Consequences of increased antibacterial consumption and change in pattern of antibacterial use in Danish hospitals

Antibacterial consumption is increasing in many countries around the world, and it is increasingly recognized as the main reason for the emergence of resistance. This study was implemented to analyse antibacterial consumption in public hospitals in Denmark during 2001-07 as a follow-up on a prior analysis and furthermore, to investigate the consequences of the occurrence of resistance. National data on the consumption of antibacterials for systemic use in Danish public hospitals were obtained from 2001 through 2007. Consumption data were compared with antimicrobial resistance in all isolates recorded from either blood samples (Escherichia coli and Klebsiella pneumoniae) or urine samples (E. coli) submitted for susceptibility testing to the participating Departments of Clinical Microbiology during 2001-07. The consumption of combinations of penicillins including beta-lactamase inhibitors, cephalosporins, carbapenems and fluoroquinolones continued to increase from 19.2% of the total consumption in hospitals in Denmark in 2001 to 38.2% in 2007. Quinolone resistance in E. coli isolates from blood and urine samples increased significantly from 2001 through 2007. Furthermore, multiresistant K. pneumoniae emerged. The consumption of 'broad-spectrum' antibacterial agents has continued to increase in Danish hospitals. At the same time, an increasing resistance in clinical isolates towards the same antibacterial agents has been observed. However, more detailed information on the specific consumption of the antibacterial agents might help to restrict or reverse the increasing use of 'broad-spectrum' antibacterial agents and perhaps also the increasing antimicrobial resistance.