Surgical site infection—the next frontier in global surgery

Genomic characterization of extended-spectrum β-lactamase-producing Enterobacterales isolated from abdominal surgical patients

Rectal swabs of 104 patients who underwent abdominal surgery were screened for ESBL producers. Sequence types (STs) and resistance genes were identified by whole-genome sequencing of 46 isolates from 17 patients. All but seven isolates were assigned to recognized STs. While 18 ESBL-producing E. coli (EPEC) strains were of unique STs, ESBL-producing K. pneumoniae (EPKP) strains were mainly ST14 or ST15. Eight patients harboured strains of the same ST before and after abdominal surgery. The most prevalent resistant genes in E. coli were blaEC (69.57%), blaCTX-M (65.22%), and blaTEM (36.95%), while blaSHV was present in only K. pneumoniae (41.30%). Overall, genes encoding β-lactamases of classes A (blaCTX-M, blaTEM, blaZ), C (blaSHV, blaMIR, and blaDHA), and D (blaOXA) were identified, the most prevalent variants being blaCTX-M-15, blaTEM-1B, blaSHV-28, and blaOXA-1. Interestingly, blaCMY-2, the most common pAmpC β-lactamase genes reported worldwide, and mobile colistin resistance genes, mcr-10-1, were also identified. The presence of blaCMY-2 and mcr-10-1 is concerning as they may constitute a potentially high risk of pan-resistant post-surgical infections. It is imperative that healthcare professionals monitor intra-abdominal surgical site infections rigorously to prevent transmission of faecal ESBL carriage in high-risk patients.

The Practice of Antimicrobial Stewardship in Thoracic Surgery and its Effectiveness

This study examines the effects of the bundle of antimicrobial stewardship measures for prophylactic antibiotics among thoracic surgery patients. A local protocol, based on current guidelines starting from December 2014, was developed by the Infection Control and Thoracic Surgery Teams. The effects of this protocol were assessed by monitoring a total of 1380 patients before and after its implementation from January 1, 2011, to December 31, 2022.

Impact of preoperative infection on the outcomes of liver transplant recipients: a national propensity score-matched retrospective cohort study in China

BACKGROUND

Impact of preoperative infection on liver transplantation (LT) needs further investigation.

MATERIALS AND METHODS

From January 1, 2015 to December 31, 2022, 24,122 eligible patients receiving LT were enrolled from the China Liver Transplant Registry database. The outcomes of LT were compared after using the propensity score-matched analysis.

RESULTS

Compared to the non-infection group, patients in the infection group were more likely to have postoperative effusion, infection, abdominal bleeding and biliary complications (all P<0.01), and they had shorter 30-day, 90-day survival and overall survival (OS) (all P<0.01). Cox proportional hazards regression analysis revealed that MELD score and cold ischemia time were risk factors for the OS in the infection group (both P<0.05). Besides, compared to the non-pulmonary group, patients in the pulmonary group were more likely to have postoperative effusion and infection (both P<0.0001), and less likely to have postoperative abscess and early allograft dysfunction (both P<0.05). Patients in the non-abdominal group also had a higher proportion of postoperative infection than those in the abdominal group (P<0.05). Furthermore, compared to the number=1 group, patients in the number≥2 group were more prone to postoperative effusion and infection (both P<0.01), and they also had shorter 30-day and 90-day survival (both P<0.05).

CONCLUSION

Preoperative infection can result in a higher incidence of early postoperative complications and shorter survival in liver transplant recipients. The types and number of infection sites will also influence the prognosis of liver transplant recipients.

What Is the Role of the Gut in Wound Infections?

Emerging evidence suggest a major role for the gut microbiome in wound infections. A Trojan Horse mechanism of surgical site infections has been hypothesized to occur when pathogens in the gut, gums, and periodontal areas enter an immune cell and silently travel to the wound site where they release their infectious payload. Genetic tracking of microbes at the strain level is now possible with genetic sequencing techniques and can clarify the origin of microbes that cause wound infections. An emerging field of dietary prehabilitation to modulate the microbiome before surgery is being described to improve infection-related outcomes from surgery.

