Associações entre hipergamaglobulinemia E, alterações ultra-sonográficas do fígado e fatores de risco para Larva migrans visceral, e ELISA positivo para Toxocara canis em crianças e adolescentes: Estudo caso-controle

• Main Author: Elaine Alvarenga de Almeida Carvalho
• Other Authors: Regina Lunardi Rocha
• Format: Others
• Language: Portuguese
• Published: Universidade Federal de Minas Gerais 2008
• Online Access: http://hdl.handle.net/1843/ECJS-7NAG6U

=== The lack case-control study a regard visceral larva migrans at children and adolescents encouraged accomplishment of retrospective, observational, case-control study was conducted between 2004 and 2007 to determine risk factors for pediatric toxocariasis. Sixty-eight patients aged 10 months to 14 years were included in the analysis. This sample comprised 37 cases (defined as a serum antibody titer against Toxocara canis .640 by ELISA) and 31 controls (serum antibody titer <640). All children underwent complete hemogram, abdominal ultrasonography, fundoscopy and coproparasitology screening, as well as measurement of serum immunoglobulins (Ig), anti-A and anti-B isohemaglutinins. SPSS for Windows (version 12.0, SPSS Inc., Chicago, IL) was used for statistical analysis. Most anti-T. canis-positive children were older than 5 years, and the female-to-male ratio was 1,3. Significant associations were observed between keeping dogs at home or living in an rural area and anti-T. canis seropositivity. Children who imultaneously lived in rural areas, coexisted with dogs at home and had a serum Ig-E titer >1000IU/ml were 89% likely to be positive for anti-T. canis serum antibodies.Conversely, age and sex were not significantly associated with an anti-T. canis serum antibody titer .640. Although ultrasound examination disclosed liver hypoechogenic images, with or without periportal lymphadenomegaly, in 29,7% of case-patients, these findings were not statistically associated with anti-T. canis seropositivity. Hepatomegaly was diagnosed in 21,6% of casepatients and in 45,5% of children considered to have non-normal abdominal ultrasound examinations; only one case-patient was diagnosed with esplenomegaly. Eosinophilia was common (89,2%) among case-patients. However, no statistical associations were observed between hepatomegaly, esplenomegaly or eosinophilia and the presence of serum anti-T. canis antibodies. Two (5,4%) case-patients had signs of ocular involvement (one each with unilateral uveitis and discrete impairment of visual acuity). The joint association of keeping dogs at home and living in an rural area raised the likelihood of T. canis seropositivity to 80%, so these should be regarded as important epidemiological markers of visceral larva migrans. === A escassez de estudos controlados a respeito de Larva migrans visceral em criancas e adolescentes estimulou a realizacao de estudo observacional, retrospectivo, caso-controle no periodo de 2004 a 2007 para determinar fatores de risco para toxocariase em criancas e adolescentes.Foram estudadas 68 criancas entre 10 meses e 14 anos de idade distribuidas em dois grupos: 37 casos mostrando IgG positivo para Toxocara canis (ELISA- Ensaio imunoenzimatico) com titulo . 640, e 31 controles com titulo ELISA para T. canis < 640. Todas as criancas foram submetidas a hemograma, dosagem serica de imunoglobulinas e isohemaglutininas anti-A e anti-B, exame parasitologico de fezes, sorologia ELISA para T. canis alem de ultra-som abdominal e fundoscopia. Os dados obtidos foram analisados por meio do programa estatistico SPSS 12.0. Foram observadas associacoes entre presenca de caes no domicilio, residir em area rural e a variavel resposta sorologia (ELISA) positivo para toxocariase. Essas variaveis juntamente com imunoglobulina E total acima 1000UI/mL contribuiram em 89% para a presenca de anticorpos anti-Toxocara canis no sangue humano. A maioria das criancas com sorologia positiva (51,4%) tinham acima de cinco anos de idade e a relacao masculino:feminino foi 1,3:1.No entanto, idade e sexo nao foram associadas a variavel resposta estudada. Embora tenham sido encontradas imagens hipoecoicas hepaticas com ou sem linfadenomegalia periportal ao ultra-som abdominal em 29,7% dos casos, essas alteracoes ultra-sonograficas nao se associaram a sorologia positiva para toxocariase. A hepatomegalia estava presente em 21,6% dos casos e em 45,5% daquelas criancas com ultra-som alterado. Esplenomegalia ocorreu em um caso. A eosinofilia foi observada em 89,2% dos casos. Entretanto, hepatomegalia, esplenomegalia e eosinofilia nao se associaram a presenca de anticorpos anti-T.canis. O comprometimento ocular - uveite unilateral e reducao discreta da acuidade visual - ocorreu em dois pacientes (5,4% dos casos). A presenca de caes no domicilio associada ao fato de residir em area rural contribuiram em 80% para ocorrencia de ELISA positiva para T.canis sendo, portanto, importantes fatores epidemiologicos para diagnostico presuntivo da larva migrans visceral.