Perioperative medicine training resources: U5M4: Management of pathogens of surgical site infections

Abstract
These guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of post-operative surgical site infections (SSIs) in solid organ transplantation. SSIs are a significant cause of morbidity and mortality in SOT recipients. Depending on the organ transplanted, SSIs occur in 3%-53% of patients, with the highest rates observed in small bowel/multivisceral, liver, and pancreas transplant recipients. These infections are classified by increasing invasiveness as superficial incisional, deep incisional, or organ/space SSIs. The spectrum of organisms implicated in SSIs in SOT recipients is more diverse than the general population due to other important factors such as the underlying end-stage organ failure, immunosuppression, prolonged hospitalizations, organ transportation/preservation, and previous exposures to antibiotics in donors and recipients that could predispose to infections with multidrug-resistant organisms. In this guideline, we describe the epidemiology, clinical presentation, differential diagnosis, potential pathogens, and management. We also provide recommendations for the selection, dosing, and duration of peri-operative antibiotic prophylaxis to minimize post-operative SSIs.

Abstract in English, French
Background: Surgical site infection (SSI) is one of the most common complications of abdominal surgery and is associated with substantial discomfort, morbidity and cost. The goal of this study was to describe the incidence, bacteriology and risk factors associated with SSI in patients undergoing abdominal surgery.

Methods: In this prospective cohort study, all patients aged 14 years or more undergoing abdominal surgery between Feb. 1 and July 31, 2016, at a single large academic hospital were included. Patients undergoing vascular, gynecological, urological or plastic procedures were excluded. Patients were followed prospectively for 30 days. Wound assessment was done with the Centers for Disease Control and Prevention definition of SSI. We performed multivariate analysis to identify factors associated with SSI.

Results: A total of 337 patients were included. The overall incidence of SSI was 16.3% (55/337); 5 patients (9%) had deep infections, and 25 (45%) had combined superficial and deep infections. The incidence of SSI in open versus laparoscopic operations was 35% versus 4% (p < 0.001). The bacteria most commonly isolated were extended-spectrum β-lactamase-producing Escherichia coli, followed by Enterococcus species. Only 23% of cultured bacteria were sensitive to the prophylactic antibiotic given preoperatively. The independent predictors of SSI were open surgical approach, emergency operation, longed operation duration and male sex.

Conclusion: Potentially modifiable independent risk factors for SSI after abdominal surgery including open surgical approach, contaminated wound class and emergency surgery should be addressed systematically. We recommend tailoring the antibiotic prophylactic regimen to target the commonly isolated organisms in patients at higher risk for SSI.

Abstract
Objectives: To examine trend, prevalence, and outcomes of surgical site infection (SSI) in head and neck surgery.

Study design: Retrospective cross-sectional analysis.

Setting: The Nationwide Readmissions Database (2010-2014), which represents 56.6% of all US hospitalization.

Subjects: Adult patients (≥18 years) who underwent head and neck surgery. Patients with SSI were compared with controls.

Methods: Analysis included chi-square test and multivariate logistic and linear regression models.

Results: A total of 427 cases and 116,921 controls were identified. SSI prevalence among patients who underwent head and neck surgery was 0.37%, of which 41.0% was reported within the initial admission while the remaining 59.0% was reported on readmission within 30 days of first surgery. SSI was associated with a higher mortality risk (odds ratio, 3.95; 95% CI, 1.25-12.50; P = .019). Multivariate analysis demonstrated that a higher risk of SSI was associated with major surgery of the ear, nose and paranasal sinuses, mouth and tonsil, salivary glands and ducts, maxillofacial bones and mandible, and pharynx and larynx (P < .05 each). However, a lower risk of SSI was reported in thyroid and parathyroid and nonmajor procedures (P < .05 each). Other factors associated with a higher risk of SSI included multiple comorbidities, smoking, cancer diagnosis, concomitant neck dissection, and tracheostomy (P < .05 each). SSI was associated with a mean ± SE additional hospital stay of 8.1 ± 0.8 days per case (P < .001) and an additional cost on the health system of $20,953.00 ± $186.3 per case (P < .001).

