Comparison of BCG test and tuberculin test in children

ABSTRACT

In recent years, several articles have been published about BCG test in the diagnosis of tuberculosis infection particularly in children. The test is reportedly more sensitive and more specific than tuberculin test [PPD]. We evaluated the results of simultaneous application of tuberculin and BCG tests in order to assess their efficacy in normal children [n=52]. The study also included children suffering from PEM [n=38] and children on steroid therapy [n=20]. Assessment of the results of the tests was done after 48 and 72 hours. We found that there were more positive cases with BCG test [44 cases 84.6%] against [23 cases 44.2%] with tuberculin test in normal children. We noticed also that there were no positive cases with tuberculin test in children suffering from PEM while there were 25 positive cases [65.8%] with BCG test which showed that BCG test is better than tuberculin test for detection of tuberculosis infection and less affected by nutritional status. We also found that there were 10 positive cases [50%] with children under steroid therapy with BCG test while there were 7 positive cases [35.0%] with tuberculin test. We noticed also that there were no side effects from BCG vaccination which make it safe to be used. Our results revealed no relation of age to the response to BCG or tuberculin tests. We recommend that BCG test showed more positive results than tuberculin test to detect TB infection and that BCG not only provides immunization against tuberculosis but can be also used as a screening test to detect TB infection less affected by nutritional status. For these reasons we recommend wide use of BCG vaccine as a test to detect TB infection over tuberculin test especially in malnourished children and children under steroid therapy. Wide scale studies are required on tuberculosis patients to .highlight the importance and superiority of BCG over tuberculin tes