Surgical site infections remain a major challenge in modern surgical practice despite advances in aseptic techniques, antimicrobial therapy, and perioperative care. According to the Centers for Disease Control and Prevention (CDC), SSI is defined as an infection occurring within 30 days after surgery or within one year in patients with implants, involving the incision or deeper tissues manipulated during the operative procedure.⁴ SSIs constitute one of the most common healthcare-associated infections worldwide and account for a substantial proportion of preventable postoperative complications.

The burden of SSI is particularly significant in low- and middle-income countries, where limitations in healthcare infrastructure, overcrowding, delayed diagnosis, and inconsistent adherence to infection prevention protocols contribute to higher infection rates. The World Health Organization (WHO) has emphasized that SSI not only increases morbidity and mortality but also prolongs hospitalization, increases antimicrobial consumption, and imposes a considerable financial burden on healthcare systems and patients.³^,⁸⁻¹⁰

The development of SSI is influenced by multiple factors including patient characteristics, type and duration of surgery, wound classification, perioperative antimicrobial prophylaxis, and postoperative care. Surgical wounds are traditionally categorized as clean, clean-contaminated, contaminated, and dirty. This classification remains a valuable predictor of postoperative infection risk and guides preventive strategies.⁵

While several surveillance studies have documented SSI incidence among postoperative survivors, relatively few investigations have focused on fatal postoperative cases. Autopsy-based studies offer a unique opportunity to objectively identify infectious complications that may remain clinically unrecognized during life. Such studies provide valuable insights into the actual contribution of SSI to postoperative mortality and facilitate the development of strategies aimed at reducing preventable deaths.¹¹^,¹²

The present study was therefore undertaken to evaluate the occurrence and extent of SSI among fatal postoperative cases subjected to medicolegal autopsy and to determine the relationship between wound classification and surgical site infection in an Eastern Indian setting.

MATERIALS AND METHODS

This retrospective observational study was conducted in the Department of Forensic Medicine of an anonymized tertiary care teaching institution in Eastern India. The study included all postoperative deaths subjected to medicolegal autopsy between January 2025 and December 2025.

A total of 75 postoperative deaths fulfilling the inclusion criteria were analyzed. Cases with a history of surgical intervention prior to death and adequate clinical documentation were included. Cases with incomplete records preventing wound classification were excluded.

Data were obtained from hospital records, operative notes, laboratory investigations, and autopsy findings. Detailed autopsy examination was performed in each case to identify evidence of infection and establish the cause of death.

SSI was classified according to CDC criteria into superficial incisional SSI, deep incisional SSI, and organ/space SSI.⁴ Surgical wounds were categorized into clean, clean-contaminated, contaminated, and dirty wounds.⁵ based on standard definitions.

Statistical analysis was performed using the Chi-square test to evaluate the association between wound classification and SSI occurrence. A p-value less than 0.05 was considered statistically significant.

Inclusion criteria

• All postoperative deaths subjected to medicolegal autopsy during the study period.
• Availability of operative and clinical records.

Exclusion criteria

• Incomplete documentation.
• Advanced decomposition preventing assessment.

RESULTS

Among the 75 postoperative deaths, SSI was identified in 29 cases, yielding an overall prevalence of 38.7%.

Contaminated wounds constituted the largest category (37 cases; 49.3%), followed by clean wounds (25 cases; 33.3%), clean-contaminated wounds (9 cases; 12.0%), and dirty wounds (4 cases; 5.4%).

SSI was observed in six clean wounds (24%), none of the clean-contaminated wounds, 20 contaminated wounds (54%), and three dirty wounds (75%).

Organ/space SSI represented the predominant infection pattern, accounting for 21 of the 29 infected cases (72.4%). Deep incisional SSI occurred in seven cases (24.1%), while superficial SSI was observed in only one case (3.5%).

Chi-square analysis demonstrated a statistically significant association between wound classification and SSI occurrence (χ²=13.862; df=3; p=0.0031), indicating an increasing probability of infection with increasing wound contamination.

Of the 29 infected cases, organ/space SSI accounted for the majority (72.4%), followed by deep incisional SSI (24.1%) and superficial SSI (3.5%). This distribution indicates that fatal postoperative outcomes were more frequently associated with deeper infections rather than superficial wound involvement.

