OHW 89 - An Expedient Response to a Mycobacterium tuberculosis Exposure and Its Impact on Post-exposure Testing Compliance

Background: Persons with infectious Mycobacterium tuberculosis (MTB) pose a significant risk to others in crowded areas, such as emergency department (ED) waiting rooms. After a slow response to a first MTB exposure was associated with poor compliance with post-exposure MTB testing, we sought to determine if a more expedient response would improve compliance with post-exposure testing.

Methods: We compared two large MTB exposures occurring six months apart in the ED of an acute care academic hospital. Exposed patients and accompanying guests were contacted by phone and certified mail and offered baseline and follow-up QuantiFERON-TB Gold (QFT) tests, obtained 10-12 weeks apart.

Results: In the first exposure investigation, a positive MTB PCR test resulted three days after an infectious patient presented to the ED. Sixty-one non-staff were identified as potentially exposed (39 patients + 22 guests). Exposed persons were notified by telephone starting 16 days post-exposure. In the second exposure investigation, 90 non-staff exposures were identified (54 patients + 36 guests). Exposed persons were notified starting six days post-exposure. Baseline QFT testing was obtained by 30/61 (49%) and 39/90 (43%) persons in the first exposure and second exposures, respectively (p=0.48). Follow-up QFT testing was obtained by 13/61 (21%) and 17/90 (19%) in the first and second exposures, respectfully (p=0.68). 38/76 (50%) of exposed persons who were contacted directly by telephone obtained QFT testing, while 3/14 (21%) of persons only contacted indirectly (voicemail or certified mail) obtained QFT testing (p=0.049).

Conclusions: A more expedient response did not have an impact on post-exposure QFT test compliance. Direct communication was associated with a statistically greater likelihood of persons following through with post-exposure testing. A greater focus on initiating direct contact via telephone and communicating that two QFT tests are needed may be essential to compliance with post-exposure MTB testing.