Prevalence and factors associated with residual bacteria on diathermy pencils after high-level disinfection at Mulago National Referral Hospital

Abstract

Introduction: Globally, hundreds of millions of patients get infected annually by hospital care associated infections (HCAIs). Sterilization and high-level disinfection of surgical instruments are recommended preventive measures for HCAIs. However, sterilization or high-level disinfection (HLD) processes are often inadequate. General objective: To determine prevalence and factors associated with residual bacteria on high-level disinfected diathermy pencils at Mulago National Referral Hospital (MNRH). Methods: An analytical cross-sectional study from August 2022 through September 2022 in MNRH theatres. We purposively sampled 93 pre-use HLD diathermy pencils and each aseptically submerged in tryptic soy broth, agitated for two minutes, removed, the broth was transported to the laboratory. Independent variables were assessed and recorded on a questionnaire. Prevalence was determined as the proportion of diathermy pencils which contained bacteria. Factors associated with pathogenic bacteria were assessed using Poisson regression. The factors included theatre, expiry date, time since constitution, storage infrastructure, test kits, immersion(partial/complete), appearance on inspection, disinfection time, cadre, and quality control audits. Results: Among 93 HLD pencils sampled, bacterial growth was 82 (88.2%); 56 (60.2%) environmental and skin flora, and 26 (28%) pathogenic bacteria. Pathogenic bacteria were predominantly Pseudomonas species 10 (34%) and Acinetobacter species 6 (20%). Enterobacteriaceae were 66.7% multidrug resistant (MDR), Klebsiella pneumoniae and Escherichia coli were MDR, and Staphylococcus aureus was MRSA. A disinfectant that had particles was associated with pathogenic bacteria. Other factors did not show statistically significant association with pathogenic bacteria. The factors included test kits that were not present in the MNRH theatres. Conclusion: Pathogenic bacteria grew on 28% of HLD diathermy pencils, and a disinfectant that had particles was associated with pathogenic bacteria. This should prompt Mulago theatres HLD practice improvement. Policy makers should introduce test kits, for testing constituted disinfectants as per instruction for use. Further research can be carried on a smaller set of variables to streamline contributing factors.