A Compartmental Model for the Assessment of Exposure to Methicillin-Resistant Staphylococcus Aureus

A compartmental model was developed to estimate the exposure of methicillin-resistant Staphylococcus aureus (MRSA) in health care settings. For the model, five compartments were selected. The first compartment is the source. The source is defined as a MRSA-colonized or infected individual, where colonized means that the individual’s body has MRSA on it but does not show signs of adverse health effects. An infected individual both has MRSA bacteria present and shows signs of adverse health effects. The second compartment is a susceptible site. A susceptible site is any location on an individual that may become colonized or infected with MRSA bacteria. The third and fourth compartments are the air and surfaces, respectively. The fifth compartment is loss of viability. The loss of viability compartment represents the dynamic survival of MRSA bacteria. The transmission dynamics between compartments were described to represent the movement of pathogens in the model. The model utilized a mass-balance approach, such that all pathogens that entered and exited the model were accounted for. Pathogens were able to transfer from the source to susceptible sites, air, surfaces, or loss of viability. The model can be used to make MRSA exposure estimates or to test the effectiveness of interventions. To estimate MRSA exposure with the proposed compartmental model, parameters must be developed in future research that describe transmission dynamics of MRSA bacteria. These parameters must also be developed and used to test the effectiveness of interventions. The compartmental MRSA exposure model provides the initial building blocks to carry out proposed future research regarding MRSA exposure and effectiveness of interventions to be used in health care settings to reduce MRSA exposure.