Conclusions: SSI is associated with a significant mortality risk and burden on the health system. More than half of SSI cases were identified on readmission.

Abstract
Objective: Despite evidence favoring perioperative antibiotic prophylaxis (ABP) use in patients undergoing craniotomy to reduce rates of surgical site infections (SSIs), standardized protocols are lacking. We describe demographic characteristics, risk factors, and ABP choice in patients with craniotomy complicated with SSI.

Design: Retrospective case series from January 1, 2017, through December 31, 2020.

Setting: Tertiary-care referral center.

Patients: Adults who underwent craniotomy and were diagnosed with an SSI.

Methods: Logistic regression to estimate odds ratios and 95% confidence intervals to identify factors associated with SSIs.

Results: In total, 5,328 patients undergoing craniotomy were identified during the study period; 59 (1.1%) suffered an SSI. Compared with non-SSI cases, patients with SSI had a significantly higher frequency of emergency procedures: 13.5% versus 5.8% (P = .02; odds ratio [OR], 2.52; 95% confidene interval [CI], 1.10-5.06; P = .031). Patients with SSI had a higher rate of a dirty (5.1% vs 0.9%) and lower rate of clean-contaminated (3.3% vs 14.5%) wound class than those without infection (P = .002). Nearly all patients received ABP before craniotomy (98.3% in the SSI group vs 99.6% in the non-SSI group; P = .10). Combination of vancomycin and cefazolin as dual therapy was more prevalent in the group of patients without infection (n = 1,761, 34.1%) than those with SSI (n = 4, 6.8%) (P < .001), associated with decreased odds for SSI (OR, 0.17; 95% CI, 0.005-0.42; P ≤ .001).

Conclusions: SSI are frequently seen after an emergent neurosurgical procedure and a dirty wound classification. Combination of prophylactic cefazolin and vancomycin is associated with decreased risk for SSI.

Abstract
Background: Infections complicating neurosurgery pose unacceptable mortality and morbidity.

Aims: To summarize what is known about the epidemiology, diagnosis and treatment of post-neurosurgical meningitis (PNM).

Sources: PubMed, references of identified studies and reviews, and personal experience when evidence was lacking.

Content: The incidence and pathogen distribution of PNM is highly variable. A shift towards Gram-negative bacteria has been observed with use of antibiotic prophylaxis and antibiotic-coated devices directed mainly against Gram-positive bacteria. However, knowledge of the local epidemiology is necessary to treat PNM. The diagnosis of PNM is difficult because, unlike community-acquired meningitis, symptoms are less specific; patients are ill at baseline and many neurosurgical conditions mimic meningitis and cause cerebrospinal fluid (CSF) abnormalities. Pivotal CSF findings for diagnosis of PNM are the CSF glucose, CSF lactate and Gram stain. CSF leucocyte counts are not specific in PNM. Current diagnostic capabilities leave a non-negligible category of patients with microbiologically negative, uncertain diagnosis of PNM. There is no high-quality evidence on several cardinal issues in PNM management, including the effectiveness of intraventricular or intrathecal (IV/IT) antibiotics, effectiveness of dual antibiotic therapy for multidrug-resistant Gram-negative bacteria; clinical benefit of routine therapeutic drug monitoring; and safest timing of shunt replacement. Some data point to a potential benefit of IV/IT antibiotic treatment, mainly for PNM caused by carbapenem-resistant Gram-negative bacteria. Carbapenem-colistin combination therapy is suggested for PNM caused by carbapenem-resistant Gram-negative bacteria with a carbapenem MIC ≤8 mg/L.

Implications: Guiding the optimal management of PNM will necessitate collaborative multicentre efforts and unique study designs.

Abstract
Importance: Surgical site infection (SSI) complicates 2-5% of surgeries in the United States. Severity of SSI ranges from superficial skin infection to life-threatening conditions such as severe sepsis, and SSIs are responsible for increased morbidity, mortality, and economic burden associated with surgery. Staphylococcus aureus (S. aureus) is a commonly-isolated organism for SSI, and methicillin-resistant S. aureus SSI incidence is increasing globally.

