Secular trends in nosocomial bloodstream infections: antibiotic-resistant bacteria increase the total burden of infection.
Clin Infect Dis. 2012 Dec 7;
Authors: Ammerlaan HS, Harbarth S, Buiting AG, Crook DW, Fitzpatrick F, Hanberger H, Herwaldt LA, van Keulen PH, Kluytmans JA, Kola A, Kuchenbecker RS, Lingaas E, Meessen N, Morris-Downes MM, Pottinger JM, Rohner P, Dos Santos RP, Seifert H, Wisplinghoff H, Ziesing S, Walker AS, Bonten MJ
Abstract
Background.?It is unknown whether rising incidence rates of nosocomial bloodstream infections [BSIs] caused by antibiotic-resistant bacteria [ARB] replace nosocomial BSIs caused by antibiotic-susceptible bacteria [ASB], leaving the total BSI incidence rate unaffected.Methods.?We investigated temporal trends in annual incidence densities [events/100.000 patient-days] of nosocomial BSIs caused by methicillin-resistant Staphylococcus aureus [MRSA], ARB other than MRSA [non-MRSA ARB], and ASB in 7 ARB-endemic and 7 ARB-non-endemic hospitals between 1998 and 2007.Results.?33.140 nosocomial BSIs (14% caused by ARB) yielded 36.679 microorganisms. From 1998 to 2007, the MRSA incidence density increased from 0.2 to 0.7 (annual increase 22%) in ARB-non-endemic hospitals, and from 3.1 to 11.7 (annual increase 10%) in ARB-endemic hospitals (p=0.2), increasing the incidence density-difference between ARB-endemic and ARB-non-endemic hospitals from 2.9 to 11.0. The non-MRSA ARB incidence density increased from 2.8 to 4.1 (annual increase 5%) in ARB-non-endemic hospitals, and from 1.5 to 17.4 (annual increase 22%) in ARB-endemic hospitals (p<0.001), changing the incidence density-difference from -1.3 to 13.3. Trends in incidence densities of ASB were similar in both groups (p=0.7). With annual increases of 3.8% and 5.4% of all nosocomial BSIs in ARB-non-endemic and ARB-endemic hospitals, respectively (p<0.001), the overall incidence density-difference of 3.8 increased to 24.4.Conclusion.?Increasing nosocomial BSI rates due to ARB occur in addition to infections caused by ASB, increasing the total burden of disease. Hospitals with high ARB-infection rates in 2005 had an excess burden of BSI of 20.6/100.000 patient-days in a 10-year period, mainly caused by infections with ARB.
PMID: 23223600 [PubMed - as supplied by publisher]