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California Annual Antibiograms



To see the annual antibiograms, please see the following links

  • Demographic and susceptibility data were submitted to the 2008-2010 California Antibiogram Project from 59 laboratories representing 85 hospitals; 75% self-identified as laboratories serving community hospitals. Of participating laboratories, 93% produce annual antibiograms and of these, 95% eliminate duplicate isolates; 72% of laboratories eliminating duplicate isolates reported including only the first isolate per patient per analysis period (Clinical Laboratory Standards Institute (CLSI) M39 recommendation). Of participating laboratories, 58% reported computerized prescription order entry availability and 67% reported having an electronic medical record in place. Seventy-three percent (n=43) of participating laboratories reported their hospitals had an antimicrobial stewardship program (ASP); these were developed between 1990 and 2011 with a median of 2010. Of these ASPs, 33 were developed following the 2008 California mandate requiring the oversight of the judicious use of antibiotics in acute care hospitals statewide (California Senate Bill 739 (Health & Safety Code §§ 1288.5 to 1288.9). Twenty percent of laboratories reported using revised CLSI breakpoints for cefotaxime/ceftriaxone and Enterobacteriaceae in 2010 and 31% reported using revised CLSI breakpoints for carbapenems and Enterobacteriaceae in 2010. 
  • Susceptibility data submitted to this project represents all isolates, including blood, urine, and wound.  The location of the patient population from which isolates were taken (eg. inpatient and outpatient combined, inpatient only, outpatient only) differed by year and organism (Tables 1-3).  From 2008 to 2010, the overall pooled prevalence of susceptibility of one drug-organism combination (Acinetobacter baumannii to imipenem/meropenem/doripenem) decreased by 14%; 5 other combinations improved susceptibility (8-10%) while 15 combinations changed <5% (Table 4). 
  •  Participating laboratories reported adherence to CLSI guidelines for antibiogram development, but had lower adherence to recently revised breakpoints for Enterobacteriaceae, emphasizing the need for clinician awareness of which breakpoints are utilized by their laboratory. While drug-organism susceptibility rates mostly remained unchanged or improved somewhat from 2008 to 2010, the marked decrease in carbapenem susceptibility to Acinetobacter baumannii is concerning, prompting California hospitals to consider targeted antibiotic stewardship strategies.

    The 2008-2010 Project provided clinical and public health laboratories with a summary of these results in two webinars held in January 2013.  The webinar slides were prepared and presented by Kavita Trivedi, Medical Epidemiologist with the Healthcare Associated Infections Program at CDPH, Kelsey Oyong, MPH, CSTE HAI Fellow with the LA County Public Health Department and Janet Hindler, MCLS MT (ASCP), Senior Specialist with Clinical Microbiology at UCLA Medical Center.

    Their presentations are here: Webinar Part One and Webinar Part Two



     To see the number of laboratories, isolates and inpatient or outpatient population included, See the following Tables 1-3


      1. by organism, in 2008 California Antibiogram Project, see table 1
      2. by organism, in 2009 California Antibiogram Project, see table 2
      3. by organism, in 2010 California Antibiogram Project, see table 3  


     To see an aggregate susceptibility changes


  •  Aggregate susceptibility changes reported by 60 laboratories representing 85 hospitals from 2008 to 2010, California Antibiogram Project,
  • See Table 4


    Last modified on: 3/1/2013 1:08 PM