Incidence of surgical site infection, bacterial isolate, and their antimicrobial susceptibility pattern among patients who underwent surgery at Dessie Comprehensive Specialized Hospital, Northeast Ethiopia

Objective

Surgical site infection is the most common postoperative complication worldwide, representing a major burden for patients and health systems. The aim of the study is to determine the incidence and bacterial profile that cause surgical site infection among patients who underwent surgery in parts of Northeast Ethiopia.

Methods

A health facility-based cross-sectional study was conducted in Dessie Comprehensive Specialized Hospital from July 22 to October 25, 2016. A total of 338 patients from the obstetrics and gynecology and general surgical wards were included, through consecutive sampling technique. The specimens were collected aseptically on the first day when the patients had presented with clinical evidence of infection and then sent to the microbiology laboratory. The data were entered and analyzed by SPSS version 20, and the results were explained by frequency distribution in tables and figures.

Results

The majority of participants were female (74.3%) and more than half (61.2%) of the surgeries were performed in the gynecology and obstetrics ward. Clinically, 49 patients (14.5%) were diagnosed as developing surgical site infection, and wound swabs were taken for bacteriological study. About 41 (83.7%) swabs showed bacterial growth, indicating 12.13% overall prevalence of bacterial surgical site infection. Out of 48 bacterial isolates, more than half (56.25%) of them were Gram negative. The most frequent isolate was Staphylococcus aureus, 14 (66.67%), followed by Escherichia coli, 9 (33.33%). Out of the total bacterial isolates, 38 (79.2%) isolates were found to be multidrug resistant, and the rate of multidrug resistant was higher among Gram-negative isolates.

Conclusion

An average rate of surgical site infection was found to be reported and significant numbers of bacterial isolates were also detected. The highest rate of surgical site infection was reported in prostate surgery, followed by small bowel, vaginal hysterectomy, and exploratory laparotomy surgical procedures. Periodic surveillance on the incidence rate and bacterial profile along with the determination of their antibiotic susceptibility should be performed.

Remote assessment of surgical site infection (SSI) using patient-taken wound images: Development and evaluation of a method for research and routine practice

BACKGROUND/AIM

Clinical assessment of wounds for surgical site infection (SSI) after hospital discharge is challenging and resource intensive. Remote assessment using digital images may be feasible and expedite SSI diagnosis. Acceptable and accurate methods for this process are needed. This study developed and evaluated the feasibility, acceptability and usability of a method for patients to capture standardised wound images for remote wound assessment to detect SSI.

MATERIALS AND METHODS

The work was conducted in two phases. Phase I involved: i) a review of literature to identify key components of photography relevant to taking wound images, ii) development of wound photography instructions for patients and a secure process for transmission of images using electronic survey software and iii) pre-testing of the photography instructions and processing method with a sample of 16 patients using cognitive interviews and observations. Phase II involved a prospective cohort study of 89 patients to evaluate the feasibility, acceptability and usability of the remote method following discharge from hospital after surgery. Quality of the images was assessed by three independent clinical reviewers.

RESULTS

Some 21 key components for photographing wounds were identified from 11 documents. Of these, 16 were relevant to include in instructions for patients to photograph their wounds. Pre-testing and subsequent iterations improved understanding and ease of use of the instructions and the process for transmitting images. Fifty-two of 89 (58.4%) patients testing the method remotely took an image of their wound(s) and 46/52 (88.5%) successfully transmitted images. When it was possible to ascertain a reason for not taking/transmitting images, this was primarily health problems (n = 7) or lack of time/poor engagement with the study (n = 4) rather than problems relating to technology/competency (n = 2) or practical issues relating to the wound itself (n = 2). Eighty-seven (85.3%) of the 102 images received were evaluated to be of high quality and sufficient to remotely assess SSI by at least two independent reviewers.

CONCLUSION

A simple, standardised and acceptable method for patients to take and transmit wound images suitable for remote assessment of SSI has been developed and tested and is now available for use in routine clinical care and research.

