Ana Maria Carvalho de Souza

Visceral larva migrans: a seroepidemiological survey in five municipalities of São Paulo State, Brazil

An enzyme-linked immunosorbent assay (ELISA), employing antigens from Toxocara canis larvae and the absortion of suspected sera with Ascaris lumbricoides extracts was used in a seroepidemiological study performed in five municipalities of São Paulo State, Brazil (São Paulo, Campinas, Santos, Marília and Presidente Prudente) in order to determine the frequency of antibodies to Toxocara. In 2,025 blood samples collected, 806 proceeded from male subjects and 1,219 from females; 483 samples were collected from subjects under 15 years of age and the remaining 1,542 from subjects aged 15 years or over. Among the 2,025 sera investigated, 3.60% had antibodies to Toxocara at significant levels. A moderate predominance of infection with Toxocara among male subjects (3.72%) was observed, although the difference was not statistically significant when this rate was compared with that for female (3.28%). Related to age, a higher frequency of positive results was detected among subjects under 15 years (6.41%) against the older group (2.53%). A trend of more elevated rates of infection was observed in municipalities with high demographic densities (São Paulo, Campinas and Santos). Nevertheless, such findings only appeared to be statistically significant in subjects younger than 15 years.

Contacto domiciliar e profissional com cães como fatores de risco para infecção humana por larvas de Toxocara

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.Investigou-se o papel do contacto com caes no domicilio e na atividade profissional como fatores de risco para transmissao de larvas de Toxocara sp. a seres humanos, acarretando a sindrome de larva migrans visceral. Atraves de tecnica imunoenzimatica (E.L.I.S.A.) pesquisou-se a presenca de anticorpos anti-Toxocara no soro de 79 mulheres adultas, residentes no municipio de Sao Paulo, que possuiam, ou possuiram nos dois ultimos anos, caes em seus domicilios e de 123 homens adultos, funcionarios da Prefeitura Municipal de Sao Paulo, encarregados da captura de caes vadios e de sua manutencao em canis. Como controles utilizaram-se os soros de 205 mulheres adultas que nao possuiram, nos dois ultimos anos, caes em suas casas e de 139 homens adultos, cuja atividade profissional nao os obrigava a manter contacto com caes. Os resultados indicaram que, nas condicoes do presente trabalho, a posse de caes no domicilio constitui fator de risco para transmissao de larvas de Toxocara a seres humanos, ao contrario do verificado para o contacto profissional com caes.

Estudo comparativo de testes sorológicos no diagnóstico imunológico da neurocisticercose

Estudamos comparativamente quatro tecnicas imunologicas para o diagnostico da neurocisticercose (NC) utilizando liquido cefalorraquiano (LCR) como especime clinico: as reacoes de fixacao de complemento (RFC), hemaglutinacao passiva (RHA), imunofluorescencia indireta (RIF) e teste imunoenzimatico ELISA Foram ensaiadas 125 amostras de LCR de pacientes com NC comprovada e 94 amostras de LCR do grupo controle (60 de pacientes com quadros clinicos neurologicos diversos e 34 de pacientes supostamente normais). Os indices de sensibilidade e especificidade obtidos para os testes foram, respectivamente, de 48,0% e 90,4% para a RFC; 88,8% e 96,8% para a RHA; 87,2 e 98,9% para a RIF e 97,6% e 98,9% para o teste ELISA. A diferenca significativa (p < 0,05) observada entre os testes permite concluir que o melhor teste para o diagnostico de NC foi o teste ELISA seguido das reacoes de HA e IF.

