The incidence of Clostridium difficile-associated disease (CDAD) appears to be increasing. Population-based estimates of disease have been limited, and analyses of hospital-level risk factors for CDAD are lacking. We sought to determine the incidence and trends of CDAD in Oregon and to identify hospital-level factors associated with increases in disease.

We analyzed hospital discharge data to calculate the incidence and to describe trends of CDAD in Oregon from 1995 through 2002. We administered questionnaires to hospital laboratory directors, infection control practitioners, and pharmacists to determine the status of laboratory, infection control, and pharmacy policies over time.

The overall incidence of CDAD in Oregon was 3.5 case patients per 10,000 residents in 2002. Incidence increased from 1.4 to 3.3 cases per 1,000 hospital discharges from 1995 to 2002. Rates of disease increased most in hospitals with licensed bed capacity of more than 250 beds and more than 5 intensive care unit beds. Few laboratories, infection control practitioners, and pharmacists were able to identify changes in specific policies over the study period.

This is the first study to determine a statewide population-based incidence of CDAD. Incidence of CDAD in Oregon has more than doubled over the past decade; larger hospitals experienced the greatest increase in disease rates. We did not identify hospital-level policies that could explain the increase. A study of patients with CDAD at the hospitals with the largest increases is underway to further identify risk factors.

To evaluate the epidemiology, outcomes, and importance of Clostridium difficile colonization pressure (CCP) as a risk factor for C. difficile–associated disease (CDAD) acquisition in intensive care unit (ICU) patients.

Secondary analysis of data from a 30-month retrospective cohort study.

A 19-bed medical ICU in a midwestern tertiary care referral center.

Consecutive sample of adult patients with a length of stay of 24 hours or more between July 1, 1997, and December 31, 1999.

Seventy-six (4%) of 1,872 patients were identified with CDAD; 40 (53%) acquired CDAD in the ICU, for an incidence of 3.2 cases per 1,000 patient-days. Antimicrobial therapy, enteral feeding, mechanical ventilation, vancomycin-resistant enterococci (VRE) colonization or infection, and CCP (5.5 vs 2.0 CDAD case-days of exposure for patients with acquired CDAD vs no CDAD; P = .001) were associated with CDAD acquisition in the univariate analysis. Only VRE colonization or infection (45% of patients with acquired CDAD vs 16% of patients without CDAD; adjusted odds ratio, 2.76 [95% confidence interval, 1.36-5.59]) and a CCP of more than 30 case-days of exposure (20% with acquired CDAD vs 2% with no CDAD; adjusted odds ratio, 3.77 [95% confidence interval, 1.14-12.49]) remained statistically significant in the multivariable analysis. Lengths of stay (6.1 vs 3.0 days; P < .001 by univariate analysis) and ICU costs ($11,353 vs $6,028; P < .001 by univariate analysis) were higher for patients with any CDAD than for patients with no CDAD.

In this nonoutbreak setting, the CCP was an independent risk factor for acquisition of CDAD in the ICU at the upper range of exposure duration. Having CDAD in the ICU was a marker of excess healthcare use.

Recent outbreaks of severe cases of Clostridium difficile-associated diarrhea (CDAD) reported in North America, the United Kingdom, and The Netherlands have emphasized the importance of an ongoing epidemiological surveillance of CDAD.

To determine the epidemiology of CDAD over the years 2000-2004 and the rate of nosocomial transmission of C. difficile.

Retrospective survey of inpatients with CDAD and molecular characterization of the strains isolated.

A 760-bed teaching hospital.

