[Increased accumulation of some trace elements in peripheral blood and bile of patients infested with Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890)].

The invasion with Opisthorchis felineus (Rivolta, 1884) is known to be common in the Ob River region, West Siberia. These trematodes parasitize biliary tract of devinitive host (man or some species of animals). Other opisthorchiid species occurring in West Siberia, Metorchis bilis (Braun, 1890), has also been recorded recently as human parasite. Life cycles of both these trematodes include fish-eating mammal hosts. Eggs of O. felineus and M. bilis are very similar morphologically and can hardly be indentified. Chronic invasion with the helminthes is found to be a cause of disbolism of trace elements or high accumulation of some essential and toxic elements in the organism of definitive host. The aim of the present study was to determine concentrations of some essential and toxic elements in samples of peripheral blood and bile obtained from patients infested with Opisthorchis and/or Metorchis using instrumental neuron-activation technique. At first, all patients with microscopically confirmed opisthorchiasis (by microscopic examination of faeces and bile for the helminth eggs) were examined with serological method (ELISA) for specific anti-Opisthorchis and anti-Metorchis antibodies. Among 139 examined patients, 56.1% had specific antibodies against both Opisthorchis and Metorchis, 41.7% showed anti-Opisthorchis antibodies only, and 2.1% turn out to be seropositive for anti-Metorchis antibodies only. Of 31 elements detected in the samples of peripheral blood and bile, the concentration of nine essential and toxic elements (mercury, chromium, cesium, rubidium, lanthanum, bromine, selenium, zinc, and cobalt) in the patients with the mixt-infection of Opisthorchis and Metorchis (78 individuals) and with the Opisthorchis mono-infection (58 individuals) were significantly higher than those in healthy uninfested individuals. Among these elements, mercury and chromium showed the highest concentrations in infested patients. We suggest that the significant increase in concentrations of some toxic elements in blood and bile of patients may be associated with increased bioaccumulation of these elements in environment, especially in the local river water and fish. Moreover, concentrations of such elements as chromium, mercury, cesium, lanthanum, selenium, and zinc in blood and/or bile of the patients with mixt-infection of Opisthorchis and Metorchis were significantly higher than those in the patients with mono-infection of Opisthorchis. Accumulation of these elements in the organisms of patients was positively correlated with the number of parasites and the duration of helminth infection.