Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa isolation from pharyngeal swab cultures among the Japanese elderly at admission to a geriatric hospital

The isolation rate of Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa from pharyngeal swab cultures in the Japanese elderly was studied at admission to a geriatric hospital which had long-term care units. The subjects were 233 consecutive patients who were admitted to K Hospital in the time period April 1994 to March 1996. The isolation rate of MRSA and of Pseudomonas aeruginosa was 10.3% and 8.2% respectively. The proportions of the patients with severely to moderately limited Activities of Daily Living (ADL) (ADL score = 0–1) (P < 0.01), those with fever (P < ;0.01), those with CRP positive (P = 0.04) and those with hypoalbuminemia (serum albumin<3.5 g/dl) (P < 0.01) were higher in the MRSA positive patients than in the negative patients while the proportion of the patients with fever was higher in the Pseudomonas aeruginosa positive patients than in the negative patients (P < 0.02). In the multiple logistic regression analysis, the limitation of ADL (ADL score 0–1 vs 2–3, OR = 1.54, 95% CI = 1.02–2.33) and fever (with vs without, OR = 1.77, 95% CI = 1.18–2.66) remained as risk factors for the isolation of MRSA while only fever (with vs without, OR = 1.67, 95% CI = 1.11–2.53) remained as a risk factor for the isolation of Pseudomonas aeruginosa.