Risk factors for Opisthorchis viverrini Infection in Nong Khai Province, Thailand

Background: Opisthorchis viverrini (OV) infection is the main risk factor for cholangiocarcinoma and is oftenfound in Northeastern Thailand. The prevalence of OV infection and the incidence of cholangiocarcinoma aremajor public health problems in this region.
Objectives: The objectives of this study were to identify factorsassociated with OV infection among people in Nong Khai Province in order to develop a prevention programmein the community. Materials and
Methods: The data were collected in July 2013. Stool specimens were examinedfor intestinal parasites within hours after collection using a normal saline wet preparation and the modified Kato-Katz technique. A case-control study was conducted to collect information about demographic data, the habit ofeating unsafely prepared fish, the safe disposal of waste food, and the practice of defaecating in fields. Structuredquestionnaires were used to interview 351 participants (117 cases and 234 controls) in a random selection of 30villages across Nong Khai Province. Multiple logistic regression was used to identify risk factors for OV infection.
Results: In the multivariate analysis, the results showed that the factors which had a statistically significantassociation with OV infection were the habit of consuming unsafely prepared fish (ORadj=5.17, 95%CI=2.49-10.74), the similar habit of family members (ORadj=3.25, 95%CI=1.63-6.49) , a history of O. viverrini infection(ORadj=5.64, 95%CI=2.10-15.18), a history of taking praziquantel (ORadj=5.66, 95%CI=3.11-10.29), and theunsafe disposal of waste food (ORadj=2.1, 95%CI=1.10-3.80).
Conclusions: The findings of this study highlightthe features on which a community programme should focus in order to reduce the prevalence of opisthorchiasisand incidence of bile duct cancer.