Objective: The objective of this systematic review was to characterize risk factors for SSI within observational studies describing incidence of SSI in a real-world setting.

Evidence review: An initial search identified 328 titles published in 2002-2012; 57 were identified as relevant for data extraction. Extracted information included study design and methodology, reported cumulative incidence and post-surgical time until onset of SSI, and odds ratios and associated variability for all factors considered in univariate and/or multivariable analyses.

Findings: Median SSI incidence was 3.7%, ranging from 0.1% to 50.4%. Incidence of overall SSI and S. aureus SSI were both highest in tumor-related and transplant surgeries. Median time until SSI onset was 17.0 days, with longer time-to-onset for orthopedic and transplant surgeries. Risk factors consistently identified as associated with SSI included co-morbidities, advanced age, risk indices, patient frailty, and surgery complexity. Thirteen studies considered diabetes as a risk factor in multivariable analysis; 85% found a significant association with SSI, with odds ratios ranging from 1.5-24.3. Longer surgeries were associated with increased SSI risk, with a median odds ratio of 2.3 across 11 studies reporting significant results.

Conclusions and relevance: In a broad review of published literature, risk factors for SSI were characterized as describing reduced fitness, patient frailty, surgery duration, and complexity. Recognition of risk factors frequently associated with SSI allows for identification of such patients with the greatest need for optimal preventive measures to be identified and pre-treatment prior to surgery.

Abstract
Objective: Our objective was to estimate the occurrence of surgical site infections (SSI) after hysterectomy and the associated risk factors.

Study design: We conducted a cross-sectional analysis of the 2005-2009 American College of Surgeons National Surgical Quality Improvement Program participant use data files to analyze hysterectomies. Different routes of hysterectomy were compared. The primary outcome was to identify the occurrence of 30-day superficial SSI (cellulitis) after hysterectomy. Secondary outcomes were the occurrence of deep and organ-space SSI after hysterectomy. Logistic regression models were conducted to further explore the associations of risks factors with SSI after hysterectomy.

Results: A total of 13,822 women were included in our final analysis. The occurrence of postoperative cellulitis after hysterectomy was 1.6% (n = 221 women). Risk factors that were associated with cellulitis were route of hysterectomy with an adjusted odds ratio (AOR) of 3.74 (95% confidence interval [CI], 2.26-6.22) for laparotomy compared with the vaginal approach, operative time >75th percentile (AOR, 1.84; 95% CI, 1.40-2.44), American Society of Anesthesia class ≥ 3 (AOR, 1.79; 95% CI, 1.31-2.43), body mass index ≥40 kg/m(2) (AOR, 2.65; 95% CI, 1.85-3.80), and diabetes mellitus (AOR, 1.54; 95% CI, 1.06-2.24) The occurrence of deep and organ-space SSI was 1.1% (n = 154 women) after hysterectomy.

Conclusion: Our finding of the decreased occurrence of superficial SSI after the vaginal approach for hysterectomy reaffirms the role for vaginal hysterectomy as the route of choice for hysterectomy.

Abstract
Background: Surgical site infection (SSI) is a common complication following craniotomy that increases morbidity, mortality, and medical expenses. The objectives of this study were to determine the relevant risk factors associated with SSI after elective craniotomy for brain tumor and analyse the treatments for SSI.

Methods: A retrospective nested case‒control study was conducted using data from patients who underwent craniotomy for brain tumor resection at the Neurosurgical Oncology Department No. 6 of Beijing Tiantan Hospital, Capital Medical University, between January 2019 and December 2021. Risk factors for SSI were determined using multivariate logistic regression analysis. We analyzed microbiological and related treatment data for different SSI types.

Results: Among 2061 patients who underwent craniotomy for brain tumor, 31 had SSI (1.50%). In the multivariate logistic regression analysis, body mass index (BMI) and operative duration were identified as independent risk factors for SSI. The most common microorganism isolated from SSIs was Staphylococcus epidermidis (22.9%), and drug sensitivity results showed that gram-positive bacteria were sensitive to linezolid, vancomycin and tigecycline, whereas gram-negative bacteria were sensitive to meropenem, cefepime and ceftazidime. Six of the seven patients who underwent bone flap removal due to osteomyelitis were infected with gram-negative bacteria.