The Burden of Surgical Site Infection at Hospital Universiti Sains Malaysia and Related Postoperative Outcomes: A Prospective Surveillance Study

Surgical site infections (SSIs) are the most common healthcare-associated infections that occur among surgical patients. Surgical site infections result in longer hospital stays, hospital readmissions, and higher death and morbidity rates. The current study was designed to highlight the importance of such surveillance studies in a Malaysian surgical population with a motive to evaluate and revise concurrent infection control and prevention policies by exploring the burden of surgical site infection and identifying its associated risk factors for future considerations. In this prospective observational cohort study, a total of 216 patients admitted to a surgical ward were identified and studied. Of these 216 patients, 142 elective procedures and 74 emergency procedures were included in the study, of which 13 patients (9.2%) undergoing elective procedures and 15 (20.3%) patients undergoing emergency procedures were SSI positive (OR: 2.5, p = 0.02). Among surgical site infections, 21 were superficial and 7 were deep incisional SSI. No case of organ/space SSI was identified. The time taken for SSIs to develop ranged from 2-17 days with a median of 6 days. Risk factors such as presence of comorbidities (p = 0.011), major co-existing medical diagnosis ≥2 (p = 0.02), and pre-existing infection (p = 0.027) were statistically significant. SSI-positive patients experienced an increase in the post-operative length of hospital stay. In the current population, it was seen that identifying patients who were at high risk of malnutrition via MUST and the NNIS risk index will help clinicians in identifying high risk patients and in managing their patients appropriately. Identifying patients who were at high risk of malnutrition will also improve postoperative outcomes considerably.

Silver-Based Dressings in the Prevention of the Incisional Surgical Site Infection: A Prospective Multicenter Observational Controlled Trial

Background: A new silver-based dressing has been designed to reduce surgical sited infections. Patients and Methods: A prospective multicenter observational study was conducted from January 2020 to October 2021. Patients with and without silver-based dressing after surgical incision were observed and their data analyzed. The study aimed to assess the incidence of incisional surgical site infection and primary healing after general surgery procedures. Results: Overall, 218 patients with silver-based (n = 109) and conventional silver-free dressing (n = 109) were analyzed. Surgical site infection (SSI) and primary incision healing were reported in 10 (9.2%) versus 21 (19.3%) (p = 0.037) and in 95 (87.2%) versus 86 (78.9%) (p = 0.107) patients treated with and without silver-based dressing, respectively. Conclusions: Silver-based dressing demonstrated a lower incidence of incisional SSI and improved primary healing in comparison with patients in whom conventional non-silver-based dressing has been used.

Prophylactic negative pressure wound dressings reduces wound complications following emergency laparotomies: A systematic review and meta-analysis

BACKGROUND

Wound complications are a common cause of postoperative morbidity and incur significant healthcare costs. Recent studies have shown that negative pressure wound dressings reduce wound complication rates, particularly surgical site infections, after elective laparotomies. The clinical utility of prophylactic negative pressure wound dressings for closed emergency laparotomy incisions remains controversial. This meta-analysis investigated the rates of wound complications after emergency laparotomy when a negative pressure wound dressing was applied.

METHODS

A systematic review and meta-analysis were performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, Cochrane Registry, Web of Science, and Clinialtrials.gov databases were searched from January 1, 2005, to April 1, 2022. All studies comparing negative pressure wound dressings to standard dressings on closed emergency laparotomy incisions were included.

RESULTS

A total of 1,199 (negative pressure wound dressings: 566, standard dressing: 633) patients from 7 (prospective: 4, retrospective: 3) studies were identified. Overall, the surgical site infection (superficial/deep) rate was 13.6% (77/566) vs 25.1% (159/633) in the negative pressure wound dressing versus standard dressing groups, respectively (odds ratio 0.43, 95% confidence interval 0.30-0.62). Wound breakdown (skin/fascial dehiscence) was significantly lower in the negative pressure wound dressing (7.7%) group compared to the standard dressing (16.9%) group (odds ratio 0.36, 95% confidence interval 0.19-0.72). The incidence of overall wound complications was significantly lower in the negative pressure wound dressing (15.9%) group compared to the standard dressing (30.4%) group (odds ratio 0.41, 95% confidence interval 0.28-0.59). No significant differences were found in hospital length-of-stay and readmission rates.

