To evaluate the impact of postdischarge surveillance on surgical site infection (SSI) rates after orthopedic surgery.

Nine hospitals participating in the Finnish Hospital Infection Program.

All patients who underwent hip or knee arthroplasty or open reduction of a femur fracture during 1999-2002.

The date of discharge was available for 11,812 procedures (90%). The median length of hospital stay was 8 days (range per hospital, 6-9 days). The overall SSI rate was 3.3% (range, 0.8%-6.4%). Of 384 SSIs detected, 216 (56%; range, 28%-90%) were detected after discharge: 93 (43%) were detected on readmission to the hospital, 73 (34%) at completion of a postdischarge questionnaire, and 23 (11%) at a follow-up visit. For 27 postdischarge SSIs (13%), the location of detection was unknown. Altogether, 32 (86%) of 37 of organ/space SSIs, 57 (80%) of 71 deep incisional SSIs, and 127 (46%) of 276 superficial incisional SSIs were detected after discharge. Most SSIs (70%) detected on readmission were severe (organ/space or deep incisional), whereas most SSIs (86%) detected at follow-up visits or at completion of a postdischarge questionnaire were superficial. Of all SSIs, 78% (range, 48%-100%) were microbiologically confirmed. Microbiologic confirmation was less common after discharge than during postoperative hospital stay (66% vs 93%; P< .001).

Postdischarge surveillance had a large impact on the rate of SSI detected after orthopedic surgery. However, postdischarge surveillance conducted by means of a questionnaire detected only a minority of deep incisional and organ/space SSIs.

The incidence of extended-spectrum β-lactamase (ESβL)–mediated resistance has increased markedly during the past decade. Risk factors for colonization with ESβL-producing Escherichia coli and Klebsiella species (ESβL-EK) remain unclear, as do methods to control their further emergence.

Case–control study.

Two hospitals within a large academic health system: a 725-bed academic tertiary-care medical center and a 344-bed urban community hospital.

Thirteen patients with ESβL-EK fecal colonization were compared with 46 randomly selected noncolonized controls.

Duration of hospitalization was the only independent risk factor for ESβL-EK colonization (odds ratio, 1.11; 95% confidence interval, 1.02 to 1.21). Of note, 8 (62%) of the patients had been admitted from another healthcare facility. In addition, there was evidence for dissemination of a single K. oxytoca clone. Finally, the prevalence of ESβL-EK colonization decreased from 7.9% to 5.7% following restriction of third-generation cephalosporins (P = .51).

ESβL-EK colonization was associated only with duration of hospitalization and there was no significant reduction following antimicrobial formulary interventions. The evidence for nosocomial spread and the high percentage of patients with ESβL-EK admitted from other sites suggest that greater emphasis must be placed on controlling the spread of such organisms within and between institutions.

Prevalence of multidrug-resistant microorganisms (MDROs) continues to increase, while infection control gaps in healthcare settings facilitate their transmission between patients. In this setting, 5 distinct yet interlinked pathways are responsible for transmission. The complete transmission process is still not well understood. Designing and conducting a single research study capable of investigating all 5 complex and multifaceted pathways of hospital transmission would be costly and logistically burdensome. Therefore, this scoping review aims to synthesize the highest-quality published literature describing each of the 5 individual potential transmission pathways of MDROs in the healthcare setting and their overall contribution to patient-to-patient transmission.

In 3 databases, we performed 2 separate systematic searches for original research published during the last decade. The first search focused on MDRO transmission via the HCW or the environment to identify publications studying 5 specific transmission pathways: (1) patient to HCW, (2) patient to environment, (3) HCW to patient, (4) environment to patient, and (5) environment to HCW. The second search focused on overall patient-to-patient transmission regardless of the transmission pathway. Both searches were limited to transmission of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus, multidrug-resistant A. baumannii, and carbapenem-resistant Enterobacteriaceae. After abstract screening of 5,026 manuscripts, researchers independently reviewed and rated the remaining papers using objective predefined criteria to identify the highest quality and most influential manuscripts.

High-quality manuscripts were identified for all 5 routes of transmission. Findings from these studies were consistent for all pathways; however, results describing the routes from the environment/HCW to a noncolonized patient were more limited and variable. Additionally, most research focused on MRSA, instead of other MDROs. The second search yielded 10 manuscripts (8 cohort studies) that demonstrated the overall contribution of patient-to-patient transmission in hospitals regardless of the transmission route. For MRSA, the reported cross-transmission was as high as 40%.

This scoping review brings together evidence supporting all 5 possible transmission pathways and illustrates the complex nature of patient-to-patient transmission of MDROs in hospitals. Our findings also confirm that transmission of MDROs in hospitals occurs frequently, suggesting that ongoing efforts are necessary to strengthen infection prevention and control to prevent the spread of MDROs.