Conclusions: BMI and operative duration were identified as independent risk factors for SSI. Diabetes mellitus, previous ratio therapy, type of incision, recurrence tumor and other risk factors were not found to be associated with the occurrence of SSI in this study.

Abstract
EXECUTIVE SUMMARY The "Guideline for Prevention of Surgical Site Infection, 1999" presents the Centers for Disease Control and Prevention (CDC)'s recommendations for the prevention of surgical site infections (SSIs), formerly called surgical wound infections. This two-part guideline updates and replaces previous guidelines.1,2 Part I, "Surgical Site Infection: An Overview," describes the epidemiology, definitions, microbiology, pathogenesis, and surveillance of SSIs. Included is a detailed discussion of the pre-, intra-, and postoperative issues relevant to SSI genesis. Part II, "Recommendations for Prevention of Surgical Site Infection," represents the consensus of the Hospital Infection Control Practices Advisory Committee (HICPAC) regarding strategies for the prevention of SSIs.3 Whenever possible, the recommendations in Part II are based on data from well-designed scientific studies. However, there are a limited number of studies that clearly validate risk factors and prevention measures for SSI. By necessity, available studies have often been conducted in narrowly defined patient populations or for specific kinds of operations, making generalization of their findings to all specialties and types of operations potentially problematic. This is especially true regarding the implementation of SSI prevention measures. Finally, some of the infection control practices routinely used by surgical teams cannot be rigorously studied for ethical or logistical reasons (e.g., wearing vs not wearing gloves). Thus, some of the recommendations in Part II are based on a strong theoretical rationale and suggestive evidence in the absence of confirmatory scientific knowledge.It has been estimated that approximately 75% of all operations in the United States will be performed in "ambulatory," "same-day," or "outpatient" operating rooms by the turn of the century.4 In recommending various SSI prevention methods, this document makes no distinction between surgical care delivered in such settings and that provided in conventional inpatient operating rooms. This document is primarily intended for use by surgeons, operating room nurses, postoperative inpatient and clinic nurses, infection control professionals, anesthesiologists, healthcare epidemiologists, and other personnel directly responsible for the prevention of nosocomial infections. This document does not: Specifically address issues unique to burns, trauma, transplant procedures, or transmission of bloodborne pathogens from healthcare worker to patient, nor does it specifically address details of SSI prevention in pediatric surgical practice. It has been recently shown in a multicenter study of pediatric surgical patients that characteristics related to the operations are more important than those related to the physiologic status of the patients.5 In general, all SSI prevention measures effective in adult surgical care are indicated in pediatric surgical care. Specifically address procedures performed outside of the operating room (e.g., endoscopic procedures), nor does it provide guidance for infection prevention for invasive procedures such as cardiac catheterization or interventional radiology. Nonetheless, it is likely that many SSI prevention strategies also could be applied or adapted to reduce infectious complications associated with these procedures. Specifically recommend SSI prevention methods unique to minimally invasive operations (i.e., laparoscopic surgery). Available SSI surveillance data indicate that laparoscopic operations generally have a lower or comparable SSI risk when contrasted to open operations.6-11 SSI prevention measures applicable in open operations (e.g., open cholecystectomy) are indicated for their laparoscopic counterparts (e.g., laparoscopic cholecystectomy). Recommend specific antiseptic agents for patient preoperative skin preparations or for healthcare worker hand/forearm antisepsis. Hospitals should choose from products recommended for these activitie

Abstract
Background: Regardless of the available antifungals, intraabdominal candidiasis (IAC) mortality continues to be high and represents a challenge for clinicians.