CONCLUSION

Prophylactic negative pressure wound dressings for closed emergency laparotomy incisions were associated with a significant reduction in surgical site infections, wound breakdown, and overall wound complications, thus supporting its clinical use.

Incidence and risk factors of surgical site infections and related antibiotic resistance in Freetown, Sierra Leone: a prospective cohort study

BACKGROUND

There is limited information on surgical site infections (SSI) and the related antibiotic resistance needed to guide their management and prevention in Sierra Leone. In this study, we aimed to establish the incidence and risk factors of SSI and the related antibiotic resistance among adults attending a tertiary hospital, and a secondary health facility in Freetown, Sierra Leone.

METHODS

This is a prospective cohort study designed to collect data from adult (18 years or older) patients who attended elective and emergency surgeries at two hospitals in Freetown between February and July, 2021. Data analysis was done using STATA version 16.

RESULTS

Of 338 patients, 245 (72.5%) and 93 (27.5%) had their surgeries at the tertiary and secondary hospitals, respectively. Many were males 192 (56.8%), less than 35 years 164 (48.5%), and 39 (11.5%) developed an SSI. Of the 39 patients who acquired an SSI, 7 (17.9%) and 32 (82.1%) had their surgeries at the secondary and tertiary hospitals, respectively. The incidence of SSI is higher in contaminated 17 (43.6%) than in clean-contaminated 12 (30.8%) and clean 10 (25.6%) wounds. Wound swabs were collected in 29 (74.4%) patients, of which 18 (62.1%) had bacterial growth. In total, 49 isolates of 14 different bacteria including gram-negative 41 (83.7%) and gram-positive 8 (16.3%) isolates were identified. Of these, 32 (65.3%) were Enterobacteriaceae, 9 (18.4%) were Non-fermenting gram-negative bacilli and 10 (12.2%) were Enterococci. The most common isolates were Escherichia coli (12, 24.5%), Klebsiella pneumoniae (10, 20.4%), Acinetobacter baumannii (5, 10.2%), Klebsiella oxytoca (4, 8.2%) and Enterococcus faecalis (4, 8.2%). The Enterobacteriaceae were either resistance to carbapenems (4, 8.2%) or were extended-spectrum beta-lactamase (ESBL) producing organisms (29, 59.2%). Male sex [p = 0.031], an ASA score ≥ 2 [p = 0.020), administration of general anaesthesia [p = 0.018] and elevated fasting glucose [p = 0.033] were predictive of SSI.

CONCLUSION

The incidence of SSI in this study is comparable to other low- and middle-income countries, but a substantial proportion of these postoperative wounds have an ESBL-producing Enterobacteriaceae. Therefore, routine surveillance of SSI and related antibiotic resistance is required in resource-limited settings.

Prophylactic Negative-pressure Wound Therapy Prevents Surgical Site Infection in Abdominal Surgery: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials and Observational Studies

BACKGROUND

Prevention of surgical site infection (SSI) is a public health challenge. Our objective was to determine if prophylactic negative-pressure wound therapy (pNPWT) allows preventing SSI after laparotomy.

METHODS

Medline, Embase, and Web of Science were searched on 6 October 2019 for original studies reporting the incidences of SSI in patients undergoing open abdominal surgery with and without pNPWT. Risk differences (RDs) between control and pNPWT patients and risk ratios (RRs) for SSI were obtained using random-effects models.

