Surgical site infections are the infections of the tissues, organs, or spaces exposed by surgeons during an invasive procedure manifested in the postoperative period. Due to the wide spectrum of possible clinical and pathological features, it is challenging to define SSI accurately. As per the NNIS program, SSIs are classified into incisional and organ/space infections[1]. Incisional SSI is further subclassified into superficial and deep incisional categories. Superficial incisional SSI occurs within 30 days after the surgery, while deep incisional, organ or space SSI includes infections within 30 days and up to 1 year if the implant is present[1]. The development of SSIs is not only related to the degree of microbial contamination of the wound during surgery but also the duration of the procedure and host factors such as diabetes, malnutrition, obesity, immune suppression, and several other underlying disease states

Surgical site infection still causes considerable morbidity and high cost to the health care system and is becoming increasingly crucial in medico-legal aspects. It is the third most common cause of nosocomial infections and most common among surgical patients complicating nearly one out of four surgeries. While the global estimate of SSI varied from 0.5 % to 15 % in different studies, still in India, it ranges from 23 to 38%[2]. Even with the advancement in aseptic techniques and standard patient care in the world, lack of optimisation of patient condition, the poor operational environment, inappropriate assessment and lack of appropriate measures leads to a higher rate of SSI in most of the cities. Surgical site infection is an essential factor related to the outcome of the surgery but is also treated as a failure of surgery in this modern era[3]. This study was proposed to find out the associated factors responsible for SSI in our community and analyse the microflora of SSl.

Study design: This was a descriptive cross-sectional study done for a period of one year (Nov 2012 to Oct 2013) in a tertiary care centre in Bareilly, U.P. All the patients underwent surgeries related to git pathology in the surgery department, either emergency or elective with surgical site infections were included in this study. Patients less than 18, all cases operated else were, or re-operated were excluded from this study.

surgeries. SSI was associated with 82 (9.4%) cases among elective and 80 (21%) in emergency surgeries. Superficial incision SSI was found to be most common (90 cases), followed by deep incisional SSI (60 cases) and organ/space SSI (12 cases). The patients in the elective surgery group ranged from 18 years to 74 years, with a mean of 42 years. Of these, 545(43.6%) were females, and 705 (56.4%) were males. In the emergency surgery group, 45 (56.25%) were males, and 35(53.75%) were females with a mean age of 38 years. SSI was commonest in patients with more than 60 years (18%) and least in the 18-40 age group (12%). (Table 1) However, these differences were not statistically significant. Co-morbidities associated with these patients operated either elective or emergency are Diabetes mellitus (15% vs 10 %), COPD (18% vs 25%), Hypoalbuminemia (8% vs 28%) anemia (2% vs 15%). Smoking was commonly associated with males in the elective and emergency surgery group (25% vs 30%). (Table1)The surgical procedure most commonly associated with SSI in this study was done for small intestine pathology, and the most common indication was ileal perforation peritonitis. The number of cases associated with SSS in this group was 24.6 %, followed by gastric/ duodenal (21.6%). The Least SSI rate was found in hernioplasty. The most common surgery done in this study was cholecystectomy followed by urological surgeries, ventral and inguinal hernias and perforation peritonitis. (Table2)

Out of 162 SSI, the microbial culture report was sterile in 53 cases (32.7%). The microbiological organism most commonly isolated were E. Coli (41.2%) followed by Staphylococcus aureus (27.5%), Klebsiella (16.5%), group A beta-hemolytic streptococci (9.1%) and Pseudomonas (5.5%). (Table.3) E.Coli was found as the most typical organism (45 among 109 cases), causing 41.28 % of the surgical site infections. Staphylococcus Aureus were the second most common organism (30 among 109 patients) accounted for 27.5 % of the infections, followed by Klebsiella in 16.5 %, Streptococci in 9.1 % and Pseudomonas in 5.5%. Escherichia coli were most sensitive to Imepenam followed by piperacillin + Tazobactum while sensitive to Ciprofloxacin was 40%, Ceftriaxone 71.1 % and amikacin 73.3 %. The sensitivity of Staphylococcus for ampicillin was found to be only 10 %, while cephalosporins were found to be more sensitive than aminoglycosides and fluoroquinolones.

The incidence of SSI varies from surgeon to surgeon, from hospital to hospital, from one surgical procedure to another and most importantly, from one patient to another for the same procedure[4]. SSI remains one of the most critical factors responsible for the more extended stay of the patient at the hospital, increasing the burden of cost, additional surgical procedures and significant mental trauma to the patient. As in most studies in India, the incidence of SSI in our study was also high at 9.4% in elective and 21% in emergency surgeries. The high incidence of SSI in developing countries like India might be due to lack of modular O.T. due to high cost, inadequate postoperative care, poor aseptic environment and sterility during surgical procedures, inadequate infection control and lack of proper surveillance by authorities. In this study, wound class, anaemia, low serum albumin, and hypoxia were significantly associated with surgical site infection.

Surgical wound classification has long been established as an important predictor of postoperative surgical site infections. According to the degree of contamination, wounds may be classified as clean, clean/ contaminated, contaminated and dirty.[5] The incidence of infection increases from 1-5.4 % in clean to 12.8 % in dirty wounds. The risk of infection is highest among colorectal surgeries (9-25 %) [6-8]. In our study, the risk of SSI was higher in dirty and contaminated wounds than in clean and clean-contaminated wounds. Emergency surgeries were associated with a higher SSI rate than elective surgeries in this study. The present study showed an SSI rate of 9.4% for elective surgeries and 21% for emergency surgeries. Among the three types, superficial incision SSI was most prevalent (90 cases), followed by deep incisional SSI (60 cases) and finally by organ/space SSI (12 cases).

In clean surgical procedures, Staphylococcus aureus was most commonly isolated from cases with SSI, which is usually residing in the exogenous environment or the patient's skin flora. SSI associated with clean-contaminated, contaminated and dirty were usually polymicrobial in origin and closely resembling the normal endogenous microflora of the surgically resected organ. [11]. It has also been reported by the National Nosocomial Infections Surveillance System (NNIS) that the microflora of SSI has not shifted significantly in the last decade. [1] In few studies, the predominant isolate of SSI was Klebsiella pneumoniae, followed by Staphylococcus aureus, E. coli, and Pseudomonas spp. Klebsiella pneumonia is also natural habitat in the gastrointestinal tract as E. Coli. In their study, most of the operations performed were laparotomies, and most wounds were either clean-contaminated, contaminated or dirty with spillage from the GIT content. Most SSIs were caused by multi-drug resistant (MDR) organisms[12]. Duration of operation time was not significantly associated with SSI in this study. Previous studies have reported the duration of surgery as a risk factor for surgical site infections [13,14].

Although prolonged operative time leads to fatigue awareness and practice of aseptic measures along with advancement in surgical technique, improvement in the operative environment has improved the surgical outcome.

Surgical site infection still causes considerable morbidity and high cost to the health care system and is becoming increasingly crucial in medico-legal aspects. Prevention of SSI requires a targeted approach to improve health care workers' knowledge, practising the guidelines strictly regarding asepsis and optimising the patient before surgery. Reduction in rate of SSI will improve cosmesis and make the results of operations better as a whole.