The role of chest radiographs and tuberculin skin tests in tuberculosis screening of internationally adopted children.

BACKGROUND

Internationally adopted children (IAC) are a growing group of US immigrants who often come from countries with high tuberculosis (TB) burdens. There is limited evidence to support current TB screening guidelines in these high-risk children. Therefore, we have prospectively examined the clinical utility of tuberculin skin testing (TST) and subsequent chest radiograph screening for TB disease in recently immigrated, asymptomatic IAC.

METHODS

Within 6 months of immigration to the United States, we collected demographic information and assessed the nutritional status of 566 IAC who presented for routine postadoptive care. Children completed standardized clinical examination and TSTs. Chest radiographs were recommended for children with TST induration ≥ 5 mm. The association between TST induration and clinical outcome was assessed. The clinical utility of chest radiographs was evaluated.

RESULTS

There was no difference in age, birth country, or nutritional status between IAC with TST induration of 0 to < 5 mm and those with 5 to < 10 mm; IAC with TST ≥ 10 mm were older, more chronically malnourished, and more likely to emigrate from Guatemala. Among children with TST ≥ 5 mm (35%), 4 IAC had chest radiographs which were initially interpreted to be abnormal and consistent with TB; ultimately none were diagnosed with TB.

CONCLUSIONS

The 5-mm TST cut point did not capture IAC with risk factors for latent TB infection or progression to TB disease, suggesting that this is not a useful screening threshold. In contrast, a 10-mm cut point identified IAC at risk for TB infection and therefore should be a more useful screening threshold. We question the clinical utility of radiographic screening for pulmonary TB in asymptomatic children.