In the latest call for “diagnostic stewardship,” a leading epidemiology group advises against routine testing for Clostridium difficile in NICU patients.
In contrast to adult patients, infants under 12 months rarely develop C. diff infection (CDI) but can be frequently colonized. A positive test may reveal colonization that poses little threat of disease or subsequent transmission, possibly triggering unnecessary treatment and unneeded isolation measures, warns the Society for Healthcare Epidemiology of America (SHEA) in a new whitepaper.1
“It can sometimes be a reflex in the hospital when somebody develops diarrhea to send out a whole panel of tests that includes C. diff,” says Thomas J. Sandora, MD, MPH, lead author of the SHEA whitepaper. “We want people to avoid testing for C. diff in NICU patients, because it is unlikely to be the source of their diarrhea and there are many other causes that should be explored.”
SHEA recommends testing a NICU patient for CDI “only if there is evidence of pseudomembranous colitis or if the patient has clinically significant diarrhea and other noninfectious and infectious causes of diarrhea have been excluded.”
“Many infants under 12 months of age are colonized with [C. diff], so they basically can carry it in the intestines without it causing any signs and symptoms of illness,” Sandora says. “That makes it difficult to interpret the results of testing in this age group.”
C. diff, a leading cause of healthcare-associated infections in adults, colonizes the gut of about one-third of infants while rarely manifesting as disease.
“This is still not completely understood, but there seems to be some factors in that local intestinal environment in infants that makes them more resistant to C. difficile causing disease,” says Sandora, a pediatric infectious diseases physician at Boston Children’s Hospital. “It probably has to do to with the microbiome being different than it is later in childhood and in adults. Another potential protective factor is breast milk.”
SHEA recommends ruling out other routine causes of noninfectious diarrhea, like feeding and medications, before testing for CDI. In addition, test the stool for norovirus, rotavirus, adenovirus, and enterovirus. Consider culturing the stool for bacteria like Salmonella and Shigella for infants who were admitted to the NICU from the community, SHEA recommends.
A positive C. diff test in the NICU may lead to unnecessary antibiotic treatment. “We always want to avoid exposing anyone to antibiotics if they are not necessary, especially infants,” Sandora says.
Citing the rare occurrence of C. diff infection, some hospital labs have standing orders to reject tests for the spore-forming bacteria in infants, he says. “But other hospitals do allow tests to be ordered in all age groups,” Sandora says. “Sometimes, the labs in those hospitals will provide some language with the results reminding people that a positive test in infants may not represent real disease.”
Try to avoid testing, but if it is done, use a test that picks up C. diff toxins, “because that is really going to be the most specific result you can get,” he says.
In cases where CDI is detected in an NICU infant, the SHEA paper includes contact isolation recommendations and addresses the complicated issue of hand hygiene. Alcohol hand rubs are not effective against C. diff, thus recommendations for adults raise the option of switching to soap and water. This is certainly a less clear-cut call in the NICU, where C. diff rarely occurs and diarrhea from symptomatic infants may not be that infectious. The other tradeoff is that compliance typically drops with soap handwashing, and you lose some of the benefit of alcohol’s ability to eradicate a broad range of pathogens. C. diff, unfortunately, is not one of them.
“This is an issue that is still a little controversial,” he says. “We know that alcohol is not sporicidal. So, if you have C. diff spores on your hands and use alcohol hand rubs, you are moving them around rather than getting rid of them. That’s why soap and water are used, but there are really not strong studies that show that your choice of hand hygiene approach really impacts the C. diff rate at your institutions.”
Indeed, previous studies2 have shown that a significant level of C. diff spores lingers on the hands after a soap and water wash. This has prompted the CDC to emphasize glove use in recent years. Given the asymptomatic carriage of infants and the lack of C. diff disease in this population, NICUs are unlikely to have a C. diff outbreak similar to an adult unit.
“In a non-outbreak setting, there is no consensus on the optimal approach to hand hygiene when caring for a patient with CDI,” the SHEA guidelines state.
SHEA lists several options depending on the local risk assessment. These include “standard hand hygiene using alcohol-based hand rub (ABHR) for room entry and exit” and “soap and water hand hygiene for room exit only, with ABHR for room entry and when needed between tasks for a single patient unless hands are visibly soiled.”
Soap and water could be used both for room entry and exit, but SHEA reminds that the alcohol rubs are effective against many more pathogens and tend to have higher hand hygiene compliance.
- Sandora TJ, Bryant KK, Cantey JB, et al. SHEA neonatal intensive care unit (NICU) white paper series: Practical approaches to Clostridioides difficile prevention. Infect Control Hosp Epidemiol 2018; Aug 30:1-5. doi:10.1017/ice.2018.209.
- Dubberke, ER, Carling, P, Carrico, R, et al. Strategies to prevent Clostridium difficile infections in acute care hospitals: 2014 update. Infect Control Hosp Epidemiol 2014;35:628–645.