Background: Opisthorchis viverrini is still a serious problem in rural areas of Thailand particularly Northeastern and Northern region. Active surveillance is required to determine the update data for further prevention and control planning.
Objective: To determine the population at risk and analyze the risk areas for O. viverrini in rural communities of Nakhon
Ratchasima province, Thailand.
Material and Method: A cross-sectional survey was conducted between October 2015 and March 2016 at Kang Sanam Nang district, Nakhon Ratchasima province, Thailand. The population at risk for O. viverrini was screened by SUT-OV-001 with Cronbach’ alpha coefficient, 0.724. O. viverrini infection was examined by using Kato thick smear. The risk areas were analyzed by using geographic information system.
Results: Three hundred ninety seven people were recruited for this study. The majorities were female (53.15%), age group 41
to 50 years old (35.01%), educated with primary school (59.45%), agriculture (85.64%), and of income of 2,000 baht
(47.36%). The majorities of them were high-risk (49.62%), followed by moderate risk (36.02%), and low-risk (7.3%). Risk
areas were classified as very-high-risk areas, found in Beng Samrong (11.44 km2), followed by Keang Sanam Nang (5.21
km2). High-risk areas were found in Bueng Phalai sub-district (70.16 km2), followed by Bueng Samrong (30.45 km2), and
Non Samran (27.33 km2). O. viverrini infection was 3.02%, and distributed in the moderate risk areas (four cases), high-risk
areas (three cases), low-risk areas (three cases), and very-high-risk areas (two cases).
Conclusion: The present study indicates the population at risk for O. viverrini and risk areas in the rural communities by using SUT-OV-001 and GIS. These tools are useful to display the risk areas for further prevention and control planning and monitor.

Keywords: Opisthorchis viverrini, SUT-OV, Geographic Information System, Nakhon Ratchasima, Thailand