Association between nasal colonization of Staphylococcus aureus and surgical site infections in spinal surgery patients: a systematic review and meta-analysis

OBJECTIVE: The study aimed at examining the relationship between nasal colonization of Staphylococcus aureus (SA) or methicillin-resistant Staphylococcus aureus (MRSA) and the risk of SSI after spinal surgeries MATERIALS AND METHODS: PubMed, CENTRAL, Scopus, Web of Science, and Embase databases up to 24(th) September 2022 for articles on nasal colonization of SA/MRSA and spine surgeries. RESULTS: Ten studies were included. Meta-analysis revealed that the incidence of SSI was not significantly different between SA-positive and SA-negative patients (RR: 0.75, 95% CI: 0.47, 1.18 I-2=2% p=0.21). It was noted that when no decolonization was done, there was no statistically significant difference in the risk of SSI between MRSA positive and MRSA negative patients, but a tendency of higher SSI in MRSA carriers (RR: 2.40, 95% CI: 0.91, 6.32, I-2=37% p=0.08). However, in the subgroup analysis with decolonization, the risk of SSI was significantly higher in the MRSA-positive group (RR: 2.99, 95% CI: 1.27, 7.03, I-2=24% p=0.01). Specifically, the risk of MRSA-SSI was significantly higher in MRSA carriers with (RR: 6.05, 95% CI: 1.14, 31.99, I-2=43% p=0.03) and without decolonization (RR: 7.54, 95% CI: 1.43, 39.85, I-2=38% p=0.02). CONCLUSIONS: Evidence from observational studies indicates that only MRSA nasal colonization increases the risk of SSIs in spinal surgery patients. Nasal decolonization was unable to reduce the risk of overall or MRSA-specific SSIs in MRSA carriers. Evidence was biased due to the extremely small number of MRSA- positive patients in the studies and the lack of adjustment of confounding factors.