[Specific features of tuberculosis in the similar biogeochemical subareas of the biosphere in the Chuvash and Sakha (Iakutia) republics].

The use of biogeochemical zoning of the territories of the Chuvash and Sakha (Yakutia) Republics revealed that due to silicon deficiency in the food biogeochemical chain, the indigenous population had reduced cellular immunity, accumulated residual tuberculous changes leading to higher morbidity, disease aggravation, more frequent complications, high tuberculosis mortality.