From Big Medical Encyclopedia

AFFECT PRIMARY — primary center of infectious process arising usually in the place of penetration of an infekt into an organism. Is a component of primary infectious complex. Depending on the nature of a disease And. the item can be localized in this or that site of skin or mucous membranes. The concept A is the most frequent. the item is used for the characteristic of the first changes on site of fixing in fabric of a pathogenic microorganism at tuberculosis, syphilis, plague, a brucellosis, etc. However even at these infections And. the item can not develop or be short-term, slightly expressed and quickly to heal though infekt circulates in an organism and the disease develops as the general infectious disease. And. the item represents not only local process, but also reflection of an initial cycle of systemic infection of an organism. Morphologically And. the item is the center of an inflammation which character is inherent in this infectious disease. In the changed fabric a large number of disease-producing factors is always observed. Emergence And. items (as well as absence), its expressiveness, features of evolution — progressing or healing — reflect an immunobiological condition of an organism at the beginning of development of an infection. At some diseases (tuberculosis) And. the item remains is long and in it there is a viable disease-producing factor that at change of an immunobiological condition of an organism can conduct to an aggravation and progressing of a disease.

See also Primary complex .

M. M. Averbakh.