Staphylococcus aureus in patients with rheumatoid arthritis under conventional and anti-tumor necrosis factor-alpha treatment.
OBJECTIVE
To compare the prevalence of nasal and oral Staphylococcus aureus in patients with rheumatoid arthritis (RA) with the prevalence in controls with other rheumatic diseases, and to determine predictors of S. aureus carriage and the influence of treatment with anti-tumor necrosis factor-a (anti-TNF-alpha) agents.


METHODS
Eighty-one patients with RA and 83 other control patients of 2 outpatient rheumatology clinics were cultured for nasal and oral carriage of S. aureus. Quantitative nasal cultures for S. aureus were performed from swabs of the anterior nares, the posterior pharynx, and the soft palate. Information on medications, medical conditions, and risk factors for S. aureus carriage was collected from all participants by a questionnaire and confirmed by chart review.


RESULTS
The S. aureus carriage rate (nasal and/or oral colonization) was 34.6% among RA patients and 32.5% among controls (p = 0.87). Being treated with an anti-TNF-alpha agent plus methotrexate (MTX) was the only independent predictor of S. aureus carriage (OR 3.24, 95% CI 1.16-9.05, p = 0.025). The S. aureus carriage rate among RA patients treated with an anti-TNF-alpha agent plus MTX was 60% (9/15) versus 23.1% (3/13) in RA patients treated with an anti-TNF-alpha agent only (p = 0.049). All S. aureus isolates were susceptible to oxacillin.


CONCLUSIONS
The S. aureus carriage rate among patients with RA was not higher than among controls. Treatment with anti-TNF-alpha agents was not associated with an increased S. aureus carriage rate. However, treatment with an anti-TNF-alpha agent plus MTX may predispose patients to S. aureus carriage.
Bassetti
Stefano
S
Division of Infectious Diseases and Hospital Epidemiology, Microbiology Laboratory, University Hospital Basel, Switzerland. sbassetti@uhbs.ch
Wasmer
Sarah
S
Hasler
Paul
P
Vogt
Thomas
T
Nogarth
Danica
D
Frei
Reno
R
Widmer
Andreas F
AF
D000068879:Adalimumab; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000009:adverse effects; D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents / Q000008:administration & dosage / Q000009:adverse effects; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000453:epidemiology* / Q000276:immunology; D000068800:Etanercept; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000008:administration & dosage / Q000009:adverse effects; D000069285:Infliximab; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage / Q000009:adverse effects; D008828:Microbiological Techniques; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology; D009666:Nose / Q000382:microbiology; D010068:Oxacillin / Q000627:therapeutic use; D015995:Prevalence; D018124:Receptors, Tumor Necrosis Factor / Q000008:administration & dosage; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
D000900:Anti-Bacterial Agents; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D000068879:Adalimumab; D000068800:Etanercept; D010068:Oxacillin; D008727:Methotrexate