Tuberculin skin testing in San Francisco schools as an instrument of tuberculosis casefinding. A five year study.

INTRODI S INCE 1956, TUBERCULIN SKIN TESTING has k e n done annually in all public and parochial elementary and secondary schools in San Francisco. Since there are 120,185 pupils in 202 schools, from kindergarten through the twelfth grade, it would be impossible to test every student and do an adequate follow-up examination of all positive reactors and their families. Therefore , it was decided to t& the entire first, seventh, tenth and twelfth grades, and all students recently moved to San Frandsco. The first grade was chcsen to determine the prevalence of tuberculous infection in children beginning school. Since pupils must attend the elementary school in their neighborhood, the number of positive reactors should compare w d with the prevalence of tuberculosis in the immediate area. Public school pupils entering the seventh grade go to district junior high schools, whereas p m h i a l students remain in parish schools through the eighth grade. It was decided to determine the prevalence of tuberculous infection in children entering junior high school, so the seventh grade was chcsen. The senior high schools serve a larger area: students from several districts and many neighborhoods. Public high schools smt with the tenth grade, whereas the parochial begin with the ninth. Following the tenth grade the school population falls off rapidly, so that between the tenth and the twelfth grade there is approximately a 25 per cent decrease. The tenth grade was lCTlON selected to test the maximum number of pupils at this level and to determine the prevalence of reactors beginning senior high school. The last opportunity to test the group as a whole is in the twelfth grade. The findings indicate not only the prevalence of tuberculous infection in this grade, but may be contrasted with thcse of other grades tested. Since the end of the 1958-1959 school year every class in junior and senior high schools has been tested. The tuber-culin conversion rates from the seventh to the tenth, and from the tenth to the twelfth grades cannot be determined precisely, since reactors moving into San Francisco from other areas will alter the figures. However , the difference in reactor rate will be a good index of the rate of infection. Since 1942, there has k n a large transient population who reside in the city for a few months to as long as two or tpree years. Many of …