Available February 1, 2014
MEDLAB introduces Molecular Clostridium difficile test
MEDLAB is proud to introduce a cutting edge DNA based C diff test, with outstanding sensitivity and specificity, that does not require confirmation testing. This translates into superior positive and negative predictive value for toxigenic Clostridium difficile bacterial DNA with a 1-2 day turn-around-time.
C. difficile infections are a major problem among recently hospitalized patients and those living in long term care facilities. The infections are the most common cause of healthcare-associated diarrhea in adults and can often lead to dehydration or electrolyte imbalance or even death. Furthermore, it has been widely reported that C diff infections are becoming increasingly virulent and less responsive to metronidazole therapy, resulting in rising incidence and worse outcomes[i]. Since the infection can range in severity from asymptomatic to life-threatening, rapid and accurate diagnosis is critical for treatment decisions and infection control intervention. Relapses are also common in 20% to 60% of the cases, often leading to rehospitalizations[ii],[iii].
The new Guidelines for Diagnosis, Treatment and Prevention of Clostridium difficile published in 2013 by American Journal of Gastroenterology recommends first-line molecular DNA testing for diagnosis of the disease[iv]. This new test conforms to this recommendation. In addition, it detects BOTH Toxigenic A and B strains of C diff.
Comparison of the current test with the new test is shown below and clearly demonstrates why the current test will be discontinued effective March 1, 2014.
Test Code / Test Methodology / Sensitivity / Specificity / Positive Predictive Value / Negative Predictive Value / Reflex Confirmation205300 / GDH EIA[v] (current test) / 39.7% / 97.7% / 74.0% / 90.5% / Required
205303 / DNA Molecular[vi] / 98.6% / 99.1% / 95.9% / 99.7% / Not Required
Specimen is loose stool (formed stools will be rejected) and should be in a sterile, labeled cup and kept at 2-8 degrees C, and is stable for up to 7 days. Turn-around-time is 24hrs from receipt at the MEDLAB laboratory.
The DNA Molecular test is FDA cleared and payable by both Medicare and Medicaid. Retesting of previous C diff negative patients can be useful after 7 days, when still presenting with clinically significant symptoms.
Bottom-line: Switching testing from traditional EIA to amplified DNA leads to:
· Significant decrease in patient isolation days
· Decrease in number of tests ordered
· Decrease in metronidazole treatment for patients with negative C diff tests
· Decrease in hospital readmissions
· Decrease in care providers time caring for isolated patients
· Increase in patient satisfaction
SEE FOLLOWING PAGE FOR TEST ORDERING SPECIFICS
Effective February 1, 2014 MEDLAB will introduce a new Molecular C. diff test
TEST NAME: C diff Amplified DNA test
NEW TEST CODE: 205303
AVAILABLE: February 1, 2014
SPECIMEN: Loose Stool – Two Patient Identifiers Necessary (Any formed stools will be rejected)
SAMPLE STABILITY: 7 days, Refrigerated (4 degrees C)
TURN-AROUND-TIME: 24-48 hours
SENSITIVITY: 98.6% (New Test) vs 39.7% (Old Test)
SPECIFICITY: 99.1% (New Test) vs 97.7% (Old Test)
FDA STATUS: FDA cleared
REIMBURSEMENT: Medicare/Medicaid Reimbursable
COMPLIANCE: Complies with 2013 Guidelines for Diagnosis, Treatment, and Prevention of Clostridium difficile Infections (J Gastroenterology, 108:478, April 2013) (available by request from MEDLAB Account Managers)
eMEDLAB: Orderable in eMEDLAB effective February 1, 2014
NOTE: Old C diff test (GDH EIA) will be discontinued on March 1, 2013. Any unspecified C diff Orders will be tested utilizing the new DNA based technology with superior sensitivity and specificity.
For any further questions or concerns please contact your account manager or our client solutions
department at 1-800-522-7556.
[i] Peterson, L. R. et al. Laboratory Testing for Clostridium difficile Infection, Light at the End of the Tunnel. Microbiology and Infectious Disease, Am J Clin Pathol (2011) 136:372-380.
[ii] Ryan, K. J., Ray, C. G. (editors) Sherris Medical Microbiology (4th edition) McGraw Hill. Pp. 322-324.
[iii] Kelly, C.P., LaMont, J.T., Clostridium difficile—more difficult than ever. N Eng J Medicine, Oct (2008) 18:1932-1940.
[iv] Surawicz C.M. et al., Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections. Am J Gastroenterol. (2013) 108:478-498.
[v] Peterson, L. R. et al. Laboratory Testing for Clostridium difficile Infection, Light at the End of the Tunnel. Microbiology and Infectious Disease, Am J Clin Pathol (2011) 136:372-380.
[vi] Quidel Molecular FDA submission data following discordant resolution. (2013).