C. difficile Update 2013
Patients getting medical care can catch serious infections called healthcare-associated infections (HAIs). While most types of HAIs are declining, one — caused by the bacterium Clostridium difficile –continues to grow. C. difficile causes diarrhea linked to 14,000 American deaths each year. Participants in this video discuss epidemiological studies showing that the instance of C. difficile infections in U.S. hospitals has more than doubled in the last decade as well as new strategies for antibiotic treatment of this difficult to treat infection.
Michael Schmidt, Medical University of South Carolina, Charleston, SC
Kelly Daniels, The Univ. of Texas at Austin, Austin, TX
Philip Chung, Albert Einstein Coll. of Med., Bronx, NY
“These data underscore the importance of directing resources to the prevention of [C. difficile infection], as well as developing public policy for reducing the incidence of these infections in U.S. hospitals,” Kelly R. Daniels, Pharm.D., said in an interview prior to the annual Interscience Conference on Antimicrobial Agents and Chemotherapy, where the study was presented.
“Judicious use of antibiotics is essential to reducing these infections, as antibiotics are the main risk factor for the development of CDI,” she noted. “Compliance with other infection control measures, such as hand washing, is also key. Further research is needed to identify effective measures for preventing CDI and improving outcomes in patients with CDI.”
Dr. Daniels, a graduate student in the translational science PhD program at the University of Texas, Austin, and her associates retrospectively reviewed U.S. National Hospital Discharge Surveys from 2001 to 2010. They included patients aged 18 years and older who were discharged from the hospital with an ICD-9-CM diagnosis code for CDI (008.45) and used data weights to determine national estimates. They presented incidence rates as CDI cases per 1,000 hospitalizations, and they used multivariable logistic and linear regression models to compare mortality and hospital length of stay between primary and secondary CDI.
Over the 10-year study period, 2.2 million patients were discharged from the hospital with CDI. Their median age was 75 years, most (86%) were white, and more than half (59%) were female. One-third of cases (33%) were primary CDI, while the remainder were secondary CDI. The three most common concomitant infectious diagnoses were urinary tract infection (21%), pneumonia (14%), and sepsis/septicemia (12%).
Dr. Daniels reported that the incidence of CDI increased from 4.5 cases/1,000 hospitalizations in 2001 to 8.2 cases/1,000 hospitalizations in 2010. Similar trends were observed in patients with primary and secondary CDI.
The overall mortality rate was 7.1% for the study period and was significantly higher among patients with secondary CDI, compared with those who had primary CDI (8.8% vs. 3.3%, respectively; relative risk, 1.8). The median hospital length of stay was 8 days and was significantly higher among patients with secondary CDI, compared with those who had primary CDI (9 days vs. 5 days, respectively; RR, 13.3).
“We found that in-hospital mortality among patients with primary CDI is decreasing, while mortality among patients with secondary CDI is increasing,” Dr. Daniels said. “This trend is different from prior studies, which demonstrated increases in CDI-related mortality from the 1990s to the early 2000s.”
The decline in in-hospital mortality among patients with primary CDI might reflect improvements in care in recent years, she explained. In contrast, the increase in mortality among those with secondary CDI may be caused by changes in the frequency or severity of other comorbid illnesses. However, “this was not specifically examined as part of our study,” Dr. Daniels added.