Nose picking and nasal carriage of Staphylococcus aureus

OBJECTIVE: Nasal carriage of Staphylococcus aureus is an important risk factor for S. aureus infection and a reservoir for methicillin-resistant S. aureus. We investigated whether nose picking was among the determinants of S. aureus nasal carriage. SETTING AND PARTICIPANTS: The study cohort comprised 238 patients who visited the ear, nose, and throat (ENT) disease outpatient clinic of a tertiary care hospital and did not have a nose-specific complaint (defined as ENT patients) and 86 healthy hospital employees (including medical students and laboratory personnel). MEASUREMENTS: All participants completed a questionnaire on behavior regarding the nose and were screened for S. aureus nasal carriage; only ENT patients underwent nasal examination by an ear, nose, and throat physician for clinical signs of nose picking. RESULTS: Among ENT patients, nose pickers were significantly more likely than non-nose pickers to carry S. aureus (37 [53.6%] of 69 vs 60 [35.5%] of 169 patients; relative risk, 1.51 [95% confidence interval, 1.03-2.19]). Among healthy volunteers, there was a statistically significant positive correlation between the self-perceived frequency of nose picking and both the frequency of positive culture results (R=0.31; P=.004) and the load of S. aureus present in the nose (R=0.32; P=.003). CONCLUSION: Nose picking is associated with S. aureus nasal carriage. The role of nose picking in nasal carriage may well be causal in certain cases. Overcoming the habit of nose picking may aid S. aureus decolonization strategies