Imunodiagnóstico da leptospirose humana através do teste ELISA-IgM, empregando-se diferentes preparações antigênicas a partir de sorotipos prevalentes de Leptospira interrogans

Realizou-se estudo comparativo de diferentes sorotipos de Leptospira interrogans utilizados na preparacao de antigenos empregados no teste ELISA, para a deteccao de anticorpos da classe IgM, em amostras de soro na fase precoce e tardia da leptospirose humana. Foram utilizados dez sorotipos, escolhidos entre os que apresentaram maior reatividade na soroaglutinacao microscopica (SAM), na cidade de Sao Paulo. Os cinco sorotipos que apresentaram melhores resultados individualmente no teste ELISA-IgM (canicola, hebdomadis, icterohaemorrhagiae, cynopteri e brasiliensis), foram tambem estudados em mistura antigenica. Os antigenos nao tratados apresentaram maior reatividade do que os antigenos tratados com Triton X - 100 (4%) a temperatura de 50oC, durante 4 horas. O teste ELISA-IgM empregando os sorotipos nao tratados, isoladamente, e em mistura antigenica, mostrou-se altamente sensivel, podendo ser empregado como teste de triagem para o diagnostico precoce da leptospirose humana. Outra aplicacao do teste e permitir a deteccao do inicio de situacoes epidemicas ou de surtos, possibilitando acionar medidas de vigilância epidemiologica.

Teste imunoenzimático (ELISA) para detecção de anticorpos circulantes da classe IgM na leptospirose humana

An Enzyme-linked immunosorbent assay ELISA was evaluated for the detection of IgA antibodies in the human leptospirosis. The assay proved to be sensitive and specific when compared with the ELISA-IgM, in the examinated serum samples. The results found suggest that IgA antibodies became positive later in leptospirosis, and will can be an evolutive indicator in the development of the diseaseFoi avaliado o teste imunoenzimatico (ELISA), para deteccao de anticorpos da classe IgM na leptospirose humana. Nas amostras de soros analisadas, o teste ELISA demonstrou ser mais sensivel, especifico e precoce, quando comparado ao teste de soroaglutinacao microscopica. A analise dos resultados obtidos nesta avaliacao demonstra que o teste ELISA permite detectar niveis baixos de anticorpos circulantes, e tambem anticorpos nao aglutinantes. nao detectaveis atraves do teste de soroaglutinacao microscopica.

Teste imunoenzimático para pesquisa de anticorpos anti-Cysticercus cellulosae em líquidos cefalorraquianos de pacientes com meningites de etiologia indeterminada

The enzyme-linked-immunosorbent assay using a new type of support consisting of discs of synthetic fabric-resin (ELISA-d) with antigenic components of Cysticercus cellulosae covalently bound, was employed with the purpose of investigating the presence of specific antibodies to the cysticerci (neurocysticercosis) in the cerebrospinal fluid (CSF) of patients with meningitis without etiological agent determined by the conventional methods. The test was performed in 277 CSF samples (128 children and 149 adults). The mean of optical density values (OD) obtained for 22 CSF normal patients (the diagnostic hyphotesis of meningitis was discarded) was of 0.03. The 44 CSF of patients with meningitis caused by other agents but C. cellulosae, showed OD of 0.05. The cut off determined with these two groups (control group) was 0.13 (OD + 3 SD). The group of 13 CSF of neurocysticercotic meningitis presented OD of 0.41 (0.10 to 0.91). Among the 198 CSF samples of indetermined meningitis, 23 (11.6%) presented OD above the cut off, which suggests the possibility that Cysticercus cellulosae was the etiological agent in this meningitis episode. The ELISA-d test has proved to be efficient for the immunodiagnosis of neurocysticercosis when conducted on CSF samples. The alterations observed in the 23 CSF reactive on ELISA-d were: increased number of lymphomononuclear cells in five, of polymorphonuclear cells in 13 and both cells in five samples.

Leptospirose em doentes com anticorpos anti-HIV: relato de dois casos

Two patients with concomitant leptospirosis and the acquired immunodeficiency syndrome (AIDS) are reported. In these cases different clinical aspects that can be attributed to simultaneity of these pathologies was not observed.

