To describe the frequency of selected antimicrobial resistance patterns among pathogens causing device-associated and procedure-associated healthcare-associated infections (HAIs) reported by hospitals in the National Healthcare Safety Network (NHSN).

Data are included on HAIs (ie, central line-associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated pneumonia, and surgical site infections) reported to the Patient Safety Component of the NHSN between January 2006 and October 2007. The results of antimicrobial susceptibility testing of up to 3 pathogenic isolates per HAI by a hospital were evaluated to define antimicrobial-resistance in the pathogenic isolates. The pooled mean proportions of pathogenic isolates interpreted as resistant to selected antimicrobial agents were calculated by type of HAI and overall. The incidence rates of specific device-associated infections were calculated for selected antimicrobial-resistant pathogens according to type of patient care area; the variability in the reported rates is described.

Overall, 463 hospitals reported 1 or more HAIs: 412 (89%) were general acute care hospitals, and 309 (67%) had 200-1,000 beds. There were 28,502 HAIs reported among 25,384 patients. The 10 most common pathogens (accounting for 84% of any HAIs) were coagulase-negative staphylococci (15%), Staphylococcus aureus (15%), Enterococcus species (12%), Candida species (11%), Escherichia coli (10%), Pseudomonas aeruginosa (8%), Klebsiella pneumoniae (6%), Enterobacter species (5%), Acinetobacter baumannii (3%), and Klebsiella oxytoca (2%). The pooled mean proportion of pathogenic isolates resistant to antimicrobial agents varied significantly across types of HAI for some pathogen-antimicrobial combinations. As many as 16% of all HAIs were associated with the following multidrug-resistant pathogens: methicillin-resistant S. aureus (8% of HAIs), vancomycin-resistant Enterococcus faecium (4%), carbapenem-resistant P. aeruginosa (2%), extended-spectrum cephalosporin-resistant K. pneumoniae (1%), extended-spectrum cephalosporin-resistant E. coli (0.5%), and carbapenem-resistant A. baumannii, K. pneumoniae, K. oxytoca, and E. coli (0.5%). Nationwide, the majority of units reported no HAIs due to these antimicrobial-resistant pathogens.

To determine mortality, morbidity, and costs attributable to surgical-site infections (SSIs) in the 1990s.

A matched follow-up study of a cohort of patients with SSI, matched one-to-one with patients without SSI.

A 415-bed community hospital.

255 pairs of patients with and without SSI were matched on age, procedure, National Nosocomial Infection Surveillance System risk index, date of surgery, and surgeon.

Mortality, excess length of hospitalization, and extra direct costs attributable to SSI; relative risk for intensive care unit (ICU) admission and for readmission to the hospital.

Of the 255 pairs, 20 infected patients (7.8%) and 9 uninfected patients (3.5%) died during the postoperative hospitalization (relative risk [RR], 2.2; 95% confidence interval [CI95], 1.14.5). Seventy-four infected patients (29%) and 46 uninfected patients (18%) required ICU admission (RR, 1.6; CI95,1.3-2.0). The median length of hospitalization was 11 days for infected patients and 6 days for uninfected patients. The extra hospital stay attributable to SSI was 6.5 days (CI95, 5-8 days). The median direct costs of hospitalization were $7,531 for infected patients and $3,844 for uninfected patients. The excess direct costs attributable to SSI were $3,089 (CI95, $2,139-$4,163). Among the 229 pairs who survived the initial hospitalization, 94 infected patients (41%) and 17 uninfected patients (7%) required readmission to the hospital within 30 days of discharge (RR, 5.5; CI95, 4.0-7.7). When the second hospitalization was included, the total excess hospitalization and direct costs attributable to SSI were 12 days and $5,038, respectively.

In the 1990s, patients who develop SSI have longer and costlier hospitalizations than patients who do not develop such infections. They are twice as likely to die, 60% more likely to spend time in an ICU, and more than five times more likely to be readmitted to the hospital. Programs that reduce the incidence of SSI can substantially decrease morbidity and mortality and reduce the economic burden for patients and hospitals.

To describe antimicrobial resistance patterns for healthcare-associated infections (HAIs) reported to the National Healthcare Safety Network (NHSN) during 2009-2010.

Central line-associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated pneumonia, and surgical site infections were included. Pooled mean proportions of isolates interpreted as resistant (or, in some cases, nonsusceptible) to selected antimicrobial agents were calculated by type of HAI and compared to historical data.

