISA), and two parasitological methods, Kato-Katz and miracidium hatching. The IgM-ELISA presented a sensitivity of 98%, when the parasitologic fecal examination was defined as reference diagnostic method, and a specificity of 98 and 97.3%, respectively for the group of clinically healthy individuals and other helminth carriers. A comparative analysis between the results of IgM-ELISA and those obtained by other serologic tests showed a good degree of agreement, with Kappa indices ranging from 0.95 to 0.98. The diagnostic efficacy of 97.8%, as determined with schistosomiasis patients with low parasitic burden, suggests the excellent performance of the IgM-ELISA and its usefulness for the diagnosis of schistosomiasis when applied in low endemic areas

Utilização de método sorológico como ferramenta diagnóstica para implementação da vigilância e controle da esquistossomose no Município de Holambra, São Paulo, Brasil

O presente estudo teve como objetivo avaliar a incorporação da reação de imunofluorescência indireta para pesquisa de anticorpos IgM (RIF-IgM) como método diagnóstico no programa de controle da esquistossomose do Município de Holambra, Estado de São Paulo, Brasil. O município foi selecionado para este estudo considerando-se a notificação dos primeiros casos de esquistossomose a partir de 1993 e a necessidade do município de implementar o programa com técnicas diagnósticas mais sensíveis, tendo em vista ser caracteristicamente área de baixa endemicidade. Duzentos e dois indivíduos foram submetidos à RIF-IgM, dos quais 48 apresentaram-se positivos, sendo 28 destes submetidos à técnica de Kato-Katz, examinando-se três amostras de fezes. Ovos de Schistosoma mansoni foram encontrados em 14, com carga parasitária variando de 2,7 a 224,0 ovos por grama de fezes. Os resultados indicam a potencialidade da RIF-IgM como método de triagem, para posterior confirmação exaustiva por método parasitológico, em áreas de baixa endemicidade

IgM-immunofluorescence test as a diagnostic tool for epidemiologic studies of schistosomiasis in low endemic areas

The high sensitivity and the ability to diagnose schistosomiasis in a very early phase after infection have indicated the detection of IgM antibodies to Schistosoma mansoni gut antigens by the immunofluorescence test (IgM-IFT) as a useful serological test for epidemiological studies in low endemic areas. When applied in a follow-up study for two years, higher rates of seroconversion from IFT negative to positive were observed during the summer months, suggesting seasonal transmission of schistosomiasis in the rural area of the municipality of Itariri (São Paulo, Brazil). In each survey, blood samples from about 600 schoolchildren were collected on filter paper and submitted to IgM-IFT. When the blood samples were classified for the IgM antibody levels, according to the intensity of fluorescent reaction observed at fluorescence microscopy, and correlated to the egg counts in the Kato-Katz positive patients, no association was observed. This observation might suggest that the intensity of fluorescence observed in the IgM-IFT, as an indicator of IgM antibody levels, could not be an useful seroepidemiological marker for classifying areas of low endemicity according to degrees of infection

Quantitative Coprotest®: quantification of helminth eggs in fecal samples by commercial diagnostic kit

Made available in DSpace on 2019-09-12T16:25:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2003A técnica coproparasitológica de concentração em formol acetato de etila foi empregada para a quantificação de ovos de helmintos. O método quantitativo proposto foi padronizado utilizando-se o sistema comercial Coprotest® e amostras fecais contendo diferentes cargas de ovos de Ascaris lumbricoides. Para a comparação do Coprotest® quantitativo com outros métodos de quantificação de ovos, foi preparada em laboratório uma série de amostras fecais, com carga decrescente de ovos de A. lumbricoides, Trichuris trichiura e Schistosoma mansoni. Discutem-se as vantagens de se empregar um método capaz de detectar maior número de espécies de helmintos, além de protozoários, e que permita, concomitantemente, estimar a intensidade das infecções por geo-helmintos e S. mansoni nas populações. O Coprotest® quantitativo mostrou ser de aplicação viável, fornecendo resultados comparáveis a outros métodos quantitativos já descritos na literatura.The formol ethyl acetate concentration technique was applied for the quantification of helminth eggs in fecal samples. The proposed quantitative method was standardized through the use of a commercial kit, Coprotest®, and fecal samples with different counts of Ascaris lumbricoides eggs. For the comparison of the quantitative Coprotest® with other methods of egg quantification, a series of fecal samples was prepared in laboratory, with decreasing number of A. lumbricoides, Trichuris trichiura and Schistosoma mansoni eggs. It is discussed the advantages of a method that is able of detecting different helminth and also protozoa species, allowing, in concomitance, to estimate in the populations the intensity of S. mansoni and geohelminth infections. The quantitative Coprotest® showed to be feasible, providing results that were comparable to the other quantitative methods already described in the literature.[Kanamura, Hermínia Yohko] Instituto Adolfo LutzDias, Luiz Cândido de Souza] Universidade Estadual de Campinas, BrazilAraújo, Ana Julia Urias Santos] Universidade de São Paulo, BrazilGomes, Jancarlo Ferreira] Immunoassay Produtos Hospitalares LtdaAraújo, Sérgio de Moura] Unita

