Spatial Association Patterns of Geographic Factors and Opisthorchis Viverrini Infection in the Northeast of Thailand

Background: Thailand is the world highest prevalence’s of Opisthorchis Viverrini (OV) infection. This study aimed to determine the spatial association of geographic factors with OV infection in the highest prevalence region, the Northeast (NE) of Thailand.

Method: This study was conducted using four geographic factors data sets of years 2016 and 2017. A Moran’s I and Local Indicators of Spatial Association (LISA) were used to identify the spatial autocorrelation between geographic factors and OV infection within the region.

Results: Among the total of 189,231 participants in the NE, the regional prevalence of OV infection was 10.60%. The results indicated a spatial global autocorrelation of geographical factors with OV infections, those geographical factors included water sources including dams, reservoirs, weirs, canals and lagoons; proportion of rice field areas and number of dogs and cats per village, (Moran’s I values of 0.28, 0.34, 0.11, 0.40 and 0.17, respectively). The LISA analysis identified significant positive spatial local autocorrelation of water resource: one of high-high cluster for the numbers of dams and reservoirs, three low-low clusters for the number of weirs and two of high-high clusters for the numbers of canals and lagoons. In addition, there were two high-high clusters and three low-low clusters of the proportion of rice field areas, and one low-low cluster of dogs and cats with OV infection.

Conclusion: There were spatial associations between physical geographic factors and OV infection in the NE of Thailand which should be taken into new policy recommendations for OV infection control. Especially, in the province with more rice fields, big water resources and had more dogs and cats.