Overall, 2,039 hospitals reported 1 or more HAIs; 1,749 (86%) were general acute care hospitals, and 1,143 (56%) had fewer than 200 beds. There were 69,475 HAIs and 81,139 pathogens reported. Eight pathogen groups accounted for about 80% of reported pathogens: Staphylococcus aureus (16%), Enterococcus spp. (14%), Escherichia coli (12%), coagulase-negative staphylococci (11%), Candida spp. (9%), Klebsiella pneumoniae (and Klebsiella oxytoca; 8%), Pseudomonas aeruginosa (8%), and Enterobacter spp. (5%). The percentage of resistance was similar to that reported in the previous 2-year period, with a slight decrease in the percentage of S. aureus resistant to oxacillins (MRSA). Nearly 20% of pathogens reported from all HAIs were the following multidrug-resistant phenotypes: MRSA (8.5%); vancomycin-resistant Enterococcus (3%); extended-spectrum cephalosporin-resistant K. pneumoniae and K. oxytoca (2%), E. coli (2%), and Enterobacter spp. (2%); and carbapenem-resistant P. aeruginosa (2%), K. pneumoniae/oxytoca (<1%), E, coli (<1%), and Enterobacter spp. (<1%). Among facilities reporting HAIs with 1 of the above gram-negative bacteria, 20%-40% reported at least 1 with the resistant phenotype.

While the proportion of resistant isolates did not substantially change from that in the previous 2 years, multidrug-resistant gram-negative phenotypes were reported from a moderate proportion of facilities.

Infection control programs were created three decades ago to control antibiotic-resistant healthcare-associated infections, but there has been little evidence of control in most facilities. After long, steady increases of MRSA and VRE infections in NNIS System hospitals, the Society for Healthcare Epidemiology of America (SHEA) Board of Directors made reducing antibiotic-resistant infections a strategic SHEA goal in January 2000. After 2 more years without improvement, a SHEA task force was appointed to draft this evidence-based guideline on preventing nosocomial transmission of such pathogens, focusing on the two considered most out of control: MRSA and VRE.

Medline searches were conducted spanning 1966 to 2002. Pertinent abstracts of unpublished studies providing sufficient data were included.

Frequent antibiotic therapy in healthcare settings provides a selective advantage for resistant flora, but patients with MRSA or VRE usually acquire it via spread. The CDC has long-recommended contact precautions for patients colonized or infected with such pathogens. Most facilities have required this as policy, but have not actively identified colonized patients with surveillance cultures, leaving most colonized patients undetected and unisolated. Many studies have shown control of endemic and/or epidemic MRSA and VRE infections using surveillance cultures and contact precautions, demonstrating consistency of evidence, high strength of association, reversibility, a dose gradient, and specificity for control with this approach. Adjunctive control measures are also discussed.

Active surveillance cultures are essential to identify the reservoir for spread of MRSA and VRE infections and make control possible using the CDC's long-recommended contact precautions.

To study the possible role of contaminated environmental surfaces as a reservoir of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals.

A prospective culture survey of inanimate objects in the rooms of patients with MRSA.

A 200-bed university-affiliated teaching hospital.

Thirty-eight consecutive patients colonized or infected with MRSA. Patients represented endemic MRSA cases.

Ninety-six (27%) of 350 surfaces sampled in the rooms of affected patients were contaminated with MRSA. When patients had MRSA in a wound or urine, 36% of surfaces were contaminated. In contrast, when MRSA was isolated from other body sites, only 6% of surfaces were contaminated (odds ratio, 8.8; 95% confidence interval, 3.725.5; Pく.0001). Environmental contamination occurred in the rooms of 73% of infected patients and 69% of colonized patients. Frequently contaminated objects included the floor, bed linens, the patient's gown, overbed tables, and blood pressure cuffs. Sixty-five percent of nurses who had performed morning patient-care activities on patients with MRSA in a wound or urine contaminated their nursing uniforms or gowns with MRSA. Forty-two percent of personnel who had no direct contact with such patients, but had touched contaminated surfaces, contaminated their gloves with MRSA.

We concluded that inanimate surfaces near affected patients commonly become contaminated with MRSA and that the frequency of contamination is affected by the body site at which patients are colonized or infected. That personnel may contaminate their gloves (or possibly their hands) by touching such surfaces suggests that contaminated environmental surfaces may serve as a reservoir of MRSA in hospitals.

