Epidemiological survey of clonochiasis in Henan Province

Objective To understand the prevalent situation of clonorchiasis and the factors associated in Henan Province. Methods Fecal samples were examined by Kato-Katz thick smear technique and questionnaire survey of relevant factors associated with Clonorchis sinensis infection was conducted among the egg-positive individuals and the negative control persons. Results Among 25 894 people from 51 sites in 17 counties examined, 23 persons (0.09%) were found infected with C. sinensis in 2000, with an average EPG of 35. The infection rate in Pingyu County was 0.86% (13/1 513), the highest at county level. The positive rate in the age group of between 35～39 years old was the highest being 0.42% and the positive rate in house women group was also high,being 1.64%. Conclusion The measures adopted for control of clonorchiasis in Henan Province are very successful and the infection rate and infectiosity of clonorchiasis are now both at the low levels. But the expansion of endemic areas and the change of the transmission pattern become new challenge for the control of the disease.