Outcomes of annual tuberculosis screening by mantoux test in children considered to be at high risk: Results from one urban clinic

Background. In January 1994, the American Academy of Pediatrics recommended that annual screening with the purified protein derivative tuberculin skin test, Mantoux method, be used for tuberculosis screening in high-risk children. This test has a better sensitivity and specificity than the previously used multiple puncture test, and patients need to return for a reading done by palpation by a health care professional. Objective. To estimate the prevalence of reactivity to purified protein derivative tuberculin in an urban primary care clinic whose patients meet high-risk criteria and to determine if annual screening is warranted, to determine the adherence to return to the clinic for reading of the skin test, and to describe the characteristics of patients who have tuberculosis infection and disease. Research Design. Cross-sectional study. Setting. Inner-city, hospital-based primary care pediatric clinic in Baltimore, MD. Subjects. A total of 1433 consecutive children attending this clinic from March through September, 1994, who were at risk for tuberculosis because of frequent exposure to poor and medically indigent city dwellers. Methods. The Mantoux test (STU intradermal injection of purified protein derivative) was administered to children at annual health supervision visits. Patients were tracked to determine those who returned for a reading by a health care professional and find those with a positive Mantoux test. The charts of children with a positive test were reviewed. Results. Five hundred seventy- three (40%) patients returned for a reading by a health care professional. Five patients had a positive Mantoux test, giving a prevalence rate of 0.8% of reactivity to purified protein derivative tuberculin. One child with a positive Mantoux test also had chest radiograph findings consistent with tuberculosis disease but was asymptomatic. Conclusions. In our city with a low prevalence of disease, children whose only risk factor for tuberculosis was exposure to poor and medically indigent city dwellers did not represent a high-risk group. Our results are supportive of the 1996 American Academy of Pediatrics screening statement that annual screening is not warranted. Sixty percent of children did not return for a reading of the Mantoux test by a health care professional. Alternative strategies that are more convenient for parents are needed to obtain accurate readings by health care professionals when skin testing is deemed necessary.