title: Hospital-acquired infection with methicillin-resistant and methicillin-sensitive staphylococci.
abstract: In-patients at a London hospital over one year from whom the south-east England strain of 'epidemic' methicillin-resistant Staphylococcus aureus (MRSA) was isolated were compared with in-patients with strains of methicillin-sensitive Staphylococcus aureus (MSSA). MRSA were virtually entirely hospital-acquired; isolates before 10 days were uncommon and related to recent previous admission. Thereafter first isolates occurred at a fairly constant daily rate of about 1.9 per 1,000 in-patients. Acquisition of MSSA after more than 4 days in hospital occurred at a similar constant rate. Such strains were less likely to be penicillin-sensitive than strains isolated in the first 4 days after admission (11 vs. 22%) and were considered to be hospital-acquired. The single MRSA strain caused 40 infections in a year, about half of all hospital-acquired staphylococcal infections. Patients prescribed anti-staphylococcal antibiotics and patients with indwelling cannulae both had about a ninefold increased risk of acquiring MRSA. There was no reciprocal increase in MSSA infections after control measures had substantially reduced the number of MRSA infections.
authors.affiliation: Department of Environmental and Preventive Medicine, Medical College of St Bartholomew's Hospital, London.
authors.forename: M R
authors.initials: MR
authors.lastname: Law
authors.forename: O N
authors.initials: ON
authors.lastname: Gill
mesh_terms: D003428:Cross Infection / Q000382:microbiology* / Q000517:prevention & control; D004739:England; D006801:Humans; D008712:Methicillin; D010403:Penicillin Resistance; D013203:Staphylococcal Infections / Q000382:microbiology*; D014552:Urinary Tract Infections / Q000382:microbiology
chemical_list: D008712:Methicillin