Antimicrobial resistance trends and outbreak frequency in United States hospitals.

We assessed resistance rates and trends for important antimicrobial-resistant pathogens (oxacillin-resistant Staphylococcus aureus [ORSA], vancomycin-resistant Enterococcus species [VRE], ceftazidime-resistant Klebsiella species [K-ESBL], and ciprofloxacin-resistant Escherichia coli [QREC]), the frequency of outbreaks of infection with these resistant pathogens, and the measures taken to control resistance in a stratified national sample of 670 hospitals. Four hundred ninety-four (74%) of 670 surveys were returned. Resistance rates were highest for ORSA (36%), followed by VRE (10%), QREC (6%), and K-ESBL (5%). Two-thirds of hospitals reported increasing ORSA rates, whereas only 4% reported decreasing rates, and 24% reported ORSA outbreaks within the previous year. Most hospitals (87%) reported having implemented measures to rapidly detect resistance, but only approximately 50% reported having provided appropriate resources for antimicrobial resistance prevention (53%) or having implemented antimicrobial use guidelines (60%). The most common resistant pathogen in US hospitals is ORSA, which accounts for many recognized outbreaks and is increasing in frequency in most facilities. Current practices to prevent and control antimicrobial resistance are inadequate.

Are United States hospitals following national guidelines for the analysis and presentation of cumulative antimicrobial susceptibility data?

The National Committee for Clinical Laboratory Standards recently published guidelines for analysis and presentation of cumulative antimicrobial susceptibility test data (antibiograms). We sought to determine how well US hospitals already adhere to standards for antibiogram compilation, and to examine the relationship between hospital characteristics and guideline adherence. We surveyed laboratory directors at 670 hospitals and examined 3 guideline criteria: compilation of an antibiogram, annual updating, and distribution to infection control staff and medical staff yearly; 494 surveys were returned (74%). Almost all of the hospitals surveyed publish an antibiogram (95%, n = 481); however, only 60% (n = 296) met all three criteria. Hospital laboratories meeting criteria were more likely to serve as referral laboratories (OR = 1.82; 95% CI = 1.26-2.63), perform susceptibility testing on site (OR = 4.47; 95% CI = 1.84-10.84), use confirmatory tests to detect extended-spectrum beta-lactamases (OR = 1.8; 95% CI = 1.2-2.6), and have more laboratory personnel per bed (3.0 vs. 2.0 FTEs/bed, p = 0.0031). Adherence to guidelines for preparation and dissemination of antibiograms could be improved. Institutional commitment to high quality, on-site microbiology laboratory services will improve adherence to these guidelines.