Variations in the Organisms Causing Deep Surgical Site Infections in Fracture Patients at a Level I Trauma Center (2006-2015)

Abstract

Objectives: To quantify the current bacteriology of deep surgical site infections (SSIs) after fracture surgery at 1 institution and to compare those data with historical controls at the same institution, assessing variations in infecting organisms over the past decade.

Design: Retrospective review.

Setting: Level I trauma center.

Patients/participants: Two hundred forty-three patients requiring surgical intervention for deep SSI between January 2011 and December 2015 were compared with 211 patients requiring surgical intervention for deep SSI between December 2006 and December 2010.

Intervention: None.

Main outcome measurements: Bacteria were categorized as Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus, Enterococcus, gram-negative rods (GNR), gram-positive rods, anaerobes, or negative cultures. The proportion of each bacterial type was determined and compared with previously published data from the same trauma center (December 2006 to December 2010).

Results: Patients most commonly had S. aureus infections (48%), followed by GNR (40%) and CoNS (19%). The proportion of CoNS species (26% vs. 12%, P < 0.01) in infected patients was significantly higher during the current study period compared with historical controls. The proportion of S. aureus species in infected patients was significantly less during the current study period (39% vs. 56%, P < 0.01). The reduction in the proportion of S. aureus species in infected patients was driven by a decrease in the proportion of methicillin-resistant S. aureus (MRSA) in the overall sample.

Conclusions: Bacteriology of deep SSI of fractures has changed substantially over the past decade at our center, specifically the proportions of GNR, CoNS, and MRSA.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.