Prevalence of nasal carriage of Staphylococcus aureus in allergic rhinitis patients and healthy controls in Thailand.

Background: Staphylococcus aureus has been proposed as a disease modifier of allergic rhinitis (AR) severity. Although several studies have investigated the prevalence of nasal carriage of S. aureus in healthy controls and AR patients, data from Thailand is scarce.

Objective: The aim of this study was to determine the prevalence of nasal carriage of S. aureus in AR patients compared with healthy controls in Thailand.

Methods: This prospective study enrolled non-AR healthy controls and confirmed AR aged 18-60 years who attended the Department of Otorhinolaryngology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand during June 2013 and December 2013. To detect nasal carriage of S. aureus, nasal swab was used for specimen collection from the nasal vestibule. S. aureus prevalence was compared between groups. All AR patients were assessed for disease severity and quality of life.

Results: The 200 enrolled participants were evenly divided between the AR and healthy control groups. Nasal swab cultures were positive for S. aureus in 20 of 100 subjects in the healthy control group, and in 21 of 100 subjects in the AR group (p = 0.86). Nasal carriage of S. aureus was significantly more prevalent in males than in females (p = 0.01). None of the investigated factors were found to be significantly associated with AR severity among S. aureus-positive AR subjects.

Conclusions: The 20% prevalence of S. aureus in AR patients is not different from that of healthy controls in Thailand, and is similar to other reported rates. No significant associations with AR severity were identified.