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

Abstract

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.

Human toxocariasis: a seroepidemiological survey in the Amazonian city of Yurimaguas, Peru

“…*Some subjects had more than one sign/symptom; **p < 0.05 = significant value (Chi-square); *** variables in the model: sex, age, pulmonary and hepatic manifestations, headache, and weakness and/or fatigue. In agreement with other authors, we have also found statistically significant differences between gender and positive serology indicating that male subjects are more associated at risk of toxocariasis than female subjects, probably because of their close contact with soil, as is the case with this population, who are farmers 4,5,21,22,26 .…”

Prevalence of Toxocara infection in schoolchildren from the Butantã region, São Paulo, Brazil

“…The population studied here was from an urban area with a high demographic density, a fact favoring the existence of a significant number of individuals with anti-Toxocara antibodies as well as a closer man-dog contact and high exposure to dog feces-contaminated environments (Chieffi et al 1990).…”

“…The criterion adopted for the diagnosis of Toxocara infection was a serology (ELISA) titer ≥ 1/160 (Chieffi et al 1990).…”

Frequency and risk factors for toxocariasis in children from a pediatric outpatient center in southeastern Brazil

“…A goat antihuman IgG (Gamma-Chain) specific peroxidase conjugate was used. Absorbance was read at 492 nm to establish optical density; sera with titers higher than or approximating 1:160 were considered positive 11 .…”