Outbreak C. difficile strain common in Chicago hospitals, investigation finds

In response to Illinois Department of Public Health reports of rising rates of C. difficile infection as a hospital discharge diagnosis, the Chicago and Cook County health departments surveyed 25 Chicago-area hospitals over one month in 2009. They identified 263 total cases of C. difficile illness. Of 129 C. difficile isolates cultured from these patients, 61 percent were the outbreak C. difficile strain known as BI/NAP1.

The BI strain, which is known to cause more serious illness, is usually associated with large acute outbreaks of C. difficile. However this investigation suggests that BI is endemic in the Chicago area and patients could be at risk for severe disease even in the absence of a large acute outbreak.

“Our findings highlight the need for effective interventions aimed at reducing the risk of C. difficile infection,” said Stephanie Black, MD with the Chicago Department of Public Health and the investigation's lead author.

The investigation suggests that the transfer of patients from one facility to another has helped to spread the BI strain. Dr. Black and her team found that half of the patients with the BI strain were transferred from one healthcare facility to another. “Inter-facility transfer of recently infected patients is a plausible mechanism for the spread of the BI group and may explain in part how BI became the dominant [strain] in this region,” the authors write.

C. difficile is most common in elderly patients and those receiving treatment with antibiotics. It is considered to be one of the most important health care-related infections in the U.S.

The Society for Healthcare Epidemiology of America recommends that patients take the following steps to reduce the spread of C. difficile:

Make sure that all doctors, nurses, and other healthcare providers clean their hands with soap and water.

Only take antibiotics as prescribed by your doctor.

Be sure to clean your own hands often, especially after using the bathroom and before eating.

Stephanie R. Black, Kingsley N. Weaver, Roderick C. Jones, Kathleen A. Ritger, Laurica A. Petrella, Susan P. Sambol, Michael Vernon, Stephanie Burton, Sylvia Garcia-Houchins, Stephen G. Weber, Mary Alice Lavin, Dale Gerding, Stuart Johnson, Susan I. Gerber, “Clostridium difficile Outbreak Strain BI Is Highly Endemic in Chicago Area Hospitals.” Infection Control and Hospital Epidemiology 32:9 (September 2011)

Published through a partnership between The Society of Healthcare Epidemiology of America and The University of Chicago Press, Infection Control and Hospital Epidemiology provides original, peer-reviewed scientific articles for anyone involved with an infection control or epidemiology program in a hospital or healthcare facility. ICHE is ranked 15 out of 140 journals in its discipline in the latest Journal Citation Reports from Thomson Reuters.

SHEA is a professional society representing more than 1,900 physicians and other healthcare professionals around the world with expertise in healthcare epidemiology and infection prevention and control. SHEA's mission is to prevent and control healthcare-associated infections and advance the field of healthcare epidemiology. The society leads this field by promoting science and research and providing high-quality education and training in epidemiologic methods and prevention strategies. SHEA upholds the value and critical contributions of healthcare epidemiology to improving patient care and healthcare worker safety in all healthcare settings. www.shea-online.org