Albendazole can be used as an alternative.A randomized controlled trial published in 2011 showed that tribendimidine, a broad-spectrum anthelmintic, appears to be at least as efficacious as praziquantel. Artemisinin was also found to have anthelmintic activity against Opisthorchis viverrini. Epidemiology
Opisthorchiasis is prevalent where raw cyprinid fishes are a staple of the diet. Prevalence rises with age; children under the age of 5 years are rarely infected by Opisthorchis viverrini. Males may be affected more than females. The WHO estimates that foodborne trematodiases (infection by worms or "flukes", mainly Clonorchis, Opisthorchis, Fasciola and Paragonimus species) affect 56 million people worldwide and 750 million are at risk of infection. 80 million people are at risk of opisthorchiasis (67 million from infection with Opisthorchis viverrini in Southeast Asia and 13 million from Opisthorchis felineus in Kazakhstan, Russia, and Ukraine). In the lower Mekong River basin, the disease is highly endemic, and more so in lowlands, with a prevalence up to 60% in some areas of northeast Thailand. However, estimates using polymerase chain reaction-based diagnostic techniques indicate that prevalence is probably grossly underestimated. In one study from the 1980s, a prevalence of over 90% was found in persons greater than 10 years old in a small village near Khon Kaen in northeast Thailand in the region known as Isan. Sporadic cases have been reported from Malaysia, Singapore, and the Philippines. Although the overall prevalence has declined since initial surveys performed in the 1950s, an increase has occurred since the 1990s in some areas, possibly related to large increases in aquaculture.
Opisthorchiasis is a parasitic disease caused by certain species of genus Opisthorchis (specifically, Opisthorchis viverrini and Opisthorchis felineus). Chronic infection may lead to cholangiocarcinoma, a cancer of the bile ducts. Medical care and loss of wages caused by Opisthorchis viverrini in Laos and in Thailand costs about $120 million annually. In Asia, infection by Opisthorchis viverrini and  other liver flukes affects the poorest people. Along with other foodborne trematode infections such as clonorchiasis, fascioliasis and paragonimiasis, opisthorchiasis is listed among the World Health Organizations list of neglected tropical diseases. Signs and symptoms
Symptoms of opisthorchiasis are indistinguishable from clonorchiasis. About 80% of infected people have no symptoms, though they can have eosinophilia. Asymptomatic infection can occur when there are less than 1000 eggs in one gram of feces. Infection is considered heavy when there are 10,000-30,000 eggs in one gram of feces. Symptoms of heavier infections may include diarrhea, epigastric and right upper quadrant pain, lack of appetite, fatigue, yellowing of the eyes and skin and mild fever.These parasites are long-lived and cause heavy chronic infections that may lead to accumulation of fluid in the legs (edema) and in the peritoneal cavity (ascites), enlarged non-functional gallbladder and also ascending cholangitis, which can lead to periductal fibrosis, cholecystitis and cholelithiasis, obstructive jaundice, hepatomegaly and/or portal hypertension. Chronic opisthorchiasis and cholangiocarcinoma
Both experimental and epidemiological evidence strongly implicates Opisthorchis viverrini infections in the etiology of a malignant cancer of the bile ducts (cholangiocarcinoma) in humans which has a very poor prognosis.