Russia: 100s of cases of Opisthorchiasis reported in the Krasnoyarsk Territory
Officials in the central Russian territory of Krasnoyarsk are reporting 733 cases of the parasitic infection, opisthorchiasis since the beginning of the year.
Of the total, 128 were children, including 5 preschool children under 6 years of age.
The department of Rospotrebnadzor in the Krasnoyarsk Territory reports most cases (87%) were reported in urban areas.
The largest number of cases was recorded in Uzhursky, Bogotolsky, Tyukhtetsky, Pirovsky, Taseevsky districts, the city of Nazarovo, and the urban-type settlement of Solnechny.
Opisthorchiasis is caused by a trematode, or fluke parasite. There are two species- Opisthorchis viverrini (Southeast Asian liver fluke) which is found mainly in northeast Thailand, Laos, Cambodia, and central and southern Vietnam and Opisthorchis felineus (cat liver fluke), which is found mainly in Italy, Germany, Belarus, Russia, Kazakhstan, and Ukraine.
The parasite is contracted by eating raw or undercooked freshwater fish, which can contain larvae (young worms).
Most infections are asymptomatic. Most pathologic manifestations result from inflammation and intermittent obstruction of the biliary ducts. In mild cases, manifestations include dyspepsia, abdominal pain, diarrhea, or constipation. With infections of longer duration, the symptoms can be more severe, and hepatomegaly and malnutrition may be present. In rare cases, cholangitis, cholecystitis, and chlolangiocarcinoma may develop. In addition, infections due to Opisthorchis felineus may present an acute phase resembling Katayama fever (schistosomiasis), with fever, facial edema, lymphadenopathy, arthralgias, rash, and eosinophilia. Chronic forms of Opisthorchis felineus infections present the same manifestations as Opisthorchis viverrini, with in addition involvement of the pancreatic ducts.
Opisthorchis is associated with cholangiocarcinoma (CCA), a rare cancer of the biliary duct system, which comprise of the gallbladder and bile ducts. Only a small percentage of people infected with Opisthorchis develop complications such as CCA.
People can avoid Opisthorchis infection by not eating raw or undercooked freshwater fish from countries where the parasite occurs. Lightly salted, smoked, or pickled fish can also contain infectious parasites.