Bacteriological Profile of Post-Operative Wound Infections in Women: Insights from DMCH Study

Introduction

Post-operative wound infections (POWIs) remain a significant challenge in surgical recovery, especially in obstetrics and gynecology. These infections contribute to prolonged hospital stays, increased healthcare costs, and heightened morbidity. Understanding the bacteriological landscape and associated risk factors is crucial for timely diagnosis, targeted treatment, and improved clinical outcomes. 

A recent cross-sectional study conducted at Dhaka Medical College Hospital (DMCH) sheds light on the bacterial pathogens commonly implicated in post-operative infections among women, along with contributing comorbid conditions such as anemia and diabetes mellitus.

Study Period: October 2019 – September 2021

• Location: Department of Gynecology and Obstetrics, DMCH, Dhaka, Bangladesh

• Sample Size: 200 women diagnosed with post-operative wound infections

• Sampling Technique: Purposive sampling

• Data Tools: Clinical evaluation, wound swab culture and sensitivity testing, SPSS version 24 for statistical analysis

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Key Objectives

1. Identify the bacterial pathogens involved in post-operative wound infections.

2. Analyze the antibiotic sensitivity patterns of the isolated organisms.

3. Examine associated risk factors, anemia, diabetes, surgical variables, and obstetric conditions.

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Bacteriological Findings

Out of the 200 patients studied, 67% had culture-positive wound infections. The bacterial isolates were divided into:

1. Gram-Positive Bacteria

• Staphylococcus aureus: Most prevalent, found in 33.6% of cases.

• Strongly associated with anemia, present in 91.1% of these infections.

2. Gram-Negative Bacteria

• Escherichia coli: 20.9%

• Pseudomonas spp.: 20.9%

• Acetobacter spp.: 14.2%

• Klebsiella spp.: 10.4%

• Significantly associated with diabetes mellitus (23.6%).

🔍 Note: The presence of multiple pathogens in a single wound sample was not specified, but mixed infections are often seen in similar clinical contexts.

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Risk Factors and Associations

Comorbid Conditions

• Anemia: Predominant among patients with gram-positive infections.

• Diabetes Mellitus: Commonly associated with gram-negative infections.

Surgical & Obstetric Variables

• No statistically significant relationship was found between:

  • Type of surgery

  • Duration of hospital stay

  • Prolonged rupture of membranes

  • Preeclampsia

This suggests that host factors and immune status may be more crucial than surgical or obstetric variables in determining infection risk.

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Discussion

The dominance of Staphylococcus aureus mirrors global trends in post-operative infections, particularly in gynecological settings. Gram-negative organisms like E. coli and Pseudomonas also pose significant treatment challenges due to emerging antibiotic resistance.

This study’s findings emphasize the role of underlying conditions like anemia and diabetes, which may impair wound healing and host immunity, thus predisposing patients to infections.

Comparison with Global Literature

• Similar bacteriological patterns have been observed in studies from India, Nepal, and Nigeria.

• The antibiotic resistance trends in these pathogens underscore the need for updated local antibiograms and targeted antibiotic policies.

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Preventive and Management Strategies

1. Pre-Operative Optimization

• Screen and treat anemia and diabetes before elective surgeries.

• Nutritional counseling and iron supplementation for women at risk.

2. Surgical Asepsis

• Adherence to the CDC’s surgical site infection (SSI) prevention guidelines, including hand hygiene, sterile technique, and pre-operative skin preparation.

3. Post-Operative Care

• Early detection of wound abnormalities.

• Use of culture-guided antibiotics to prevent resistance and improve outcomes.

4. Institutional Measures

• Regular surveillance of hospital-acquired infections (HAIs).

• Antimicrobial stewardship programs to regulate antibiotic use.

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Conclusions

This study highlights that both gram-positive and gram-negative bacteria are responsible for post-operative wound infections among women at DMCH. The strong associations with anemia and diabetes mellitus call for proactive management of these conditions as part of the surgical care protocol.

✅ Recommendation: Broader multicenter research is warranted to validate these findings and guide evidence-based clinical practice across diverse surgical departments in Bangladesh.

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Key Takeaways

• Staphylococcus aureus remains the most common isolate in post-operative wound infections.

• E. coli and Pseudomonas are dominant gram-negative pathogens.

• Anemia and diabetes mellitus significantly influence risk.

• Surgical and obstetric factors were not strongly linked to bacterial type.

• Infection control must focus on the host's health, sterile technique, and antibiotics.

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