Toxocariasis in Brazilian Children: A Case-Control Study - Abstract
Introduction: The identification of epidemiological, clinical, behavioral, and ultrasonographic and laboratory features could aid in the diagnosis of visceral larva migrans (VLM) in children and adolescents in Brazil.
Methods: A case-control study was conducted in ambulatory patients aged 6 months to 16 years cared for 4 years at a pediatric infectious diseases outpatient service in Belo Horizonte, Brazil. Patients with serum ELISA (enzyme-linked immunosorbent assay) anti-T. canis IgG antibody titers>1:640 were assigned to
the case group, and the remaining subjects were assigned to the control group. The statistical significance of univariate associations between the outcome variable and exposure (i.e., epidemiological, clinical, behavioral, laboratory and ultrasonographic findings) was assessed using Pearson’s chi-square (?2
) test or Fisher’s exact test. Multiple logistic regression analyses were used to assess the independent effect of each variable on the odds of the serologic status.
Results: Thirty-seven cases and 31 controls were studied. In multiple analyses, residence in a rural area (OR = 4.23; 95% CI = 0.66-27.06), keeping a dog at home (OR = 9.71; 95% CI = 1.02-92.67), and total serum immunoglobulin E (IgE)>1,000 IU/mL (OR = 2.05; 95% CI = 0.67-6.30) were the most important explanatory variables for VLM. Age, gender, hepatomegaly, splenomegaly, serum isohemagglutinins,
total serum immunoglobulinG, immunoglobulin A (IgA) and immunoglobulinM, hypereosinophilia and abdominal ultrasonographic findings were not different in cases and controls.
Conclusions: Keeping dogs at home and residing in rural areas are important epidemiological risk factors for VLM. In the presence of one or more of these risk factors, patients should undergo anti-Toxocara ELISA. However; with larger sample studies should be performed.