Post-Discharge Methicillin-Resistant Staphylococcus aureus Infections: Epidemiology and Potential Approaches to Control

Antimicrobial Stewardship

Antimicrobial therapy, especially with fluoroquinolones and third- or fourth-generation cephalosporins, is associated with increased risk of MRSA colonization and infection [43,49,50]. Implementation of an antimicrobial stewardship program, coupled with infection control measures, in a region of Scotland resulted in decreased incidence of MRSA infections among hospital inpatients and in the surrounding community [51]. Thus a robust antimicrobial stewardship program is likely to reduce post-discharge MRSA infections.

Role of Hand Hygiene

The importance of hand hygiene in the prevention of infection has been observed for nearly 2 centuries [52]. Multiple quasi-experimental studies have demonstrated a decreased infection rate when hand hygiene practices for health care workers were introduced or strengthened. A randomized trial in a newborn nursery documented a decrease in transmission of S. aureus when nurses washed their hands after handling a colonized infant [53]. In addition to health care providers, patient hand hygiene can reduce health care–associated infections [54]. Traditional handwashing with soap and water will be familiar to most patients and families. Waterless hand hygiene, typically using alcohol-based hand rubs, is more efficacious and convenient for cleaning hands that are not visibly soiled [52]. If products containing emollients are used, it can also reduce skin drying and cracking. Patients and families should be taught to wash their hands before and after manipulating any medical devices and caring for wounds. Education of patients and family members on the techniques and importance of hand hygiene during hospitalization and at the time of discharge is a simple, low-cost strategy to reduce post-discharge MRSA infections. Teaching can be incorporated into the daily care of patients by nursing and medical staff, both verbally and by example. As a horizontal infection control measure, hand hygiene education has the additional benefit of reducing infections due to all pathogens.

Role of Environmental Cleaning in the Home Setting

Multiple studies have found that the immediate environment of patients who are colonized or infected with MRSA is contaminated with the organism, with greater organism burdens associated with infected patients compared to those who are only colonized [55–59]. Greater environmental contamination is observed when MRSA is present in the urine or wounds of patients [59]. This can lead to transmission of MRSA to family members [23,60,61]. Risk factors for transmission include participation in the care of the patient, older age, and being the partner of the case patient. For the patient, there can be transmission to uninfected body sites and a cycle of recolonization and re-infection. Successful decolonization strategies have included frequent laundering of bedclothes and towels, as well as screening and decolonization of family members. While these strategies may succeed in decolonization, there is no consensus on efficacy in preventing infection in patients or family members. More research in this area is needed, particularly for decolonization strategies, which carry risk of resistance. Attention to cleanliness in the home is a basic hygiene measure that can be recommended.

Conclusion

Post-discharge MRSA infections are an important and underestimated source of morbidity and mortality. Strategies for prevention include infection control measures to prevent incident colonization during hospitalization, removal of any nonessential invasive devices, nursing care for essential devices, wound care, avoiding nonessential antimicrobial therapy, hand hygiene for patients and caregivers, and cleaning of the home environment. Decolonization therapies currently play a limited role, particularly in outbreak situations. The future research agenda should include identification of post-discharge patients who are most likely to benefit from decolonization strategies, and testing those strategies.