A study of bacteremias in Denmark from 1977-1978.

The results of blood cultures from a large number of Danish hospitals examined at Statens Seruminstitut in 1977 and 1978 have been analysed. Out of a total of 17, 518 cultures in 1977 and 17,820 in 1978, 1,626 from 830 patients and 1,544 from 832 patients yielded growth of pathogenic microorganisms. Cases of bacteremia with Enterobacteriaceae constituted approximately 50% of cases both in 1977 and 1978. Polymicrobial bacteremia occurred in 8.1% of bacteremic cases in 1977 and 7.5% of those in 1978. The microorganisms isolated and their frequencies were surprisingly similar to those found in 1965 and 1971 in an earlier investigation from this department. No change in antibiotic susceptibility was observed between 1977 and 1978. Retesting of 50 E. coli strains from 1965, 1971 and 1978 for susceptibility towards ampicillin, cephalotin, streptomycin and tetracycline indicated that no significant changes had occurred, contrary to the results of the earlier investigation. This fact stresses the importance of exploring the possibility of unnoticed methodological changes having occurred in the sensitivity testing systems before any conclusions can be drawn concerning apparent differences in antibiotic susceptibilities.