Infections with "O. viverrini" and of other liver flukes in Asia affect the poor and poorest people. Opisthorchiasis has received less attention in comparison to other diseases, and it is a neglected disease in Asia. There is no approved drug for the infection; however, Swiss researchers have tested tribendimidine and achieved a 70% cure rate. Surgery and supportive treatment are complicated and generally unavailable in the endemic areas. A general trematocide praziquantel is used for the infection, but is not technically recommended. In addition to praziquantel other commonly used anthelmintics such as albendazole, artesunate, and miltefosine are found to be effective on the cercariae but not on the metacercariae. Its ability to cause cancer is worsened by the discovery that its infection is often associated with those of "Helicobacter" species (including "H. pylori", which is primarily associated with ulcers, but also may cause stomach cancers).