Background and objective:
Staphylococcus aureus is a leading cause of surgical site infections. Risk factors are age, comorbidity and prolonged hospitalization. Since up to 45% of S. Aureus infections are Methicillin-resistant, targeted treatment are required to stop nosocomial infection following surgical procedures. In order to explore the incidence and management of methicillin-resistant and methicillin-sensitive S. Aureus (MRSA and MSSA) infections, a prospective observational multicentre study was conducted in patients undergoing elective arthroplasty surgery at the Clinical Institutes of Pavia and Vigevano (Italy).

Methods:
We examined data flow from screening nasal swabs performed within 30 days before surgery (arthroplasty surgery or prosthetic revision) in patients treated between March and November 2022. Eradication treatment consisted in nasal drainage with Mupirocin twice a day and skin washings with 4% chlorhexidine or 7.5% povidone iodine or 2% triclosan once a day.

Results:
A total of 737 subjects were recruited, 37% men and 63% women. The average age was 72 years, with the following distribution: 39-52 years, 3.7%; 53-62 years, 13.2%; 63-72 years, 32.5%; 73-82 years, 41%; 83-92 years, 9.6%. Seven (0.9%) patients were MRSA positive and 142 (19.3%) MSSA positive. The outcome of the MRSA eradication treatment will be evaluated through an Active Registry reporting infectious or secondary events (movement impairment, persistent joint pain, inflammation signs) during the follow-up phase performed at 6 and 12 months either on site or by telephone.

Conclusions:
The early identification of MRSA strains through patients screening allows targeted antibiotic treatment to prevent surgical site infections. Further prospective studies are needed in order to characterise population contamination and define the best therapeutic strategies.