Located in Los Angeles County’s South Bay, Torrance Memorial Medical Center (TMMC) is a 533-bed, nonprofit facility. Sharing space with the core laboratory within TMMC, the microbiology and molecular biology department is a full-service laboratory covering disciplines in routine culture microbiology, mycobacteriology, mycology, parasitology, and molecular testing.

Facing Down C. Diff

Prior to March 2018, the C. difficile standardized infection ratio (SIR) for the organization was approximately 1.3, and in terms of laboratory testing, performing C. diff positivity by polymerase chain reaction (PCR) alone, our rates were approximately 17%. In looking at these rates and considering current IDSA guidelines,1 laboratory leadership determined there was a need for a 2-step algorithm for toxins and antigens. One alternative for these actions, PCR testing, was deemed costly and it did not guarantee the timely turnaround necessary for expeditious isolation of patients or administration of proper antibiotic treatment. In reviewing our options for rapid ID of C. diff, we became aware of another local facility using the TechLab C. Diff Quik Chek Complete product, so we contacted a representative from the company to request an overview.

A team comprising key TMMC decision makers, including the chief medical officer and representatives from infection prevention, pharmacy, and laboratory collaborated to determine whether implementation of the Quik Chek system was appropriate for our patient population. All team members recognized that rapid and reliable detection of C. diff is an important factor in reducing the spread of hospital-acquired infections (HAIs) and improving overall patient safety. As part of an interdisciplinary Lean project, it was decided that Quik Chek would be used as a first-line test and PCR as a secondary means in the 2-step algorithm.

 

System in Use

The criteria in use for selecting stool for testing is based on the Bristol Stool Chart; specifically, type 6 and type 7 stool for inpatient sample testing. While clear positive and negative results have always been reported as such, discrepant results in which a sample was found to be positive for glutamate dehydrogenase (GDH) but a negative toxin line were previously tested by PCR only. As part of the transition to Quik Chek, the verification of the assay was a simple process in correlating between the previous PCR system and Techlab’s. No discrepancies were found during the verification process.

The nine lab staff members who underwent training on the Quik Chek did not experience any difficulty or challenges in the learning process, and they have utilized the educational materials and appreciated the pre-demarcated pipettes, which eliminate the step of precise measuring and reduce the possibility of user error. Benefits were also realized in terms of turnaround time; with a 20- to 30-minute time for results, the Quik Chek Complete is quicker than the previous system, as PCR tests may take at least one hour.

Conclusion

With C. Diff Quik Chek Complete, the laboratory has improved results turnaround time and has lowered positivity rates due to the two-step algorithm and differentiating between possible colonization versus active infection. Post implementation, we have seen a dramatic reduction in SIR from an average of 1.3 to 0.3, which is markedly below the national average.1

Staff members appreciate the system’s ease of use, as well as the quick time to result. While our testing is currently performed from 6:00am to 6:00pm, our goal is to have the test operational around the clock.

Marc Bernaldez, MBA, CLS, MLS(ASCP)CM is the microbiology and molecular microbiology manager at Torrance Memorial Medical Center. He currently serves as a board member at both the California Association from Medical Laboratory Technology (CAMLT) and the Southern California Branch for the American Society for Microbiology (SCASM).

Reference

1. Infectious Diseases Society of America. Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). www.idsociety.org/practice-guideline/clostridium-difficile. Accessed September 19, 2019.