Toxocara canis: antibody seroprevalence and riskfactors in children, Ciudad Bolívar, Bogotá, 2000

Abstract

Human toxocariasis is a zoonotic infection caused by larvae of the nematode parasites Toxocara canis and Toxocara cati. The adult stages inhabit the intestine of dogs and cats, respectively In order to estimate the prevalence of antibodies against T canis and the relationship between seropositivity and some risk factors, a survey was conducted on 193 schoolchildren aged between 4 and 14 years from basic primary schools in the locality of Ciudad Bolívar, Bogotá. Fecal samples from 21 puppies were also examined to determine the prevalence of infected pet dogs. Serum IgG antibodies were determined by the indirect ELISA technique and parasitological examination of dog faeces was carried out by the modified McMaster method. The prevalence of antibodies was 7.3% with a higher prevalence in children under 5 years but with the mean titre increasing with age. The prevalence of infected puppies was 66.7%. The only risk factor found to be correlated significantly with positive antibody titres was not washing hands before eating (RR=9.91, IC 95%=1.27.77.21). However, several other factors such as age, gender, geophagy, and the increase in the densiiy of the canines favored the transmission of this zoonosis.