All CDAD cases diagnosed from January 1, 2000, to December 31, 2004, were reviewed. A CDAD case was defined as diarrhea in a hospitalized patient who had a stool specimen that tested positive for C. difficile cytotoxin or had a positive toxigenic culture result. CDAD was considered to be severe if a patient fulfilled at least 1 of the following 3 criteria: (1) presence of a fever (defined as temperature higher than 38.5°C), abdominal pain, and leukocyte count greater than 10,000 cells/mm3; (2) endoscopically or histologically proven pseudomembranous colitis; or (3) complications (defined as death with C. difficile infection as the primary or a contributing cause, toxic megacolon, perforation, toxic shock, and/or colectomy). CDAD was considered community-acquired if the diarrhea occurred in the patient within 72 hours after admission and if the patient had no history of hospitalization in the previous month; otherwise, CDAD was considered healthcare-associated. All the strains isolated were serogrouped and were characterized by toxinotyping and PCR ribotyping. Detection of toxin A, toxin B, and binary toxin was performed by PCR.

One hundred fifty-one cases of CDAD were diagnosed; 147 clinical records could be reviewed, and 131 strains were studied. The overall incidence of CDAD was 1.1 cases per 1,000 patients admitted, but incidence rates were higher in 2003-2004, compared with 2000-2002 (P = .017). Diarrhea was community acquired in 28 patients (19%). For patients with healthcare-associated CDAD, transmission of the strain from patient to patient (ie, infection with a strain of the same serogroup and PCR ribotype as the strain isolated from another patient hospitalized in the same ward or in a linked ward in the previous 2 months) was demonstrated in 12 cases (10.1%). Eleven percent of strains were positive for binary toxin. Binary toxin-positive strains were associated with more-severe diarrhea (P = .01 ) and with a higher case-fatality rate (P = .03). A specific clone of C. difficile (serogroup H, PCR ribotype sa026) accounted for 35 (26.7%) of all the strains isolated, but this clone was found both in healthcare-associated and community-acquired cases. Three strains belonged to toxinotype III, but only 1 was related to the hypervirulent clone involved in recent outbreaks.

The incidence of CDAD is low in our hospital, and cross-infection is limited. These results also suggest that strains with binary toxin might be more virulent.

The epidemiology of Clostridium difficile-associated disease (CDAD) is changing, with evidence of increased incidence and severity. However, the understanding of the magnitude of and reasons for this change is currently hampered by the lack of standardized surveillance methods.

An ad hoc C. difficile surveillance working group was formed to develop interim surveillance definitions and recommendations based on existing literature and expert opinion that can help to improve CDAD surveillance and prevention efforts.

A CDAD case patient was defined as a patient with symptoms of diarrhea or toxic megacolon combined with a positive result of a laboratory assay and/or endoscopic or histopathologic evidence of pseudomembranous colitis. Recurrent CDAD was defined as repeated episodes within 8 weeks of each other. Severe CDAD was defined by CDAD-associated admission to an intensive care unit, colectomy, or death within 30 days after onset. Case patients were categorized by the setting in which C. difficile was likely acquired, to account for recent evidence that suggests that healthcare facility-associated CDAD may have its onset in the community up to 4 weeks after discharge. Tracking of healthcare facility–onset, healthcare facility–associated CDAD is the minimum surveillance required for healthcare settings; tracking of community–onset, healthcare facility–associated CDAD should be performed only in conjunction with tracking of healthcare facility–onset, healthcare facility–associated CDAD. Community–associated CDAD was defined by symptom onset more than 12 weeks after the last discharge from a healthcare facility. Rates of both healthcare facility–onset, healthcare facility–associated CDAD and community–onset, healthcare facility–associated CDAD should be expressed as case patients per 10,000 patient–days; rates of community-associated CDAD should be expressed as case patients per 100,000 person-years.

Disinfection and sterilization are critical components of infection control. Unfortunately, breaches of disinfection and sterilization guidelines are not uncommon.

To describe a method for evaluating a potential breach of guidelines for high-level disinfection and sterilization of medical devices.

The appropriate scientific literature was reviewed to determine the frequency of failures of compliance. A risk assessment model was constructed.

A 14-step protocol was constructed to aid infection control professionals in the evaluation of potential disinfection and sterilization failures. In addition, a model is presented for aiding in determining how patients should be notified of the potential adverse event. Sample statements and letters are provided for communicating with the public and individual patients.

