Contribution of Interfacility Patient Movement to Overall Methicillin-Resistant Staphylococcus aureus Prevalence Levels

Abstract

Objectives The effect of patient movement between hospitals and long-term care facilities (LTCFs) on methicillin-resistant Staphylococcus aureus (MRSA) prevalence levels is unknown. We investigated these effects to identify scenarios that may lead to increased prevalence in either facility type. Methods We used a hybrid simulation model to simulate MRSA transmission among hospitals and LTCFs. Transmission within each facility was determined by mathematical model equations. The model predicted the long-term prevalence of each facility and was used to assess the effects of facility size, patient turnover, and decolonization. Results Analyses of various healthcare networks suggest that the effect of patients moving from a LTCF to a hospital is negligible unless the patients are consistently admitted to the same unit. In such cases, MRSA prevalence can increase significantly regardless of the endemic level. Hospitals can cause sustained increases in prevalence when transferring patients to LTCFs, where the population size is smaller and patient turnover is less frequent. For 1 particular scenario, the steady-state prevalence of a LTCF increased from 6.9% to 9.4% to 13.8% when the transmission rate of the hospital increased from a low to a high transmission rate. Conclusions These results suggest that the relative facility size and the patient discharge rate are 2 key factors that can lead to sustained increases in MRSA prevalence. Consequently, small facilities or those with low turnover rates are especially susceptible to sustaining increased prevalence levels, and they become more so when receiving patients from larger, high-prevalence facilities. Decolonization is an infection-control strategy that can mitigate these effects.

Molecular tracing of the emergence, adaptation, and transmission of hospital-associated methicillin-resistant Staphylococcus aureus

“…Nonetheless, these data provide evidence for transmission routes from hospitals in major cities to UK regions, leading to endemic strains circulating in local hospitals. These findings are consistent with a recent US study that estimated high transmission rates between large hospitals and long-term care facilities using a simulation model (46). It has previously been postulated that an increase in the willingness of patients to travel further for treatment, coupled with the centralization of specialist treatment centers have been contributing factors to the spread of MRSA throughout the United Kingdom (47).…”

Models to predict prevalence and transition dynamics of methicillin-resistant Staphylococcus aureus in community nursing homes

“…12–16 Residents in these facilities transition frequently between community and other healthcare settings, and nursing homes likely play a critical role in the regional spread of multidrug-resistant organisms, including MRSA. 17–19 While a number of mathematical models have been used to describe the dynamics of MRSA in acute-care settings 7,10,11,20 and to predict the role of nursing homes in the regional spread of MRSA, 17,20–22 their use in describing the dynamics of MRSA within the nursing home remains limited.…”

The Importance of Nursing Homes in the Spread of Methicillin-resistant Staphylococcus aureus (MRSA) Among Hospitals

“…Should hospitals and nursing homes work together to reduce MDROs? While previous mathematical and computational models have explored MRSA spread among just hospitals(17–20), a single nursing home(21), or a small group of closely associated nursing homes and hospitals that directly transfer patients to one another(22), these studies did not examine all of the inpatient facilities in a large real-life region. One study modeled hospitals and nursing homes in a region of Canada (which has a different healthcare system)(23).…”