Prevalence of clonorchiasis among permanent residents in Harbin municipality, 2018: a cross-sectional survey

  Objective  To examine the infection of Clonorchiasis sinensis among permanent residents in Harbin city for providing evidences to the prevention and treatment of clonorchiasis.

  Methods  Using cluster random sampling, we recruited 9 000 permanent residents at 27 rural and 18 urban survey points in 9 districts/counties of Harbin municipality for a survey conducted in 2018. The eggs of Clonorchis sinensis in feces samples of the participants were detected with modified Kato-Katz method. The information on behaviors of fresh water fish were also collected. Descriptive statistics was performed to analyze the data collected.

  Results  Among the 8 980 enrollees completing the survey, 351 Clonorchis sinensis infections were detected; the average infection rate of was 3.91% for all the participants and the infection rate was 6.30% and 0.33% for rural and urban participants. Of the Clonorchis sinensis infections, 239 (68.09%), 89 (25.36%), and 23 (6.55%) were mild, moderate, and severe infection, respectively. The infection rate of male participants (5.05%, 236/4 674) was significantly higher than that (2.67%, 115/4 306) of female participants (χ² = 34.620, P < 0.001). The highest infection rate (7.12%, 77/1 082) was detected among the participants aged 60 – 69 years and the infection rate differed significantly by age among the participants (χ² = 116.741, P < 0.001). The infection rate was different significantly among the participants of various occupations (χ² = 233.979, P < 0.001), with the highest infection rate of 5.64% (330/5 855) among farmers (herdsmen and fishermen). The infection rate was also differed significantly by education (χ² = 125.798, P < 0.001) and the highest infection rate (10.39%, 16/154) was detected in the participants being illiterate or semi-illiterate.

  Conclusion  The prevalence of clonorchiasis is relatively serious among rural and urban permanent residents in Harbin municipality and various health education programs on prevention and control of the disease should be promoted in the population.