In our study, a confirmatory test was done by morphological andmolecular identification of adult worms recovered from stools ofpatients after treatment. All 11 consenting individuals shed adultO. viverrini following praziquantel treatment. Although we wereable to confirm O. viverrini infection in only 11 of the 29 individualsshedding trematode eggs, our findings strongly suggest O. viver-rini infections in all those people. We found a strong correlationbetween the faecal egg output and the number of expelled wormsin these consenting individuals.