Main body: This opinion paper discusses alternative antifungal options for treating IAC. This clinical entity should be addressed separately from candidemia due to the peculiarity of the required penetration of antifungals into the peritoneal cavity. Intraabdominal concentrations may be further restricted in critically ill patients where pathophysiological facts alter normal drug distribution. Echinocandins are recommended as first-line treatment in guidelines for invasive candidiasis. However, considering published data, our pharmacodynamic analysis suggests the required increase of doses, postulated by some authors, to attain adequate pharmacokinetic (PK) levels in peritoneal fluid. Given the limited evidence in the literature on PK/PD-based treatments of IAC, an algorithm is proposed to guide antifungal treatment. Liposomal amphotericin B is advocated as first-line therapy in patients with sepsis/septic shock presenting candidemia or endophthalmitis, or with prior exposure to echinocandins and/or fluconazole, or with infections by Candida glabrata. Other situations and alternatives, such as new compounds or combination therapy, are also analysed.

Conclusion: There is a critical need for more robust clinical trials, studies examining patient heterogeneity and surveillance of antifungal resistance to enhance patient care and optimise treatment outcomes. Such evidence will help refine the existing guidelines and contribute to a more personalised and effective approach to treating this serious medical condition. Meanwhile, it is suggested to broaden the consideration of other options, such as liposomal amphotericin B, as first-line treatment until the results of the fungogram are available and antifungal stewardship could be implemented to prevent the development of resistance.

Abstract
Introduction: Knowledge of the microbiology of surgical infections after abdominal surgery can be of use when prescribing effective empirical antibiotic treatments.

Method: Analysis of surgical infections after abdominal surgery in patients enrolled in the Prevalence of Infections in Spanish Hospitals (EPINE) corresponding to the years 1999-2006.

Results: During the period of the study, 2,280 patients who were subjected to upper or lower abdominal tract surgery were diagnosed with an infection at the surgical site (SSI). Eight hundred and eighty three patients (37%) had an operation of the upper abdominal tract (gastric, hepatobiliary, and pancreatic surgery) and 1,447 patients (63%) lower abdominal tract surgery (appendectomy and colon surgery). A total of 2,617 bacterial species were isolated in the 2,280 patients included in the analysis. The most frequent microorganisms isolated were, Escherichia coli (28%), Enterococcus spp. (15%), Streptococcus spp. (8%), Pseudomonas aeruginosa (7%), and Staphylococcus aureus (5%, resistant to methicillin 2%). In the surgical infections after upper abdominal tract procedures, there were a higher proportion of isolations of staphylococci, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp. and Candida albicans and less Escherichia coli, Bacteroides fragilis and Clostridium spp.

Conclusion: The microbiology of SSI produced after upper abdominal tract surgery did not show any significant differences compared to those of the lower tract. However, more cases of SSI were detected due to staphylococci, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp. and Candida albicans and less caused by Escherichia coli, Bacteroides fragilis and Clostridium spp.

Abstract
Background and Objectives: Surgical site infection (SSI) is a significant complication of non-reconstructive and reconstructive breast surgery. This study aimed to assess SSI after breast surgery over five years in a single center in Poland. The microorganisms responsible for SSI and their antibiotic susceptibilities were determined. Materials and Methods: Data from 2129 patients acquired over five years postoperatively by the Department of Surgical Oncology, Medical University of Gdansk in Poland were analyzed. Results: SSI was diagnosed in 132 patients (6.2%) and was an early infection in most cases (65.2%). The incidence of SSI was highest in patients who underwent subcutaneous amputation with simultaneous reconstruction using an artificial prosthesis (14.6%), and breast reconstruction via the transverse rectus abdominis muscle (TRAM) flap method (14.3%). Gram-positive bacteria were responsible for SSI in most cases (72.1%), and these were mainly Staphylococcus strains (53.6%). These strains were 100% susceptible to all beta-lactam antibiotics (except penicillin) but were less susceptible to macrolides and lincosamides. Conclusions: SSI is a serious problem, and attention should be focused on its prevention. Reconstruction using an artificial prosthesis or via the TRAM flap method is connected to increased SSI incidence. Further studies are required to prevent SSI following breast surgery.

Abstract
Background/aims: Surgical site infection (SSI) is a major complication after radical neck dissection (RND) in patients with head and neck cancer (HNC). We investigated the incidence, risk factors, and etiology of SSI among patients who underwent RND.

Methods: A retrospective cohort study was performed on HNC patients, excluding those with thyroid cancer, who underwent first RND at a teaching hospital between January 2006 and June 2010. Medical records were collected and analyzed to evaluate the risk factors and microbiological etiologies.

