Infections with the intestinal superbug C. difficile nearly doubled from 2001 to 2010 in U.S. hospitals without noticeable improvement in patient mortality rates or hospital lengths of stay, according to a study of 2.2 million C. difficile infection (CDI) cases published in the October issue of the American Journal of Infection Control, the official publication of the Association for Professionals in Infection Control and Epidemiology (APIC).

In this retrospective study from The University of Texas College of Pharmacy, researchers analyzed 10 years of data from the U.S. National Hospital Discharge Surveys (NHDS). From 2001 to 2010, rates of CDI among hospitalized adults rose from 4.5 to 8.2 CDI discharges per 1,000 total adult hospital discharges.

"Several factors may have contributed to the rise in CDI incidence in recent years," said Kelly Reveles, PharmD, PhD, lead author on the study. "Antibiotic exposure remains the most important risk factor for CDI."

According to the Centers for Disease Control and Prevention (CDC), C. difficile is the most common bacteria responsible for causing healthcare-associated infections in U.S. hospitals and is linked to 14,000 deaths each year. Reducing the use of high-risk, broad-spectrum antibiotics by 30 percent could lower CDI by 26 percent, estimates the CDC. The White House recently announced a new Executive Order and National Strategy for Combating Antibiotic-resistant Bacteria, which emphasized the need for antibiotic stewardship programs to help clinicians improve prescribing practices.

"It's been estimated that up to half of antibiotic use in humans is unnecessary," said APIC 2014 President Jennie Mayfield, BSN, MPH, CIC. "To make headway against CDI, hospitals and health facilities need to get serious about antibiotic stewardship."

According to The University of Texas College of Pharmacy study, most CDI patients were female (59 percent), white (86 percent), and more than 65 years of age (70 percent).

Of the 2.2 million adult CDI discharges, 33 percent had a principal diagnosis of CDI; 67 percent were classified as secondary CDI, meaning that CDI was not the primary reason they were hospitalized. Approximately 7.1 percent, or 154,184 patients, died during the study period.

"Our study found that peak CDI incidence occurred in 2008, with a slight decline through 2010," said Dr. Reveles. "The leveling off of CDI incidence toward the end of our study period may be the result of increased antibiotic stewardship programs and improved infection control measures, such as use of contact precautions, cleaning and disinfection of equipment, and environment, and hand hygiene."

According to a 2013 survey conducted by APIC, 60 percent of US hospitals had implemented antibiotic stewardship programs by 2013, up from 52 percent in 2010.

"With bugs like C. diff, it takes everyone asking -- 'are these antibiotics really necessary?' to help curb inappropriate use and protect patients," said Mayfield.

Antibiotic resistance and stewardship is the theme of International Infection Prevention Week led by APIC, October 19-25, 2014. A free webinar and Twitter chat are being offered, along with an infographic poster for consumers on the "ABC's of antibiotics."