To describe antimicrobial resistance patterns for healthcare-associated infections (HAIs) that occurred in 2011–2014 and were reported to the Centers for Disease Control and Prevention’s National Healthcare Safety Network.

Data from central line–associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated pneumonias, and surgical site infections were analyzed. These HAIs were reported from acute care hospitals, long-term acute care hospitals, and inpatient rehabilitation facilities. Pooled mean proportions of pathogens that tested resistant (or nonsusceptible) to selected antimicrobials were calculated by year and HAI type.

Overall, 4,515 hospitals reported that at least 1 HAI occurred in 2011–2014. There were 408,151 pathogens from 365,490 HAIs reported to the National Healthcare Safety Network, most of which were reported from acute care hospitals with greater than 200 beds. Fifteen pathogen groups accounted for 87% of reported pathogens; the most common included Escherichia coli (15%), Staphylococcus aureus (12%), Klebsiella species (8%), and coagulase-negative staphylococci (8%). In general, the proportion of isolates with common resistance phenotypes was higher among device-associated HAIs compared with surgical site infections. Although the percent resistance for most phenotypes was similar to earlier reports, an increase in the magnitude of the resistance percentages among E. coli pathogens was noted, especially related to fluoroquinolone resistance.

This report represents a national summary of antimicrobial resistance among select HAIs and phenotypes. The distribution of frequent pathogens and some resistance patterns appear to have changed from 2009–2010, highlighting the need for continual, careful monitoring of these data across the spectrum of HAI types.

Infect Control Hosp Epidemiol 2016;1–14

To estimate the proportion of healthcare-associated infections (HAIs) in US hospitals that are “reasonably preventable,” along with their related mortality and costs.

To estimate preventability of catheter-associated bloodstream infections (CABSIs), catheter-associated urinary tract infections (CAUTIs), surgical site infections (SSIs), and ventilator-associated pneumonia (VAP), we used a federally sponsored systematic review of interventions to reduce HAIs. Ranges of preventability included the lowest and highest risk reductions reported by US studies of “moderate” to “good” quality published in the last 10 years. We used the most recently published national data to determine the annual incidence of HAIs and associated mortality. To estimate incremental cost of HAIs, we performed a systematic review, which included costs from studies in general US patient populations. To calculate ranges for the annual number of preventable infections and deaths and annual costs, we multiplied our infection, mortality, and cost figures with our ranges of preventability for each HAI.

AS many as 65%–70% of cases of CABSI and CAUTI and 55% of cases of VAP and SSI may be preventable with current evidence-based strategies. CAUTI may be the most preventable HAI. CABSI has the highest number of preventable deaths, followed by VAP. CABSI also has the highest cost impact; costs due to preventable cases of VAP, CAUTI, and SSI are likely less.

Our findings suggest that 100% prevention of HAIs may not be attainable with current evidence-based prevention strategies; however, comprehensive implementation of such strategies could prevent hundreds of thousands of HAIs and save tens of thousands of lives and billions of dollars.

To assess the prevalence and correlates of compliance and noncompliance with hand hygiene guidelines in hospital care.

A systematic review of studies published before January 1, 2009, on observed or self-reported compliance rates.

Articles on empirical studies written in English and conducted on general patient populations in industrialized countries were included. The results were grouped by type of healthcare worker before and after patient contact. Correlates contributing to compliance were grouped and listed.

We included 96 empirical studies, the majority (n = 65) in intensive care units. In general, the study methods were not very robust and often ill reported. We found an overall median compliance rate of 40%. Unadjusted compliance rates were lower in intensive care units (30%–40%) than in other settings (50%–60%), lower among physicians (32%) than among nurses (48%), and before (21%) rather than after (47%) patient contact. The majority of the time, the situations that were associated with a lower compliance rate were those with a high activity level and/or those in which a physician was involved. The majority of the time, the situations that were associated with a higher compliance rate were those having to do with dirty tasks, the introduction of alcohol-based hand rub or gel, performance feedback, and accessibility of materials. A minority of studies (n = 12) have investigated the behavioral determinants of hand hygiene, of which only 7 report the use of a theoretical framework with inconclusive results.