RESULTS

Twenty-one studies (2930 patients, 5 randomized controlled trials [RCTs], 16 observational studies) were retained for the analysis. Pooled RD between patients with and without pNPWT was -12% (95% confidence interval [CI], -17% to -8%; I2 = 57%; P < .00001) in favor of pNPWT. That risk difference was -12% (95% CI, -22% to -1%; I2 = 69%; P = .03) when pooling only RCTs (792 patients). pNPWT was protective against the incidence of SSI with a RR of 0.53 (95% CI, .40-.71; I2 = 56%; P < .0001). The effect on pNPWT was more pronounced in studies with an incidence of SSI ≥20% in the control arm. The preventive effect of pNPWT on SSI remained after correction for potential publication bias. However, when pooling only high-quality observational studies (642 patients) or RCTs (527 patients), significance was lost.

CONCLUSIONS

Existing studies suggest that pNPWT on closed wounds is protective against the occurrence of SSI in abdominal surgery, but these findings need to be confirmed by more high-quality evidence, preferentially in subgroups of patients with an incidence of SSI ≥20% in the control arm.

Efficacy comparison of chlorhexidine and iodine preparation in reduction of surgical site infection: A systemic review and meta-analysis

BACKGROUND

Chlorhexidine and povidone-iodine are the most common disinfectants used in preoperative skin preparation. However, there is no consistent conclusion regarding the prevention of surgical site infection (SSI) and bacterial culture data.

OBJECTIVE

To assess the efficacy of chlorhexidine and povidone-iodine in the prevention of postoperative SSI and relevant bacterial data.

DESIGN

Systematic Review and Meta-Analysis SETTINGS: N/A PARTICIPANTS: N/A METHOD: Literature relevant to "skin antisepsis" and "surgical site infections" was retrieved from PUBMED, Web of Science, EMBASE, CINHAL and CNKI. The incidence of SSI was the primary outcome, while the secondary outcome was bacterial data from the infected incision. All data were analyzed with Revman 5.3 and Stata Statistical Software.

RESULTS

A total of 36 studies were identified in this study, which included 16,872 participants. This study revealed that chlorhexidine is superior to povidone-iodine in the prevention of postoperative SSI (risk ratio [RR], 0.73; 95% confidence interval [CI], 0.61-0.87; p = 0.019, I² = 39%). Further meta-regression analysis revealed that the effect of chlorhexidine was directly associated with the type of incision, but failed to differentiate between the subgroups divided according to the type of incision. With respect to bacteria colonization, the most common bacteria for chlorhexidine arm were propionibacterium's, while the most common bacteria for the iodine arm were staphylococci species.

CONCLUSION

In comparison to povidone-iodine, chlorhexidine showed better results in preventing postoperative SSI.

Improving surgical site infection prevention in Asia-Pacific through appropriate surveillance programs: Challenges and recommendation

BACKGROUND

Surgical site infections (SSIs) represent a substantial clinical and economic burden on patients and the healthcare system. The prevention of SSIs entails surveillance activities which lead to effective mitigation strategies, which are lacking across Asia Pacific (APAC). This manuscript aims to document gaps and challenges across APAC that affect the undertaking of a successful SSI surveillance activities and to provide recommendations on overcoming such challenges.

METHODS

A targeted literature review with relevance to APAC identified a series of salient points pertaining to SSI prevention guidelines, implementation, surveillance and outcomes, which was discussed in July 2019 at the APAC Surgical Site Infection Prevention Symposium. An expert panel, comprising eight multidisciplinary experts from APAC and the USA, subsequently amalgamated the key discussion points from the Symposium and their clinical experiences in developing this article.

RESULTS

The barriers to implementing a successful and effective APAC SSI surveillance program were identified as: (a) lack of standardized definitions, reporting methodology and accountability, (b) lack of fiscal resources, (c) reporting variability and under-reporting, and (d) lack of safety culture. Implementing an effective surveillance program in APAC will require countries to develop a well-designed and robust surveillance plan and ensure adequate training for staffs involved.

CONCLUSION

To improve SSI prevention in the region, it is imperative to encourage implementation of national programs with standardized methodologies and accountabilities. An ongoing APAC information exchange, including data and methodologies, will enable continuous learning within the APAC region.

