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

In summary, decolonization may be a useful strategy to reduce invasive MRSA infection in post-discharge patients, but more data are needed for most patient populations. The evidence for decolonization therapy is strongest for dialysis patients, in whom implementation of routine decolonization of MRSA colonized nares is a useful intervention [37]. There are not yet clinical trials of decolonization therapy in patients at time of hospital discharge showing a reduction in invasive MRSA infection. Decolonization strategies have important drawbacks, including emergence of resistance to mupirocin, chlorhexidine, and systemic agents. Furthermore, there is a risk of hypersensitivity reactions, Clostridium difficile infection, and potential for negative impacts onthe normal microbiome. The potential for lesser efficacy in a chronically ill outpatient population must also be considered in the post-discharge setting. Randomized controlled trials with invasive infection outcomes should be performed prior to implementing routine decolonization therapy of hospital discharge patients.

Care of Invasive Devices

Discharge with a central venous catheter was associated with a 2.16-fold increased risk of invasive MRSA infection; other invasive devices were associated with a 3.03-fold increased risk [25]. Clinicians must carefully assess patients nearing discharge for any opportunity to remove invasive devices. Idle devices have been reported in inpatient settings [42] and could occur in other settings. Antimicrobial therapy is a common indication for an outpatient central venous catheter and can also be associated with increased risk of invasive MRSA infection [25,43]. Duration and route of administration of antimicrobial agents should be carefully considered, with an eye to switching to oral therapy whenever possible. When a central venous catheter must be utilized, it should be maintained as carefully as in the inpatient setting. Tools for reducing risk of catheter-associated bloodstream infection include keeping the site dry, scrubbing the hub whenever accessing the catheter, aseptic techniques for dressing changes, and chlorhexidine sponges at the insertion site [44,45]. Reporting of central line–associated bloodstream infection rates by home care agencies is an important quality measure.

Wound Care

The presence of a chronic wound in the post-discharge period is associated with a 4.41-fold increased risk of invasive MRSA infection [25]. Although randomized controlled trials are lacking, it is prudent to ensure that wounds are fully debrided to remove devitalized tissue that can be fertile ground for a MRSA infection. The burden of organisms on a chronic wound is often very large, creating high risk of resistance when exposed to antimicrobial agents. Decolonization therapy is not likely to meet with durable success in such cases and should probably be avoided, except in special circumstances, eg, in preparation for cardiothoracic surgery.

Infection Control in Nursing Home Settings

In the Active Bacterial Core cohort, discharge to a nursing home was associated with a 2.1- to 2.65-fold increased risk of invasive MRSA infection [24,25]. It is notable that the authors controlled for the Charlson comorbidity index, suggesting that nursing home care is more than a marker for comorbidity [25]. The tension between the demands of careful infection control and the home-like setting that is desirable for long-term care creates challenges in the prevention of invasive MRSA infection. Nevertheless, careful management of invasive devices and wounds and antimicrobial stewardship are strategies that may reduce the risk of invasive MRSA infection in long-term care settings. Contact precautions for colonized nursing home residents are recommended only during an outbreak [46]. Staff should be trained in proper application of standard precautions, including use of gowns and gloves when handling body fluids. A study of an aggressive program of screening, decolonization with nasal mupirocin and chlorhexidine bathing, enhanced hand hygiene and environmental cleaning demonstrated a significant reduction in MRSA colonization [47]. An increase in mupirocin resistance during the study led to a switch to retapamulin for nasal application. The Association of Practitioners of Infection Control has issued guidance for MRSA prevention in long-term care facilities [48]. The guidance focuses on surveillance for MRSA infection, performing a MRSA risk assessment, hand hygiene, and environmental cleaning.