Surgical site infection (SSI) is a major global health concern, representing a significant burden on patients and healthcare systems. It's the most common postoperative complication, causing pain, suffering, and substantial costs, potentially leading to catastrophic health expenditure and impoverishment, especially in low- and middle-income countries (LMICs). While single-center retrospective studies have suggested the prevalence of SSI in LMICs, prospective, standardized, internationally comparable data have been lacking, hindering effective resource allocation. The WHO has published recommendations for SSI prevention, but these are largely based on data from high-income countries and may not be fully applicable to resource-limited settings. This study aims to address these knowledge gaps by providing global data on SSI incidence and antimicrobial resistance in various income settings, thus informing strategies to improve prevention and treatment.

Existing multinational research on SSI after abdominal surgery, particularly in LMICs, is limited. A review of PubMed, MEDLINE, Google Scholar, and ClinicalTrials.gov (Jan 1, 1997 – June 1, 2017) revealed several low-volume, single-center studies with low to medium methodological quality and high heterogeneity, preventing meta-analysis. Reported SSI incidence ranged from 0.4% to 30.9%. One multinational study since 2010 included patients from various income settings, but had limitations, such as passive 30-day follow-up, limited data from lowest-income countries, and exclusion of children. The lack of high-quality global data on SSI incidence and antimicrobial resistance, along with limited information on the origin of causative organisms, hampers the refinement of prevention and quality-improvement interventions. This study addresses the need for high-quality global data to inform effective strategies.

This international, multicentre, prospective cohort study enrolled consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week periods at various healthcare facilities globally. Countries were stratified into high, middle, and low HDI groups based on the UN's Human Development Index. Data collection involved standardized variables from the GlobalSurg 1 study and other relevant factors (age, sex, physical status, immune suppression, smoking, diagnostic category, surgical technique, antibiotic use, intraoperative contamination). Intraoperative contamination was categorized as clean, clean-contaminated, contaminated, or dirty. Data on antimicrobial treatment length and resistance were also collected. Data were collected using REDCap and vetted centrally. A three-part data validation process was implemented, including self-reported processes, independent quantitative validation, and qualitative assessment of collaborator engagement. The primary outcome was 30-day SSI incidence (defined by US CDC criteria), while secondary outcomes included 30-day mortality, reintervention rate, organ space infection prevalence, antimicrobial resistance, in-hospital SSI incidence, and overall 30-day SSI incidence. Bayesian multilevel logistic regression models were used for statistical analysis, accounting for casemix and using random effects for hospital and country. A restricted cubic spline transformation was applied to the HDI to account for potential non-linearity.

Between January 4, 2016, and July 31, 2016, 12,539 patient records were analyzed from 343 hospitals in 66 countries. The overall 30-day SSI incidence was 12.3%. Unadjusted SSI incidence varied significantly across HDI groups (high: 9.4%, middle: 14.0%, low: 23.2%, p<0.001). The highest SSI incidence in each HDI group was observed after dirty surgery. Following multivariable adjustment, patients in low-HDI countries had a significantly higher risk of SSI (adjusted OR 1.60, 95% CI 1.05–2.37, p=0.030) compared to high-HDI countries. Middle-HDI countries showed no significant difference compared to high-HDI countries. Antibiotic-resistant infections were significantly more prevalent in low-HDI countries (35.9%) compared to high (16.6%) and middle (19.8%) HDI countries (p<0.001). 30-day mortality was higher in patients with SSI (4.7%) than in those without (1.5%). Length of hospital stay was three times longer for patients with SSI. Pre- and postoperative antibiotic use was higher in low-HDI countries, with longer postoperative courses not fully explained by casemix (adjusted OR 4.37, 95% CI 1.65–11.85, p=0.002). Microbiological analysis showed bowel-derived organisms were frequently implicated in SSIs. Failure to use a surgical safety checklist was associated with a higher SSI rate.

This study demonstrates a substantial global burden of SSI following gastrointestinal surgery, with a disproportionately higher incidence in LMICs. Even after adjusting for various confounding factors, the increased risk of SSI in low-HDI countries remains significant. The higher rates of antibiotic-resistant infections in these settings are concerning. The association between SSI and increased mortality, longer hospital stays, and higher rates of reintervention underscore the significant clinical impact of this preventable complication. The high prevalence of antibiotic-resistant SSIs highlights the need for improved infection control practices and antibiotic stewardship. The association between the lack of surgical safety checklist usage and increased SSI rates warrants further investigation into broader safety culture within healthcare systems. While this study's findings contribute significantly to the global understanding of SSI burden and antimicrobial resistance, future research is crucial to develop and evaluate targeted interventions for LMICs.

This large, multinational study reveals a significant and disproportionate burden of SSI in low-HDI countries, characterized by higher rates of infection and antibiotic resistance. These findings underscore the urgent need for high-quality, pragmatic, randomized controlled trials in LMICs to evaluate interventions aimed at reducing SSI incidence and improving patient outcomes. Further research is warranted to explore the factors contributing to the observed differences in SSI rates across income settings and to develop context-specific strategies for prevention and management.

This study had some limitations. Complete 30-day follow-up was not achieved for all patients, although a sensitivity analysis using in-hospital SSI rates yielded similar results. Microbiological methods were not standardized across sites. Although validation efforts were undertaken, potential for missed cases or inaccurate data exists, though mitigated by the large sample size, prospective design, and use of local coordinators. Further, the study is observational; therefore, causal inferences cannot be drawn from all associations.