Noncompliance with hand hygiene guidelines is a universal problem, which calls for standardized measures for research and monitoring. Theoretical models from the behavioral sciences should be used internationally and should be adapted to better explain the complexities of hand hygiene.

To describe the epidemiology of nosocomial infections in combined medical-surgical (MS) intensive care units (ICUs) participating in the National Nosocomial Infection Surveillance (NNIS) System.

Analysis of surveillance data on 498,998 patients with 1,554,070 patient-days, collected between 1992 and 1998 from 205 MS ICUs following the NNIS Intensive Care Unit protocol, representing 152 participating NNIS hospitals in the United States.

Infections at three major sites represented 68% of all reported infections (nosocomial pneumonia, 31%; urinary tract infections (UTIs), 23%; and primary bloodstream infections (BSIs), 14%: 83% of episodes of nosocomial pneumonia were associated with mechanical ventilation, 97% of UTIs occurred in catheterized patients, and 87% of primary BSIs in patients with a central line. In patients with primary BSIs, coagulase-negative staphylococci (39%) were the most common pathogens reported; Staphylococcus aureus (12%) was as frequently reported as enterococci (11%). Coagulase-negative staphylococcal BSIs were increasingly reported over the 6 years, but no increase was seen in candidemia or enterococcal bacteremia. In patients with pneumonia, S aureus (17%) was the most frequently reported isolate. Of reported isolates, 59% were gram-negative bacilli. In patients with UTIs, Escherichia coli (19%) was the most frequently reported isolate. Of reported isolates, 31% were fungi. In patients with surgical-site infections, Enterococcus (17%) was the single most frequently reported pathogen. Device-associated nosocomial infection rates for BSIs, pneumonia, and UTIs did not correlate with length of ICU stay, hospital bed size, number of beds in die ICU, or season. Combined MS ICUs in major teaching hospitals had higher device-associated infection rates compared to all other hospitals with combined medical-surgical units.

Nosocomial infections in MS ICUs at the most frequent infection sites (bloodstream, urinary, and respiratory tract) almost always were associated with use of an invasive device. Device-associated infection rates were die best available comparative rates between combined MS ICUs, but the distribution of device-associated rates should be stratified by a hospital's major teaching affiliation status.

To measure the impact of orthopedic surgical-site infections (SSIs) on quality of life, length of hospitalization, and cost.

A pairwise-matched (1:1) case-control study within a cohort.

A tertiary-care university medical center and a community hospital.

Cases of orthopedic SSIs were prospectively identified by infection control professionals. Matched controls were selected from the entire cohort of patients undergoing orthopedic surgery who did not have an SSI. Matching variables included type of surgical procedure, National Nosocomial Infections Surveillance risk index, age, date of surgery, and surgeon.

Quality of life, duration of postoperative hospital stay, frequency of hospital readmission, overall direct medical costs, and mortality rate.

Fifty-nine SSIs were identified. Each orthopedic SSI accounted for a median of 1 extra day of stay during the initial hospitalization (P = .001) and a median of 14 extra days of hospitalization during the follow-up period (P = .0001). Patients with SSI required more rehospitalizations (median, 2 vs 1; P = .0001) and more total surgical procedures (median, 2 vs 1; P = .0001). The median total direct cost of hospitalizations per infected patient was $24,344, compared with $6,636 per uninfected patient (P = .0001). Mortality rates were similar for cases and controls. Quality of life was adversely affected for patients with SSI. The largest decrements in scores on the Medical Outcome Study Short Form 36 questionnaire were seen in the physical functioning and role-physical domains.

Orthopedic SSIs prolong total hospital stays by a median of 2 weeks per patient, approximately double rehospitalization rates, and increase healthcare costs by more than 300%. Moreover, patients with orthopedic SSIs have substantially greater physical limitations and significant reductions in their health-related quality of life.

To evaluate the impact of methicillin resistance in Staphylococcus aureus on mortality, length of hospitalization, and hospital charges.

A cohort study of patients admitted to the hospital between July 1, 1997, and June 1, 2000, who had clinically significant S. aureus bloodstream infections.

A 630-bed, urban, tertiary-care teaching hospital in Boston, Massachusetts.

Three hundred forty-eight patients with S. aureus bacteremia were studied; 96 patients had methicillin-resistant S. aureus (MRSA). Patients with methicillin-susceptible S. aureus (MSSA) and MRSA were similar regarding gender, percentage of nosocomial acquisition, length of hospitalization, ICU admission, and surgery before S. aureus bacteremia. They differed regarding age, comorbidities, and illness severity score.

