The issue of tuberculin skin testing in pregnant health care workers of third-world ethnicity who may have previously received bacille Calmette-Guerin (BCG) immunization is complex and multifaceted. The relevant issues are:
• Is tuberculin skin testing safe in the pregnant female?
• Is tuberculin skin testing indicated in the pregnant female?
• Is tuberculin skin testing accurate and reliable in the pregnant female?
• Does previous BCG vaccination alter the diagnostic utility of tuberculin skin testing?
• Finally, is tuberculin skin testing safe in the BCG-immunized pregnant female?
Is tuberculin skin testing safe in the pregnant female?
When purified protein derivative (PPD) tuberculin is injected locally into the skin, most of it is removed within hours by lymphocytes. The remainder is engulfed by macrophages, and a mild brief local inflammatory reaction develops in both nonsensitive and hypersensitive patients. The reaction goes no further in the nonsen-sitized patient. In the sensitized patient-who has had Mycobacterium tuberculosis infection in the past-the area becomes heavily infiltrated by mononuclear cells, and an inflammatory reaction continues to increase for several days.