Screening for tuberculosis infection in urban children.

OBJECTIVES

To determine the proportion of children who are at high risk for tuberculosis (TB) as defined by the American Academy of Pediatrics (AAP) criteria, the rate of compliance with visits for tuberculin skin test (TST) interpretation, and the prevalence of TB infection.

DESIGN

A cross-sectional study of 401 children, 12 months to 18 years of age, who attended a hospital-based, urban pediatric clinic for well-child visits was undertaken from April 13, 1994, through August 30, 1994. Respondents completed a self-administered questionnaire, an intradermal TST was applied, and an appointment was scheduled for skin test interpretation in 48 to 72 hours.

SETTING

Hospital-based, pediatric primary care center in Rochester, NY, serving children of low to moderate income (67% were receiving Medicaid).

RESULTS

Of the 401 children, 342 (85%) had at least 1 risk factor for TB identified: 96 (24%) reported contact with persons who were considered to be at high risk for TB; 170 (42%) had at least 1 parent who was born in a high prevalence country; and 269 (67%) reported a household income of less than $15,500. Of the 401 children, 300 returned for TST interpretation, 257 (64%) by 48 to 72 hours and an additional 43 (11%) by 96 hours. Four (1.3%) of the 300 children had a positive TST (ie, induration > or = 10 mm). All 4 of the children who were TST positive had at least 1 parent from a high-risk country and were identified using AAP-defined risk criteria. The mean age of children who were TST positive was 15.3 years (range 13-17 years) compared with 8.1 years for those who were TST negative (P < .01). The positive predictive value of the questionnaire, which included income as a risk factor for TB, was only 1.5 (95% confidence interval = 0.5-4.0); when household income was not considered a risk factor, the positive predictive value was 2.0 (95% confidence interval = 0.7, 5.5). The estimated cost per child who was TST positive ranged from $430 for those who had contact with an incarcerated adult to $855 per child who was TST positive identified by using AAP-defined criteria.

CONCLUSIONS

The overall sensitivity of the AAP-defined criteria and having at least 1 parent from a TB-endemic country were high. However, because of the low prevalence of TB infection, the positive predictive value of these criteria was very low. These data support AAP recommendations only to skin test children who are at high risk for TB, but they also suggest that annual testing may not be cost-effective for many communities in the United States.