During the 12-year period from 1993 to 2004, antimicrobial susceptibility profiles of 74,394 gram-negative bacillus isolates recovered from intensive care unit (ICU) patients in United States hospitals were determined by participating hospitals and collected in a central location. MICs for 12 different agents were determined using a standardized broth microdilution method. The 11 organisms most frequently isolated were Pseudomonas aeruginosa (22.2%), Escherichia coli (18.8%), Klebsiella pneumoniae (14.2%), Enterobacter cloacae (9.1%), Acinetobacter spp. (6.2%), Serratia marcescens (5.5%), Enterobacter aerogenes (4.4%), Stenotrophomonas maltophilia (4.3%), Proteus mirabilis (4.0%), Klebsiella oxytoca (2.7%), and Citrobacter freundii (2.0%). Specimen sources included the lower respiratory tract (52.1%), urine (17.3%), and blood (14.2%). Rates of resistance to many of the antibiotics tested remained stable during the 12-year study period. Carbapenems were the most active drugs tested against most of the bacterial species. E. coli and P. mirabilis remained susceptible to most of the drugs tested. Mean rates of resistance to 9 of the 12 drugs tested increased with Acinetobacter spp. Rates of resistance to ciprofloxacin increased over the study period for most species. Ceftazidime was the only agent to which a number of species (Acinetobacter spp., C. freundii, E. aerogenes, K. pneumoniae, P. aeruginosa, and S. marcescens) became more susceptible. The prevalence of multidrug resistance, defined as resistance to at least one extended-spectrum cephalosporin, one aminoglycoside, and ciprofloxacin, increased substantially among ICU isolates of Acinetobacter spp., P. aeruginosa, K. pneumoniae, and E. cloacae.Gram-negative bacilli (GNB) are a common cause of sepsis, pneumonia, urinary tract infections, and postsurgical infections in patients in acute care hospitals (14, 24). Antimicrobial resistance among GNB is increasing worldwide (21). This is a major public health problem and a cause for both substantial morbidity and mortality among hospitalized patients. A direct correlation has been shown between resistance of GNB and patient mortality, cost of patient care, and length of stay in the hospital (3,22,26,28). The problem of GNB resistance is of particular concern in the intensive care unit (ICU) setting.The most important determinant in the successful management of infections in patients in the ICU is prompt institution of effective empirical antimicrobial therapy; inappropriate empirical therapy affects both patient mortality rates and patient time spent in the ICU (12, 17). Optimizing empirical therapy requires knowledge of likely antimicrobial resistance patterns. With the aim of tracking resistance rates among GNB as the causes of infection in patients in U.S. ICUs, Merck Research Laboratories (Merck & Co., Upper Gwynedd, PA) established a multicenter laboratory-based surveillance program in 1993. Two previous reports from this investigation were published in 1996 and 2003 (13, 20). The current report describes the ...

