Surgical site Infections and antimicrobial susceptibility patterns among patients undergoing abdominal surgery at Mulago National Referral Hospital: A prospective cohort study

Abstract

Background: Surgical site infections (SSIs) remain a major cause of morbidity and mortality among post-operative patients. The care for these patients is further compromised by the ever-increasing antimicrobial resistance. This calls for periodic assessment of antimicrobial susceptibility patterns tailored to individual hospitals. Objective: To determine the incidence of surgical site infections, associated factors, causative microorganisms and susceptibility patterns to antimicrobial agents, among patients undergoing abdominal surgery in Mulago National Referral Hospital (MNRH). Method This was a prospective study of consecutively sampled patients aged 13 years and older, who had abdominal surgery done at MNRH between May 2023 and November 2023. Sociodemographic data, clinical characteristics and management parameters were assessed for each participant. The participants were then followed up until development of features of SSI and up to a maximum of 30 days postoperatively to assess for presence of surgical site infection. Those with features of surgical site infection had wound swabs collected for microbial culture and sensitivity testing. Incidence of SSI, etiology and antimicrobial sensitivity patterns were measured as percentage proportions. Logistic regression model was used to assess associated factors for development of SSI.Results: 276 participants who underwent abdominal surgery were evaluated. The median age was 38 years (IQR: 27-52 years); male participants were 160 (58%) and females, 116 (42%). Cumulative incidence of SSI was 12% (33 cases). Escherichia coli, 16 (48.5%) and Klebsiella pneumoniae, 8 (24.2%) were the commonest isolated organisms from SSI wound swabs. Approximately 91% of the bacteria isolated were multi drug resistant (MDR), with 78% of the enterobactericeae isolated being extended spectrum beta-lactamase (ESBL) producers and 14.8% of them had resistance to Carbapenem antibiotics (CRE). Multivariate logistic regression model revealed contaminated (adjusted RR= 4.1; 95% CI: 1.1 – 15.3, p=0.035) and dirty wound (adjusted RR=16.9, 95% CI: 2.7 – 104.6, p=0.002) classifications to be significantly associated with development of SSI. Conclusion Surgical site infection rate following abdominal surgery at MNRH is lower than rates reported within the region. Contaminated and dirty surgical wounds are major risk factors for abdominal SSI. Enterobacteriaceae are the commonest causative organisms, with high proportion of multi-drug resistant strains.