A comparative study on IgG-ELISA, IgM-IFT and Kato-Katz methods for epidemiological purposes in a low endemic area for schistosomiasis

The high sensitivity and the possibility of automation of the enzyme-linked-immunosorbent-assay (ELISA) has indicated this technique as one of the most useful serological test for epidemiological studies. In the present study, an ELISA for detection of IgG antibodies against adult worm antigens (IgG-ELISA) was investigated for epidemiological purposes, in a rural area of the municipality of Itariri (São Paulo, Brazil). Blood on filter paper (1,180 samples) from about 650 schoolchildren were submitted to ELISA and the data compared to the results of the parasitological method of Kato-Katz and also to the IgM-IFT (immunofluorescence test for IgM antibodies to gut associated antigens). The prevalence rates respectively of 8.5%, 43.0%, and 56.2% by the Kato-Katz, IgG-ELISA, and IgM-IFT methods suggest the poor sensitivity of the parasitological method for detection of Schistosoma mansoni eggs in individuals with low worm burden, situation commonly observed in low endemic areas. These results can partially explain the poor degree of agreement between the IgG-ELISA and the Kato-Katz, as suggested by the Kappa index of 0.170. Otherwise, the Kappa index of 0.675 showed substantial agreement between the two serological tests. Some discrepancy of results between the two serological techniques must be better investigated

Application of synthetic peptides in development of a serologic method for laboratory diagnosis of schistosomiasis mansoni

The immunoreactivity of seven peptides synthesized from Schistosoma mansoni proteins, was evaluated by dot-blot and ELISA assays using two different sensitization methodologies. The best results were obtained on wells of the Costar 3590 microplates coated with peptides P1, P2, P3, P6, and P7 using conventional methodology. The signals increased considerably (p < 0.0003) on wells sensitized with P1 to P6 using alternative methodology. In contrast, the well coated with peptide P7 presented lower signal when compared with conventional methodology (p = 0.0019). These results, establish the basis for the application of synthetic peptides for laboratory diagnosis of schistosomiasis mansoni

The epidemiology and control of schistosomiasis mansoni where Biomphalaria tenagophila is the snail host Epidemiologia e controle da esquistossomose mansônica em área onde o hospedeiro intermediário é Biomphalaria tenagophila

The epidemiology and control of schistosomiasis mansoni in the Municipality of Pedro de Toledo (State of S. Paulo, Brazil) since 1980, has been studied. In 1980 the prevalence evaluated by stool exams (Kato-Katz method) was 22.8% and no statistical difference at 5.0% level was observed between rural and urban zones. The intensity of infection was low (58.5 eggs/g of faeces); the highest prevalence and intensity of infection rates were observed within the group of from 5 to 29 years of age, respectively. The transmission of schistosomiasis usually occurred during leisure time. The majority of the carriers of the parasite were asymptomatic. Of the B. tenagophila examined only 0.4% were found to be infected. The control programme has been intensified from 1981 on resulting in a sharp decrease in the prevalence from 22.8% in 1980 to 6% at the present time. This result shows that, in spite of the control programme there is a residual human prevalence. A beginning has been made on the investigation into the possible causes of this residual prevalence (6.0% was maintained through out 1987).<br>Desde 1980, está-se estudando a epidemiologia e o controle da esquistossomose mansônica no Município de Pedro de Toledo (Estado de São Paulo, Brasil). Em 1980 a prevalência avaliada por exame de fezes (método de Kato-Katz) foi de 22,8%. Estatisticamente, ao nível de 5%, não houve diferença nas prêvalencias observadas nas zonas rural e urbana. A intensidade de infecção foi baixa (média geométrica de 58,5 ovos por grama de fezes). As maiores prevalências e intensidades de infecção foram registradas na faixa etária de 5 a 29 anos. Geralmente a transmissão da endemia verificou-se durante o lazer. Apenas 0,4% de B. tenagophila mostraram-se positivos para cercárias de S. mansoni. A maioria dos portadores era assintomático. O programa de controle foi intensificado após avaliação dos dados de 1980, resultando em diminuição acentuada da prevalência de 22,8% em 1980 para 6%. Esta prevalência residual vem se mantendo até 1987. Agora iniciamos estudos para investigar as possíveis causas dessa prevalência residual