Resource-Intensive Contact Investigation Resulting from an Unrecognized Pulmonary Tuberculosis Case at a Rheumatology Clinic

Abstract

Background. An adalimumab-treated patient was seen in a rheumatology clinic with cough that was considered a non-infectious sequel to community-acquired pneumonia previously diagnosed by the primary care provider. Four weeks later, the patient was found to have smear-positive cavitary tuberculosis (TB); no isolation precautions were observed during the rheumatology clinic visit, leading to possible high-risk exposures. Methods. We conducted a contact investigation with health department colleagues. We reviewed the clinic schedule and interviewed staff to develop a list of exposed patients and reviewed medical records to evaluate risk of transmission. An exposed person was defined as someone who shared clinic airspace with the index case within 2 hours of the visit. Symptom screening, QuantiFERON-TB Gold (QFT) and/or TB skin test (TST) were performed 8 weeks after exposure. Exposed healthcare workers (HCWs) and community contacts were similarly screened. Results. There were 17 patients who were exposed in the clinic. They resided in 6 counties in 3 states. The mean age was 50. 6 years (range 21-71); 59% were female. Twelve (71%) were on immunosuppressive medications. Fourteen patients had negative follow-up TST or QFT tests; 2 had previously positive QFT tests without pulmonary symptoms or chest X-ray abnormalities. At 1 year, none of these patients had developed TB disease. One patient was lost to follow-up. Among 17 community contacts who were tested, 7 (41%) had positive QFT or TST. None of the 7 exposed HCWs converted TSTs. The genotype of the patient's mycobacterial isolate was unrelated to any Oregon isolate; no source patient was identified. Conclusion. Lackof symptomscreening andisolationat the time of clinic arrival resulted in high-risk TB exposures among immunocompromised patients, requiring a resourceintensive, collaborative investigationbetweenhealth departments and hospital infection preventionists. To prevent future exposures, we have implemented a standard protocol for symptom screening and patient isolation at all ambulatory care clinic check-in desks.