[Tuberculosis infection prevalence in children younger than 7 years of age in Cantabria. What is the recommended periodicity for the tuberculin tes?].

OBJECTIVE Because of the disparity between the recommendations regarding age and frequency for the realization of tuberculin testing during childhood, a study of tuberculous infection prevalence according to age was made in order to establish at which ages tuberculin testing would be recommendable and to determine if there is a difference in prevalence between vaccinated and non-vaccinated children. PATIENTS AND METHODS A study was carried out by performing annual tuberculin tests (4,454) using the Mantoux technique on 1,710 boys and girls between 1 and 6 years of age. Of these, 796 (46.54%) had been vaccinated with BCG at birth. Children on which a diagnostic tuberculin test had been carried out were excluded from the study. Indurations larger or equal to 10mm were considered positive, in vaccinated as well as in non-vaccinated children, until the publication and adoption of the criterion recommended by the National Concensus for Tuberculosis Control in Spain in 1992. Thereafter, indurations larger or equal to 5 mm in non-vaccinated children and larger than 14 mm in vaccinates children were considered positive. RESULTS The prevalence of tuberculosis infection was 0.49%, 1.87%, and 6,66% at one, 4 and 6 years of age, respectively, in non-vaccinated children and 0.31%, 2.25% and 8,69% at the same ages in vaccinated children was compared and no statistically significant difference was found. CONCLUSIONS We recommend the realization of tuberculin tests at one and 4 years of age and show that, in our medium, vaccinated children have a tuberculous infection prevalence during early childhood similar to their non-vaccinated counterparts.