[Studies on the changes in infection rates of whipworm and ascaris in population after continuous chemotherapy].

The inhabitants with positive eggs of whipworm and ascaris in a village of Jiangdou County were examined and treated with different antihelmintic drugs twice a year. The uncured population were treated by drug administration once again. On an average the efficiency of drug treatment (cure rate x treatment rate) was 56.7% in whipworm and 64.5% in ascaris. The program had been carried out for five years. The positive rate of eggs of whipworm and ascaris in the population decreased from 64.7% and 52.1% to 2.7% and 4.1%, respectively, the mean increase in infection rates among population at 5 or 7 months after treatment was 2.68 (0.86-5.74)% and 6.94(1.72-17.27)%, respectively.