Increase in the Number of Tuberculosis Cases Treated following Tuberculin Skin Testing in First-Year Schoolchildren in Madagascar

BACKGROUND Tuberculosis continues to cause unacceptably high levels of disease and death worldwide. Active preventive strategies are required to improve tuberculosis control and to increase the number of cases treated in developing countries. The aim of this study was to evaluate the utility of the tuberculin skin test (TST) in first-year schoolchildren as a means of increasing the number of tuberculosis cases detected through the screening of close contacts. METHODS All members of the households of 90 schoolchildren assigned to three groups on the basis of TST category (≤ 5 mm, [5-15)mm, ≥ 15 mm) were screened for sputum smear-positive pulmonary tuberculosis. The percentage detection of tuberculosis in close contacts was compared between TST categories. RESULTS We identified 433 close contacts of the 90 schoolchildren, who were then evaluated for tuberculosis. We identified 11 cases of pulmonary tuberculosis among the close contacts (7 already on treatment and 4 previously undiagnosed): 0 in TST category ≤ 5 mm, 3 in TST category [5-15) mm and 8 in TST category ≥ 15 mm). This approach increased the detection of tuberculosis cases by a factor of 1.6 in first-year schoolchildren of the TST ≥ 5 mm group. CONCLUSION TST in first-year schoolchildren is a potentially effective method for improving the detection of tuberculosis in close contacts.