It's expensive to test every patient, and even those facilities that do only take nasal swabs. Gupta's team wrote that "it is increasingly recognized that a significant number of people may be colonized only extranasally."
For nine of 20 patients found with MRSA, the bacteria were found on the patients in sites other than the nose. Gupta's team recommends that hospitals with large numbers of patients at high risk for MRSA consider testing other body sites in addition to taking nasal swabs.
The study sample was small, only 400 patients, because many of the 2,197 approached to be tested were ineligible or refused, because they were too tired, too ill, had too much pain or lacked interest.
The survey did discover a three-fold higher risk for MRSA infection for patients with a history of diabetes, HIV infection, those who were brought from a nursing home or long-term care facility, had been hospitalized in the last year, were in jail or played contact sports. Of these, HIV infection was the strongest, with a 14-fold higher risk factor for MRSA colonization, compared with patients not infected with HIV.