We performed a prospective study of bloodstream infection to determine factors independently associated with mortality. Between February 1999 and July 2000, 929 consecutive episodes of bloodstream infection at two tertiary care centers were studied. An ICD-9-based Charlson Index was used to adjust for underlying illness. Crude mortality was 24% (14% for community-onset versus 34% for nosocomial bloodstream infections). Mortality attributed to the bloodstream infection was 17% overall (10% for community-onset versus 23% for nosocomial bloodstream infections). Multivariate logistic regression revealed the independent associations with in-hospital mortality to be as follows: nosocomial acquisition (odds ratio [OR] 2.6, P < 0.0001), hypotension (OR 2.6, P < 0.0001), absence of a febrile response (P ‫؍‬ 0.003), tachypnea (OR 1.9, P ‫؍‬ 0.001), leukopenia or leukocytosis (total white blood cell count of <4,500 or >20,000, P ‫؍‬ 0.003), presence of a central venous catheter (OR 2.0, P ‫؍‬ 0.0002), and presence of anaerobic organism (OR 2.5, P ‫؍‬ 0.04). Even after adjustments were made for underlying illness and length of stay, nosocomial status of bloodstream infection was strongly associated with increased total hospital charges (P < 0.0001). Although accounting for about half of all bloodstream infections, nosocomial bloodstream infections account for most of the mortality and costs associated with bloodstream infection.Bloodstream infections cause substantial morbidity and mortality (7,18,24). Increasing rates of antimicrobial resistance (1, 6-8, 21), changing patterns of antimicrobial usage (8), and the wide application of new medical technologies (e.g., indwelling catheters and other devices) may change the epidemiology and outcome of bloodstream infection. It is therefore important to continually review and update the epidemiology and outcome of bloodstream infection, including an examination of the variables most strongly associated with mortality. Understanding these variables will help to prioritize resources and plan strategies for decreasing the mortality associated with bloodstream infection.We sought to determine the current epidemiology and outcome of bloodstream infection by prospectively evaluating consecutive patients at two large tertiary-care hospitals. Using multivariate models and controlling for underlying illness, we sought to determine which variables were most strongly and independently associated with mortality among patients with bloodstream infection. We were particularly interested in the relative contributions of nosocomial bloodstream infection to the overall mortality and costs associated with bloodstream infection.

It appears that, as fluoroquinolone resistance emerges among S. pneumoniae in the United States, resistance to other antimicrobial classes is becoming less common.

The majority of adult infectious disease physicians across the United States and Canada support PrEP but have vast differences of opinion and practice, despite the existence of CDC guidance documents. The success of real-world PrEP will likely require multifaceted programs addressing barriers to its provision and will be assisted with the development of comprehensive guidelines for real-world PrEP.

To examine factors associated with blood exposure and percutaneous injury among health care workers, we assessed occupational risk factors, compliance with standard precautions, frequency of exposure, and reporting in a stratified random sample of 5123 physicians, nurses, and medical technologists working in Iowa community hospitals. Of these, 3223 (63%) participated. Mean rates of hand washing (32%-54%), avoiding needle recapping (29%-70%), and underreporting sharps injuries (22%-62%; overall, 32%) varied by occupation (P<.01). Logistic regression was used to estimate the adjusted odds of percutaneous injury (aOR(injury)), which increased 2%-3% for each sharp handled in a typical week. The overall aOR(injury) for never recapping needles was 0.74 (95% CI, 0.60-0.91). Any recent blood contact, a measure of consistent use of barrier precautions, had an overall aOR(injury) of 1.57 (95% CI, 1.32-1.86); among physicians, the aOR(injury) was 2.18 (95% CI, 1.34-3.54). Adherence to standard precautions was found to be suboptimal. Underreporting was found to be common. Percutaneous injury and mucocutaneous blood exposure are related to frequency of sharps handling and inversely related to routine standard-precaution compliance. New strategies for preventing exposures, training, and monitoring adherence are needed.

