MRSA Transmission in a Personal Care Home Facility: A Spatially Explicit Agent Based Modeling Approach

The purpose of this study is to estimate the effects of hand washing, cleaning, cohorting, isolation rooms and duration of cleaning on Methicillin Resistant Staphylococcus Aureus (MRSA) colonization and infections. The study uses spatially explicit agent-based modeling approach together with a Susceptible-Exposed-Infected-Recovered (SEIR) to characterize infection spread in an 8-bedroom personal care home facility. The model consists of 8 residents, 2 nurses and 1 cleaner. The model explicitly simulates the dynamics of pathogen reservoirs associated with both surfaces and people, and further counts the colonization and infection events over a 1-year period. To account for stochastics, the model is iterated 100 times for each of five different 'what if' scenarios. Model results suggest that cohorting is the most effective method to reduce the events of MRSA colonization and infections in the personal care home facility. When compared to baseline, cleaning at a higher intensity led to a 35 percent reduction (p-value is less than 0.0005) in the median counts of MRSA colonization (median 202 vs 132 colonization events) and 41 percent reduction (p-value is equal to 0.0335) in the median counts of MRSA infections (median 17 vs 10 MRSA infection events). In terms of intervention that were not effective, we found no statistically significant difference in the efficacy of having duration of cleaning more than 8 hours per day, higher intensity hand washing and use of an isolation room.