The efficacy of calcium mupirocin in the eradication of nasal Staphylococcus aureus carriage.

In an open, non-comparative clinical study conducted at 102 hospitals in the UK and Ireland, 1,510 subjects were treated with 2% calcium mupirocin in a white soft paraffin/Softisan 649 base (Bactroban 'Nasal') during hospital outbreaks of methicillin-resistant Staphylococcus aureus (MRSA). In most subjects treatment was applied two or three times daily to both anterior nares for three to eight days. Of the 766 assessable subjects, nasal carriage of S aureus was cleared in 744 (97.1%). Initially, MRSA was present in 628 cases (79.4%), and the organism was eliminated in 609 of these (97.0%). Isolates of S aureus were tested for susceptibility to a variety of antibiotics by disc test: of 523 nasal isolates tested against mupirocin, 516 (98.7%) were sensitive. Treatment was very well tolerated. Adverse events were reported by 22 subjects (1.5%); these were mostly mild local effects and necessitated withdrawal of treatment only in three subjects. The results indicate that topical calcium mupirocin is a highly effective and well tolerated treatment for the eradications of nasal carriage of S aureus, including MRSA.