Screening for C. diff on admission

A surgical service found screening for carriers reduced hospital-acquired Clostridium difficile.


Background

At the VA Boston, clusters of hospital-acquired C. difficile infections persisted despite a quality improvement (QI) project implementing five evidence-based practices. “We improved for a short period, but then the number of hospital-acquired cases went right back up, so we needed a new strategy,” said Katherine Linsenmeyer, MD, associate hospital epidemiologist.

Around that time, a Canadian hospital reported reducing its rates of hospital-acquired C. difficile by screening patients on admission and isolating carriers of the bug in a study published in June 2016 in JAMA Internal Medicine. “We were having a huge problem on our surgical services, so we wondered if we could implement a similar protocol and see if we could break the pattern of transmission,” said Dr. Linsenmeyer, who implemented the concept as a QI project while she was an infectious diseases fellow.

How it works

As part of the new project, nurses screened patients admitted to the hospital's surgical service for C. difficile as per standard nursing intake, which also involves screening for methicillin-resistant Staphylococcus aureus colonization, Dr. Linsenmeyer noted. “We included it as the second step to their screening process,” she said. “Upon every admission, it followed the same pattern so that it became part of their daily routine.”

Asymptomatic carriers with positive C. diff perirectal swabs were put on isolation precautions similar to standard precautions for patients with active C. difficile infection. Screening test results appeared in the electronic health record, along with a flag (if positive) and an educational note stating that treatment wasn't necessary unless the patient was clinically symptomatic.

Results

Over a 10-month study period, 15 (1.9%) patients developed symptomatic C. difficile infection within 90 days of hospitalization: seven (29%) of 24 asymptomatic carriers and eight (1%) of 749 patients with negative results, according to results published online in May 2018 by Clinical Infectious Diseases. Rates of hospital-acquired C. difficile infection per 10,000 bed-days of care were 10.9 in 2015, 10.2 in 2016, and decreased during the intervention to 3.0 in 2017 (January through October).

Statistical modeling showed a reduction of five hospital-acquired C. diff cases over a 10-month period compared to the 10 cases that would be expected based on seven years of prior data. This resulted in a number needed to screen of 197 and a number needed to isolate of 4.4 to prevent one case. “We were pretty surprised to find that we were able to avert about half of the likely 10 cases of hospital-acquired C. diff on the surgical wards,” said Dr. Linsenmeyer.

Challenges

The project required substantial buy-in from hospital leadership, nursing staff, and the lab. “They were very gracious, so that was helpful,” Dr. Linsenmeyer said. The biggest challenge of the project, especially when considering hospital-wide implementation, is bed flow due to the number of patients who would require private rooms, she said. (In the study, nurses were allowed to place asymptomatic carriers in the same room, but this wasn't necessary due to the low number of cases, Dr. Linsenmeyer added.) “I think if we had had more positives, we probably would've been playing ‘musical beds,’ and nursing may have pushed back a little bit more, but it really wasn't an issue in our hospital,” she said.

Cost wasn't much of an issue, either. Although there was no formal cost-benefit analysis, each test costs about $30 (for a total cost of around $36,000), and each case of hospital-acquired C. difficile costs the hospital about $25,000 to $30,000, Dr. Linsenmeyer said. “We would need to factor in nursing time and lab time, but that being said...it was probably a cost savings for the hospital,” she said.

Next steps

The project ended in October 2017, but the plan is to implement it hospital-wide to see if C. difficile cases can be prevented during a challenging time of the year. “We always seem to have a spike of hospital-acquired cases in the months of October, November, and December,” Dr. Linsenmeyer said. “We know that C. diff follows flu and antibiotic patterns, but we haven't figured out exactly why that time period is particularly problematic, so our plan is to see if we can prevent the spike in cases that we usually see during that time.”

Words of wisdom

“For us and many hospitals who are really struggling to break the pattern of C. diff transmission, I think as long as you have nursing and leadership on board, this is a fairly easy program to implement,” Dr. Linsenmeyer said. “It seems like this is promising and could potentially be a third tier in your infection prevention steps to preventing hospital-acquired transmission of C. diff.”