Health care-associated infections (HAIs) are acquired by patients when receiving care and are the most frequent adverse event affecting patient safety worldwide. Common HAIs include urine, chest, blood and wound infections. HAIs are caused mainly by microorganisms resistant to commonly-used antimicrobials, which can be multidrug-resistant.
Although the global burden remains unknown because of the difficulty to gather reliable data, it is estimated that hundreds of millions of patients are affected by HAIs each year, leading to significant mortality and financial losses for health systems. At present, no country is free from the burden of disease caused by HAIs and antimicrobial resistance (AMR).
Of every 100 hospitalized patients at any given time, seven in developed and 15 in developing countries will acquire at least one HAI. The endemic burden of HAI is also significantly (at least 2–3 times) higher in low- and middle-income countries (LMICs) than in high-income nations, particularly in patients admitted to intensive care units, and neonates.
Recent work by the World Health Organization (WHO) Clean Care is Safer Care programme (http://www.who.int/gpsc/en) shows that surgical site infection (SSI) is the most surveyed and frequent type of HAI in LMICs and affects up to one third of patients who have undergone a surgical procedure. In LMICs, the pooled incidence of SSI was 11.8 per 100 surgical procedures (range 1.2 to 23.6) (1, 2). Although SSI incidence is much lower in high-income countries, it remains the second most frequent type of HAI in Europe and the United States of America (USA). In some European countries, it even represents the most frequent type of HAI. The European Centre for Disease Prevention and Control (ECDC) reported data on SSI surveillance for 2010–2011. The highest cumulative incidence was for colon surgery with 9.5% episodes per 100 operations, followed by 3.5%for coronary artery bypass graft, 2.9% for caesarean section, 1.4% for cholecystectomy, 1.0% for hip prosthesis, 0.8% for laminectomy and 0.75% for knee prosthesis (3).
Many factors in a patient’s journey through surgery have been identified as contributing to the risk of SSI. The prevention of these infections is complex and requires the integration of a range of measures before, during and after surgery. However, the implementation of these measures is not standardized worldwide and no international guidelines are currently available.
No full guidelines have been issued by WHO on this topic, although some aspects related to the prevention of SSI are mentioned in the 2009 WHO guidelines for safe surgery (4). Some national guidelines are available, especially in Europe and North America, but several inconsistencies have been identified in the interpretation of evidence and recommendations and validated systems to rank the evidence have seldom been used. Importantly, none of the currently available guidelines have been based on systematic reviews conducted ad hoc in order to provide evidence-based support for the development of recommendations. In addition, important topics with a global relevance that can lead to potentially harmful consequences for the patient if neglected are mentioned in only a few guidelines, for example, surgical hand antisepsis or the duration of surgical antibiotic prophylaxis (SAP). Of note, the prolongation of antibiotic prophylaxis is one of the major determinants of AMR.
Given the burden of SSI in many countries and the numerous gaps in evidence-based guidance, there is a need for standardization based on strategies with proven effectiveness and a global approach. International, comprehensive SSI prevention guidelines should include also more innovative or recent approaches. To ensure a universal contribution to patient safety, recommendations should be valid for any country, irrespective of their level of development and resources.
The aim of these guidelines is to provide a comprehensive range of evidence-based recommendations for interventions to be applied during the pre-, intra- and postoperative periods for the prevention of SSI, while taking into consideration resource availability and values and preferences.
1.1. Target audience
The primary target audience for these guidelines is the surgical team, that is, surgeons, nurses, technical support staff, anaesthetists and any professionals directly providing surgical care. Pharmacists and sterilization unit staff will be concerned also by some recommendations or aspects of these guidelines. The guidelines will be an essential tool for health care professionals responsible for developing national and local infection prevention protocols and policies, such as policy-makers and infection prevention and control (IPC) professionals. Of note, it will be crucial to involve senior managers, hospital administrators, individuals in charge of quality improvement and patient safety and those responsible for staff education and training to help advance the adoption and implementation of these guidelines.
1.2. Scope of the guidelines
Population and outcome of interest
The guidelines focus on the prevention of SSI in patients of any age undergoing any surgical procedure. However, there are recommendations that are either not proven for the paediatric population due to lack of evidence or inapplicable. The primary outcomes considered for developing the recommendations were the occurrence of SSI (SSI incidence rates) and SSI-attributable mortality.
Priority questions
The priority research questions guiding the evidence review and synthesis according to each topic addressed by these guidelines are listed in the table of recommendations included in the executive summary. These were further developed as a series of questions structured in a PICO (Population, Intervention, Comparison, Outcomes) format (available in full in web Appendices 2–27) (https://www.who.int/infection-prevention/publications/ssi-web-appendices/en/).
