Preventing Staphylococcal (Staph) Infection

The purpose of this study is to determine if mupirocin 2% in polyethylene glycol (PEG) ointment [Treatment Arm] is effective in preventing moderate to severe re-infection with Staphylococcus aureus compared with treatment with polyethylene glycol (PEG) ointment [Placebo Arm].

Treatment of staphylococcal carriage with the topical antibiotic, mupirocin, has led to decreased infections in some hemodialysis patients and intensive care unit (ICU) patients. However, most of these studies were not placebo controlled and only certain subsets of patients benefited. Relapse of colonization, generally within 90 days after treatment is stopped, presumably with increased risk of infection, approaches 50%. Continuous use of mupirocin on daily, three times weekly, or weekly basis has resulted in increased resistance to the drug. Despite this lack of evidence, the use of mupirocin has become commonplace because it is perceived as an effective and simple means to prevent infection. In a National Institutes on Aging/Claude D. Pepper Older Americans Independence Center (NIA/OAIC)-sponsored proposal, we found that a 2 week treatment regimen with mupirocin ointment was effective in decolonizing older chronically ill nursing home residents of S. aureus when compared with placebo ointment. Decolonization began to decline by 3 months post-treatment, and resistance occurred only once in 52 treated patients. That study was not powered to detect differences in infection between the 2 study groups; the end point was eradication of colonization. However, a trend towards reduction in staphylococcal infection with mupirocin was seen. In addition, there were more therapeutic failures in residents who were colonized with methicillin-resistant S. aureus (MRSA) than methicillin-sensitive S. aureus (MSSA). We hypothesize that intermittent treatment with mupirocin ointment every 3 months may be an effective means of preventing recolonization and infection with S. aureus. We propose to study a patient population that has already had treatment for severe S. aureus infection and is at significant risk for a subsequent infection. Patients will receive mupirocin 2% polyethylene glycol (PEG) ointment [Treatment Arm] or polyethylene glycol (PEG) ointment [Placebo Arm] for 14 days every 3 months. The effect of these two regimens on S. aureus re-infection, re-colonization, and development of mupirocin resistance will be assessed.

Treatment arm or active comparator [mupirocin 2% polyethylene glycol (PEG) ointment] will be compared with its placebo comparator [polyethylene glycol (PEF) in patients with a prior history of S. aureus infection. Drug or placebo will be applied topically to nares and/or wounds twice daily for 14 days at 3 month intervals for up to 18 months

Treatment arm or active comparator [mupirocin 2% polyethylene glycol (PEG) ointment] will be compared with its placebo comparator [polyethylene glycol (PEF) in patients with a prior history of S. aureus infection. Drug or placebo will be applied topically to nares and/or wounds twice daily for 14 days at 3 month intervals for up to 18 months

The impact of the treatment arm versus placebo arm on development of new (recurrent) S. aureus infection will be assessed as the primary end point. Change in S. aureus strains (MSSA versus MRSA) will be assessed as the secondary end point.

The impact of the treatment arm versus placebo arm on development of S. aureus re-infections will be assessed as the primary end point. Change in S. aureus strains (MSSA versus MRSA) will be assessed as the secondary end point.

During the study, patients with prior well-documented infections with Staphylococcus aureus who developed new signs and symptoms of infection, met standardized clinical criteria for infection, and had S. aureus isolated on culture were considered to have re-infection with S. aureus. The number of S. aureus re-infections were compared in the mupirocin ointment (Treatment Arm) versus polyethylene glycol ointment (Placebo Arm) for all participants enrolled in the study and in participants who completed each study time point (visit)

In the Mupirocin Ointment (Treatment) and Polyethylene Glycol (Placebo) Arms, S. aureus isolates (MSSA or MRSA) that caused infection prior to enrollment in the study were compared with S. aureus infecting isolates (MSSA or MRSA) that occurred during the study (re-infections). Infecting isolates that were found to be MRSA at enrollment and MRSA during the study were considered to be the same strain; this same strain definition was also applied to MSSA isolates. Infecting isolates that changed from MRSA at enrollment to MSSA during the study (or vice versa) were considered to be different strains.

The anatomic site of each S. infection at enrollment and S. aureus re-infection that occurred during the study was compared. S. aureus isolated from a different site of infection than at baseline was considered to represent a new infection. Isolation of S. aureus from the same site as the baseline infection was considered to represent a recurrent infection.

Inclusion Criteria: All patients who receive care at Ann Arbor VA Medical Center, University of Michigan Medical Center, or St. Joseph Mercy Hospital, Ypsilanti who have been hospitalized for documented S. aureus infection will be eligible for enrollment. Staphylococcal infections may be community or hospital-acquired. Patients with S. aureus infection will be identified on a daily basis with the assistance of the Infection Control Practitioner, the Clinical Microbiology Laboratory, the Infectious Diseases Consultation Services, and Infectious Diseases physicians caring for patients in their offices. Patients will provide written informed consent. The patient's guardian or next of kin will be contacted for informed consent in the event that the patient is incapable of doing so. Exclusion Criteria: Patients who are unable to cooperate with treatment or follow-up. Patients who are not likely to survive beyond one month or those who are transferred back to another acute care hospital. Patients who require treatment with rifampin will be excluded since this drug is effective in decolonization of some staphylococcal carriers. Patients with known hypersensitivity to mupirocin ointment or polyethylene glycol base. Patients with ulcers obviously related to pressure will be excluded because they are frequently large, difficult to keep clean, and infections are difficult to diagnose. Patients with small vascular or neuropathic ulcers < 3 cm in circumference and < 2 cm in depth may be enrolled. Pregnant women.