Use of a protocol can guide an institution in managing potential disinfection and sterilization failures.

To examine the association between working conditions and needlestick injury among registered nurses. We also describe needle use and needlestick injuries according to nursing position, workplace, and specialty.

Three-wave longitudinal survey conducted between November 2002 and April 2004.

A probability sample of 2,624 actively licensed registered nurses from 2 states in the United States. Follow-up rates for waves 2 and 3 were 85% and 86%, respectively. Respondents who had worked as a nurse during the past year (n = 2,273) prior to wave 1 were included in this analysis.

Of the nurses, 15.6% reported a history of needlestick injury in the year before wave 1, and the cumulative incidence by wave 3 was 16.3%. The estimated number of needles used per day was significantly related to the odds of sustaining a needlestick injury. Hours worked per day, weekends worked per month, working other than day shifts, and working 13 or more hours per day at least once a week were each significantly associated with needlestick injuries. A factor combining these variables was significantly associated with needlestick injuries even after adjustment for job demands, although this association was somewhat explained by physical job demands.

Despite advances in protecting workers from needlestick injuries, extended work schedules and their concomitant physical demands are still contributing to the occurrence of injuries and illnesses to nurses. Such working conditions, if modified, could lead to further reductions in needlestick injuries.

To evaluate the effect of introducing an engineered device for preventing injuries from sharp instruments (engineered sharps injury prevention device [ESIPD]) on the percutaneous injury rate in healthcare workers (HCWs).

We undertook a controlled, interventional, before-after study during a period of 3 years (from January 1998 through December 2000) at a major medical center. The study population was HCWs with potential exposure to bloodborne pathogens. HCWs who sustain a needlestick injury are required by hospital policy to report the exposure. A confidential log of these injuries is maintained that includes information on the date and time of the incident, the type and brand of sharp device involved, and whether an ESIPD was used.

Introduction of an intravenous (IV) catheter stylet with a safety-engineered feature (a retractable protection shield), which was placed in clinics and hospital wards in lieu of other IV catheter devices that did not have safety features. No protective devices were present on suture needles during any of the periods. The incidence of percutaneous needlestick injury by IV catheter and suture needles was evaluated for 18 months before and 18 months after the intervention.

After the intervention, the incidence of percutaneous injuries resulting from IV catheters decreased significantly (P < .01), whereas the incidence of injuries resulting from suture needle injuries increased significantly (P < .008).

ESIPDs lead to a reduction in percutaneous injuries in HCWs, helping to decrease HCWs' risk of exposure to bloodborne pathogens.

The rate of influenza vaccination among healthcare workers (HCWs) is approximately 40%. Differences in vaccination rates among HCW groups and reasons for accepting or rejecting vaccination are poorly understood.

To determine vaccination rates and motivators among different HCW groups during the 2004-2005 influenza season.

Cross-sectional survey conducted between July 10 and September 30, 2005.

Two tertiary care teaching hospitals in an urban center.

Physicians, nurses, nursing aides, and other staff. Surveys were collected from 1,042 HCWs (response rate, 42%).

Sixty-nine percent of physicians (n = 282) and 63% of medical students (n = 145) were vaccinated, compared with 46% of nurses (n = 336), 42% of nursing aides (n = 135), and 29% of administrative personnel (n = 144). Physicians and medical students were significantly more likely to be vaccinated than all other groups (P < .0001). Pediatricians (84%) were more likely than internists (69%) and surgeons (43%) to be vaccinated (P < .0001). Among the HCWs who were vaccinated, 33.4% received the live attenuated influenza vaccine (LAIV) and 66.6% received trivalent inactivated influenza vaccine (TIV). Vaccinated HCWs were less likely than unvaccinated HCWs to report an influenza-like illness (P = .03). Vaccination with LAIV resulted in fewer episodes of influenza-like illness than did receiving no vaccine (P = .03). The most common reason for rejecting vaccination was a concern about availability. Understanding that HCWs may transmit the virus to patients correlated with vaccine acceptance (P = .0004).

