title: [Prevalence of tuberculosis infection as an important indicator of endemic aspects and its continuous decline in the population--past and future aspects].
abstract: For tuberculosis the prevalence of infection, i.e. the rate of occurrence of infection among the population, is one essential measure in defining the profile of this endemic disease. The present account is based primarily on a set of tuberculin-test records which was compiled as the result of periodic BCG inoculation programmes on over 200,000 people tested in the Zurich Canton. In our analysis figures from the period from 1950 to 1978 were included. Longitudinal sections indicate infection profiles within, for example, birth cohorts (BC), i.e. groups of people of the same age. According to various investigations by our group, the principle of the theory advanced by K. Styblo et al (1969), which is based on figures from the Netherlands, also applies to Swiss conditions. According to this, the progress of infection rate with time, in terms of the percentage incidence within the age scale of each BC, follows a rigid pattern. Quantitatively there are differences between the Netherlands and Swiss results. Where in the Netherlands within a particular BC relative percentages (R%) of 40 R% for 4-year olds, 82 R% for 14-year olds and 95 R% for 24-year olds occur--compared to the maximum figure of 100% relative per cent for 50-year-olds--the comparable figures for Switzerland are 24.4 R%, 48.9 R% and 85 R%. Irrespective of the size of the observed, actual infection rate, its progress follows this rigid pattern. Wiping out tuberculosis without eliminating the sum of infection prevalence accumulated in the population as a result of earlier tuberculosis infections is inconceivable. According to extrapolations, the prevalence will still be 12.5% in our country in the year 2028. It will probably take several decades yet to eradicate tuberculosis in Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Haefliger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D019353:Endemic Diseases / Q000706:statistics & numerical data*; D005260:Female; D005544:Forecasting; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D013557:Switzerland / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000517:prevention & control
vernacular_title: Zur Infektionsprävalenz bei Tuberkulose als wichtiger Indikator der Endemie und ihr kontinuierlicher Rückzug aus der Bevölkerung--Aspekte der Vergangenheit und der Zukunft.