Bacteraemia in a London teaching hospital 1966-75.

Analysis of blood-cultures done at St. Bartholomew's Hospital over the decade 1966-75 has revealed a five-fold increase in the incidence of bacteraemia. This increase was particularly prominent in patients with non-malignant disease. The predominance of bacteraemia caused by gram-negative organisms declined in recent years, whereas bacteraemia due to gram-positive organisms, anaerobes, and Candida spp. increased. A recent increase in the number of blood-cultures performed was associated with the introduction of commercially prepared bottles. This led to a higher rate of investigation of patients who ultimately proved to have negative results, and also to a higher incidence of contamination which exceeded the positivity-rate.