| Community-Acquired Methicillin-Resistant Staphylococcus aureus (MRSA) has been emerging as a significant public health problem in otherwise healthy individuals. Because individuals who are homeless live in close quarters, have limited access to hygiene facilities, and often have poor health status, it is possible that they have an increased risk for colonization with MRSA.;The aims of this study were to evaluate a modified saline rinse technique compared to conventional swabs for the detection of Staphylococcus aureus (SA)and MRSA and to identify risk factors for colonization in homeless individuals. A preliminary investigation was performed on the sensitivity of a moistened swab from inanimate surfaces and a second pilot compared commercially available test kits.;Two hundred and fifteen participants from homeless service agencies in Ohio completed a risk factor questionnaire and had paired nasal swabs obtained. The first swab was obtained using a dry conventional swab. After instilling sterile normal saline in to each nostil, a second swab was taken from the nasal mucosa.;Of 215 participants, 75/215 (34.9%) had cultures positive for Staphylococcus aureus. Of all tested isolates, 55/71 (77.5%) were positive for MRSA.;Conventional dry swabs had a sensitivity of 81.3% while the modified saline rinse technique had a sensitivity of 94.7%. Dry swabs had sensitivity of 75.5% for MRSA while wet swabs had a sensitivity of 88.7%. This represents a relative True Positive Fraction of (rTPF) of 1.164 (95% CI, 1.03-1.32) for the detection of SA and a rTPF of 1.18 (95% CI, 1.13-1.22) for the detection of MRSA.;Multivariable logistic regression identified significant risk factors for MRSA colonization including living with a friend (OR 0.18), recent antibiotic use (OR 2.73), and a reported history of alcoholism (OR 5.14).;The modified nasal rinse technique was superior to conventional dry swabs for the detection of colonization in this sample. Although the overall rate of colonization was similar to previous population estimates, the proportion of subjects colonized with MRSA was significantly higher in this group. Recent antibiotic exposure and a history of alcoholism were associated with higher odds of colonization while living with a friend reduced the odds of colonization. |
