Comparison of screening for methicillin-resistant Staphylococcus aureus (MRSA) at hospital admission and discharge

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant contributor to the growing concern of antibiotic resistant bacteria, especially given its stubborn persistence in hospitals and other health care facility settings. In combination with this characteristic of S. aureus (colloquially referred to as staph), MRSA presents an additional barrier to treatment and is now believed to have colonized two of every 100 people worldwide. According to the CDC, MRSA prevalence sits as high as 25-50% in countries such as the United Kingdom and the United States. Given the resistant nature of staph as well as its capability of evolving to compensate antibiotic treatment, controlling MRSA levels is more a matter of precautionary and defensive measures. This study examines the method of "search and isolation," which seeks to isolate MRSA positive patients in a hospital so as to decrease infection potential. Although this strategy is straightforward, the question of just whom to screen is of practical importance. We compare screening at admission to screening at discharge. To do this, we develop a mathematical model and use simulations to determine MRSA endemic levels in a hospital with either control measure implemented. We found that screening at discharge was the more effective method in controlling MRSA endemicity, but at the cost of a greater number of isolated patients.