Risk factors for Clonorchis sinensis infections and control measures reinforced with focused interviews

Clonorchiosis, a disease that develops following the consumption of raw freshwater fish that harbors Clonorchis sinensis metacercariae, seriously threatens the health of residents in endemic areas. We aimed to assess the level of awareness of liver fluke infections among infected residents and restaurant workers in liver fluke infection-endemic areas. To identify and provide a more realistic description of C. sinensis infections, we conducted a focused interview and questionnaire survey of local residents in endemic areas in Korea. Most residents knew that freshwater fish are a source of C. sinensis infection. Nevertheless, the consumption of raw freshwater fish was the main risk factor for their infection with C. sinensis. The residents had little knowledge regarding their residential area being endemic to C. sinensis or about the symptoms and complications of C. sinensis infection. Although the participants had no experience with C. sinensis prevention or health education, they preferred on-site education during visits to village halls. The in-depth interviewees had a high level of knowledge about C. sinensis infection but were unaware that eating raw freshwater fish was its cause. Family and social gatherings encourage the habit of eating raw freshwater fish, which is a risk factor for repetitive infections. Based on these findings, to eliminate clonorchiosis, we propose strengthening the capacity of public health care personnel, giving C. sinensis prevention education, and screening educational videos during visits to village halls. Furthermore, intensive education is recommended for reinfected people and community opinion leaders, as well as reservoir host control.