Management of Brucella exposure among employees at an urban hospital

Abstract

University of Washington Abstract Management of Brucella exposure among employees at an urban hospital Heather Richards Chair of the Supervisory Committee: Dr. Anna Wald Department of Epidemiology Objectives: This study was a longitudinal, descriptive study that used data collected by Harborview Medical Center (HMC) in June 2019 to evaluate adherence to the Centers for Disease Control and Prevention (CDC) recommended protocol for post-exposure prophylaxis (PEP), symptom reporting, and serology testing following a Brucella exposure among hospital employees. Our aim was to describe the factors associated with early PEP cessation among persons following an exposure event, to explore the proportion of exposed persons who took part in serial serologic testing and symptom reporting, and to better inform antimicrobial stewardship, employee health, and infection prevention efforts in the future. Methods: Descriptive data concerning the course of treatment for each exposed person were abstracted from electronic medical records and summarized in a customized REDCap tool. In response to a Brucella exposure event, the CDC recommends that high-risk exposures receive a combination of 100 mg doxycycline twice daily, and 600 mg rifampin once daily, for three weeks. Weekly symptom screening and sequential serological monitoring every six weeks is recommended for high- and low-risk exposures through 24 weeks post exposure. Minimal risk exposures are not recommended to take PEP but 4 symptom screening and serological monitoring may be considered. Therefore, weekly electronic symptom reports and the results from five Brucella serology tests were collected for each exposed person. Characteristics of the entire exposed population (N=236) were summarized as well as those classified as having high-risk exposures (N=150), low-risk exposures (N=8), and minimal-risk exposures (N=78) per CDC criteria. A summary of adherence to the CDC recommended guidelines and an analysis of the required follow-up efforts along with commonly reported symptoms was completed on the highrisk population. Lastly, a regression analysis was completed to explore the independent variables associated with PEP cessation. Results: Of the 236 persons involved in this event, 150 (57.3%) were determined to have had highrisk exposure for Brucella. Most persons with high-risk exposures were prescribed the CDC recommended antibiotic combination of doxycycline and rifampin (112, 75.2%). However, only 82 (54.7%) completed the full course of PEP. Taking ≤2 additional medications for conditions unrelated to the exposure, i.e., in addition to the PEP regimen, was the only statistically significant variable associated with PEP cessation in the unadjusted model, with such persons being less likely to cease taking PEP in comparison with persons taking >2 additional medications (OR=0.4, 95% CI=0.2-0.9, pvalue= 0.028). Mostly non-statistically significant findings indicate that symptom complaints may not be associated with early cessation of PEP. Conclusions: The proportion of exposed persons who were able to complete and partially complete CDC recommended symptom and serologic monitoring was lower than recommended. Follow-up with 5 exposed persons reporting adverse symptoms during PEP was laborious for employee health. Although the majority of results were not statistically significant, this study offers valuable information on what variables may be predictive of PEP cessation.