ATTEMPTS TO ERADICATE METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS FROM A LONG-TERM-CARE FACILITY WITH THE USE OF MUPIROCIN OINTMENT

PURPOSE: To assess the impact of the use of mupirocin ointment on colonization, transmission, and infection with methieillin-resistant Staphylococcus aureus (MRSA) in a long-term-care facility. PATIENTS AND METHoDs: All 321 residents of a Veterans Affairs long-term-care facility from June 1990 through June 1991 were studied for MRSA colonization and infection. MRSA-colonized patients received mupirocin ointment to nares in the first 7 months and to nares and wounds in the second 5 months. The effect of mupirocin use on MRSA colonization and infection was monitored. All S. aureus strains isolated were tested for the development of resistance to mupirocin. RESULTs: A total of 65 patients colonized with MRSA received mupirocin ointment. Mupirocin rapidly eliminated MRSA at the sites treated in most patients by the end of 1 week. Weekly maintenance mupirocin was not adequate to prevent recurrences-40% of patients had recurrence of MRSA. Overall, MRSA colonization in the facility, which was 22.7 % +/- 1 % prior to the use of mupirocin, did not change when mupirocin was used in nares only (22.2 % +/- 2.1 %), but did decrease to 11.5% +/- 1.8% when mupirocin was used in nares and wounds. Although colonization decreased, roommate-to-roommate transmission and MRSA infection rates, low to begin with, did not change when mupirocin was used. Mupirocin-resistant MRSA strains were isolated in 10.8% of patients. CONCLUSIONS: Mupirocin ointment is effective at decreasing colonization with MRSA. However, constant surveillance was required to identify patients colonized at admission or experiencing recurrence of MRSA during maintenance treatment. Long-term use of mupirocin selected for mupirocin-resistant MRSA strains. Mupirocin should be saved for use in outbreak situations, and not used over the long term in facilities with endemic MRSA colonization.