蛔虫的种群动力学和药物控制效果的研究

实验村社区居民蛔虫感染率为53.5％。125个阳性居民的蛔虫平均虫荷数为1.9条。用数学模型算得的种群动力学参数负二项分布值(K)、密度依赖限制值(Z)和基本繁殖率值(R)分别为0.54,0.92及1.17。蛔虫感染者经药物治疗后第4、7及12个月的再感染率分别为14.3％、30.8％和40.7％。再感染者的EPG值分别为13000、17500和22600。理论感染率分别为22.2％、35.5％和42.6％。理论平均虫负荷数分别为0.430、0.676和0.967。据此认为,单纯运用化疗措施控制和消灭蛔虫病流行的效果不理想。

THE POPULATION DYNAMICS AND CONTROL OF ASCARIS LUMBRICOIDES

Adults of Ascaris lumbricoides were recovered from 125 persons in a village of Wujiang county after treatment with albendazole and mebendazole complex. The result of study showed that the mean worm burden was 1. 9 worm/host. The K value of this community was low,ranging from 0. 13 to 0. 90 in each age group (with an average value of 0. 54) ,indicating a high degree of variability within the community. there was a clear relationship between egg output per female worm and worm burden (male and female, the average sex ratio being 1. 00:1. 00). The mean Z value in this study was 0. 922,ranging from 0. 879 to 0. 952 in each worm burden class.The rate of recruitment of Ascaris lumbricoides within the human community was 14. 3, 30. 8 and 40. 7 at 4,7and 12 months after treatment. It is shown that it will be difficult to eradicate ascaris by means of chemotherapy alone ,even if the drugs were of high efficacy and used repeatedly.