Antibiotic use, incidence and risk factors for surgical site infections among orthopaedic patients in a rural, private teaching hospital in India

Background: Orthopaedic surgeries are one of the major contributors to the overall surgical site infection (SSI) events worldwide. In India, SSI rates vary considerably depending on geographical location (1.6%- 38%); however, there is a lack of a national SSI surveillance system to identify risk factors for SSIs.
Aim: To identify the incidence and risk factors for SSIs, and antibiotic prescription and susceptibility patterns of infecting bacteria among the operated orthopaedic patients in a tertiary-care, teaching hospital (TH) in Central India.
Methods: Data for 1205 operated orthopaedic patients were collected prospectively from 2013 to 2016 in the TH. SSIs were identified and categorized based on the Centre for Disease Control and Prevention guidelines. The American Society for Anesthesiologists classification system was used to predict patients’ physiological status and operative risk. Patients were grouped and analysed based on the occurrence of SSIs. The Clinical and Laboratory Standard Institute guidelines were followed to process the samples, and antibiotic susceptibility tests were performed using Kirby Bauer’s disc diffusion method according to performance CLSI guidelines. Univariate and multivariable backward stepwise logistic regression was performed to identify risk factors for SSIs.
Results: Overall, 7.6% (91/1205) operated patients developed SSIs over three years. Out of 68 samples sent for culture and sensitivity testing, 22% were culture positive. The most common SSIs causing microorganism was Staphylococcus aureus (7%). Strains of S. aureus were resistant to penicillin (100%), erythromycin (80%), cotrimoxazole (80%), amikacin (60%) and cefoxitin (60%). The most commonly prescribed antibiotic was amikacin (36%). Male sex (OR 2.64; 95%CI 1.32-5.30), previous hospitalisation (OR 2.15; 95%CI 1.25-3.69), prescription of antibiotics during hospital stay before perioperative antibiotic prophylaxis (OR 4.19; 95%CI 2.51-7.00), postoperative length of hospital stay longer than 15 days (OR 3.30; 95%CI 1.83-5.95) and preoperative shower (OR 4.73; 95%CI 2.72-8.22) were identified as significant risk factors for orthopaedic SSIs.
Conclusion: Incidence rate of SSIs was relatively low compared to reported incidence range for India, yet higher than reported SSI incidences for orthopaedic procedures in high- and middle-income countries. Majority of the SSIs were caused by S. aureus. Preoperative shower was found to be a significant risk factor for developing SSIs, which is unforeseen so far. Identification of the incidences and risk factors for SSIs supports the measures to prevent and mitigate SSI events in hospitals.