Surgical Site Infection (SSI) is a nosocomial infection occurring at the surgical wound site within 30 days postoperatively or within one year in the case of implanted devices [1][2].

Surgical site infection is the third most common nosocomial infection after urinary tract and respiratory tract infections [1][2]. Despite advances in surgical care, perioperative asepsis, and antibiotic therapy, SSI remains a major public health problem because it can increase antibiotic resistance and healthcare costs, prolong hospital stays, and increase morbidity and mortality [1][3]. It is a disaster in surgery, as it can ruin the benefits of an operation aimed at improving joint function or repairing trauma [4]. Many factors contribute to its occurrence, some related to the patient, others to the patient’s immediate environment (operating theatre, air quality, hygiene of the surgical team and caregivers), and still others to the surgical procedure [4]. Poor management of biomedical waste is thought to be responsible for surgical site infections caused by antibiotic-resistant bacteria [5][6]. Many studies have identified a number of independent factors that promote the occurrence of SSI, namely diabetes, revision surgery (reoperation), long-term surgery, advanced age, obesity, and incorrect or absent antibiotic prophylaxis [7]. For effective management, it is essential to know the causative organism and its sensitivity to antibiotics [8]. Broad-spectrum probabilistic antibiotic therapy is often necessary, but unfortunately, this approach exposes the patient to the selection of resistant bacteria and has consequences for the bacterial ecology of the ward [8].

The incidence of SSI in developed countries varies from 0.7% to 5%, reaching up to 33% in cases of abdominal surgery [1][2]. In the United States, SSI accounts for 14% to 16% of all nosocomial infections, making it the second most frequently reported cause after urinary tract infection. It is estimated that 2% to 5% of patients who undergo surgery develop SSI. This depends on patient-related factors (comorbidities), the surgical procedure (type of operation, duration of the operation), and environmental and organizational factors [9][10].

In Canada, more than 40 hospitals submitted data between 2009 and 2018 on hip and knee surgical site infections, cerebrospinal fluid shunt surgical site infections, and pediatric cardiac surgical site infections. Overall, 4599 pathogens were detected from surgical site infections. Coagulase-negative Staphylococci (29%) and Staphylococcus aureus(14%) were the most frequently reported organisms [11].

In France, surveillance of 95,388 procedures revealed 1560 SSIs, representing an incidence of 1.64% occurring within 17 days after surgery [12][13]. The risk factors for SSI are well identified as the type of surgery according to the Altemeier classification, the duration of the procedure, and the condition of the patient undergoing surgery, often represented by the ASA class. In the absence of risk factors, the incidence of SSI decreases to 0.72% [12][14]. The European Surveillance Network has identified the three bacteria mainly involved in surgical site infections of all types, regardless of the area of intervention: Enterococcus sp. (17.6%), Escherichia coli(17.2%), and Staphylococcus aureus(15.2%) [12][13]. In France, data from the Network for the Surveillance and Prevention of Infectious Risk in Surgery show that in 2021, an enterobacterium was found in 31% of SSI cases (including Escherichia coli in 14.3% of cases) and a Gram-positive coccus in 53% (Staphylococcus aureus 21.9%, Staphylococcus epidermidis 10.2%, and Enterococcus faecalis 9%) [12][13]. Enterobacteria and enterococci are more often responsible for SSI after digestive surgery, while staphylococci are more common in orthopedics and traumatology [12].

In sub-Saharan Africa, SSI is common, with prevalence varying from 6% to over 40% depending on the case [15]. In Mali, the WHO estimates that an average of 240 million patients contract a surgical site infection, with approximately 1 million of them dying each year from this infection [16]. A study conducted by Bengali et al. on surgical site infections in B surgery at the Point G University Hospital found an overall prevalence of SSI of 4.74%. It identified the following germs in order of frequency: Escherichia coli, Staphylococcus aureus, Acinetobacter baumannii, and Enterococcus spp. The frequency of germs responsible for surgical site infections depends on the working environment, the rigor of asepsis, and the type of surgery [16].

