The mechanisms of chronic infectious diseases remain poorly understood, and optimal methods for their treatment are still to be found. An attempt is made to analyze available data by analogy with natural chronic foci of normal microflora, which are useful and even necessary to the host. The analogy is justified because both normal and pathogenic infective microfloras are basically similar in their essential characteristics, such as contagiousness, conditional pathogenicity, the possibility of healthy carriage, and chronic persistence in the host body. On this basis, it is assumed that foci of any persistent microflora are formed because they are necessary for the host, which explains the difficulty of curing chronic infections. Alternative ways of their treatment are discussed.
Keywords: Chronic infection, infectivity, contagiousness, normal microflora, active susceptibility