Table 1. Distribution of Fatal Postoperative Cases According to Surgical Wound Classification

Table 2. Relationship Between Surgical Wound Classification and Occurrence of SSI

Chi-square=13.862; df=3; p=0.0031.

Table 3. Distribution of Types of Surgical Site Infection Among Fatal Postoperative Cases

Figure Legends

Figure 1:

Bar chart showing SSI rates according to wound classification. Infection rates increased progressively from clean wounds (24%) to contaminated wounds (54%) and dirty wounds (75%).

Figure 2:

Pie chart demonstrating the distribution of SSI types among infected cases. Organ/space SSI constituted 72.4% of all infections, followed by deep incisional SSI (24.1%) and superficial SSI (3.5%).

DISCUSSION

The present study demonstrated that more than one-third of fatal postoperative cases exhibited evidence of SSI. The prevalence observed was considerably higher than that reported in routine surgical surveillance studies.⁶^,⁹ However, this finding reflects the unique study population comprising exclusively fatal postoperative cases and underscores the potential contribution of SSI to adverse outcomes. The study population represented fatal cases only, which explains the markedly higher prevalence compared with routine surveillance studies.

A progressive increase in SSI rates was observed with increasing wound contamination. This finding is consistent with the classical observations of Cruse and Foord, who reported increasing infection rates with higher wound contamination categories. Although absolute rates differed, the overall trend supports the continuing relevance of wound classification as a predictor of postoperative infection risk.⁵

A noteworthy finding was the predominance of organ/space SSI. These infections are frequently associated with delayed diagnosis, progression to systemic sepsis, and increased mortality. The higher frequency of organ/space infections in this study likely contributed substantially to fatal outcomes.⁶^,¹⁰

Autopsy remains the gold standard for establishing pathological causes of death and provides objective evidence regarding infectious complications that may be clinically underestimated. This represents an important strength of the present study and distinguishes it from conventional clinical surveillance investigations.¹¹^,¹²

The findings emphasize the importance of strict adherence to infection prevention protocols, appropriate timing and selection of antimicrobial prophylaxis, early postoperative surveillance, and prompt intervention when deep-seated infections are suspected.²^,⁷^,¹⁴

Clinical and Pharmaceutical Implications

The study findings highlight the need for effective antimicrobial stewardship programs involving surgeons, microbiologists, pharmacists, and infection control teams. Rational antimicrobial prophylaxis, appropriate antibiotic selection, optimization of dosing schedules, and regular audit of prescribing practices may reduce SSI-related morbidity and mortality while limiting the emergence of antimicrobial resistance. Pharmacists can play a critical role in monitoring antimicrobial utilization, promoting guideline adherence, and facilitating multidisciplinary infection prevention initiatives.²^,⁷^,¹^4,16

Limitations

The present study has certain limitations. It was a single-centre retrospective study involving only fatal postoperative cases subjected to medicolegal autopsy, thereby limiting generalizability to the broader surgical population. The absence of a control group comprising postoperative survivors prevented the assessment of independent predictors of mortality. Certain perioperative variables, including detailed antimicrobial prophylaxis practices and postoperative management protocols, were not uniformly available. In addition, referral bias cannot be excluded, as medicolegal autopsies often represent more complex or unexpected clinical scenarios. Nevertheless, the study provides valuable autopsy-based evidence regarding the burden and pattern of SSI in fatal postoperative cases.

The autopsy-based design represents a major strength of the present study by enabling objective identification and characterization of SSI in fatal postoperative cases. The integration of clinical, laboratory, operative, and autopsy findings enhanced diagnostic accuracy and provided valuable insight into the contribution of SSI to postoperative mortality.

CONCLUSION

Surgical site infection was present in more than one-third of fatal postoperative cases and was significantly associated with increasing wound contamination. Organ/space SSI emerged as the predominant infection pattern. These findings emphasize the importance of strengthening infection prevention practices, optimizing antimicrobial stewardship, and promoting early recognition of deep infections to reduce preventable postoperative mortality. Integration of robust infection prevention strategies, timely antimicrobial stewardship interventions, and multidisciplinary postoperative surveillance may substantially reduce SSI-related mortality.¹¹

Conflict of Interest

The authors declare that they have no conflict of interest.

Funding

No funding was received for this study

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