Similar numbers of MRSA and MSSA patients died (22.9% vs 19.8%; P = .53). Both the median length of hospitalization after S. aureus bacteremia for patients who survived and the median hospital charges after S. aureus bacteremia were significantly increased in MRSA patients (7 vs 9 days, P = .045; $19,212 vs $26,424, P = .008). After multivariable analysis, compared with MSSA bacteremia, MRSA bacteremia remained associated with increased length of hospitalization (1.29 fold; P = .016) and hospital charges (1.36 fold; P = .017). MRSA bacteremia had a median attributable length of stay of 2 days and a median attributable hospital charge of $6,916.

Methicillin resistance in S. aureus bacteremia is associated with significant increases in length of hospitalization and hospital charges.

Carbapenem-resistant Klebsiella pneumoniae is an emerging healthcare-associated pathogen.

To describe the epidemiology of and clinical outcomes associated with carbapenem-resistant K. pneumoniae infection and to identify risk factors associated with mortality among patients with this type of infection.

Mount Sinai Hospital, a 1,171-bed tertiary care teaching hospital in New York City.

Two matched case-control studies.

In the first matched case-control study, case patients with carbapenem-resistant K. pneumoniae infection were compared with control patients with carbapenem-susceptible K. pneumoniae infection. In the second case-control study, patients who survived carbapenem-resistant K. pneumoniae infection were compared with those who did not survive, to identify risk factors associated with mortality among patients with carbapenem-resistant K. pneumoniae infection.

There were 99 case patients and 99 control patients identified. Carbapenem-resistant K. pneumoniae infection was independently associated with recent organ or stem-cell transplantation (P = .008), receipt of mechanical ventilation (P = .04), longer length of stay before infection (P = .01), and exposure to cephalosporins (P = .02) and carbapenems (P < .001). Case patients were more likely than control patients to die during hospitalization (48% vs 20%; P < .001) and to die from infection (38% vs 12%; P < .001). Removal of the focus of infection (ie, debridement) was independently associated with patient survival (P = .002). The timely administration of antibiotics with in vitro activity against carbapenem-resistant K. pneumoniae was not associated with patient survival.

Carbapenem-resistant K. pneumoniae infection is associated with numerous healthcare-related risk factors and with high mortality. The mortality rate associated with carbapenem-resistant K. pneumoniae infection and the limited antimicrobial options for treatment of carbapenem-resistant K. pneumoniae infection highlight the need for improved detection of carbapenem-resistant K. pneumoniae infection, identification of effective preventive measures, and development of novel agents with reliable clinical efficacy against carbapenem-resistant K. pneumoniae.

Fluoroquinolones have not been frequently implicated as a cause of Clostridium difficile outbreaks. Nosocomial C. difficile infections increased from 2.7 to 6.8 cases per 1,000 discharges (P < .001). During the first 2 years of the outbreak, there were 253 nosocomial C. difficile infections; of these, 26 resulted in colectomy and 18 resulted in death. We conducted an investigation of a large C. difficile outbreak in our hospital to identify risk factors and characterize the outbreak.

A retrospective case-control study of case-patients with C. difficile infection from January 2000 through April 2001 and control-patients matched by date of hospital admission, type of medical service, and length of stay; an analysis of inpatient antibiotic use; and antibiotic susceptibility testing and molecular subtyping of isolates were performed.

On logistic regression analysis, clindamycin (odds ratio [OR], 4.8; 95% confidence interval [CI95], 1.9-12.0), ceftriaxone (OR, 5.4; CI95, 1.8-15.8), and levofloxacin (OR, 2.0; CI95, 1.2-3.3) were independently associated with infection. The etiologic fractions for these three agents were 10.0%, 6.7%, and 30.8%, respectively. Fluoroquinolone use increased before the onset of the outbreak (P < .001); 59% of case-patients and 41% of control-patients had received this antibiotic class. The outbreak was polyclonal, although 52% of isolates belonged to two highly related molecular subtypes.

Exposure to levofloxacin was an independent risk factor for C. difficile-associated diarrhea and appeared to contribute substantially to the outbreak. Restricted use of levofloxacin and the other implicated antibiotics may be required to control the outbreak.