Surgical site infection (SSI) is a postoperative infection involving the incision, deeper soft tissues, organ, or operative space and remains one of the most important healthcare-associated complications after surgery. Standardized surveillance definitions have improved comparability across institutions, while contemporary prevention guidance emphasizes that a meaningful proportion of SSIs can be avoided through coordinated perioperative practice [1-3]. Despite advances in antimicrobial prophylaxis, sterilization, skin antisepsis, operative technique, and postoperative wound care, SSI continues to contribute to delayed wound healing, additional procedures, prolonged antimicrobial use, readmission, and greater healthcare expenditure. A global meta-analysis published in 2023 demonstrated substantial variation in SSI incidence across regions and healthcare settings, underscoring the continued need for locally generated surveillance data [1]. The occurrence of SSI is multifactorial. Patient characteristics, host defense, nutritional status, diabetes, microbial colonization, wound contamination, emergency presentation, operative duration, tissue handling, blood loss, and perioperative infection-control practices interact to determine risk [4,5]. International evidence has consistently linked contaminated or dirty wounds and longer procedures with increased infection rates. The GlobalSurg Collaborative reported a marked gradient in SSI after gastrointestinal surgery across different development settings, with the greatest burden in low-resource environments [6]. Indian data also demonstrate that wound classification, duration of surgery, and preoperative hospitalization are important determinants of SSI [7]. A systematic review of surgical populations identified multiple patient- and procedure-related risk factors, confirming that SSI prevention requires more than a single intervention [8]. Children and adults differ in physiology, disease spectrum, comorbidity burden, immune maturity, nutritional vulnerability, surgical indications, and patterns of emergency presentation. Consequently, adult-derived risk models do not always translate directly to paediatric practice. Paediatric studies have documented associations between SSI and younger age, invasive devices, procedure characteristics, hospital exposure, and duration of surgery [9-11]. Evidence focused specifically on neonates and children remains less extensive than adult literature, and prevention recommendations for younger patients still rely partly on extrapolation from adult surgical care [11]. Direct comparison of paediatric and adult general surgery patients within the same institutional environment can therefore provide clinically useful information by reducing variability related to operating-room protocols, microbiology services, antimicrobial policies, and surveillance practices. The present study was undertaken at a tertiary teaching institution in Andhra Pradesh to characterize the burden of SSI across paediatric and adult general surgery populations. The objectives were to compare the incidence and pattern of SSI between paediatric and adult patients, identify clinical and operative factors associated with SSI, describe the microbiological profile of infected wounds, and assess the effect of SSI on postoperative length of stay, wound intervention, readmission, and short-term outcome.

Study design and place of study This was a hospital-based comparative observational study conducted in the Department of General Surgery, Government Medical College, Anantapuramu, Andhra Pradesh, India. The study was designed to compare SSI occurrence and associated perioperative characteristics in paediatric and adult general surgery patients managed within the same institutional environment. Study period The study was conducted for 12 months, from July 2023 to June 2024. Eligible patients were recruited consecutively during the study period until the predefined sample of 100 participants was reached. Study population and sample A total of 100 patients undergoing general surgical procedures were included: 50 paediatric patients aged <14 years and 50 adults aged ≥18 years. Elective and emergency procedures across all wound classes were eligible when performed under the general surgery service and adequate postoperative follow-up was available. Eligibility criteria Patients of either sex undergoing elective or emergency general surgical procedures and