TOPIC: Transplantation
      TYPE: Fellow Case Reports
      INTRODUCTION: Lung transplant recipients are at an increased risk for microbial infection, which may at times be difficult to isolate or properly identify, even with repeat transbronchial biopsies (1).
      CASE PRESENTATION: We reviewed the unique, potential route of transmission and infectious disease course of an enigmatic microbial pathogen that was challenging to identify and associated with an abscess of the lung allograft in a 59-year-old bilateral lung re-transplant recipient. Interestingly, the patient reported having multiple pets at home, including dogs, lizards, cows, horses, and chickens residing on her property, which may have been a source of infection.
      DISCUSSION: This lung re-transplant recipient presented to our advanced lung disease center at 9-years post-transplant with complaints of sudden fever and chills alongside a 2-week history of productive cough with yellow-tinged sputum. Maintenance immunosuppression consisted of tacrolimus, sirolimus, and prednisone. The patient denied unintentional weight loss, night sweats, or known tuberculosis contacts or exposures; COVID-19 testing was negative in the interim. On thoracic imaging (Figure A), a right upper lobe cavitary lesion was identified. Bronchoscopy was negative for microorganismal growth. She was treated empirically with meropenem, isoniazid, and amikacin. The fever resolved, but the patient reported continued malaise over the next several weeks. Repeated bronchoscopies failed to identify any microorganisms. After six weeks of antibiotic therapy, the size of the lung abscess decreased (Figure B), but all cultures and transbronchial biopsies had failed to determine the infectious origin. The only note regarding her history prior to presentation was that she performed mouth-to-mouth resuscitation on her pet dog who unexpectantly collapsed. It is surmised that this event served as the basis for an oral transmission of a microbial pathogen.
      CONCLUSIONS: Lung abscesses are generally an early complication in the post-lung transplant period, yet our patient seemingly developed an abscess from an unknown microbial infection at 9-years post-transplant, potentially from a zoonotic source. Although infrequently observed, lung transplant recipients (and other immunosuppressed groups) may be at risk for severe harm or prolonged infection due to direct zoonosis.
      REFERENCE #1: Påhlman LI, Manoharan L, Aspelund AS. Divergent airway microbiomes in lung transplant recipients with or without pulmonary infection. Respir Res. 2021 Apr 23;22(1):118. doi: 10.1186/s12931-021-01724-w. PMID: 33892717.
      DISCLOSURES: No relevant relationships by Ashwini Arjuna, source=Web Response
      No relevant relationships by David Bowman, source=Web Response
      No relevant relationships by Michael Olson, source=Web Response
      No relevant relationships by Ali Saeed, source=Web Response