The problem with C difficile Infection

This article originally appeared in the April 2012 issue of Infectious Disease Alert.

Source: Centers for Disease Control and Prevention. Vital Signs: Preventing Clostridium difficile infection. MMWR 2012;61(9): 157-162.

This report attempts to catalogue the ballooning number of cases of C difficile infection (CDI) in the United States using available resources, including data collected from the IDSA Emerging Infections Program (which has a catchment area of 111 acute-care hospitals and 310 nursing homes); the 2010 National Health and Safety Network data, which covers 711 acute care hospitals in 28 States; and data derived from 3 CDI prevention programs in 3 different states. A case of CDI was defined a positive test for CD in persons without a positive test within the previous 8 weeks. Enzyme immunoassay for toxin A and/or B was used to diagnose 51% of cases, while nucleic acid amplification test was used in 33% (other tests, not clarified, were used in 12%).

Based on the Emerging Infection Program data, 10,342 cases of CDI occurred in 2010, 44% of which occurred in people < 65 years of age. Based on available data, 94% of these had some kind of health care exposure within the preceding 12 weeks. A total of 75% occurred outside of the hospital (44% were attributed to community-onset and 25% to nursing home onset), while 24% were hospital onset. The authors argue this data may, on the surface, be misleading and that deeper analysis reveals that 21% of hospital-onset cases occurred in nursing home residents and 67% of nursing home cases occurred in patients who had recently been hospitalized.

According to the 2010 NHSN data from acute care hospitals in 28 states, 42,157 laboratory-incidents of CDI were identified, 52% of which were present on admission to hospital (pooled hospital-onset CDI rate = 7.4/10,000 hospital days).

A collection of 71 hospitals in 3 different States participating in CDI prevention programs served as a third source. Using a variety of measures, these programs demonstrated a 20% reduction in CDI rates during a 21-month period of observation (from 9.3 to 7.5 per 10,000 hospital days). The specific measures were not detailed, but involved prompt testing of suspect cases, isolation of suspect and confirmed cases, improved environmental measures, and antibacterial stewardship.

The authors acknowledge problems with this data, including the definition of CDI — while some cases are defined based on laboratory test results alone, the NHSN data requires concurrent symptoms with 3 or more loose stools per day. Test assays with varying sensitivity also differ between facilities, yielding potentially different results (hospitals using the newer nucleic acid testing may get unfairly dinged for enhanced case detection). In addition, adherence to the case definition of hospital-onset if > 72 post-admission obviously biases the results towards implicating hospitals as the "source" for infection — since the inherent time delay in the recognition of symptoms, ordering the test, and submitting a sample all serve to push forward the time of diagnosis — at least based on a lab report and not symptom-onset.

While the effort to enhance reporting of CDI is laudable (CDI is not even listed as a "reportable" pathogen in our country) does anyone truly believe the problem begins with hospitals or that hospitals are to blame? The plan for Medicare and Medicaid Services Inpatient Prospective Payment System Quality Reporting Program to tie reimbursement to CDI hospital rates is preposterous — and only serves to take much needed dollars away from hospital efforts to prevent this infection.

These punitive efforts are missing the point: Every patient should feel comfortable their life is not in danger when receiving appropriate and necessary antibiotics — which is presently not the case. I recently saw a patient nearly die from CDI following receipt of a single dose of peri-operative cefazolin for a routine hip procedure. What we really need is a focus on how people acquire this organism, limiting exposure in long-term care facilities (where isolation and environmental hygiene is often lacking), eliminating CD from food sources, methods to quickly identify patients at risk before they receive antibacterials, and improving methods to prevent infection in patients at risk.