Abstract:

Objective To understand the current endemic status of Clonorchis sinensis infection in opulation of Jilin Province so as to provide a scientific basis for better prevention and control of clonorchiasis. Methods According to the National Survey Program and Implementation Rules for the status of human key parasites, total 78 pilot survey sites in rural areas and 21 sites in township from 35 counties (cities and districts) in Jilin Province were selected using stratified cluster sampling method in 2015. No less than 250 permanent residents over 3 years old were recruited from each site in the survey. Fecal samples were collected from each participant and the eggs of C. sinensis in the feces were examined using a modified Kato-Katz thick smear microscopy. The general demographic and personal information were collected by a written questionnaire. The infection status among residents was analyzed based on their different gender, age and occupation with statistical analysis using Chisquare test. Some residents from 50 pilot survey sites were randomly selected to conduct a questionnaire survey on clonorchiasis related knowledge to understand their awareness of parasites and infection risks. Results A total of 24 963 people were examined, of whom the total prevalence of C. sinensis infection was 3.0% (749/24 963), mainly with mild infection 88.5% (663/749). The medium and heavy infections only accounted for 11.0% (82/749) and 0.4% (3/749), respectively. The infection rate in rural areas (3.8%, 746/19 683) was significantly higher than that in urban areas (0.1%, 3/5 280) with statistical difference (P < 0.05). Male people had higher infection rate (3.6%, 459/12 843) than female (2.4%, 290/12 120）with statistical difference (P < 0.05). Among different age groups, it was shown that people with age between 41-50 had the highest infection rate (4.4%, 227/5 175) with significant difference compared to other age groups (P < 0.01). Among different occupations, the infection rate was highest in famers ( 4.1%, 712/17 455) (P < 0.01). In terms of educational levels, people educated with junior high school had the highest infection rate (4.4%, 546/12 322) (P < 0.01). With respect to different ethnic groups, Han population had the highest infection rate (3.1%, 746/23 794) (P < 0.01), possibly related to different food and cuisine habit. Totally 2 850 questionnaires were collected from 50 pilot survey sites. The awareness rate for clonorchiasis in people living in urban cites (58.5%, 350/598) was higher than that in people living in rural area（34.9%, 787/2 252）(P < 0.01), however, more people in urban areas ate raw freshwater fish and shrimp (19.0%, 113/598) than people living in rural areas (11.9%, 269/2 252) (P < 0.01), even though the former knew better about the parasite and the infection risks. Conclusion The prevalence of C. sinensis infection in Jilin Province still remains at a relatively high level. The awareness for the knowledge of infection and behavior-related infection risks among people are low and not much changed.

Key words: Jilin province, Clonorchiasis, Epidemiology