Passive haemagglutination test for human neurocysticercosis immunodiagnosis: I. Standardization and evaluation of the passive haemagglutination test for the detection of anti-Cysticercus cellulosae antibodies

Foi padronizada e avaliada a reacao de hemaglutinacao passiva (RHA) para pesquisa de anticorpos especificos, anti-Cysticercus cellulosae, no liquido cefalorraquiano (LCR). Foram utilizadas hemacias humanas O Rh-formolizadas e sensibilizadas com extrato antigenico salino total de cisticercos, ainda pouco estudado. De 115 amostras estudadas de LCR de pacientes com neurocisticercose, 94 foram reagentes, resultando em 81,7% de sensibilidade, com intervalo de confianca de 95% de probabilidade (IC95%) abrangendo de 74,5% e 88,9%. Tambem foram ensaiadas 89 amostras de LCR de individuos do grupo controle, sendo tao reagentes em 94,4%, com IC95%, de 89,6% a 99,2%. Os valores preditivos positivo e negativo obtidos para a RHA foram, respectivamente, de 1,4% e 99,9%, considerando a prevalencia media de neurocisticercose na America Latina de 0,1%. Os resultados indicam que a RHA como um metodo simples, altamente reprodutivel e moderadamente sensivel para a deteccao de anticorpos especificos no LCR, porem apropriados para a triagem de infectados.

Passive haemagglutination test for human neurocysticercosis immunodiagnosis: II - Comparison of two standardized procedures for the passive haemagglutination reagent in the detection of anti-Cysticercus cellulosae antibodies in cerebrospinal fluids

Sao descritas duas metodologias para o preparo de reagente para a reacao de hemaglutinacao passiva (RHA) destinada a pesquisa de anticorpos anti-Cysticercus cellulosae no liquido cefalorraquiano (LCR). Foram utilizadas hemacias humanas O Rh-formolizadas (HA-1) e hemacias de carneiro tratadas com glutaraldeido (HA-2), sensibilizadas com extrato antigenico salino total (ST) de cisticercos. Cento e quinze amostras de LCR de pacientes com neurocisticercose foram ensaiadas pelos testes HA-1 e HA-2, resultando em positividade de 81,7% e 88,7%, respectivamente. A especificidade obtida foi de 94,4% para HA-1 e 96,6% para HA-2. Nao foi observada diferenca significativa quanto a capacidade diagnostica dos reagentes na RHA em neurocisticercose (p < 0.05).

Immunoenzymatic assay for the detection of antibodies to Cysticercus cellulosae in the cerebrospinal fluid of patients with indetermined etiology meningitis

The enzyme-linked-immunosorbent assay using a new type of support consisting of discs of synthetic fabric-resin (ELISA-d) with antigenic components of Cysticercus cellulosae covalently bound, was employed with the purpose of investigating the presence of specific antibodies to the cysticerci (neurocysticercosis) in the cerebrospinal fluid (CSF) of patients with meningitis without etiological agent determined by the conventional methods. The test was performed in 277 CSF samples (128 children and 149 adults). The mean of optical density values (OD) obtained for 22 CSF normal patients (the diagnostic hyphotesis of meningitis was discarded) was of 0.03. The 44 CSF of patients with meningitis caused by other agents but C. cellulosae, showed OD of 0.05. The cut off determined with these two groups (control group) was 0.13 (OD + 3 SD). The group of 13 CSF of neurocysticercotic meningitis presented OD of 0.41 (0.10 to 0.91). Among the 198 CSF samples of indetermined meningitis, 23 (11.6%) presented OD above the cut off, which suggests the possibility that Cysticercus cellulosae was the etiological agent in this meningitis episode. The ELISA-d test has proved to be efficient for the immunodiagnosis of neurocysticercosis when conducted on CSF samples. The alterations observed in the 23 CSF reactive on ELISA-d were: increased number of lymphomononuclear cells in five, of polymorphonuclear cells in 13 and both cells in five samples.