2320. Decolonization of the Oropharynx, an Important and Neglected Reservoir of Staphylococcus aureus Colonization

BACKGROUND: Community-associated S. aureus skin and soft-tissue infections are common and recur in 20 to >50% of cases. Decolonization trials have been disappointing for unclear reasons, but may be related to untreated reservoirs. Given recent data that oropharyngeal (OP) S. aureus colonization is common with a prevalence comparable to nasal colonization, we performed a double-blind, placebo controlled trial of the efficacy of oral chlorhexidine gluconate (CHG) for OP S. aureus colonization. METHODS: We enrolled healthy outpatient children from ages 5 to 17 who were tested for OP S. aureus colonization. Colonized subjects were randomized to 0.12% CHG or placebo gargle twice daily × 7 days. Primary endpoint was OP colonization at the End of Therapy (EOT) visit using an intention to treat (ITT) model. We also measured OP colonization at 28 days and nasal S. aureus colonization at all study visits. RESULTS: Among 189 consented subjects, 120 (63%) had OP colonization; 81/120 (66%) were randomized and 67 were analyzable (CHG: N = 33; Placebo: N = 34). Fourteen subjects were not analyzable due to product error or loss to follow-up prior to study drug receipt (figure). In the ITT analysis, EOT OP S. aureus colonization was 45% (15/33) in the CHG group and 79% (27/34) in the placebo group (P = 0.004). In the as treated analysis, OP colonization was 40% (11/29) and 77% (23/30) in the CHG group and placebo groups (P = 0.003). At Day 28 in the ITT model, OP colonization was 61% (20/33) vs. 85% (29/34) in the CHG and placebo groups (P = 0.03). At EOT nasal colonization in those without OP colonization was 11/25 (44%) vs. 15/34 (44%) in those still OP colonized. At Day 28, nasal colonization was 0/18 (0%) in those without OP colonization vs. 19/38 (50%) in those with OP colonization. CONCLUSION: One week of 0.12% oral CHG gargle was more effective than the placebo at eradicating S. aureus OP colonization in S. aureus colonized children. Significant differences persisted at Day 28. Persistent OP colonization at Day 28 was associated with nasal S. aureus colonization, suggesting that nasal colonization may contribute to persistence and relapse of OP S. aureus colonization. Our findings support decolonization trials that include OP S. aureus decolonization as part of a more aggressive S. aureus decolonization strategy. [Image: see text] DISCLOSURES: All authors: No reported disclosures.