This study was conducted in 55 villages in five provinces located in
central and south Cambodia from March 2006 to August 2012
(Table 1, Fig. 1). The five provinces are located in the Mekong River
basin and tributary areas. The target villages were located near streams,
lakes, or ponds formed after flooding in the rainy season. The survey
began in Takaev province, where two villages in which high endemic
rates of opisthorchiasis were found in March 2006. It continued in
Kandal province to the north of Takaev, then moved to adjoining Prey
Veng and Kampong Cham provinces, and finally to Kampong Thom
bordering on Kampong Cham (Fig. 1).