An agent-based modeling approach to estimate pathogen exposure risks from wheelchairs

Abstract

Contributions of contaminated wheelchairs to nosocomial pathogen transmission are relatively unknown. Our aim was to develop a model predicting pathogen exposures for patients utilizing wheelchairs and estimate exposure reduction potential of wheelchair disinfection between rides. An agent-based model was informed by wheelchair location data from a connected 215-bed acute care and 250-bed long-term care facility. Simulated scenarios varied in frequencies of patient wheelchair contamination and wheelchair disinfection in between trips. Clostridioides difficile and methicillin-resistant Staphylococcus aureus concentrations on patient hands at the end of wheelchair trips were estimated. Exposure reductions due to disinfection, assuming low real-world efficacies (50%, 70%, and 90%), were compared. In the simulation, when few patients introduced contamination to wheelchairs, disinfection in between patients 50% of the time decreased baseline (no disinfection) estimated exposures for the 50th wheelchair rider by >99.999%. When patients had a 50% chance of being contaminated before the wheelchair ride, disinfection did not reduce exposures consistently. The efficacy of disinfection in between patient rides as an exposure mitigation strategy likely depends on the frequency of infected patient wheelchair use. During outbreak, high contamination conditions, disinfection, alone, is not enough to protect patients from wheelchair-mediated exposures.