Study Shows Bacterial Infection, C. dificile, Widespread in the United States

Digitally colorized scanning electron microscopic (SEM) of Clostridioides difficile bacteria. Credit: CDC/Janice Carr.

Using population-based surveillance data, new research estimates that the germ Clostridium difficile caused nearly half a million infections in the United States in a single year.

A new federal study estimates that the germ Clostridium difficile, more commonly known as C. difficile, caused nearly half a million infections in the United States in a single year, with 29,000 people dying from the exposure. The new report is based on population-based surveillance data from 10 Emerging Infection Program (EIP) sites nationwide, including one at the Yale School of Public Health.

This is the first national C. difficile burden estimate using EIP surveillance, and the first that classifies the infections as either healthcare-associated or community-associated. As a result, the Centers for Disease Control and Prevention is able to develop more robust estimates of the national burden of C. difficile disease, said James Meek, associate director of the EIP at Yale.

Because prior data on the disease only identified healthcare-associated cases, the new data are able to show the significant extent of C. difficile infection in the community. Though 66 percent of reported cases are healthcare-associated, only 24 percent of total cases occurred within hospitals, with the rest, nearly 200,000, occurring in nursing homes or elsewhere in the community.

According to the paper on the CDC findings published in The New England Journal of Medicine, C. difficile, which causes severe diarrhea, is the leading cause of gastroenteritis-related death in the U.S., and the most common cause of healthcare-related infections. Eighty percent of deaths occur in adults 65 and older. Unnecessary antibiotic use, improper cleaning procedures, and a lack of coordination on hospital transfers contribute to the spread of C. difficile in acute care settings.

Antibiotic use is the most important risk factor for C. difficile, and the over-prescription of broad-spectrum antibiotics, which kill targeted bacteria as well beneficial bacteria that may protect against C. difficile, contributes to many cases.

Meek says that healthcare-associated C. difficile infection rates have been on the decline in Connecticut, perhaps providing evidence that recent infection control measures and antibiotic stewardship programs in hospitals aimed at controlling the disease are beginning to work. However, the report’s revelation of the extent of the disease in the community means “we may need to extend our prevention efforts to new arenas, such as long-term care facilities, nursing homes, and outpatient settings,” said Meek.

Though the CDC report uses national data gathered in 2011, the EIP monitors C. difficile in Connecticut yearly and will continue to do so, said Meek. The EIP also is currently conducting a case control study of people with community-associated C. difficile to try to identify the risk factors that may contribute to the rise of community-associated infection.

Along with the Connecticut site, which conducts C. difficile surveillance in New Haven County, surveillance was conducted at EIP sites in California, Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon and Tennessee.

Reference: “Burden of Clostridium difficile Infection in the United States” by Fernanda C. Lessa, M.D., M.P.H.; Yi Mu, Ph.D.; Wendy M. Bamberg, M.D.; Zintars G. Beldavs, M.S.; Ghinwa K. Dumyati, M.D.; John R. Dunn, D.V.M., Ph.D.; Monica M. Farley, M.D.; Stacy M. Holzbauer, D.V.M., M.P.H.; James I. Meek, M.P.H., Erin C. Phipps, D.V.M., M.P.H.; Lucy E. Wilson, M.D.; Lisa G. Winston, M.D.; Jessica A. Cohen, M.P.H.; Brandi M. Limbago, Ph.D.; Scott K. Fridkin, M.D.; Dale N. Gerding, M.D. and L. Clifford McDonald, M.D., 25 February 2015, New England Journal of Medicine.
DOI: 10.1056/NEJMoa1408913