To consider statistical methods for estimating transmission rates for colonization of patients with methicillin-resistant Staphylococcus aureus (MRSA) in an intensive care unit (ICU) from three different sources: background contamination, non-isolated patients, and isolated patients.

We developed statistical methods that allowed for the analysis of interval-censored, routine surveillance data and extended the general epidemic model for the flow of patients through the ICU.

Within this ICU, the rate of transmission to susceptible patients from a background source of MRSA (0.0092 case per day; 95% confidence interval [CI95], 0.0062–0.0126) is approximately double the rate of transmission from a non-isolated patient (0.0052 case per day; CI95, 0.0013–0.0096) and six times the rate of transmission from an isolated patient (0.0015 case per day; CI95, 0.0001–0.0043). We used the methodology to investigate whether transmission rates vary with workload.

Our methodology has general application to infection by and transmission of pathogens in a hospital setting and is appropriate for quantifying the effect of infection control interventions. (Infect Control Hosp Epidemiol 2005;26:598-606)

Catheter-associated urinary tract infections (CAUTIs) are among the most common hospital-acquired infections (HAIs). Reducing CAUTI rates has become a major focus of attention due to increasing public health concerns and reimbursement implications.

To implement and describe a multifaceted intervention to decrease CAUTIs in our ICUs with an emphasis on indications for obtaining a urine culture.

A project team composed of all critical care disciplines was assembled to address an institutional goal of decreasing CAUTIs. Interventions implemented between year 1 and year 2 included protocols recommended by the Centers for Disease Control and Prevention for placement, maintenance, and removal of catheters. Leaders from all critical care disciplines agreed to align routine culturing practice with American College of Critical Care Medicine (ACCCM) and Infectious Disease Society of America (IDSA) guidelines for evaluating a fever in a critically ill patient. Surveillance data for CAUTI and hospital-acquired bloodstream infection (HABSI) were recorded prospectively according to National Healthcare Safety Network (NHSN) protocols. Device utilization ratios (DURs), rates of CAUTI, HABSI, and urine cultures were calculated and compared.

The CAUTI rate decreased from 3.0 per 1,000 catheter days in 2013 to 1.9 in 2014. The DUR was 0.7 in 2013 and 0.68 in 2014. The HABSI rates per 1,000 patient days decreased from 2.8 in 2013 to 2.4 in 2014.

Effectively reducing ICU CAUTI rates requires a multifaceted and collaborative approach; stewardship of culturing was a key and safe component of our successful reduction efforts.

Infect Control Hosp Epidemiol 2017;38:186–188

To describe variability in rates of antibacterial use in a large sample of US hospitals and to create risk-adjusted models for interhospital comparison.

We retrospectively surveyed the use of 87 antibacterial agents on the basis of electronic claims data from 130 medical-surgical hospitals in the United States for the period August 2002 to July 2003; these records represented 1,798,084 adult inpatients. Hospitals were assigned randomly to the derivation data set (65 hospitals) or the validation data set (65 hospitals). Multivariable models predicting rates of antibacterial use were created using the derivation data set. These models were then used to predict rates of antibacterial use in the validation data set, which was compared with observed rates of antibacterial use. Rates of antibacterial use was measured in days of therapy per 1,000 patient-days.

Across the surveyed hospitals, a mean of 59.3% of patients received at least 1 dose of an antimicrobial agent during hospitalization (range for individual hospitals, 44.4%-73.6%). The mean total rate of antibacterial use was 789.8 days of therapy per 1,000 patient-days (range, 454.4-1,153.4). The best model for the total rate of antibacterial use explained 31% of the variance in rates of antibacterial use and included the number of hospital beds, the number of days in the intensive care unit per 1,000 patient-days, the number of surgeries per 1,000 discharges, and the number of cases of pneumonia, bacteremia, and urinary tract infection per 1,000 discharges. Five hospitals in the validation data set were identified as having outlier rates on the basis of observed antibacterial use greater than the upper bound of the 90% prediction interval for predicted antibacterial use in that hospital.

Most adult inpatients receive antimicrobial agents during their hospitalization, but there is substantial variability between hospitals in the volume of antibacterials used. Risk-adjusted models can explain a significant proportion of this variation and allow for comparisons between hospitals for benchmarking purposes.

To compare the characteristics and risk factors for surgical site infections (SSIs) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in a nationwide survey, using shared case detection and recording systems.

Retrospective cohort study.

Twenty-six hospitals participating in the Korean Nosocomial Infections Surveillance System (KONIS).

From 2006 to 2009, all patients undergoing THA and TKA in KONIS were enrolled.

