Objective To understand the achievements of clonorchiasis sinensis control in Shandong Province during the past forty years. Methods The data of the previous annual clonorchiasis sinensis investigation in Shandong Province were collected and analyzed. Results From 1960s to 1970s, there were 107 counties existing the prevalence of clonorchiasis sinensis in Shandong Province. The infection rate of population was 1.51%, and 85.70% of the infected people were children below fifteen years old. Through the forty years' control, the decreasing of intermediate hosts such as various kinds of fishes and water-snails due to 85. 00% of ditches and ponds dried up by the lasting drying weather after 1980s, and 90. 00% of rivers polluted by increasing liquid waste, as well as the decreasing of infective chances due to 97. 90% of people breaking off the habit of eating not-well-cooked fishes by popularizing health knowledge, to 2003, the population infection rate dropped to 0.04%, 95.60% of the village where residents had the infection dropped to below 1. 00% , and 60. 00% of counties where no Clonorchis sinensis infection was found. Conclusion The clonorchiasis sinensis transmission areas reduce gradually, the infection rate of population decreases to the lowest in the history and the transmission has been controlled in Shandong Province.

Objective To understand the status of intestinal parasitic infections and the related knowledge and behavior in residents of Jiaodong area of Shandong Province,so as to provide the evidence for making an appropriate preventive and control strategy. Methods A total of 18 villages from 6 counties in Jiaodong area were selected as investigation sites according to the stratified sampling method. The feces samples of the permanent residents aged above 3 years were collected and examined by Kato-Katz technique to find the intestinal parasite eggs,and the children under 12 years old were examined by the method of cellophane anal swab to detect the Enterobius vermicularis eggs. In addition,50 households in each survey sites were randomly selected to in-vestigate the basic family situation and the condition of awareness on prevention knowledge and formation of correct behavior of res-idents by using a structured questionnaire. Results Totally 6 163 residents involved in the feces examinations,and the total in-fection rate of intestinal parasites was 6.91%. The infection rates of Trichuris trichiura,Ascaris lumbricoides and hookworm were 6.56%,0.62%and 0.21%,respectively. The infection rate of E. vermicularis in children under 12 years old was 0.51%. The eggs of Clonorchis sinensis and Taenia solium were not found in this survey. The awareness rate of knowledge about preventing parasitic diseases was 49.54%. The formation rates of washing hands before eating,washing hands after using the toilet,never eating raw fruit and vegetable without washing clean,never working in the field with bare feet,and never drinking unboiled water were 97.78%,91.95%,88.81%,92.42%and 86.48%respectively. Conclusions The infection rate of intestinal parasites is low in Ji-aodong area,but there is a significant difference among different counties. The awareness rate of knowledge about preventing para-sitic diseases is low,but the formation rate of healthy behavior is high. In the future,the health education and the strategy of tak- ing medicine among the key population should be enhanced,and the project of reconstructing safe water supply and lavatory should be advanced.

Objective To elucidate the transmission dynamic and epidemic trend of bancroftian filariasis occurred under the condition with no control measure taken 5 years after elimination of filariasis.Methods A 10-year longitudinal observation (from 1984 to 1994) was made in Huayuan Village in Shengli Township of Tancheng County, which used to be a high bancroftian filariasis-endemic area in southern part of Shandong Province.Results The microfilarial rate decreased from 0.56% before the study to 0.12% after the study and 8 out of the 9 previous microfilaria-positive cases became negative gradually. During the study period, 6 new microfilaremia cases were detected, 5 of which became negative naturally within 3 to 4 years. Eighty-eight point eight nine per cent of the detected patients with microfilaremia converted into IgG4-negative after 10 years. The natural infective rate of vectors decreased year by year and became zero by the tenth year of the study, the annual transmission potency decreased also from 3.47 to zero by the tenth year.Conclusions It showed that under the local natural environment the biting rate representing the vector density which was obtained by capture method was from 24.1 to 52.5 person/night among the residents who did not use mosquito nets,and 13.5 to 21 person/night among the residents who used mosquito nets. The microfilarial rate of 0.56% in population with the average microfilarial density of 6.6 to 20.7 capita/60 μl ear blood of residual microfilaria-positive patients might be considered as the terminal threshold of transmission.