Vital Signs: Preventing Clostridium difficile Infections

Conclusions and Comment

The incidence, mortality, and medical care costs of CDIs have reached historic highs.^[1,3,9,10] The estimated number of deaths attributed to CDI, based on multiple cause-of-death mortality data, increased from 3,000 deaths per year during 1999–2000 to 14,000 during 2006–2007, with more than 90% of deaths in persons aged ≥65 years.^[10] Recent excess health-care costs of hospital-onset CDI are estimated to be $5,042–$7,179 per case with a national annual estimate (limited to the subset of hospital-onset CDIs only) of $897 million to $1.3 billion.^[11] Much of the recent increase in the incidence and mortality of CDIs is attributed to the emergence and spread of a hypervirulent, resistant strain of C. difficile that produces greater quantities of principal virulence toxins A and B and has additional factors enhancing its virulence.^[9,12] Nonetheless, many of these infections can be prevented, as demonstrated by the 20% reduction in incidence of hospital-onset CDI among three state prevention programs conducted over approximately 21 months. In England, where a national campaign to publicly report and prevent CDIs was implemented in 2007 through an emphasis on antibiotic stewardship as well as infection control,^[13] pooled hospital-onset CDI rates declined 56% during a 3-year period (2008–2011).^[14] In the United States, the National Action Plan for Prevention of HAIs has targeted a 30% reduction of CDIs in acute-care hospitals by 2015.^[15]

Principal recommendations to prevent CDI include improving antibiotic use, early and reliable detection of CDI, isolation of symptomatic patients, and reducing C. difficile contamination of health-care environmental surfaces.^[3] Good antibiotic stewardship is an important aspect of quality health care that prevents CDI. Antibiotic use increases the risk for developing CDI by seven- to 10-fold while the patient is taking the antibiotic and for 1 month after discontinuation, and by approximately three-fold for the subsequent 2 months.^[16] CDC provides tools for facilities to develop antibiotic stewardship programs.^†

To prevent transmission of C. difficile, early detection and isolation of patients with CDI is essential. Nucleic acid amplification tests can be as much as twice as sensitive as enzyme immunoassays and can detect CDI more accurately when used in populations with an appropriate pretest probability (i.e., patients with more than three unformed stools in a 24-hour period without an identified cause).^[3,17] Because of their increased sensitivity, nucleic acid amplification tests will yield higher hospital-onset CDI rates. Currently, 35% of NHSN hospitals are using nucleic acid amplification tests (Table 1); risk adjustment will be necessary to compare rates accurately where diagnostic testing practices vary.

C. difficile frequently is transmitted between patients via hands of health-care personnel transiently contaminated after contact with symptomatic patients or their surrounding environment. Glove use, with strict adherence to changing between patient contacts, is the best proven method for preventing hand contamination with C. difficile from symptomatic patients.^[3,4] Health-care environmental services have a key role in reducing contamination that can directly transmit to patients or contaminate the hands of health-care personnel.^§ Because C. difficile spores resist killing by usual hospital disinfectants, an Environmental Protection Agency–registered disinfectant with a C. difficile sporicidal label claim^¶ should be used to augment thorough physical cleaning.

These findings emphasize how the risk for CDI from antibiotic exposure and transmission moves with patients across multiple health-care settings, leading to the interdependence of health-care settings in a region to lower their CDI rates. Because antibiotics disrupt the normally protective bacterial populations of the lower intestine in a manner that increases risk for CDI for 3 or more months, antibiotics received in one setting often predispose a patient to develop CDI in another. In contrast, because the incubation period is a median of only 2–3 days,^[3] acquisition of C. difficile is overall more likely to have occurred in the setting where symptoms have their onset and CDI is diagnosed. Meanwhile, CDIs present on hospital admission are most often related to the care delivered in other inpatient or outpatient facilities; because they are an important source for intrahospital transmission, CDIs present on admission are a risk factor for higher hospital-onset CDI rates.^[18]

The findings of this report are subject to at least six limitations. First, data on antibiotic exposure, which are important for targeting prevention efforts, were not available. An NHSN option designed to address this problem is undergoing piloting with electronic health record vendors.** Second, data on potential underlying temporal trends in prevention program hospitals were not available. Third, the various methods used to implement prevention strategies in the prevention hospitals were not described (e.g., staff training, assessment and feedback of compliance with isolation precautions, or adequacy of environmental cleaning). Although the pooled rate toward the end of these programs (7.5 per 10,000 patient-days) was similar to the rate across all NHSN hospitals in 2010 (7.4), the three programs started and ended at different rates, suggesting that locally tailored approaches to prevention might be beneficial. Fourth, the impact of ongoing CDI prevention initiatives under way during the early phase of evaluation also was not assessed. Fifth, the potential impact of any shifts in test sensitivity between different methods used (e.g., nucleic acid amplification versus enzyme immunoassay) was not assessed. Finally, in both the Emerging Infections Program and NHSN, the setting of onset was based on where the patient was located at the time of stool specimen collection; therefore, there might have been misclassification of cases if a marked delay occurred between onset of symptoms and stool specimen collection.

Because nearly 75% of all CDIs related to U.S. health care have their onset outside of hospitals, more needs to be done to prevent CDIs across all health-care settings. For its part, CDC is working to improve NHSN LabID-CDI event reporting for nursing homes as well as hospitals. Clinical document architecture specifications are available for electronic health record system vendors to use in enabling their systems to serve as electronic data sources for LabID-CDI event reporting to NHSN.^†† The option to report electronically will take on greater importance as increasing numbers of hospitals are required to report LabID-CDI events to NHSN. Currently, six states (California, Illinois, New York, Oregon, Tennessee, and Utah) mandate public reporting of facility-wide LabID-CDI events. Beginning in 2013, all hospitals participating in the Centers for Medicare and Medicaid Services' Inpatient Prospective Payment System Quality Reporting Program will be required to report facility-wide LabID-CDI events using NHSN to qualify for their 2015 annual payment update; public reporting of hospital rates will begin in 2014 at the Hospital Compare website.^[19]

Clinicians and other health-care providers, as well as inpatient and outpatient health-care facilities, state and federal public health officials (e.g., the Partnership for Patients), and partner patient safety organizations, could benefit from increased collaboration in preventing CDIs. Such collaborations could broaden and enhance the use of prevention strategies and do so across the entire spectrum of U.S. health-care delivery. State health departments, working with regional quality improvement organizations, hospital associations, and other nongovernmental patient safety partners, are positioned uniquely to work across these multiple settings.^§§ Given the emphasis of current health-care reform efforts to improve patient safety while reducing costs, now is an opportune time to begin to eliminate health-care–associated CDIs.

Morbidity and Mortality Weekly Report. 2012;61(9):157-162. © 2012 Centers for Disease Control and Prevention (CDC)