884 - Evaluation of Surgical Site Infections in Solid Organ Transplant Recipients with Beta-Lactam Allergies

Background: Beta-lactam allergies (BLA) are common, but the prevalence and impact on solid organ transplant (SOT) recipients is largely unknown. We assessed the prevalence of BLA labels in SOT recipients at the time of transplant and evaluated their influence on surgical site infection (SSI) prophylaxis and SSI incidence.

Methods: All patients undergoing first heart, kidney, liver SOT at our institution were retrospectively reviewed (1/1/2015-12/31/2019).  Antibiotic allergies, surgical antibiotic prophylaxis, and SSIs were abstracted from the electronic medical record. Reported BLA reactions were classified as potentially IgE-mediated, delayed, or non-allergic based on documentation. SSIs were reported according to NHSN definitions, and the incidence of SSI was compared between patients with and without reported BLA. SSI prophylaxis regimens were compared to institutional guidelines. Basic descriptive statistics were performed.

Results: Out of a total cohort of 751 patients (122 heart, 435 kidney, 209 liver, 4 multi-organ), 129 (17%) reported at least one BLA, with 104 (15%) with reactions to penicillins, 26 (3%) to cephalosporins, and 1 (0.1%) to carbapenems. Commonly reported reactions were rash (38%), hives (25%), and “other” (21%); 28% of documented reactions were not documented or classified as non-allergic. SSI developed in 7 (6.1%) of heart, 10 (2.5%) of kidney, and 16 (9.4%) of liver transplant recipients. Excluding 44 patients already on antibiotics for treatment of systemic infection, guideline concordant beta-lactam antibiotic surgical prophylaxis was administered to 6 (5.2%) of BLA group vs 490 (85.8%) in the non-BLA group (p< 0.01); among the BLA group who did not receive a beta-lactam, 96 (83%) received a regimen concordant with institutional guidelines for penicillin allergy and 14 (12%) received guideline non-adherent regimens. Patients reporting BLA did not have a higher incidence of SSIs compared to those without BLA: 6 (4.8%) vs 27 (4.5%) respectively, p=0.86.

Conclusion: BLA prevalence in our SOT population was similar to previously reported rates, but many reported reactions were not allergic in nature. Pre-transplant allergy evaluation for patients with reported BLA may improve SSI antibiotic prophylaxis compliance.