Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus Nasal Carriage in a Random Sample of Non-Hospitalized Adult Population in

Objective: The findings from truly randomized community-based studies on Staphylococcus aureus nasal colonization are scarce. Therefore we have examined point prevalence and risk factors of S. aureus nasal carriage in a non-hospitalized population of Braunschweig, northern Germany. Methods: A total of 2026 potential participants were randomly selected through the resident’s registration office and invited by mail. They were requested to collect a nasal swab at home and return it by mail. S. aureus was identified by culture and PCR. Logistic regression was used to determine risk factors of S. aureus carriage. Results: Among the invitees, 405 individuals agreed to participate and 389 provided complete data which was included in the analysis. The median age of the participants was 49 years (IQR: 39–61) and 61 % were females. S. aureus was isolated in 85 (21.9%; 95 % CI: 18.0–26.2%) of the samples, five of which were MRSA (1.29%; 95 % CI: 0.55–2.98%). In multiple logistic regression, male sex (OR = 3.50; 95 % CI: 2.01–6.11) and presence of allergies (OR = 2.43; 95 % CI: 1.39–4.24) were found to be associated with S. aureus nasal carriage. Fifty five different spa types were found, that clustered into nine distinct groups. MRSA belonged to the hospital-associated spa types t032 and t025 (corresponds to MLST CC 22), whereas MSSA spa types varied and mostly belonged to spa-CC 012 (corresponds to MLST CC 30), and spa-CC 084 (corresponds to MLST CC 15). Conclusion: This first point prevalence study of S. aureus in a non-hospitalized population of Germany revealed prevalence