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

Abstract

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, aswell 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 inan 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 ultrasoundexaminations; 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.