Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) infection in a Japanese geriatric hospital.

A case control study on MRSA infection was carried out, with the purpose of evaluating the effect of age, gender, hypoalbuminemia, the limitation of activities of daily living (ADL), the administration of antibiotics and the use of the new cephems which include third generation cephalosporins and monobactam and carbapenems, on the occurrence of MRSA infection among the inpatients in a geriatric hospital. From April 1991 to March 1994, 285 patients underwent a bacterial culture in the various clinical aspects. 118 patients were positive for MRSA, who were then used as cases while 167 patients who were negative for MRSA were used as controls. The level of serum albumin and the ADL score were lower in the MRSA group than in the non-MRSA group (P < 0.01) while the number of antibiotics administered before bacterial culture was greater in the MRSA group than in the non-MRSA group (P < 0.01). The third generation cephems were more commonly used in the MRSA positive patients than the negative patients (P < 0.01). Even after controlling for the other factors, hypoalbuminemia (OR = 1.73, 95% CI = 1.27-2.36), the limited ADL (partially limited vs without limitation: OR = 1.88, 95% CI = 1.19-2.96, completely limited vs without limitation: OR = 2.50, 95% CI = 1.64-3.82), the use of antibiotics other than the third generation cephems (vs without antibiotics: OR = 1.73, 95% CI = 1.20-2.50) and the administration of the third generation cephems (vs without antibiotics: OR = 3.12, 95% CI = 2.16-4.50) increased the risk of MRSA infection.