No abstract

Current automated continuous-monitoring blood culture systems afford more rapid detection of bacteremia and fungemia than is possible with non-instrument-based manual methods. Use of these systems has not been studied objectively with respect to impact on patient outcomes, including hospital charges and length of hospitalization. We conducted a prospective, two-center study in which the time from the obtainment of the initial positive blood culture until the Gram stain was called was evaluated for 917 cases of bloodstream infection. Factors showing univariate associations with a shorter time to notification included higher body temperature and respiratory rate and higher percentage of immature neutrophils. Multiple linear regression models determined that the primary predictors of both increased microbiology laboratory and total hospital charges for patients with bloodstream infection were nonmicrobiologic and included length of stay and host factors such as the admitting service and underlying illness score. Significant microbiologic predictors of increased charges included the number of blood cultures obtained, nosocomial acquisition, and polymicrobial bloodstream infections. Accelerated failure time regression analysis demonstrated that microbiologic factors, including time until notification, organism group, and nosocomial acquisition, were independently associated with length of hospitalization after bacteremia, as were the factors of admitting service, gender, and age. Our data suggest that an increased time to notification of bloodstream infection is independently associated with increased length of stay. We conclude that the time to notification is an obvious target for efforts to shorten length of stay. The newest generation of automated continuous-monitoring blood culture systems, which shorten the time required to obtain a positive result, should impact length of hospitalization.Bloodstream infections (BSIs) are now ranked as the 10th leading cause of death in the United States, with a recent increase in age-adjusted death rates (19). BSIs also have been associated with increased rates of hospitalization (2, 18), increased length of stay (23,25), and increased hospital costs (1,7,21). The earliest possible identification of BSI allows for prompt optimization of antimicrobial therapy and diminished need for additional diagnostic studies, which in turn may serve to decrease both length of stay and cost.Current automated continuous-monitoring blood culture systems afford more rapid detection of bacteremia and fungemia than is possible with non-instrument-based manual methods (5,13,14,24,27). Detection with continuous-monitoring systems has been estimated to be 1 to 1.5 days sooner than with instrumented blood culture systems that do not employ continuous monitoring (17). While such a decrease in detection time may seem intuitively important, use of these systems has not been studied objectively with respect to impact on patient outcomes, including hospital charges and length of hospitalization. Additiona...

We analyzed antimicrobial use in 509 episodes of clinically significant bloodstream infection to assess the impact that microbiology laboratory reporting had on antimicrobial management. Most therapy interventions occurred at the time of phlebotomy and after notification of Gram stain results by telephone. Release of antimicrobial susceptibility data had the least impact on antimicrobial management. The clinical microbiology laboratory plays a significant role in the management of patients with BSI. Culturing a pathogenic microorganism from blood is a highly specific indicator of BSI, and performance of antimicrobial susceptibility testing (AST) may assist in the appropriate use of antimicrobial therapy for patients with BSI (2, 4, 6). Furthermore, early and rapid administration of antimicrobial therapy to patients with BSI has been shown to reduce mortality (8-13).The purpose of this study was to evaluate the association between positive blood culture reporting by the clinical microbiology laboratory and the antimicrobial management of patients with BSI. Findings from consecutive episodes of BSI at the University of Iowa Hospitals and Clinics over a 13-month period are summarized.All patients at the University of Iowa Hospitals and Clinics from July 1999 through July 2000 with a positive signal from the BacT/Alert continuous monitoring blood culture system (bioMérieux, Marcy l'Etoile, France) were screened for inclusion in this study. An episode of BSI was considered to have begun at the time the initial positive blood culture was obtained. Referral blood cultures from outside facilities and autopsy blood cultures, as well as patients with false-positive signals (no organisms observed on Gram stain or cultivated from bottle subculture) and patients not admitted to the hospital, were excluded from the study.Of the 509 episodes of bacteremia characterized in this study, 59% were judged to be hospital acquired; the remaining 41% were judged to be community acquired. The following percentages of bacteremic episodes occurred in the patients studied: Յ1 year of age, 8%; 1 to 15 years of age, 11%; 16 to 39 years of age, 18%; 40 to 59 years of age, 32%; 60 to 79 years of age, 28%; 80 to 101 years of age, 4%. Thirty percent of patients were hospitalized in intensive-care units at the time of the septic episode; the remaining patients were in general-care areas. The six most common causes of bacteremia in this study were Staphylococcus aureus (20% of episodes), Escherichia coli (14%), coagulase-negative staphylococci (13%), enterococci (12%), Pseudomonas aeruginosa (6%), and Klebsiella pneumoniae (5%).Each positive blood culture was critically assessed and categorized as clinically significant or not clinically significant, taking into account clinical signs and symptoms, white blood cell count, number of blood samples culture positive out of the total number drawn, results of other cultures, pathology findings, imaging results, and clinical course. All indeterminate cases were reviewed by an infectious disease physician...