Evaluating the role of methicillin-resistant Staphylococcus aureus (MRSA)-specific antibiotic prophylaxis for neurosurgical patients

Objective: Surgical site infection (SSI) in neurosurgical patients increases morbidity. Despite the rise of methicillin-resistant Staphylococcus aureus (MRSA) colonization, there is little consensus regarding antibiotic prophylaxis for SSI in MRSA-colonized neurosurgical patients. Our objective was to examine the incidence of SSI in MRSA-colonized neurosurgical patients and interrogate whether MRSA-specific antibiotic prophylaxis reduces SSIs. Methods: We performed a retrospective analysis of adult patients undergoing neurosurgical procedures between 2013 and 2018. The primary outcome was SSI in patients with MRSA colonization receiving MRSA-specific antibiotics. Secondary outcomes included predictors of SSI, including whether broad use of MRSA-specific antibiotics affects SSI rate. Results: Of 9739 procedures, 376 had SSI (3.9 %). Seven hundred forty-four procedures (7.6 %) were performed on patients screened preoperatively for MRSA, including 54 procedures on MRSA-colonized patients. MRSAcolonized patients were more likely than MRSA-non-colonized patients to receive MRSA-specific antibiotics (35.2 % vs. 17.8 %, p = 0.002) for prophylaxis. Nevertheless, MRSA-colonized patients had higher SSI rates compared to MRSA-non-colonized patients (22.2 % vs. 6.4 %, p = 0.00002). MRSA-colonization led to 3.49 greater odds (95 % CI 1.52-7.65, p = 0.002) of SSI relative to MRSA-non-colonization. MRSA-colonized patients receiving MRSA-specific antibiotics, compared to those receiving non-MRSA-specific antibiotics, had lower SSI rates, but this difference was not statistically significant (15.8 % vs. 25.7 %, p = 0.40). In the non-screened population, those receiving MRSA-specific antibiotics, compared to those receiving non-MRSA-specific antibiotics, had significantly higher SSI rates (6.9 % vs. 3.0 %, p = 0.00001). The use of MRSA-specific antibiotic prophylaxis in the non-screened population increased the odds of SSI (OR 1.90, 95 % CI 1.45-2.46, p = 0.0001). Conclusion: MRSA-colonized neurosurgical patients had a higher SSI rate compared to MRSA-non-colonized patients. While MRSA-specific antibiotics may benefit those with MRSA colonization, the difference in SSI rate between MRSA-colonized patients receiving MRSA-specific antibiotics vs. non-specific antibiotics requires further investigation. The broader use of MRSA-specific antibiotics may paradoxically confer an increased risk of SSI in a non-screened neurosurgical population.