Tuberculin Skin Testing in Secondary Schools in Baltimore County, Maryland: Operation Skin Test

Abstract

1. A five-year summary of tuberculin skin testing among tenth graders in Baltimore County public and Catholic high schools is presented. 2. All students having a skin reaction measuring 5 mm. or more were considered positive, and all reactors were followed by periodic chest x-ray films. 3. There was 87.0 per cent participation by the students, and 7.3 per cent positive reactors were found. 4. The largest number of reactors was found in the non-white boys, and the lowest in the white girls with the total non-white reactors outnumbering the total white reactors by 3 to 1. 5. Catholic high schools had a higher rate of participation and a lower incidence of reactivity than public high schools. 6. Of the students tested, 93.6 per cent cooperated for the first post-tuberculin chest x-ray film with only 14 of these films showing any significant changes. 7. Although 45.7 per cent of the reactions measured 10 mm. or more and about half of these were 15 mm. or more, only 17.7 per cent of all reactors could give a reliable tuberculosis contact history. 8. Because only two new cases of tuberculosis were discovered by this program, it is felt, in Baltimore County, that tuberculin skin testing has served its purpose for epidemiology and health education rather than for case-finding.