consenting to follow-up were included. For children, consent was obtained from a parent or legally authorized guardian, with age-appropriate assent where applicable. Exclusion criteria were SSI attributable to a previous operation, procedures outside general surgery, incomplete perioperative records, or unavailability for 30-day assessment. Clinical assessment and SSI surveillance Demographic information, type of surgery, wound class, operative duration, preoperative hospital stay, diabetes status, and relevant perioperative details were recorded in a structured case-record form. Surgical wounds were assessed during inpatient care and at postoperative review. SSI was identified using standard CDC/NHSN principles and categorized as superficial incisional, deep incisional, or organ/space infection [3]. Patients were followed for 30 days after the index procedure. Time to clinical recognition of SSI, wound drainage or debridement, additional surgical intervention, postoperative length of stay, and 30-day readmission were documented. Microbiological evaluation When SSI was suspected clinically, an appropriate wound or operative-site specimen was collected using aseptic technique and submitted for bacterial culture and antimicrobial susceptibility testing. Organisms were reported according to routine microbiology procedures. Methicillin resistance among Staphylococcus aureus isolates was recorded when identified. Culture findings were interpreted together with the clinical diagnosis rather than used as the sole criterion for SSI. Outcome measures The primary outcome was the incidence of SSI in the overall cohort and in paediatric and adult groups. Secondary outcomes included SSI type, associated risk factors, microbiological spectrum, postoperative hospital stay, need for wound intervention or reoperation, 30-day readmission, and SSI-related mortality. Statistical analysis Continuous variables were summarized as mean ± standard deviation and categorical variables as frequency and percentage. Group comparisons used the independent-samples t test for continuous variables where appropriate and Pearson chi-square or Fisher's exact test for categorical variables according to expected cell counts. A two-sided p value <0.05 was considered statistically significant. Analyses focused on the supplied complete cohort of 100 patients. Ethical considerations The protocol was reviewed by the Institutional Ethics Committee of Government Medical College, Anantapuramu, Andhra Pradesh, India. Written informed consent was obtained from adults and from parents or legal guardians of children. Necessary Permissions were obtained before starting the study. Participant confidentiality was maintained throughout the study

A total of 100 patients undergoing general surgical procedures were included in the final analysis, comprising 50 paediatric patients (<14 years) and 50 adult patients (≥18 years). The mean age was 10.4 ± 4.6 years in the paediatric group and 45.7 ± 15.2 years in the adult group. Males constituted 29 (58.0%) of the paediatric group and 30 (60.0%) of the adult group. Emergency procedures accounted for 29 (58.0%) operations among children and 34 (68.0%) among adults. The baseline demographic and operative characteristics are summarized in Table 1. Table 1. Baseline demographic and operative characteristics of the study population (n = 100) Characteristic Paediatric (n = 50) Adult (n = 50) p-value Age, years, mean ± SD 10.4 ± 4.6 45.7 ± 15.2 <0.001 Male sex 29 (58.0) 30 (60.0) 0.839 Female sex 21 (42.0) 20 (40.0) Type of surgery - Elective 21 (42.0) 16 (32.0) 0.300 Type of surgery - Emergency 29 (58.0) 34 (68.0) Wound classification - Clean 18 (36.0) 13 (26.0) 0.566 Wound classification - Clean-contaminated 20 (40.0) 19 (38.0) Wound classification - Contaminated 8 (16.0) 12 (24.0) Wound classification - Dirty/infected 4 (8.0) 6 (12.0) Operative duration ≥90 minutes 14 (28.0) 22 (44.0) 0.096 Values are presented as n (%) unless otherwise specified. Incidence and pattern of surgical site infection Overall, 18 of 100 patients developed SSI, giving an incidence of 18.0%. SSI occurred in 6 (12.0%) paediatric patients and 12 (24.0%) adult patients. Although the infection rate was numerically twice as high among adults, the difference did not reach statistical significance (p = 0.118). Among the 18 patients with SSI, 11 (61.1%) had superficial incisional infection, 5 (27.8%) had deep incisional infection, and 2 (11.1%) developed organ/space infection. The distribution is presented in Table 2. Table 2. Incidence and pattern of surgical site infections SSI characteristic Paediatric (n = 50) Adult (n = 50) Total (n = 100) No SSI 44 (88.0) 38 (76.0) 82 (82.0) Any SSI 6 (12.0) 12 (24.0) 18 (18.0) Superficial incisional* 4 (66.7) 7 (58.3) 11 (61.1) Deep incisional* 1 (16.7) 4 (33.3) 5 (27.8) Organ/space infection* 1 (16.7) 1 (8.3) 2 (11.1) *Percentages for SSI type are calculated among infected patients within each group. The mean time from surgery to clinical identification of SSI was 5.8 ± 2.3 days. Most infections became clinically apparent during the first postoperative week. Factors associated with surgical site infection SSI showed significant associations with several operative characteristics. Patients undergoing procedures lasting ≥90 minutes had an SSI rate of 30.6% compared with 10.9% among those with shorter procedures (p = 0.028). Contaminated or dirty wounds were associated with a higher infection rate than clean or clean-contaminated wounds (33.3% vs. 11.4%; p = 0.020). A preoperative hospital stay exceeding 24 hours was also significantly associated with SSI (31.3% vs. 11.8%; p = 0.026). SSI occurred more frequently after emergency surgery than elective surgery, although this difference was not statistically significant (22.2% vs. 10.8%; p = 0.185). Diabetes mellitus demonstrated a borderline association with SSI (p = 0.055), as shown in Table 3. Table 3. Clinical and operative factors associated with surgical site infection Risk factor SSI n/N (%) No SSI n/N (%) p-value Emergency surgery 14/63 (22.2) 49/63 (77.8) 0.185 Elective surgery 4/37 (10.8) 33/37 (89.2) Operative duration ≥90 minutes 11/36 (30.6) 25/36 (69.4) 0.028 Operative duration <90 minutes 7/64 (10.9) 57/64 (89.1) Contaminated/dirty wound 10/30 (33.3) 20/30 (66.7) 0.020 Clean/clean-contaminated wound 8/70 (11.4) 62/70 (88.6) Preoperative hospital stay >24 hours 10/32 (31.3) 22/32 (68.8) 0.026 Preoperative hospital stay ≤24 hours 8/68 (11.8) 60/68 (88.2) Diabetes mellitus 5/13 (38.5) 8/13 (61.5) 0.055 No diabetes mellitus 13/87 (14.9) 74/87 (85.1) Microbiological profile Microbiological cultures were positive in 17 of the 18 SSI cases (94.4%). Staphylococcus aureus was the most frequently isolated organism, accounting for 6 (33.3%) infections, followed by Escherichia coli in 5 (27.8%), Klebsiella species in 3 (16.7%), Pseudomonas aeruginosa in 2 (11.1%), and Enterococcus species in 1 (5.6%). Two of the six S. aureus isolates were methicillin-resistant S. aureus (MRSA). No bacterial growth was detected in one patient. The organism distribution is shown in Table 4. Table 4. Microbiological isolates among patients with surgical site infection (n = 18) Organism Paediatric SSI (n = 6) Adult SSI (n = 12) Total n (%) Staphylococcus aureus 3 3 6 (33.3) Escherichia coli 1 4 5 (27.8) Klebsiella species 1 2 3 (16.7) Pseudomonas aeruginosa 0 2 2 (11.1) Enterococcus species 0 1 1 (5.6) No growth 1 0 1 (5.6) Total 6 12 18 (100) Postoperative outcomes Patients who developed SSI experienced a significantly prolonged hospital stay. The mean postoperative length of stay was 10.8 ± 4.1 days among patients with SSI compared with 5.4 ± 2.5 days among those without SSI (p < 0.001). All patients with SSI received antimicrobial therapy guided by clinical assessment and available culture-susceptibility results. Seven (38.9%) patients required wound drainage or debridement, while two (11.1%) required additional operative intervention. Hospital readmission within 30 days occurred in 4 (22.2%) patients with SSI compared with 2 (2.4%) patients without SSI (p = 0.009). No SSI-related mortality was recorded during the study period (Table 5). Table 5. Postoperative outcomes according to surgical site infection status Outcome SSI (n = 18) No SSI (n = 82) p-value Postoperative hospital stay, days, mean ± SD 10.8 ± 4.1 5.4 ± 2.5 <0.001 30-day readmission 4 (22.2) 2 (2.4) 0.009 Wound drainage/debridement 7 (38.9) - - Additional surgical intervention 2 (11.1) - - SSI-related mortality 0 0 - Overall, SSI affected approximately one in five surgical patients, with a higher numerical incidence among adults than children. Longer operative duration, contaminated or dirty wounds, and prolonged preoperative hospitalization were the principal factors significantly associated with SSI. Infection was also linked to longer postoperative hospitalization and increased 30-day readmission.

