1343. Infectious Diseases Consultation Avoided Delayed Therapy and Unnecessary Exposures in the Majority of GeneXpert® MTB/RIF and AFB Smear Negative Pulmonary Tuberculosis Cases in the US County Hospital in Houston, Texas

BACKGROUND: In 2017, Harris County had a total of 281 cases of newly diagnosed tuberculosis (Mtb), which was the highest incidence in Texas, United States. Lyndon B. Johnson (LBJ) hospital is one of the two HarrisHealth county hospitals which serve a wide population including immigrants and an indigent population. GeneXpert® MTB/RIF (GeneXpert) was implemented in our hospital since 4/2016. However, pulmonary Mtb cases with negative GeneXpert/AFB smears carry significant challenges in the initiation of therapy and hospital infection control. Our aim was to describe how Infectious diseases (ID) consultations helped to identify the cases of both GeneXpert and AFB smear-negative pulmonary Mtb cases without delaying therapy and unnecessary exposures. METHODS: The patients with newly diagnosed pulmonary Mtb in LBJ hospital were identified between January 2017 and December 2018. The patient’s characteristics, GeneXpert results, AFB smear results, and the presence of ID consultation were retrospectively collected. Delayed therapy is defined as the initiation of active four-drug Mtb therapy until the positive culture results. RESULTS: A total of 52 cases with newly diagnosed pulmonary Mtb confirmed by positive culture were identified, of which 44 cases who had GeneXpert on at least one sputum specimen were included in the final analysis. 7 out of 44 (20%) had negative GeneXpert on the first specimen and all three or more AFB smears were negative. The patients were the median age of 51 years and predominantly female (57%). 5 cases were Hispanic and 2 had HIV/AIDS. In 6 out of the 7 cases, ID consultation was made and anti-tuberculous therapy was empirically initiated without delay and all remained in the isolation. Only one case had delayed therapy despite ID consultation, three consecutive AFB sputum samples, and one GeneXpert was properly performed. The patient had newly diagnosed AIDS (CD4 of 2 cells/µL) and 3 weeks of chronic cough with normal lung parenchyma and minimal right pleural effusion on CT chest at his presentation. CONCLUSION: We had 7 cases (20%) of GeneXpert and AFB smear-negative pulmonary Mtb. ID consultation properly identified 6 cases without delayed therapy. Early involvement of ID should be considered when pulmonary Mtb is suspected. DISCLOSURES: All authors: No reported disclosures.