SSI occurred in 161 (2.35%) of 6,848 cases (3,422 THAs and 3,426 TKAs). Pooled mean SSI rates were 1.69% and 2.82% for THA and TKA, respectively. Of the cases we examined, 42 (26%) were superficial-incisional SSIs and 119 (74%) were “severe” SSIs; of the latter, 24 (15%) were deep-incisional SSIs and 95 (59%) were organ/space SSIs. In multivariate analysis, a duration of preoperative hospital stay of greater than 3 days was a risk factor for total SSI after both THA and TKA. Diabetes mellitus, revision surgery, prolonged duration of surgery (above the 75th percentile), and the need for surgery due to trauma were independent risk factors for total and severe SSI after THA, while male sex and an operating room without artificial ventilation were independent risk factors for total and severe SSI after TKA. A large volume of surgeries (more than 10 procedures per month) protected against total and severe SSI, but only in patients who underwent TKA.

Risk factors for SSI after arthroplasty differ according to the site of the arthroplasty. Therefore, clinicians should take into account the site of arthroplasty in the analysis of SSI and the development of strategies for reducing SSI.

To determine baseline rates of primary bloodstream infection (BSI) among a large pool of patients receiving hemodialysis using standardized surveillance tools and methodology.

Prospective, descriptive analysis of primary BSI rates.

Ten hospital-based hemodialysis centers in Connecticut.

All patients receiving long-term hemodialysis in the participating facilities.

A total of 158 BSIs occurred during 142,525 dialysis sessions within a 12-month study period. Of the BSIs, 15.2% occurred in patients with fistula or graft access and 84.8% in patients with central venous catheter access (P < .001). Rates per 100 patient-years in centers ranged from 0 to 30.8, with a mean of 16.6. Rates per 1,000 dialysis sessions ranged from 0 to 2.1, with a mean of 1.1. Coagulase-negative staphylococci and Staphylococcus aureus (including methicillin-resistant S. aureus) accounted for 61% and Klebsiella or Enterobacter species for 14.6% of infections. Of the patients, 63.3% received vancomycin, 24.7% received cefazolin, and 41.7% received aminoglycosides. Rates declined in the second 6 months of the study from 1.4 to 0.8 infections per 1,000 dialysis sessions (P < .001).

Primary BSI rates varied widely among participating centers and declined during the study period. BSIs were strongly associated with central venous catheter access. Further studies are needed to determine the reasons for variance in rates between centers and among various types of hemodialysis access.

To compare incidence of hospital-onset Clostridium difficile infection (CDI) measured by the use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge diagnosis codes with rates measured by the use of electronically available C. difficile toxin assay results.

Cases of hospital-onset CDI were identified at 5 US hospitals during the period from July 2000 through June 2006 with the use of 2 surveillance definitions: positive toxin assay results (gold standard) and secondary ICD-9-CM discharge diagnosis codes for CDI. The x2 test was used to compare incidence, linear regression models were used to analyze trends, and the test of equality was used to compare slopes.

Of 8,670 cases of hospital-onset CDI, 38% were identified by the use of both toxin assay results and the ICD-9-CM code, 16% by the use of toxin assay results alone, and 45% by the use of the ICD-9-CM code alone. Nearly half (47%) of cases of CDI identified by the use of a secondary diagnosis code alone were community-onset CDI according to the results of the toxin assay. The rate of hospital-onset CDI found by use of ICD-9-CM codes was significantly higher than the rate found by use of toxin assay results overall (P<.001), as well as individually at 3 of the 5 hospitals (P<.001 for all). The agreement between toxin assay results and the presence of a secondary ICD-9-CM diagnosis code for CDI was moderate, with an overall k value of 0.509 and hospital-specific k values of 0.489–0.570. Overall, the annual increase in CDI incidence was significantly greater for rates determined by the use of ICD-9-CM codes than for rates determined by the use of toxin assay results (P = .006).

Although the ICD-9-CM code for CDI seems to be adequate for measuring the overall CDI burden, use of the ICD-9-CM discharge diagnosis code for CDI, without present-on-admission code assignment, is not an acceptable surrogate for surveillance for hospital-onset CDI.

To investigate and control an outbreak of epidemic keratoconjunctivitis (EKC) occurring in a neonatal intensive care unit (NICU) and to determine signs specific for EKC in newborns.

Outbreak investigation and case–control study.

NICU of a 1,600-bed university hospital in Heidelberg, Germany.

Case-patients were defined as individuals who had adenoviral antigen detected by ELISA or by PCR from conjunctival swabs or who had clinical signs of conjunctivitis. Twelve newborns from the NICU who had EKC between October and November 1998 were compared with 11 who had bacterial conjunctivitis.

Control measures included cohorting patients in contact isolation, using gloves and gowns for patient care, and using a hand rub and disinfectants with virucidal activity.

