The liver fluke Opisthorchis felineus as a group III or group I carcinogen Mariya Yurievna Pakharukova, José Manuel Correia da Costa and Viatcheslav Alekseevitch Mordvinov 4open, 2 (2019) 23 Published online: 03 July 2019 DOI: 10.1051/fopen/2019016