At the National Surgery Department in Niamey, Ousmane A. et al. conducted a study on the bacteriological aspects of surgical site infections. Bacteriological analyses isolated 126 bacterial strains, predominantly S.aureus(n = 39, 31%), followed by Escherichia coli(n = 29, 23%) and Pseudomonas aeruginosa(n = 12, 9.5%). The Escherichia colistrains were 100% sensitive to imipenem. They showed marked resistance to ampicillin, amoxicillin, clavulanic acid, and ticarcillin. They showed variable resistance to aminoglycosides (62% to gentamicin and 78% to amikacin) and fluoroquinolones (nalidixic acid 74%, pefloxacin 33%, ofloxacin 69%, ciprofloxacin 61%). All Enterobacteriaceae isolates were sensitive to imipenem. S.aureusstrains showed resistance to penicillin G (88.6%) and oxacillin (83%) [17]. In the DRC, the prevalence of surgical site infection reported at Panzi Hospital in Bukavu in 2024 by Lungere et al. was 8.8% [18]. The isolated germs were, in order of frequency: E. coli, in all departments, Klebsiella pneumoniae, and Staphylococcus spp., with a high prevalence in digestive surgery [18].

Despite the efforts made, controlling resistant bacterial infections remains a national and international challenge. In 2017, the World Health Organization (WHO) updated its list of priority resistant bacteria for research and development of new antibiotics, based on their prevalence, impact on health, evolution over the past decade, transmissibility, and treatability, among other factors [19].

Several factors contribute to the increase in the frequency of ISO and antibiotic resistance in the DRC. In addition to those common to the rest of the world, these include a lack of regulation in this area, poor diagnostic tools, the precariousness of the health system, and a shortage of qualified human resources for laboratory diagnosis [20]. The precarious nature of hospital waste management, especially biomedical waste, and the lack of laminar flow are major public health problems [5][6]. Socio-economic conditions, poor hospital hygiene, the surgical environment, the behavior of operating theatre staff and dressing personnel, self-medication, probabilistic antibiotic therapy, the use of poor-quality antibiotics, and the indiscriminate use of antibiotics promote the emergence of bacterial resistance. The excessive, often incorrect and irrational prescription of antibiotics, under-dosing, and the growing number of unqualified prescribers have led to multiple resistances and increased surgical site infections caused by germs resistant to commonly used antibiotics [21]-[23]. The shortage of consumables for bacteriological tests, particularly cultures and antibiograms, makes it difficult, if not impossible, to administer appropriate and adequate antibiotic therapy. The lack of electricity seriously hinders the functioning of our laboratories and sterilization equipment, which are needed to better manage infections [21][23]. The overall objective of this study is to examine the epidemiological and bacteriological aspects of surgical site infection and determine the resistance of germs to antibiotics commonly used in the Department of Surgery at the Kisangani University Clinics in order to improve patient care.

The results of this study can be discussed in terms of three aspects: epidemiological, bacteriological, and antibiotic resistance.

The prevalence of surgical site infection in our study was 12.06%. Our prevalence was higher than that reported by N’Sinabau et al. [24] in Kinshasa (8.3%) and Lungere et al. [18] in Bukavu (8.8%), Doutchi et al. [2] (7.83%) at the National Hospital in Zinder, Niger; Bengaly et al. [18] in Mali (4.72%); and the ISO Surveillance Network in France (1.64%) [12]-[14].

However, it was lower than that reported by Bafeno et al. [25] at Makiso General Hospital, 30.65%.

We believe that this high frequency in our series could be explained in our setting by the precarious nature of certain aseptic measures, hospital practices, and a lack of information on antibiotic prophylaxis.

The sample consisted of 55 men and 19 women, giving a sex ratio of 2.89. The average age was 45.25 ± 19.24, with extremes of 0 and 83 years. Relatively similar results were reported by Lungere et al. [18] in Bukavu, where the 20 - 40 age group was predominant, with an average age of 33 ± 2 years. Our results differ from those found by Kimuni et al. [21] in Lubumbashi, where the 18 - 24 age group was predominant, with an average age of 33 ± 17 years; and Bafeno et al. [25] in Kisangani, who found a predominance of patients aged between 61 and 75 years.

