摘要：Objectives. We examined trends in tuberculosis (TB) cases and case rates among US- and foreign-born children and adolescents and analyzed the potential effect of changes to overseas screening of applicants for immigration to the United States. Methods. We analyzed TB case data from the National Tuberculosis Surveillance System for 1994 to 2007. Results. Foreign-born children and adolescents accounted for 31% of 18 659 reported TB cases in persons younger than age 18 years from 1994 to 2007. TB rates declined 44% among foreign-born children and adolescents (20.3 per 100 00 to 11.4 per 100 000 population) and 48% (2.1 per 100 000 to 1.1 per 100 000) among those who were born in the United States. Rates were nearly 20 times as high among foreign-born as among US-born adolescents. Among foreign-born children and adolescents with known month of US entry (88%), more than 20% were diagnosed with TB within 3 months of entry. Conclusions. Marked disparities in TB morbidity persist between foreign- and US-born children and adolescents. These disparities and the high proportion of TB cases diagnosed shortly after US entry suggest a need for enhanced pre- and postimmigration screening. Tuberculosis (TB) case rates continue to decline in the United States and were recently recorded at their lowest level since national recording began in 1953. 1 Although annual TB incidence among US-born persons is declining, the number of new cases reported each year among foreign-born persons has been relatively stable over the past decade; foreign-born persons accounted for almost 60% of TB cases reported in the United States in 2008. 1 TB in foreign-born persons in the United States is largely attributable to acquisition of latent TB infection (LTBI) in TB-endemic countries of origin and subsequent activation of disease after US arrival. 2 The large burden of TB among foreign-born persons in the United States likely reflects the persistently large burden of TB in many other countries. 3 An estimated 11% of all TB cases worldwide occur in children younger than age 15 years. 4 In TB-endemic settings, acquisition of TB infection often occurs in childhood because children are more likely to have frequent and close contact with adults with infectious TB. 5 , 6 Compared with adult rates of progression from infection to disease (historically 5%–10% progress to disease), rates are higher for children of all ages and highest for infants younger than 1 year (43%) and children aged 1 to 5 years (24%). 4 , 7 , 8 Furthermore, children who become infected with TB but do not progress to disease in childhood represent a potential pool for disease in adulthood. 4 , 7 Elucidating the epidemiology of TB in foreign-born children could therefore facilitate efforts to improve children's health and control TB by preventing future disease. TB cases are generally reported in the broad age categories of children (defined as < 15 years) and adults (≥ 15 years). 2 , 9 , 10 However, adolescents are an important group to study because TB rates rise in adolescence following the decline seen in the elementary school years. 11 In addition, adolescents are more likely to present with adult-type pulmonary TB (characterized by disease in the lung apices and a tendency to form cavitary lesions). 11 As a result, adolescents are more likely than are younger children to transmit TB to others. 8 , 11 As part of an effort to limit importation of TB disease, the Centers for Disease Control and Prevention in 2007 published revised requirements for overseas medical screening of applicants for US immigration. 12 All persons aged 15 years or older continue to be screened with chest radiographs. Revised technical instructions now require a tuberculin skin test (TST) for all applicants aged 2 to 14 years who live in countries with a large TB burden. Chest radiographs are performed for those whose TST is positive. 12 The potential effect of these changes is not known. We sought to describe the epidemiology of TB among foreign- and US-born children and adolescents in terms of demographic and clinical characteristics and to analyze the potential effect of the 2007 changes to the instructions for overseas screening of applicants for immigration to the United States.
