SENSITIVITY OF SURVEILLANCE CULTURES FOR THE DETECTION OF METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS IN A NURSING-HOME-CARE UNIT

This study compared the sensitivity of nasal culture alone versus mult iple-site cultures and single versus duplicate sampling for the detect ion of methicillin-resistant Staphylococcus aureus (MRSA)-colonized in dividuals in a nursing-home population. Repeat culture of 68 specimens collected from 35 colonized subjects yielded identical results for 57 specimens, (84%), and 89% of the colonized residents (31 of 35) were identified by the first culture of multiple sites. A single nares cult ure detected 27 (77%) of 35 (first screen) and 29 (83%) of 35 (second screen) residents colonized with MRSA at any site. The most cost-effec tive screening would consist of a nasal culture only or combined with a gastrostomy tube site, if applicable. To identify all colonized indi viduals, however, it would be necessary to culture more than one speci men from multiple sites on each resident.