Clinical, bacteriologie, epidemiologic and hospital infection-control observations related to an inter-hospital outbreak of methicillin-resistant Staphylococcus aureus are described. The outbreak involved 66 patients at the University of Oregon Health Sciences Center (UOHSC) and its closely affiliated VA hospital, the Portland VA Medical Center (PVAMC). No environmental source of infection was identified; person-to-person transmission was most likely responsible for its spread. Surveillance cultures demonstrated nasal colonization in house staff and nursing personnel at both hospitals. Inter-hospital transfer of infection was, in all likelihood, achieved via nasal carriage by a single physician. Case-control analysis indicated a significantly increased risk (p < 0.05) of acquisition of infection related to age, number of days hospitalized, severity of underlying disease and number of invasive procedures. Prior antibiotic receipt was a significant risk factor when analyzed by univariate analysis (p < 0.01), but, in contrast to previous studies, this was not a significant risk factor (p > 0.05) when related variables were controlled by multivariate analysis. Prevention of spread of infection by routine infection control measures was less effective at PVAMC than at UOHSC. Patients at PVAMC were significantly older and had longer durations of hospitalization (p < 0.05). Antimicrobial therapy of colonized patients and personnel appeared to assist in the control of the outbreak at PVAMC. Antimicrobial therapy with topical bacitracin and oral rifampin, alone or in combination with oral trimethoprim-sulfamethoxazole, was effective in eliminating colonization with methicillin-resistant S. aureus. [Infect Control 1981; 2(6):453-459.]

Four commercially available rapid agglutination tests for the identification of Staphylococcus aureus were compared with the tube coagulase test for the identification of 300 methicillin-resistant isolates of staphylococci. Isolates tested included 207 methicilin-resistant S. aureus and 93 coagulase-negative staphylococci, collected from five medical centers. Strain variability was documented by phage typing and antimicrobial susceptibility patterns. Results of rapid identification tests ranged between 82 and 86%o sensitivity, significantly poorer than the 98% sensitivity which the tube coagulase test provided.

Twenty patients with skin and soft-tissue infections were treated with parenteral cefonicid. Cultures obtained in cellulitis cases from an aspirate of a leading edge of inflammation were positive in 42% of these patients. Pathogens isolated were Staphylococcus aureus (six strains), Proteus mirabilis (one strain), and Streptococcus agalactiae. Adverse effects were pain on intramuscular injection (two patients), rash (one patient), and positive Coombs test (one patient). All side effects were mild and none required discontinuing antibiotic therapy. A single treatment failure occurred in a patient with an undrained perirectal abscess. Cefonicid may be a useful drug in the treatment of skin and soft-tissue infections. The long half-life of cefonicid (4.8 h) is a valuable advantage and may facilitate patient compliance and convenience.