Thirteen patients, 6 healthcare workers, and 11 relatives of the patients had EKC, according to our case definition. Case-patients were more likely than control-patients to develop lacrimal swelling (P < .001), eye redness (P = .004), and lacrimation (P = .037) involving both eyes (P = .002). Prior examination by an ophthalmologist was a significant risk factor for EKC (P = .004). For diagnosis or treatment of retinopathy, premature newborns were seen by an ophthalmologist from a nearby eye care center where an EKC outbreak was ongoing. No new cases were diagnosed more than 10 days after the implementation of control measures.

In newborns, lacrimal swelling, eye redness, and lacrimation in both eyes should evoke suspicion of EKC. Ophthalmologists who have had contact with known EKC cases should use antiseptics and disinfectants with virucidal activity before contact with newborns or abstain from examining newborns (Infect Control Hosp Epidemiol 2003;24:514-519)

To determine the added costs of hygienic measures (barrier precautions, isolation, and decontamination) required for MRSA carriers in German hospitals and possible strategies for cost reduction.

On a septic surgical ward caring for 35% of all MRSA cases in a university hospital (1,182 beds), additional costs for personnel time and materials were calculated and medical charts of all MRSA cases admitted to the ward during 1 year were analyzed retrospectively. Twelve of the ward's 13 beds were located in rooms with at least 2 beds.

Four hundred ninety-eight MRSA carrier hospital-days (of 20 MRSA cases) could be assessed. All patients (80% men, 50% older than 74.5 years) had broken skin.

In 95% of the cases, microbiological findings suggested transmission of MRSA during the current or a previous stay on this ward. The study found total avoidable costs of approximately 142,794.01 euros in 1 year, averaging 371.95 euros for one MRSA patient hospital-day and 9,261.56 euros per MRSA case. The most expensive single measure was blocked beds in multibed rooms (305.75 euros/day), which accounted for 82% of the extra costs. Costs most likely were underestimated.

Daily additional case costs amounted to 96% of social security payments. Blocked beds in multibed rooms accounted for more than 80% of these excess costs. Isolation has been scientifically validated and is required by law in Germany. Building an adequate number of single-bed rooms should help prevent spread and would greatly lower the added costs of infection.

Efficient methods are needed to monitor infections associated with long-term central venous catheters (CVCs) in both inpatient and outpatient settings. Automated medical records and claims data have been used for surveillance of these infections without evaluation of their accuracy or validity.

To determine the feasibility of using electronic records to identify CVC placement and design a system for identifying CVC-associated infections.

Retrospective cohort study at an HMO and two teaching hospitals in Boston, one adult (hospital A) and one pediatric (hospital B), between January 1991 and December 1997. Tunneled catheters, totally implanted catheters, and hemodialysis catheters were examined. Claims databases of both the HMO and the hospitals were searched for 10 CPT codes, 2 ICD-9 codes, and internal charge codes indicating CVC insertion. Lists were compared with each other and with medical records for correlation and accuracy.

All members of the HMO who had a CVC inserted at one of the two hospitals during the study period.

There was wide variation in the CVC insertions identified in each database. Although ICD-9 codes at each hospital and CPT/ICD-9 combinations at the HMO found similar total numbers of CVCs, there was little overlap between the individuals identified (62% for hospital A with HMO and 4% for hospital B).

Claims data from different sources do not identify the same CVC insertion procedures. Current administrative databases are not ready to be used for electronic surveillance of CVC-associated complications without extensive modification and validation.

New technologies have emerged in recent years for the disinfection of hospital rooms and equipment that may not be disinfected adequately using conventional methods. There are several hydrogen peroxide–based area decontamination technologies on the market, but no head-to-head studies have been performed.

We conducted a head-to-head in vitro comparison of a hydrogen peroxide vapor (HPV) system (Bioquell) and an aerosolized hydrogen peroxide (aHP) system (Sterinis).

The tests were conducted in a purpose-built 136-m3 test room.

One HPV generator and 2 aHP machines were used, following recommendations of the manufacturers. Three repeated tests were performed for each system. The microbiological efficacy of the 2 systems was tested using 6-log Tyvek-pouched Geobacillus stearo-thermophilus biological indicators (BIs). The indicators were placed at 20 locations in the first test and 14 locations in the subsequent 2 tests for each system.

All BIs were inactivated for the 3 HPV tests, compared with only 10% in the first aHP test and 79% in the other 2 aHP tests. The peak hydrogen peroxide concentration was 338 ppm for HPV and 160 ppm for aHP. The total cycle time (including aeration) was 3 and 3.5 hours for the 3 HPV tests and the 3 aHP tests, respectively. Monitoring around the perimeter of the enclosure with a handheld sensor during tests of both systems did not identify leakage.

One HPV generator was more effective than 2 aHP machines for the inactivation of G. stearothermophilus BIs, and cycle times were faster for the HPV system.