The relationship between post-surgery infection and breast cancer recurrence

Breast cancer is the second most prevalent form of cancer in women worldwide, with surgery remaining the standard treatment. The adverse impact of the surgery remains controversial. It has been suggested that systemic factors during the postoperative period may increase the risk of recurrence, specifically surgical site infection (SSI). The aim of this review was to critically appraise current published literature regarding the influence of SSIs, after primary breast cancer surgery, on breast cancer recurrence, and to delve into potential links between these. This systematic review adopted two approaches: to identify the incidence rates and risk factors related to SSI after primary breast cancer surgery; and, secondly, to examine breast cancer recurrence following SSI occurrence. Ninety-nine studies with 484,605 patients were eligible in the SSI-focused searches, and 53 studies with 17,569 patients for recurrence-focused. There was a 13.07% mean incidence of SSI. Six-hundred and thirty-eight Gram-positive and 442 Gram-negative isolates were identified, with methicillin-susceptible Staphylococcus aureus and Escherichia coli most commonly identified. There were 2077 cases of recurrence (11.8%), with 563 cases of local recurrence, 1186 cases of distant and 25 cases which recurred both locally and distantly. Five studies investigated the association between SSI and breast cancer recurrence with three concluding that an association did exist. In conclusion, there is association between SSI and adverse cancer outcomes, but the cellular link between them remains elusive. Confounding factors of retrospective study design, surgery type and SSI definition make results challenging to compare and interpret. A standardized prospective study with appropriate statistical power is justified.

Surgical site infection and costs in low- and middle-income countries: A systematic review of the economic burden

BACKGROUND

Surgical site infection (SSI) is a worldwide problem which has morbidity, mortality and financial consequences. The incidence rate of SSI is high in Low- and Middle-Income countries (LMICs) compared to high income countries, and the costly surgical complication can raise the potential risk of financial catastrophe.

OBJECTIVE

The aim of the study is to critically appraise studies on the cost of SSI in a range of LMIC studies and compare these estimates with a reference standard of high income European studies who have explored similar SSI costs.

METHODS

A systematic review was undertaken using searches of two electronic databases, EMBASE and MEDLINE In-Process & Other Non-Indexed Citations, up to February 2019. Study characteristics, comparator group, methods and results were extracted by using a standard template.

RESULTS

Studies from 15 LMIC and 16 European countries were identified and reviewed in full. The additional cost of SSI range (presented in 2017 international dollars) was similar in the LMIC ($174-$29,610) and European countries ($21-$34,000). Huge study design heterogeneity was encountered across the two settings.

DISCUSSION

SSIs were revealed to have a significant cost burden in both LMICs and High Income Countries in Europe. The magnitude of the costs depends on the SSI definition used, severity of SSI, patient population, choice of comparator, hospital setting, and cost items included. Differences in study design affected the comparability across studies. There is need for multicentre studies with standardized data collection methods to capture relevant costs and consequences of the infection across income settings.

Prophylactic negative wound therapy in laparotomy wounds (PROPEL trial): randomized controlled trial

BACKGROUND

Superficial surgical site infections are a common post-operative complication. They also place a considerable financial burden on healthcare. The use of prophylactic negative pressure wound therapy has been advocated to reduce wound infection rates. However, there is debate around its routine use. The purpose of this trial is to determine if prophylactic negative pressure wound therapy reduces post-operative wound complications in patients undergoing laparotomy.

METHODS/DESIGN

This multi-centre randomised controlled trial will compare standard surgical dressings (control) to two competing negative pressure wound therapy dressings (Prevena™ and PICO™). All patients will be over 18 years, who are undergoing an emergency or elective laparotomy. It is intended to enrol a total of 271 patients for the trial.

DISCUSSION

The PROPEL trial is a multi-centre randomised controlled trial of patients undergoing laparotomy. The comparison of standard treatment to two commercially available NPWT will help provide consensus on the routine management of laparotomy wounds.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov (NCT number NCT03871023).