[Social bases for the functioning of nanophyetiasis foci in the Amur region].

Parasitological examination of the population of the Amur Region has revealed that the nanophyetiasis foci affecting as high as 28.4% of the people are being preserved and functioning now; at the same time the highest rates of infection with the trematode Nanophyetus salmincola schikhobalowi are seen in the dwellers of the populated areas situated on the banks of the mountain Amur tributaries. It has been ascertained that the major season when the population is infected with Nanophyetus is summer and its highest incidence are noted in autumn (November) after the active fishing season is completed. It has been found that infection occurs in infants and the maximum incidence is in the age group of 21-30 years (45.5%) and remains virtually the same in a middle-aged population [31-50 years (37.0-42.2%)], by decreasing slightly in the older age groups (18.2-21.7%). According to the questionnaire survey data, fish (90% of its species are an intermediate host for Nanophyetus) is a staple food in the population of the highest incidence rural areas. The major causes of Nanophyetus infection are the wide consumption of raw and low-salt fish and a low population awareness of measures to prevent helminthiasis, the transmission factor of which is fish.