Studies on transmission of Staphylococcus aureus in an isolated ward for burned patients

A one-year epidemiological investigation was made in an isolation ward for burned patients. The transmission of Staphylococcus aureus was mainly studied. In spite of the design of the ward the cross-infection rate was high. In all, 49 of 69 patients were infected 114 times. Twenty-six of the strains causing infection were found in a patient only, 10 in a member of the staff only and 23 in both patients and staff the week before they caused a new infection. There were three epidemic outbreaks caused by three strains of Staph. aureus all belonging to phage group III; one was resistant to methicillin. Environmental studies with settle plates showed that the number of staphylococci dispersed by a burned patient was often very high. In 8% of the observations in occupied bedrooms the air count of Staph. aureus was more than 1800 col./m.(2) hr. However, the counts of Staph. aureus in the corridor and service areas were low. This seems to indicate a rather good protection against airborne transfer of bacteria. Other routes of infection were probably of greater importance.