The present study identified an overall SSI incidence of 18.0%, with infection in 12.0% of paediatric patients and 24.0% of adults. The age-group difference was not statistically significant, although the direction of effect suggests a clinically relevant adult burden. This incidence exceeds the pooled global estimate reported by Mengistu et al. [1] and the 5% rate described in a teaching hospital in Ujjain, India [7], but remains compatible with the broad variation across surgical populations [8,10]. Inclusion of emergency procedures and contaminated or dirty wounds probably contributed to the higher rate. GlobalSurg likewise demonstrated that SSI rises with wound contamination and is disproportionately frequent in resource-constrained settings [6]. Superficial incisional SSI was the commonest pattern, representing 61.1% of infections, followed by deep incisional and organ/space infection. This distribution is clinically expected because superficial infections are more readily recognized during routine wound surveillance. The mean time to detection was 5.8 days, placing most events within the first postoperative week. Standardized surveillance extending beyond hospital discharge is important because a meaningful proportion of postoperative infections are identified after patients leave hospital [3]. The present 30-day approach therefore strengthens case ascertainment compared with inpatient surveillance alone. Operative duration ≥90 minutes, contaminated or dirty wound class, and preoperative hospitalization beyond 24 hours were significantly associated with SSI. These findings align closely with the Indian study by Pathak et al., in which wound classification and surgical duration were independent predictors [7], and with the systematic review by Korol et al. [8]. Cheng et al. demonstrated a progressive rise in SSI risk as operative time increases across surgical specialties [9]. Longer operations increase tissue exposure, environmental contamination opportunities, tissue trauma, and the possibility that prophylactic antimicrobial concentrations fall below optimal levels. Prolonged preoperative hospitalization also increases contact with the healthcare environment and potential colonization by hospital flora. Staphylococcus aureus was the leading isolate, followed by E. coli, Klebsiella species, and P. aeruginosa. This mixed Gram-positive and Gram-negative profile is consistent with the known dependence of SSI microbiology on operative site and endogenous flora [10]. The detection of MRSA among S. aureus isolates reinforces the need for culture-guided therapy and local antimicrobial stewardship. Pathak et al. also reported S. aureus, including MRSA, as an important pathogen in Indian surgical patients [7]. Paediatric literature likewise recognizes SSI as a clinically important complication requiring age-appropriate prevention strategies [11-14]. The clinical consequences were substantial. SSI doubled the mean postoperative length of stay and was associated with a markedly higher 30-day readmission rate. These findings agree with established evidence that SSI increases hospital utilization, additional treatment, and costs [12]. The results support a practical prevention strategy centered on minimizing avoidable preoperative hospitalization, optimizing modifiable comorbidities, strict wound-class-based prophylaxis, appropriate antimicrobial timing, meticulous operative technique, and efficient surgery without compromising safety. CDC and WHO guidance provides a framework for implementing such bundled perioperative measures [2,4,5]. LIMITATIONS The study was conducted at a single tertiary teaching institution with a modest sample of 100 patients, limiting precision for subgroup comparisons and multivariable modeling. Equal recruitment of paediatric and adult participants does not reflect the natural surgical case mix. Procedure-specific SSI rates and detailed antimicrobial susceptibility patterns were not analyzed. Residual confounding from nutritional status, obesity, smoking, ASA class, and prophylactic antibiotic timing was not fully captured.

Surgical site infection represented a substantial postoperative complication in this mixed general surgery cohort, affecting 18.0% of patients. Adults showed a higher numerical infection rate than paediatric patients, although the between-group difference was not statistically significant. Prolonged operative duration, contaminated or dirty wounds, and preoperative hospitalization beyond 24 hours were significantly associated with SSI. Staphylococcus aureus was the predominant isolate, with Gram-negative organisms also contributing importantly. SSI was accompanied by longer hospitalization, greater need for wound intervention, and increased readmission. Consistent surveillance, rational antimicrobial prophylaxis, meticulous operative practice, early optimization of risk factors, and strengthened infection-prevention bundles should be integrated into routine surgical care for both age groups overall.

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