• Use a stool toxin test as part of a multistep algorithm (i.e., glutamate dehydrogenase [GDH] plus toxin; GDH plus toxin, arbitrated by NAATs; or NAAT plus toxin) rather than NAAT alone for all specimens received in the clinical laboratory when there are no pre- agreed institutional criteria for patient stool submission. • Use NAAT alone or a multistep algorithm for testing (i.e., GDH plus toxin; GDH plus toxin, arbitratedby NAAT; or NAAT plus toxin) rather than a toxin test alone when there are pre- agreed institutional criteria for patient stool submission. • Do not perform repeat testing (within 7 days) during the same episode of diarrhea and do not test stool from asymptomatic patients, except for epidemiological studies (strong recommendation, moderate quality of evidence). Guidelines and systematic reviews recommend only testing symptomatic patients for C. difficile, except for the purpose of epidemiological studies. The recommendations are somewhat flexible with regard to the number of episodes of diarrhea that justify the need for CDI testing, noting that providers should take into account whether the patient has risk factors for CDI, most notable of which is antimicrobial use. Before testing, physicians should attempt to rule out other causes of diarrhea. Considerations with regard to repeat testing include the background prevalence of CDI at the facility. Guidelines also recommended that, while laboratory diagnosis is pending, treatment should be initiated empirically for patients who present with fulminant CDI or if obtaining the test results takes more than 48 hours. If test results cannot be obtained on the same day, patients with suspected CDI should be placed on preemptive contact precautions pending the C. difficile test results. As treatment recommendations differ, it is important to know the severity of the infection and whether it is an initial or recurrent episode. An abdominal CT scan may be used to differentiate between CDI and other causes of colitis and to determine the extent of the disease. However, to diagnose regular CDI (e.g., while test results are pending), when an abdominal CT
has poor sensitivity, endoscopy can be used in certain urgent situations. The American College of Gastroenterology guidelines recommend endoscopy when a rapid diagnosis is needed or an initial negative toxin assay when CDI is strongly suspected, when there is an ileus and stool is not available, or when other colonic diseases are in the differential diagnosis. 73 Screening and isolation of asymptomatic carriers Preemptively identifying hospital patients at risk for CDI, and for severe courses of CDI, has been proposed as a patient safety strategy. At the patient level, it is recommended to screen symptomatic patients primarily so that providers can identify those in need of CDI treatment. The arguments in support of only screening symptomatic patients include: • Screening asymptomatic patients requires significant laboratory resources, • Studies on MRSA found that active surveillance was not more effective than enhanced infectioncontrol policies, • Isolating asymptomatic CDI carriers requires additional hospital resources (e.g., single rooms), and • Other interventions, such as hand hygiene, are effective at reducing multiple HAIs and are a better use of resources. Several published studies, however, have found public health benefits from screening asymptomatic carriers. One quasi- experimental study and three simulations found that detecting and isolating asymptomatic carriers was associated with prevention of future cases. Screening and treating high-risk populations (regardless of CDI symptomology) is also explored in the literature. Some suggest that patients at high likelihood of being asymptomatic carriers not be tested but medical staff should use enhanced infection control practices such as the use of gloves. In addition, units or facilities with high likelihood of asymptomatic carriers should carry out CDI cleaning protocols. Key findings about testing • Some research supports universal C. difficile testing for hospitalized patients with diarrhea.
• Screening and isolating asymptomatic carriers can prevent CDI transmission but is resource intensive. • NAATs of unformed stool have relatively accurate sensitivity and specificity. • Concerns with NAATs include that they detect toxigenic C. difficile genes, not the actual damaging toxins and may capture colonized patients in addition to those infected with C. difficile . • Certain multistep test algorithms (that include a test for C. difficile and for CDI toxins) perform as well as or better than NAATs but take longer. • Tools that identify patient risk for CDI couldbe useful in preventing CDI. • Tools that identify a high risk of severe CDI or mortality show promise for preventing severe CDI outcomes. Multicomponent CDI prevention interventions The most common component of multicomponent interventions is environmental cleaning and decontamination. Isolation of CDI patients and hand hygiene practices are the next most common components. Antimicrobial stewardship practices, contact precautions, testing and surveillance practices, and patient isolation/ cohorting are also common in multicomponent CDI prevention interventions. (Table 1) Cross-Cutting Practices Cross-cutting practices that can facilitate the success of a multicomponent intervention include the use of checklists and assigned roles, staff education, improved workflow systems, and communicating laboratory results and communicating CDI patient status through door signs. In a study by Power et al. (2010), an 850- bed hospital implemented a multicomponent intervention that included antimicrobial stewardship, hand hygiene, environmental cleaning and decontamination, and education about CDI. In five wards with higher baseline CDI rates, there was an implementation of an “improvement collaborative,” in which staff were broken into teams who planned, implemented, and measured the impact of selected PSPs as outlined by a systems improvement toolkit. 74
Table 1. Multicomponent CDI Prevention Interventions
Intervention Component
Specific Practices
Environmental cleaning and decontamination
Increase in environmental services hours and training, dedicated CDI cleaning teams, cleaning equipment, dedicated equipment, disposable washbowls, dailyand terminal cleaning with bleach solution, terminal hydrogen peroxide decontamination, terminal curtain change, protocols and checklists
CDI patientisolation
CDI patient cohorts, private rooms for CDI patients, wards for CDI patients, rapidisolation
Hand hygiene
Removal of ABHRs, promotion of handwashing with soap and water when workingwith CDI patients, patient hand hygiene, hand hygiene observations/audits, installation of sinks Discontinuation of nonessential antimicrobials, restriction of the use of clindamycin, cephalosporins, and quinolones, revised guidelines and formularies Use of gowns and gloves when working with CDI patients, limits on patientvisitors, empiric contact precautions
Antimicrobialstewardship
Contact precautions
Testing
Testing at first sign of diarrhea, promotion of testing, new diagnostic assay Tracking and classification of CDI cases, education, outbreak investigation
Surveillance
95
Powered by FlippingBook