Epidemiology of human toxocariasis in northern Italy.

Sera from both clinically healthy adults (2112) and adult patients (471) were tested to assess the main risk factors for Toxocara infection in humans in Northern Italy. The patient group included 257 adult epileptics, 76 Strongyloides stercoralis-infected adult patients and 142 institutionalized mentally retarded adult patients. The overall seroprevalence in healthy population was 3.98%. No significant differences in seroprevalence were observed for sex, residence (urban or rural) or dog ownership, while seroprevalence significantly increased with age (18- greater than 51 years). Highest seroprevalence values were found in outdoor or soil-related workers. The seroprevalence was 4.35% in adult epileptics, 9.21% in Strongyloides stercoralis-infected patients and 14.47%-10.61% among institutionalized mentally retarded patients. These findings suggest that the prevalent source of human toxocariasis is the environmental contamination by infectious eggs of the parasite.