Results: A total of 370 patients underwent first RND. The overall incidence of SSI was 19.7% (73/370). Multivariate analysis showed that male sex (odds ratio [OR], 4.281; p = 0.004), cardiovascular diseases (OR, 1.941; p = 0.020), large amount of blood loss during surgery (OR, 4.213; p = 0.001), and surgery lasting longer than 6 hours (OR, 4.213; p = 0.002) were significantly associated with SSI. The most common causative pathogen was Staphylococcus aureus (32.6%), and 93.2% of S. aureus isolates were methicillin-resistant. Klebsiella pneumoniae (13/92, 14.1%), Pseudomonas aeruginosa (11/92, 12.0%), and Enterococcus species (11/92, 12.0%) were also frequently detected.

Conclusions: Based on our results, we predict that certain groups of patients are at high risk for SSIs after major HNC surgery. Preventive measures or close monitoring in these patients may be required to reduce the likelihood of postoperative SSIs. Furthermore, even though additional research is required, we would consider changing the prophylactic antibiotic regimens according to the causative organisms.

Keywords: Antifungal therapy; Human; Intra-abdominal infection; Peritonitis.

Abstract
Importance: Approximately 0.5% to 3% of patients undergoing surgery will experience infection at or adjacent to the surgical incision site. Compared with patients undergoing surgery who do not have a surgical site infection, those with a surgical site infection are hospitalized approximately 7 to 11 days longer.

Observations: Most surgical site infections can be prevented if appropriate strategies are implemented. These infections are typically caused when bacteria from the patient's endogenous flora are inoculated into the surgical site at the time of surgery. Development of an infection depends on various factors such as the health of the patient's immune system, presence of foreign material, degree of bacterial wound contamination, and use of antibiotic prophylaxis. Although numerous strategies are recommended by international organizations to decrease surgical site infection, only 6 general strategies are supported by randomized trials. Interventions that are associated with lower rates of infection include avoiding razors for hair removal (4.4% with razors vs 2.5% with clippers); decolonization with intranasal antistaphylococcal agents and antistaphylococcal skin antiseptics for high-risk procedures (0.8% with decolonization vs 2% without); use of chlorhexidine gluconate and alcohol-based skin preparation (4.0% with chlorhexidine gluconate plus alcohol vs 6.5% with povidone iodine plus alcohol); maintaining normothermia with active warming such as warmed intravenous fluids, skin warming, and warm forced air to keep the body temperature warmer than 36 °C (4.7% with active warming vs 13% without); perioperative glycemic control (9.4% with glucose <150 mg/dL vs 16% with glucose >150 mg/dL); and use of negative pressure wound therapy (9.7% with vs 15% without). Guidelines recommend appropriate dosing, timing, and choice of preoperative parenteral antimicrobial prophylaxis.

Conclusions and relevance: Surgical site infections affect approximately 0.5% to 3% of patients undergoing surgery and are associated with longer hospital stays than patients with no surgical site infections. Avoiding razors for hair removal, maintaining normothermia, use of chlorhexidine gluconate plus alcohol-based skin preparation agents, decolonization with intranasal antistaphylococcal agents and antistaphylococcal skin antiseptics for high-risk procedures, controlling for perioperative glucose concentrations, and using negative pressure wound therapy can reduce the rate of surgical site infections.

Abstract
The role of empiric antifungals for post-surgical abscesses (PSAs) is controversial, and international guidelines on invasive mycoses focus on bloodstream infections. We analyzed a retrospective cohort of 319 patients with PSA at a tertiary-level hospital in Italy during the years 2013-2018. Factors associated with empiric antifungal administration were analyzed and compared with factors associated with fungal isolation from the abdomen. Forty-six patients (14.4%) received empiric antifungals (65.2% azoles). Candida was isolated in 34/319 (10.7%) cases, always with bacteria. Only 11/46 patients receiving empirical antifungals had abdominal Candida. Only 11/34 patients with a fungal isolate received empiric antifungal therapy. Upper GI surgery (OR: 4.76 (CI: 1.95-11.65), p = 0.001), an intensive care unit stay in the previous 90 days (OR: 5.01 (CI: 1.63-15.33), p = 0.005), and reintervention within 30 days (OR: 2.52 (CI: 1.24-5.13), p = 0.011) were associated with empiric antifungals in a multivariate analysis, while pancreas/biliary tract surgery was associated with fungal isolation (OR: 2.25 (CI: 1.03-4.91), p = 0.042), and lower GI surgery was protective (OR: 0.30 (CI: 0.10-0.89), p = 0.029) in a univariate analysis. The criteria for empiric antifungal therapy in our practice seem to be inconsistent with the risk factors for actual fungal isolation. Better guidance for empiric therapy should be provided by wider studies.

