Living at Ob River – Cat liver fluke infections in Siberia’s west

Her luggage got stuck in Moscow, but she made it as far as Basel, Olga Fedorova, medical professor at the Siberian State Medical University in Siberia. The scientist visits Swiss TPH to report on a topic that has been omnipresent to her since her early childhood: the

widespread infection with the cat liver fluke Opisthorchis felineus in Western Siberia. Especially in the Tyumenskaya Oblast, Tomsk Oblast region, where the great Ob River

branches into its numerous tributaries, many people are affected by the disease. “The river is more than a river. It determines the life and culture of the whole region,” says Fedorova. Many people practise fishing. Insufficiently cooked fish is traditionally high on the menu.

Contaminated carp

The lecture hall is already full when Olga Fedorova takes the floor. She clears her throat and moves her hand through her hair, which is combed backwards. In her home region, the risk of being infected with O. felineus is considerable, she says. Before the parasite enters the human liver, gall bladder and bile ducts, it had already been housed in the body of a freshwater snail in the river, and infected a carp. This carp is now the somewhat questionable object of desire

(“fishy”, as the Brit would say), which lands undercooked and only slightly salted or smoked on the plate. The fact that people do not renounce this carp also has something to do with the fact that a cat liver fluke infection can go unnoticed for a long time before the symptoms become apparent: Inflammation of the bile duct, gallstones or jaundice. Researchers also suspect a link between O. felineus and a fatal bile duct cancer. However, it has not yet been scientifically proven.

Everybody has it!

Olga Fedorova’s carrying voice can still be heard in the back row of chairs. The professor stresses that mass treatment with the drug Praziquantel is not the ideal solution to the problem. Rather, to establish preventive programs one needs to precisely study the needs and experiences of local people with social science studies. The latest results show: Many people in Siberia have accepted this helminth infection as a normal part of their life on the river. They regard opistorchiasis as an actual disease only when “too many parasites live in the body”, i.e. when the symptoms are clearly visible. “Treatment of the infection is costly,” says Olga Fedorova during her presentation. The patients must be hospitalised for two weeks and treated with the active ingredient Praziquantel. The drug is little accepted and the chance of a re-infection by a new consumption of carp is almost certain. The Tomsk OPIsthorchiasis Consortium (TOPIC) was founded in 2014 to put the disease on the international agenda. Its goal: to bundle the global activities of the researchers and in particular to develop new diagnostics and therapies against the disease.

The Future Generation

Scientists from Swiss TPH are also part of this initiative. The institute has long been committed to the fight against neglected parasitic diseases. “In addition to the development of new medicines and diagnostics, the transfer of knowledge to the affected population and new treatment protocols are important for improved health,” said Swiss TPH expert Peter Odermatt in the discussion that followed the presentation. Olga Fedorova sees it the same way. “In particular, we also have to make physicians responsible so that they treat more patients.” And then there is the younger generation. Olga Fedorova’s whole hope lies in them. “If you want to encourage people to rethink, we have to start with the young people,” she says. They are more receptive to many messages and less attached to the traditional way of life than their parents.