To better understand the role of indirect transmission in community-acquired infection with methicillin-resistant Staphylococcus aureus (MRSA).

Prospective case-control study.

A French teaching hospital.

A total of 198 case patients and 198 control patients with MRSA or methicillin-susceptible S. aureus infection diagnosed between April 2002 and July 2003.

Multivariate analysis showed a highly significant independent link between MRSA infection at admission and prior receipt of home nursing care (odds ratio [OR], 3.7; P<.001). Other independent risk factors were prior hospitalization (OR, 3.8; P<.001), transfer from another institution (OR, 2.3; P = .008), and age older than 65 years (OR, 1.6; P = .04). Prior home nursing care showed a frequency dose-response relationship. Eleven MRSA-infected patients had had home nursing procedures but no hospital stay in the previous 3 years. These patients' MRSA strains were related to the prevalent MRSA clone currently spreading in French hospitals.

Home nursing care appears to be an independent risk factor for MRSA acquisition in the community. The reservoir probably consists of MRSA carriers discharged from the hospital. Community nurses seem to be a potential vector.