Significant differences in vaccination exist among physician specialties and employee groups, and there are inadequate vaccination rates among those with the greatest amount of patient contact, potentially providing a basis for group-specific interventions.

To present a hypothetical model of the change in economic costs and health benefits to society that result from nosocomial infection control programs.

We use a modeling framework to represent how 2 types of costs change with nosocomial infection control programs: costs incurred by the hospital sector and community health services, as well as the private costs to patients. We also demonstrate how to value the health benefits of nosocomial infection control programs, using quality-adjusted life years.

Hypothetical modeling to incorporate the societal perspective.

A cohort of 50,000 simulated patients at risk of surgical site infection following total hip replacement.

A total of 8 hypothetical interventions that change costs and health outcomes among the cohort by preventing cases of surgical site infection following total hip replacement.

We demonstrate that when infection control interventions reduce economic costs and increase health benefits, they should be adopted without further question. If, however, interventions increase economic costs and increase health benefits, then the trade—off between costs and benefits should be examined. Decision-makers should assess the cost per unit of health benefit from infection control programs, consider the impact on health budgets, and compare infection control with alternative uses of scarce healthcare resources.

To determine the number of Staphylococcus aureus isolates collected in a dental clinical environment and to determine their susceptibility to antimicrobial agents commonly used in dentistry.

Undergraduate clinic of the Dental School of Piracicaba, University of Campinas, Brazil.

Sterile cotton swabs were used to collect the samples from dental-chair push buttons, light handles, 3-in-l syringes, computer “Enter” keys, doorknobs, and X-ray tubes before, during, and after clinical procedures. These samples were spread on brain-heart infusion agar and were incubated at 37°C for 24 hours. The resulting S. aureus isolates were counted and classified using Gram staining and biochemical tests. The counts among the 3 periods and the groups were analyzed by Kruskal-Wallis and Dunn tests (α = 5%). Commercial paper disks containing widely prescribed antimicrobial agents (β-lactams, macrolides, clindamycin, and vancomycin) were used to perform the antimicrobial susceptibility tests.

An increase in the number of microorganisms was observed during clinical procedures (P < .05). The highest bacterial resistance rates were observed for the β-lactam group. All isolated strains were sensitive to vancomycin, and 2% of them were resistant to methicillin.

Clinical procedures increased the number and proportion of antimicrobial-resistant S. aureus isolates dispersed in a dental clinical environment. The present study highlights the need to establish strategies to prevent emergence of drug-resistant bacterial strains in dental settings.

To evaluate the immediate, persistent and sustained in vivo activity of an alcohol-based surgical hand disinfectant, consisting of a zinc gel and a preservative system containing a synergistic combination of farnesol and benzethonium chloride (ZBF disinfectant), and to develop a pig skin model for in vitro evaluation of the immediate and persistent efficacy of alcohol-based surgical hand disinfectants against resident hand flora.

The in vivo immediate, persistent, and sustained activity of ZBF disinfectant was evaluated using human volunteers and the “glove-juice” method described in the US Food and Drug Administration's Tentative Final Monograph (FDA-TFM) for Healthcare Antiseptic Products. A novel in vitro pig skin model was developed to compare the immediate and persistent activity of alcohol-based surgical hand disinfectants against resident flora using Staphylococcus epidermidis as the test organism. Four alcohol-based surgical hand disinfectants were evaluated using this model.

The results for the ZBF disinfectant exceed the FDA-TFM criteria for immediate, persistent, and sustained activity required for surgical hand disinfectants. The reduction factors for the 4 hand disinfectants obtained using the pig skin model show good agreement with the log10 reductions in concentrations of hand flora obtained using human volunteers to test for immediate and persistent activity.

The ZBF disinfectant we evaluated met the FDA-TFM criteria for surgical hand disinfectants. The immediate and persistent efficacy of the surgical hand disinfectants evaluated with the novel pig skin model described in this study shows good agreement with the results obtained in vivo.