Rate, predictors and bacterial etiology of surgical site infection among patients undergoing open urological surgery at MNH, Dar es Salaam, Tanzania

Abstract

INTRODUCTION Surgical site infection (SSI) is among the common hospital associated infections in patients undergoing surgery. It is associated with increased length of hospitalization, morbidity as well as increased health care costs. At Muhimbili National Hospital (MNH) little is known on factors predicting the occurrence of SSI. OBJECTIVES To determine rate, predictors and bacteria etiology of SSI among patients undergoing open urological surgery at MNH. MATERIALS AND METHODS This was a prospective observational study conducted between August 2015 and March 2016, 8 months, at urological surgical ward, MNH. All patients who underwent open urological surgery were consecutively enrolled and followed for a period of 30 days. Prior to surgery, urine sample for culture were collected. On each follow up surgical site was inspected for signs of SSI. Wound swabs were then collected in case of discharge and sent to Central Pathology Laboratory (CPL) microbiology section for culture and sensitivity. Structured questionnaires were used to record socio-demographic and clinical information from patients and clinical case files. Data were entered and analyzed using Statistical Package for the Social Sciences (SPSS). Bivariate and multivariate analyses were used to find association between dependent and independent variables. FINDINGS Out of 182, 40 patients (22%) had surgical site infection. Of 152 patients of whose urine sample for culture were performed 43 (28.3%) had urinary tract infection. On univariate and multivariate analysis, urinary tract infection predicted the occurrence of SSI. Contaminated wound was also a predictor of SSI in both univariate and multivariate analysis. Other factors, shaving more than 30 minutes prior to incision, presence of urinary catheter and clean contaminated surgery were predictors of SSI in univariate analysis but were not independently associated with SSI on multivariate analysis. Shaving within 30 minutes was an independently protective predictor of occurrence of SSI (OR 0.26; 95%CI 0.088-0.79; p-value<0.05) E. coli was the commonest bacteria isolated in both UTI and SSI and the most resistant to antibiotics. Other Gram negative bacteria were also involved while Staph. aureus dominated the Gram positive isolates. Some isolates occur in both UTI the same patients. Ciprofloxacin was more sensitive to most of the pathogens. CONCLUSION Pre-operative UTI and contaminated wound are the two most important predictors of SSI. E. coli being commonest pathogens isolated in both UTI and SSI. Most of the involved pathogens were resistant to most of the routine antibiotics. RECOMMENDATIONS Education to health professionals on how to care surgical patients is important. Patients should be screened for UTI before any surgical procedure and any SSI should be treated with appropriate antibiotics after culture and sensitivity is done