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
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]