[Possibilities of evaluation of the risk of tubercular infection in children and adolescents].

Two indicators are of primary importance in the assessing the tuberculous endemia in a determined area: the prevalence of bacilliferic sources, especially of those that have been confirmed by bacteriological examinations (bacterioscopy), and the annual incidence of the tuberculous infection (the real infection risk). Possibilities are described, and examples provided, for approximation of the incidence of the tuberculous infection through: a) conversion index; b) the ratio between the prevalence of the tuberculous infection and the median tested age; c) the Styble-Meijer-Sutherland logarithmic ecuation; d) the nomogram variant with tables B and C established by Styblo-Meijer-Sutherland; e) the R. Narain graphic methods. For those countries in which BCG vaccination is practiced on an extensive scale the authors suggest the incidence risk indice could also be calculated, for supra-infection, which can be correlated and completed by the incidence (risk) of infection.