Spread of Staphylococcus aureus strains of phage-type 95 in Denmark 1968–1989

The spread of Staphylococcus aureus strains of phage-type 95 was traced retrospectively in Denmark by the review of more than 15 000 S. aureus bacteraemia isolates (1957–1988) and from data collected by phage-typing of c. 260 000 isolates from all body sites (1977–1989). The first two type 95 strains had been isolated from blood in 1968, and after an interval of 3 years there was a steady increase of bacteraemia strains all over Denmark. From 1977 to 1989 the incidence of type 95 strains among isolates from all body sites increased from 3·8 to 18·8%. Different patterns of increase were recorded in 13 major hospitals and in various clinical departments of two hospitals and these were further analysed. Conjunctival swabs gave the highest percentage of type 95 strains and those from abscesses gave the lowest percentage. Of the type 95 bacteraemia strains 90·4% were resistant to penicillin, but neither methicillin nor gentamicin resistance was recorded.