Screening asymptomatic patients admitted through the emergency department for occult Clostridium difficile infection, then isolating those found to be carriers throughout their hospital stay, substantially reduced the incidence of hospital-acquired C. difficile infection in a tertiary acute-care hospital, according to a report published online April 25 in JAMA Internal Medicine.
In what investigators described as the first study to assess the benefit of such an intervention, the Quebec Heart and Lung Institute (QHLI) in Quebec City went from being endemic for C. difficile infection to having the lowest incidence among 22 academic hospitals across the province of Quebec. “If confirmed in subsequent studies, isolating asymptomatic carriers could potentially prevent thousands of cases of hospital-acquired C. difficile infection every year in North America,” said Dr. Yves Longtin of the infection prevention and control unit at Jewish General Hospital, Montreal, and his associates.
CDC/D. Holdeman
The QHLI implemented the screen-and-isolate program because, despite robust infection-control efforts, it continued to exceed the government-imposed target level of 9.0 C. difficile infections per 10,000 patient-days. The program, which involved 7,599 patients admitted to the facility through its ED during a 17-month period, called for rectal sampling with a sterile swab, using a polymerase chain reaction (PCR) assay to detect the tcdB gene, obtaining the results within 24 hours, and isolating any carriers for the remainder of their stay. A total of 368 asymptomatic patients (4.8%) were found to be carriers.
Before the intervention, the hospital’s monthly incidence averaged 8.2 cases per 10,000 patient-days, with a high of 28.6 cases per 10,000 patient-days during an epidemic. After the intervention was implemented, the monthly incidence dropped to 3.0 per 10,000 patient-days. The hospital exceeded target levels of cases in 24.4% of the months preceding the intervention, compared with none of the months afterward. The investigators calculated that only 121 patients needed to be screened and 6 asymptomatic carriers needed to be isolated to prevent 1 case of hospital-acquired C. difficile infection.
During the same time period, rates of C. difficile infection remained stable at other hospitals across the province, Dr. Longtin and his associates said (JAMA Intern Med. 2016 Apr 25. doi: 10.1001/jamainternmed.2016.0177).
“The intervention may be effective not only by preventing direct patient-to-patient transmission but also by limiting contamination of the hospital environment,” they noted.
The study was supported by the Quebec Heart and Lung Institute, the Quebec Ministry of Health and Social Services, and the Quebec Foundation for Health Research. Dr. Longtin reported being a coapplicant on a patent for methods, reagents, and kits for the assessment of bacterial infections. His associates reported ties to Sanofi Pasteur, Merck, and Otsuka.