Postoperative Staphylococcus aureus Infections in Patients With and Without Preoperative Colonization
Authors: Troeman Darren P. R. , Hazard Derek , Timbermont Leen , Malhotra-Kumar Surbhi , van Werkhoven Cornelis H. , Wolkewitz Martin , Ruzin Alexey , Goossens Herman , Bonten Marc J. M. , Harbarth Stephan , Sifakis Frangiscos , Kluytmans Jan A. J. W. ,   ASPIRE-SSI Study Team, Vlaeminck Jelle , Vilken Tuba , Xavier Basil Britto , Lammens Christine , van Esschoten Marjolein , Paling Fleur P. , Recanatini Claudia , Coenjaerts Frank , Sellman Bret , Tkaczyk Christine , Weber Susanne , Ekkelenkamp Miquel Bart , van der Laan Lijckle , Vierhout Bastiaan P. , Couvé-Deacon Elodie , David Miruna , Chadwick David , Llewelyn Martin J. , Ustianowski Andrew , Bateman Antony , Mawer Damian , Carevic Biljana , Konstantinovic Sonja , Djordjevic Zorana , del Toro-López María Dolores , Gallego Juan Pablo Horcajada , Escudero Dolores , Rojo Miquel Pujol , Torre-Cisneros Julian , Castelli Francesco , Nardi Giuseppe , Barbadoro Pamela , Altmets Mait , Mitt Piret , Todor Adrian , Bubenek-Turconi Serban-Ion , Corneci Dan , Săndesc Dorel , Gheorghita Valeriu , Brat Radim , Hanke Ivo , Neumann Jan , Tomáš Tomáš , Laffut Wim , Van den Abeele Anne-Marie 
Published: October 2023

Importance

Staphylococcus aureus surgical site infections (SSIs) and bloodstream infections (BSIs) are important complications of surgical procedures for which prevention remains suboptimal. Contemporary data on the incidence of and etiologic factors for these infections are needed to support the development of improved preventive strategies.

Objectives

To assess the occurrence of postoperative S aureus SSIs and BSIs and quantify its association with patient-related and contextual factors.

Design, Setting, and Participants

This multicenter cohort study assessed surgical patients at 33 hospitals in 10 European countries who were recruited between December 16, 2016, and September 30, 2019 (follow-up through December 30, 2019). Enrolled patients were actively followed up for up to 90 days after surgery to assess the occurrence of S aureus SSIs and BSIs. Data analysis was performed between November 20, 2020, and April 21, 2022. All patients were 18 years or older and had undergone 11 different types of surgical procedures. They were screened for S aureus colonization in the nose, throat, and perineum within 30 days before surgery (source population). Both S aureus carriers and noncarriers were subsequently enrolled in a 2:1 ratio.

Exposure

Preoperative S aureus colonization.

Main Outcomes and Measures

The main outcome was cumulative incidence of S aureus SSIs and BSIs estimated for the source population, using weighted incidence calculation. The independent association of candidate variables was estimated using multivariable Cox proportional hazards regression models.

Results

In total, 5004 patients (median [IQR] age, 66 [56-72] years; 2510 [50.2%] female) were enrolled in the study cohort; 3369 (67.3%) were S aureus carriers. One hundred patients developed S aureus SSIs or BSIs within 90 days after surgery. The weighted cumulative incidence of S aureus SSIs or BSIs was 2.55% (95% CI, 2.05%-3.12%) for carriers and 0.52% (95% CI, 0.22%-0.91%) for noncarriers. Preoperative S aureus colonization (adjusted hazard ratio [AHR], 4.38; 95% CI, 2.19-8.76), having nonremovable implants (AHR, 2.00; 95% CI, 1.15-3.49), undergoing mastectomy (AHR, 5.13; 95% CI, 1.87-14.08) or neurosurgery (AHR, 2.47; 95% CI, 1.09-5.61) (compared with orthopedic surgery), and body mass index (AHR, 1.05; 95% CI, 1.01-1.08 per unit increase) were independently associated with S aureus SSIs and BSIs.

Conclusions and Relevance

In this cohort study of surgical patients, S aureus carriage was associated with an increased risk of developing S aureus SSIs and BSIs. Both modifiable and nonmodifiable etiologic factors were associated with this risk and should be addressed in those at increased S aureus SSI and BSI risk.