By Carol A. Kemper, MD, FIDSA
Medical Director, Infection Prevention, El Camino Hospital, Palo Alto Medical Foundation
Is Your Hospital Room Toxigenic?
SOURCE: Sood G, Truelove S, Dougherty G, et al. Clostridioides difficile infection (CDI) in a previous room occupant predicts CDI in subsequent room occupants across different hospital settings. Am J Infect Control 2022;50:1352-1354.
Environmental exposure and hand washing in the hospital are critical to the reduction of hospital-onset Clostridioides difficile infection (HOCDI). These authors performed a cohort study of all adults admitted to five acute care hospitals in the United States between 2016 and 2018. One of the facilities was a tertiary care hospital, one was a quaternary care hospital, and three were community hospitals. All five facilities terminally cleaned rooms that had housed an occupant with CDI, including the use of bleach in three facilities and OxyCide in two facilities. Two facilities also used ultraviolet-C (UVC) light disinfection “when possible.” Hospital cleaning personnel were trained and monitored using an ultraviolet gel product.
The risk of developing CDI within 90 or 365 days of occupying a room with a previous occupant with CDI was compared to those patients occupying rooms without a previous occupant with CDI. Patients with a prior history of CDI or positive testing for CD in the six months prior to their hospitalization were excluded from the analysis. A room with a previous occupant with CDI was considered “at-risk” for 30 days following their discharge. CDI was diagnosed using the Cepheid GeneXpert C. difficile and BD MAX C. difficile platforms, both of which target CD toxin B genes (tcdB gene). Only patients with liquid stool not receiving laxatives were tested.
During the study period, 2,128 cases of CDI occurred among 218,731 hospitalizations (0.97 cases/100 admissions). There was a 27% increased risk of CDI within 90 days for patients housed in an at-risk room (odds ratio [OR], 1.269; 95% confidence interval [CI], 1.12-1.44) and a 40% increased risk of CDI within 365 days if housed in an at-risk room (OR, 1.4; 95% CI, 1.25-1.57) relative to not being housed in an at-risk room. Cumulative exposure, as measured by the number of days a patient was housed in an at-risk room, was significantly associated with an increased risk of developing CDI, with a 4.5% increased odds for each day with at-risk room exposure.
This study suggests that exposure to a room within 30 days of a previous occupant with CDI significantly increases the risk of developing CDI within the next year by an odds of 40%. The risk increases for every day spent in at-risk room.
This study has several limitations. Active CDI was diagnosed based on the presence of toxigenic CD organisms, not actual toxin, which may over-estimate the prevalence of CDI. Rates of apparent HOCDI in our facility increased by 40% when switching from a toxin-based assay to a testing platform targeting toxin genes. Further, patients were not screened for colonization at baseline. Based on CD polymerase chain reaction gene testing, we have observed a frequency of colonization of 10% to 12% in patients admitted from skilled nursing facilities and long-term care, and 15% to 20% in patients requiring hemodialysis. Further, the use of UVC in two facilities was not routine, and specific data on the frequency of its use, relative to room risk, was not provided. It would have been of interest if the authors had examined whether the use of UVC reduced the risk of acquiring CDI from at-risk rooms.
SOURCE: Walter C, Soni T, Gavin MA, et al. An interprofessional approach to reducing hospital-onset Clostridioides difficile infections. Am J Infect Control 2022;50:1346-1351.
Reduction of hospital-acquired infection, specifically hospital-onset Clostridioides difficile infection (HOCDI), is a key goal of infection prevention programs, often involving the implementation of multiple evidence-based interventions. These include the use of antimicrobial stewardship, enhanced environmental cleaning, the use of specific sporicidal cleaning products, the use of ultraviolet-C (UVC) radiation for CDI rooms, systems for improving and monitoring environmental cleaning practices, programs to improve hand-washing and the use of personal protective equipment (PPE) for CDI patients, and isolation of CDI patients. Our facility has even gone so far as to perform PCR surveillance for toxigenic CD of high-risk patients on admission so colonized individuals can be pre-emptively isolated and perhaps even tested and treated more proactively.
HOCDI is defined as occurring > day 3 of hospitalization. Notably, this is not a 72-hour window, and could be as little as 49 hours, depending on the time of admission. A case is not defined at the time the patient develops symptoms, or even at the time the test is ordered, but at the time a stool is collected and submitted to the laboratory for testing. Thus, delays in recognizing diarrhea, ordering the test, and then collecting an appropriate specimen all contribute to pushing those day 2-3 cases into the HOCDI window (beyond day 3), even though we all recognize the such patients likely were admitted with CD colonization and/or infection and did not acquire their infection in-hospital. Consistently, anywhere from 20% to 40% of our HOCDI cases have a positive test between days 4-7, suggesting that if we could only get those cases recognized and tested a little sooner, we potentially could avoid owning an HOCDI case.
The problem is how to accomplish this. These authors described one further “evidence-based” practice that has been advocated as a means to reduce the rate of HOCDI: testing algorithms. During hospital days 1-3, they developed a standardized hospital procedure allowing nursing staff to submit a stool for CD testing when a loose or unformed stool was identified. Patients were pre-emptively placed in isolation at the time of testing, and isolation precautions were removed if testing was negative.
In contrast, from hospital day 4 and forward, a second algorithm was developed whereby patients were required to have three “unexplained” loose stools before testing was allowed; testing was not recommended if stool softeners or laxatives were used; and patients were required to have signs and symptoms of CDI and/or epidemiologic risk factors, such as fever, abdominal pain or distention, recent antibiotic use, elevated white blood count, age > 65 years, etc., before a physician could order a CD toxin assay. The authors stated that when the testing algorithm was first implemented, 50% of HOCDI cases were the result of one or more deviations from the algorithm. With repeated education, implementation of a double-check process, and the use of “accountability notices” with huddles and education centered around “inappropriate testing,” the authors said compliance with the algorithm improved to 80%, with a sustained reduction in HOCDI cases.
In other words, by restricting access to testing beyond day 3 of hospitalization, fewer cases of CDI were diagnosed.
Our infection prevention team has been grappling with the ethics of pushing for more testing days 1-3 and encouraging the recognition of patients with loose stool with focused nurse-driven testing protocols, especially during the first three days of hospitalization. This approach seems justified when it results in the earlier recognition and treatment of cases, which both benefits the patient while also having the happy outcome of reducing our HOCDI cases. But efforts to purposefully restrict access to testing beyond day 3 of hospitalization solely in an effort to reduce the incidence of HOCDI seems like gaming the system, especially with the implementation of such obviously dichotomous approaches to testing.