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 colo nization, transmission, and infection with methieillin-resistant Staph ylococcus aureus (MRSA) in a long-term-care facility. PATIENTS AND MET HoDs: All 321 residents of a Veterans Affairs long-term-care facility from June 1990 through June 1991 were studied for MRSA colonization an d infection. MRSA-colonized patients received mupirocin ointment to na res in the first 7 months and to nares and wounds in the second 5 mont hs. The effect of mupirocin use on MRSA colonization and infection was monitored. All S. aureus strains isolated were tested for the develop ment of resistance to mupirocin.RESULTs: A total of 65 patients coloni zed with MRSA received mupirocin ointment. Mupirocin rapidly eliminate d MRSA at the sites treated in most patients by the end of 1 week. Wee kly 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 %), b ut did decrease to 11.5% +/- 1.8% when mupirocin was used in nares and wounds. Although colonization decreased, roommate-to-roommate transmi ssion 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 de creasing colonization with MRSA. However, constant surveillance was re quired to identify patients colonized at admission or experiencing rec urrence of MRSA during maintenance treatment. Long-term use of mupiroc in 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.