Measures to control Toxocara egg contamination in sandpits of public parks.

We investigated measures to prevent Toxocara egg contamination of sandpits. Replacement of contaminated sand was not effective because 1-9 new fecal deposits per sandpit were found daily, with eggs reappearing in the sand 6-9 weeks after the replacement. When the sandpit was covered with a clear vinyl sheet, the temperature of the sand to a depth of 3 cm was 42 degrees C or more for 3 hr when the air temperature was higher than 30 degrees C. This procedure prevented contamination by fecal deposits and also resulted in the destruction of existing eggs because the sandpit was kept dry on rainy days. The method seemed safe and inexpensive. The effectiveness of a fence around a sandpit depended on user behavior, which could not be relied upon. Therefore, a practical method for the prevention of Toxocara egg contamination of sandpits is to cover the sandpit with a clear vinyl sheet at night and on rainy days.