Abstract
Background: Surgical site infections (SSIs) are associated with substantial morbidity, mortality, and cost. Few studies have examined the causative pathogens, mortality, and economic burden among patients rehospitalized for SSIs.

Methods: From 2003 to 2007, 8302 patients were readmitted to 97 US hospitals with a culture-confirmed SSI. We analyzed the causative pathogens and their associations with in-hospital mortality, length of stay (LOS), and cost.

Results: The proportion of methicillin-resistant Staphylococcus aureus (MRSA) significantly increased among culture-positive SSI patients during the study period (16.1% to 20.6%, respectively, P < .0001). MRSA (compared with other) infections had higher raw mortality rates (1.4% vs 0.8%, respectively, P=.03), longer LOS (median, 6 vs 5 days, respectively, P < .0001), and higher hospital costs ($7036 vs $6134, respectively, P < .0001). The MRSA infection risk-adjusted attributable LOS increase was 0.93 days (95% confidence interval [CI]: 0.65-1.21; P < .0001), and cost increase was $1157 (95% CI: $641-$1644; P < .0001). Other significant independent risk factors increasing cost and LOS included illness severity, transfer from another health care facility, previous admission (<30 days), and other polymicrobial infections (P < .05).

Conclusion: SSIs caused by MRSA increased significantly and were independently associated with economic burden. Admission illness severity, transfer from another health care setting, and recent hospitalization were associated with higher mortality, increased LOS, and cost.

Abstract in English, French
Background: Surgical site complications (SSCs) are an important source of morbidity after kidney transplantation. We assessed the incidence, risk factors, outcomes and economic impact of SSCs in a large, diverse population of kidney transplant recipients.

Methods: We conducted a single-centre, observational cohort study of adult (age ≥ 18 yr) patients who underwent kidney transplantation between Jan. 1, 2005, and Dec. 31, 2015, with a minimum of 1 year of follow-up. Cases of SSC, including infections and wound dehiscence, were determined from patient records. Inpatient and outpatient hospital costs were determined 6 and 12 months after transplantation. We used the Kaplan-Meier product-limit method to determine the cumulative probability of SSCs and other outcomes. We evaluated risk factors and clinical outcomes using Cox proportional hazard ratios. Linear regression models were used to study the effect of SSCs on graft function.

Results: The incidence rate of SSCs within 30 days after transplantation was 4.19 per 100 person-months. The cumulative probability of developing an SSC within 30 days after transplantation was 4.13% (95% confidence interval [CI] 3.23%-5.28%). Increased recipient body mass index (BMI) (hazard ratio [HR] 1.07, 95% CI 1.02-1.11), longer cold ischemic time (HR 1.05, 95% CI 1.01-1.09) and transplantation in 2010-2012 versus 2005-2009 (HR 2.20, 95% CI 1.19-4.04) were risk factors for SSC development. In multivariable stepwise Cox proportional hazard models, SSC was a significant risk factor for death-censored graft failure (HR 3.08, 95% CI 1.60-5.90) and total graft failure (HR 2.09, 95% CI 1.32-3.32). Cumulative median hospital costs were $2238.46 greater for patients with an SSC than for those without.

Conclusion: Increased BMI, longer cold ischemic time and the 2010-2012 transplantation period predisposed to SSCs. The development of SSCs was associated with a higher risk of graft failure. Strategies to minimize SSCs may improve outcomes after kidney transplantation and reduce costs.

