[Possible influences of climatic changes on the spread and intensity of foci of some human helminthiases].

Climatic changes on the Earth and in some of its regions have caused and will cause alterations in the natural and social factors which may influence the circulation of causative agents of helminthiases that develop both on land and in water with the participation of hydrobiont. These include changes in the size of the first and second intermediate hosts, in the hydrological conditions of water reservoirs, in the amount of precipitation, soil moisture, heat, etc. Therefore, the expected global warming may alter the areas of some helminths, the intensity of foci, etc.

[An experimental study of the susceptibility of the snakehead Ophiocephalus argus to infestation by larvae of the tapeworm Diphyllobothrium latum].

Experiments were made to infect young Ophiocephalus argus, the fish of prey delivered from eastern Asia in the Amu-Dar'ya River basin, outside the area of the broad tapeworm Diphyllobothrium latum. The dalags were infected mainly by ingesting the local copepods Arctodiaptomus salinus, the experimentally invaded larvae of the broad tapeworm. The latter larvae were obtained from the development of eggs of the helminth isolated from strobilae from the patients treated in Perm Province.

[Helminthiasis morbidity in an organized pediatric population in one of the regions of the Far North].

In 1991-1992, higher affection rates of diphyllobothriasis and enterobiasis were notified in some groups of the organized children living on the Pur River (the Yamalo-Nenets Autonomous Okrug). The children are infected by Diphyllobothrium in infancy, the risk of infection is rather high, reinfections are observed. Among other things, this makes it necessary to perform systematic educational studies among the population in their different forms.

[The characteristics of diphyllobothriasis foci in the Pur River basin (Yamalo-Nenets Autonomous Okrug)].

Diphyllobothriases are spread in the population of the Pur River basin unevenly. The population on the lower Pur is affected little, but that on the upper Pur and its tributaries is affected much more. This is largely accounted for by what fishes are prevalent in the diet of the local population and how they consume fish.

[The effect of economic activities altering water resources on the parasitological situation].

The possibilities and results of impact of some economic activities of man, which alter the hydrological regimen of reservoirs and territory irrigation on the parasitological situation in their area are outlined in the paper. It shows that in some cases economic activities favour the spread and incidence of diseases and in other cases they may lead to a reduction in the rate of infection, make the focus extinct.