Estimating the burden of healthcare-associated infections caused by selected multidrug-resistant bacteria Finland, 2010

Background: Knowledge of the burden of healthcare-associated infections (HAI) and antibiotic resistance is important for resource allocation in infection control. Although national surveillance networks do not routinely cover all HAIs due to multidrug-resistant bacteria, estimates are nevertheless possible: in the EU, 25,000 patients die from such infections annually. We assessed the burden of HAIs due to multidrug-resistant bacteria in Finland in 2010. Methods: By combining data from the National Infectious Disease Registry on the numbers of bacteremias caused by Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Pseudomonas aeruginosa and Acinetobacter spp., and susceptibility data from the National Antimicrobial Resistance Network and the Finnish Hospital Infection Program, we assessed the numbers of healthcare-associated bacteremias due to selected multidrug-resistant bacteria. We estimated the number of pneumonias, surgical site and urinary tract infections by applying the ratio of these infections in the first national prevalence survey for HAI in 2005. Attributable HAI mortality (3.2%) was also derived from the prevalence survey. Results: The estimated annual number of the most common HAIs due to the selected multidrug-resistant bacteria was 2804 (530 HAIs per million), 6% of all HAIs in Finnish acute care hospitals. The number of attributable deaths was 89 (18 per million). Conclusions: Resources for infection control should be allocated not only in screening and isolation of carriers of multidrug-resistant bacteria, even when they are causing a small proportion of all HAIs, but also in preventing all clinical infections.