Prevalence and Risk Factors for Infection by Opisthorchis viverrini in an Urban Area of Mahasarakham Province, Northeast Thailand

The aim of this cross-sectional analytic study was to investigate the prevalence and risk factors for Opisthorchis viverrini (OV) infection in an urban area of Northeastern Thailand. The participants were 254 household representatives aged 15 years or older living in the most urbanised part of Chiang Yuen municipality in Mahasarakham Province. All participants provided stool samples which were examined using the modified Kato-Katz procedure, and a structured interview questionnaire was used to collection demographic information, knowledge about OV infection, and the consumption of unsafely prepared freshwater fish. The data were analyzed using descriptive statistics and logistic regression. The overall prevalence of OV infection was 15.0%, and in the multivariate analysis male gender was found to be significantly and positively associated with OV infection ($OR_{adj}=9.75$, 95%CI: 34.03-23.58) while education to secondary school level or above was a significant protective factor ($OR_{adj}=0.30$, 95%CI: 0.12-0.74). The eating of unsafely prepared fish and knowledge about OV were not significantly related to infection status. The findings were discussed in terms of issues for future research, especially the need to consider the possibility of higher rates of OV infection in urban areas than might be expected and to investigate the sources of infected fish products which may well be different from those in rural villages.