Mycobacterium tuberculosis transmission from a pediatrician to patients

The following report describes the contact investigation of a pediatrician with tuberculosis (TB). The pediatrician's disease was discovered in late February 1993 after tuberculin skin testing (TST) of his 15-month-old son was positive (13-mm induration). Further investigation to identify the source of the child's infection revealed a positive (15-mm induration) TST in the pediatrician. The pediatrician had been symptomatic with a cough since September 1992. The pediatrician had a chest radiograph that revealed numerous cavitary lesions and a sputum smear that was positive for acid-fast bacilli. An investigation was initiated to assess whether the transmission of Mycobacterium tuberculosis had occurred in the pediatrician's office to patients, families, or other visitors. The investigation was later extended to include the hospitals and the day care center where the pediatrician worked. Methods. A letter was mailed to parents of children served by the practice, explaining the potential exposure to TB and requesting that all persons who visited the office after September 1, 1992 complete an interview and Mantoux TST. Mass interviewing, testing, and test interpretation within the practice took place seven times during March and April 1993. Results. At the completion of screening, 181 (87%) of 208 children who had close contact with the index case were reliably skin-tested and returned for interpretation. Three (1.7%) of the 181 children were TST-positive (greater than or equal to 5 mm). Thirty-seven (13%) of the 286 adults tested and returning for interpretations were TST-positive (greater than or equal to 10 mm). Thirty-two (86%) of the 37 adults who tested positive were foreign-born. Conclusion. This investigation highlighted the need for identifying childhood TB infection as a sentinel event for adult disease. It also demonstrated the difficulty associated with deciding the extent of contact investigation of a health care worker with TB. Finally, the investigation emphasized the importance of maintaining regularly scheduled and appropriate testing for TB infection in health care workers and the need for health care workers to be cognizant of their own risk and be able to identify, especially in themselves, signs and symptoms of potential TB disease.