Single-dose intranasal 10% povidone-iodine for perioperative nasal decolonization of Staphylococcus spp.: a randomized, open-lable, placebo-controlled trial

Background: Pre-operative nasal colonization with Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA]) increases surgical site infection (SSI) risk. Mupirocin requires a 5-day regimen and faces resistance concerns. We evaluated whether a single pre-operative intranasal application of 10% povidone-iodine (PI) suppresses nasal staphylococcal burden. Methods: In a prospective, randomized, open-label, placebo-controlled trial at a single academic hospital, adults undergoing outpatient surgery were randomized to intranasal 10% PI or sterile saline. Nasal swabs were obtained at baseline and at 1 h, 2 h, and 3 h after surgical start following study-agent application. The primary endpoint was reduction in nasal staphylococcal burden in the enrolled cohort. Organism-specific analyses among participants with positive baseline cultures were performed as supportive analyses. Secondary endpoints included SSIs at 7 and 30 days, respectively, and tolerability. Results: Of 192 enrolled patients, 179 were analysed (88 PI; 91 saline). At 3 h, eradication favoured PI vs saline: 33.0% vs 10.6% (S. aureus), 47.0% vs 2.9% (MRSA), and 24.0% vs 0.0% (Staphylococcus epidermidis). Median reduction in log10 enumeration per mL from baseline to 3 h was greater with PI than with saline across S. aureus, MRSA, and S. epidermidis (all P < 0.001). PI was well tolerated (2/88 [2.1%] minor irritation; no serious adverse events). Thirty-day SSIs were infrequent and were considered exploratory: 1 of 88 (1.1%) with PI vs 6 of 91 (6.6%) with saline. Conclusions: Single-dose intranasal 10% PI administered pre-operatively rapidly suppresses nasal staphylococcal carriage with excellent tolerability. Clinical outcomes, including SSIs, were exploratory. Larger studies are needed to determine whether this microbiological suppression translates into reduced postoperative infection risk.