From Pages to Practice
During rotations as a medical student and resident, infection control measures and antimicrobial stewardship were drummed into us whenever we started at a new hospital. Some specifically focused on preventing Clostridioides difficile infection and transmission. Alerts for C. difficile infection were as prominent as drug allergies on a patient’s electronic health record. Hospital-wide emails regularly published data on the local burden of C. difficile infection. An outbreak of C. difficile can be devastating for patients and hospital systems, so there was good reason to be wary. I still vividly remember the signs of “C. difficile infection, ward closed” on my on-call shifts.
A recent report published in NEJM estimated the national burden of C. difficile infection in the United States, based on data collected by the Centers for Disease Control and Prevention (CDC) Emerging Infections Program (EIP) in 10 states. Of the 15,461 cases of C. difficile infection in 2011, 10,177 were healthcare-associated and 5284 were community-associated. Of the 15,512 cases in 2017, 7973 were healthcare-associated and 7539 were community-associated.
The adjusted estimate of the burden of disease decreased 25% from 2011 through 2017 and was largely due to a decrease in healthcare-associated cases. These results suggest that despite improved awareness of C. difficile infection in healthcare settings, similar attention is needed in community care facilities.
The following NEJM Journal Watch summary describes the report in more detail.
Abigail Zuger, MD reviewing Guh AY et al. N Engl J Med 2020 Apr 2
Changing diagnostic criteria during the past decade have made local patterns in Clostridioides difficile infections difficult to interpret ― and nationwide patterns even more so. CDC researchers used a uniform case definition to identify and characterize cases drawn from a 35-county sample in 10 states (total population, ≈2 million).
Between 2011 and 2017, the annual number of cases remained stable in the sample, and the estimated nationwide burden of disease was calculated at about half a million cases annually. The fraction of these cases associated with healthcare settings (including chronic care facilities) fell by about 20% (from 306,000 to 236,000) during the study period, and the fraction associated with community acquisition correspondingly rose.
When these figures were adjusted for testing modality used (ultrasensitive nucleic acid tests are thought to overdiagnose infections), the data suggested a 25% decline in the nationwide burden of disease from 2011 through 2017. This decline was attributable entirely to a decline in healthcare-associated infections, whereas rates of community-acquired disease remained stable. Healthcare-associated infections generally were more severe than community-acquired infections and were associated with higher relapse rates and mortality.
COMMENT: These researchers tentatively ascribe an estimated decline in healthcare-associated C. difficile infections to improved antibiotic stewardship, less use of fluoroquinolone drugs, and strict testing protocols to limit false-positive diagnoses. A skeptic might wonder if any portion of the decline seen here is the result of too-stringent testing protocols in individual hospitals (pay-for-performance measures punish hospitals with high rates of C. difficile infection). That question awaits a different kind of analysis.