Abstract
Objective: To evaluate time trends in surgical site infection (SSI) rates and SSI pathogens in Australia.

Design: Prospective multicenter observational cohort study.

Setting: A group of 81 Australian healthcare facilities participating in the Victorian Healthcare Associated Infection Surveillance System (VICNISS).

Patients: All patients underwent surgeries performed between October 1, 2002, and June 30, 2013. National Healthcare Safety Network SSI surveillance methods were employed by the infection prevention staff at the participating hospitals.

Intervention: Procedure-specific risk-adjusted SSI rates were calculated. Pathogen-specific and antimicrobial-resistant (AMR) infections were modeled using multilevel mixed-effects Poisson regression.

Results: A total of 183,625 procedures were monitored, and 5,123 SSIs were reported. Each year of observation was associated with 11% risk reduction for superficial SSI (risk ratio [RR], 0.89; 95% confidence interval [CI], 0.88-0.90), 9% risk reduction for deep SSI (RR, 0.91; 95% CI, 0.90-0.93), and 5% risk reduction for organ/space SSI (RR, 0.95; 95% CI, 0.93-0.97). Overall, 3,318 microbiologically confirmed SSIs were reported. Of these SSIs, 1,174 (35.4%) were associated with orthopedic surgery, 827 (24.9%) with coronary artery bypass surgery, 490 (14.8%) with Caesarean sections, and 414 (12.5%) with colorectal procedures. Staphylococcus aureus was the most frequently identified pathogen, and a statistically significant increase in infections due to ceftriaxone-resistant Escherichia coli was observed (RR, 1.37; 95% CI, 1.10-1.70).

Conclusions: Standardized SSI surveillance methods have been implemented in Victoria, Australia. Over an 11-year period, diminishing rates of SSIs have been observed, although AMR infections increased significantly. Our findings facilitate the refinement of recommended surgical antibiotic prophylaxis regimens and highlight the need for a more expansive national surveillance strategy to identify changes in epidemiology.

Abstract
Surgical site infection (SSI) is one of the most common complications following cesarean section, and has an incidence of 3%-15%. It places physical and emotional burdens on the mother herself and a significant financial burden on the health care system. Moreover, SSI is associated with a maternal mortality rate of up to 3%. With the global increase in cesarean section rate, it is expected that the occurrence of SSI will increase in parallel, hence its clinical significance. Given its substantial implications, recognizing the consequences and developing strategies to diagnose, prevent, and treat SSI are essential for reducing postcesarean morbidity and mortality. Optimization of maternal comorbidities, appropriate antibiotic prophylaxis, and evidence-based surgical techniques are some of the practices proven to be effective in reducing the incidence of SSI. In this review, we describe the biological mechanism of SSI and risk factors for its occurrence and summarize recent key clinical trials investigating preoperative, intraoperative, and postoperative practices to reduce SSI incidence. It is prudent that the surgical team who perform cesarean sections be familiar with these practices and apply them as needed to minimize maternal morbidity and mortality related to SSI.

Abstract
Surgical site infections (SSIs) are one of the most significant complications in surgical patients and are strongly associated with poorer prognosis. Due to their aggressive character, cardiac surgical procedures carry a particular high risk of postoperative infection, with infection incidence rates ranging from a reported 3.5% and 26.8% in cardiac surgery patients. Given the specific nature of cardiac surgical procedures, sternal wound and graft harvesting site infections are the most common SSIs. Undoubtedly, DSWIs, including mediastinitis, in cardiac surgery patients remain a significant clinical problem as they are associated with increased hospital stay, substantial medical costs and high mortality, ranging from 3% to 20%. In SSI prevention, it is important to implement procedures reducing preoperative risk factors, such as: obesity, hypoalbuminemia, abnormal glucose levels, smoking and S. aureus carriage. For decolonisation of S. aureus carriers prior to cardiac surgery, it is recommended to administer nasal mupirocin, together with baths using chlorhexidine-based agents. Perioperative management also involves antibiotic prophylaxis, surgical site preparation, topical antibiotic administration and the maintenance of normal glucose levels. SSI treatment involves surgical intervention, NPWT application and antibiotic therapy.