We believe that the predominance of this age group in our series is due to the nature of our sample, which consists of many cases of peritonitis, which often occur in this age group.

The results of the pyoculture isolated 79 germs, including 5 cases of microbial association with two germs. The predominant germs were Staphylococcus aureus, Escherichia coli, Citrobacter diversus, and Pseudomonas aeruginosa with 41.7%, 17.7%, 11.4%, and 8.9%, respectively. Relatively similar results have been reported by several African and non-African authors who found a predominance of Staphylococcusaureus, notably Ousmane A. et al. [17], Ide Garba et al. [26], and the SSIs Surveillance Network in France [12]-[14]. However, our results do not corroborate those of Kimuni et al. [21], who reported a predominance of Pseudomonas aeruginosa 50%, Escherichia coli 22%, and Staphylococcus aureus 20.5%; Lungere et al. [18] reported a predominance of E.colifollowed by Staphylococcus aureus, and Bengaly et al. in Mali [16] reported a predominance of E. coli followed by S. aureus. We believe that the predominance of Staphylococcus aureus in our series is due to the fact that these germs constitute flora in the hospital environment and are commensals of the skin and mucous membranes. Contamination of the surgical site occurs more often during the surgical period, either from the patient’s flora before the incision, from the flora of the staff during the procedure or during dressing, or from antiseptic solutions or contaminated instruments. The poor hygiene of our hospital environment is thought to be the cause of SSI.

The results of the antibiogram by germ showed the following resistance: Staphylococcus aureus: ceftriaxone 59%, ciprofloxacin 60%, gentamicin 48.4%, amoxicillin 55.1%, penicillin 75%; Escherichia coli: ceftriaxone 54.5%, ciprofloxacin 45.4%, gentamicin 45%, amoxicillin 63%; Citrobacter diversus: ceftriaxone 50%, ciprofloxacin 60%, gentamicin 48.4%, penicillin 75%, amoxicillin 55.1%. Relatively similar results were reported by Nsiata et al. [27] and Ousman A. [17]. However, our results differ from those reported by Lungere et al. [20]. There is reason to believe that frequent use of antibiotic molecules ultimately leads to resistance [2][28]. The high resistance to the molecules used in our Surgery Department could also be related to their quality. This high resistance of bacteria isolated from SSIs to certain families of antibiotics confirms that these are indeed hospital germs. It must completely change the protocol for probabilistic antibiotic therapy. The antibiotics that have shown efficacy against most germs isolated from surgical site infections in the surgery department are amikacin, fosfomycin, meropenem, and imipenem. These antibiotics can be used as a first-line treatment in the case of empirical antibiotic therapy.

This study has some limitations due to its single-center design, and its retrospective and non-probabilistic nature, meaning that data recording was not exhaustive. Other patients could not be included in this database as having surgical site infections due to the loss of many medical records in the archives department. Some patients who were clinically diagnosed with surgical site infection were excluded because pus samples were not sent to the laboratory for bacteriological study. The results cannot be generalized to the entire population.

However, the results obtained are encouraging. They will allow hospital services to gain an understanding of the bacterial ecology of the department, establish their infection prevention policy for surgical sites, and improve antibiotic prescription practices.

Surgical site infection is a real public health problem. Its impact is considerable because it can lead to antibiotic resistance, long hospital stays, increased healthcare costs, and significant morbidity and mortality. Incorrect antibiotic prescriptions, self-medication, and the use of poor-quality antibiotics are responsible for the selection of multi-resistant strains in healthcare facilities. Reduced sensitivity to commonly used antibiotics has been observed in the Cukis surgery department.

Before starting the collection, we received a research permit from the faculty, granting us access to the hospitalizations register and Register of doctors’ on-call reports. The information concerning our patients has been kept confidential.