Seroepidemiological study on toxocaral infection in man by enzyme-linked immunosorbent assay.

A seroepidemiological survey for toxocaral infection was performed using samples from children and adult women in the Yamaguchi area of Western Japan. An enzyme-linked immunosorbent assay using excretory--secretory antigen was applied to these sera. Of samples tested, 3.1% from children and 3.7% from women were positive. It was found that regression analysis of positive rates by age between 20 and 70 or more years was significant in the positive direction. The positive rates from urban, rural and fishing areas were 5.7, 3.9 and 1.7% respectively. Also, the rates from northern, western and eastern parts in the research area were 5.7, 4.7 and 0.5% respectively. These findings suggested that environmental factors are important for toxocaral infection. Further, the rate for 108 samples who answered that they have owned dogs was 6.2% compared to 2.9% of 422 respondents who denied an experience of owning dogs. This fact suggested that attention should be paid to dog breeding for prevention and control of toxocaral infection in man.