Category Archives: C. diff. Lab Testing

A White Blood Cell In Motion Chasing Bacteria

What do White Blood Cells do?


White blood cells (also called leukocytes or immune cells) are cells which form a component of the blood.

They help to defend the body against infectious disease and foreign materials as part of the immune system.

There are normally between 4×109 and 11×109 white blood cells in a litre of healthy adult blood about 7,000 to 25,000 white blood cells per drop.

In conditions such as leukaemia this may rise to as many as 50,000 white blood cells in a single drop of blood.

As well as in the blood, white cells are also found in large numbers in the lymphatic system, the spleen, and in other body tissues.


Detecting White Blood Cell (Stool)

Does this test have other names?

Stool white blood cell test, fecal leukocyte (LOO-koh-site) test

What is this test?

This test looks for white blood cells in your stool, which can help your health care provider diagnose the cause of inflammatory diarrhea.

White blood cells, also called leukocytes, are immune system cells that can show up in the stool if you have inflammatory diarrhea. This type of diarrhea may be a symptom of an infection caused by bacteria such as Shigella, Clostridium difficile, Campylobacter, or Salmonella. It may also occur in inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis.

Why do I need this test?

You might have this test if you have inflammatory diarrhea. Symptoms may include:

  • Numerous small loose stools
  • Blood or mucus in the stool
  • Severe cramping in your abdomen
  • Fever

What other tests might I have along with this test?

Your doctor may order other tests that look at the stool for:

  • Lactoferrin or calprotectin, which are substances made by certain white blood cells
  • Parasites

Your doctor may also order a stool culture. For this test, bacteria in a stool sample are encouraged to grow in the lab so they can be seen.

What do my test results mean?

A result for a lab test may be affected by many things, including the method the laboratory uses to do the test.  If your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.

White blood cells in the stool may mean that you have inflammation in your gastrointestinal tract. But a negative result doesn’t rule out a problem. Some people with these illnesses don’t have white blood cells in their stool.

How is this test done?

Your health care provider will give you a special container with a tightly fitting lid to place the stool sample in. If you aren’t able to produce a stool sample, your doctor may collect a sample by inserting a swab into your rectum.

What might affect my test results?

Urine or toilet paper may contamínate the sample, affecting the results. Drinking milk can affect the results.

How do I get ready for this test?

You don’t need to prepare for this test, but it’s a good idea to tell the health care provider about other health problems you may have. Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don’t need a prescription and any illicit drugs you may use.


* Discuss stool specimens and lab testing with your health care provider for additional information.



Rapid Detection of a C. difficile Toxins Through Laboratory Testing Accelerates Diagnosis and Treatment



Clostridium difficile is an anaerobic, spore-forming and Gram-positive bacillus. It is the major cause of antibiotic-associated diarrhea prevailing in hospital settings. The morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains.

Because of the poor clinical different between CDI and other causes of hospital-acquired diarrhea, laboratory test for C. difficile is an important intervention for diagnosis of CDI.


Laboratory tests for CDI can broadly detect either the organisms or its toxins. Currently, several laboratory tests are used for diagnosis of CDI, including

toxigenic culture,

glutamate dehydrogenase detection,

nucleic acid amplification testing, cell cytotoxicity assay,

and enzyme immunoassay towards toxin A and/or B.

This review focuses on the rapid testing of C. difficile toxins and currently available methods for diagnosis of CDI, giving an overview of the role that the toxins rapid detecting plays in clinical diagnosis of CDI.


A Good Question Asked By Many In the C. diff. Community; Test? Don’t Test? and HOW

C. difficile Infections

Diagnosed, Treated, then……….


Don’t Test?

and HOW



As Viewed and Published — Editorial Collaboration

Medscape &

To read article in its entirety:

Clostridium difficile Testing

Two recent studies[1,2] demonstrate the importance of appropriate selection of patients for testing for Clostridium difficile infection (CDI), as well as evaluation of performance characteristics of tests for C difficile in asymptomatically colonized patients.

C difficile is one of the most common causes of healthcare-associated infections. However, there is increasing recognition that newer nucleic acid amplification tests for C difficile may have poor specificity for true CDI while detecting patients with asymptomatic C difficile colonization.

As such, which patients to test and which tests to use are increasingly important decisions faced by hospitals, clinicians, and clinical microbiology laboratories.

Selecting Patients for Testing

The importance of appropriately selecting patients for C difficile testing is highlighted in a study by Kwon and colleagues.[1] In this study, hospitalized patients who were tested for          C difficile were characterized as having a low, medium, or high pretest probability of CDI based on clinical, laboratory, and radiologic data. Stool was tested for C difficile with toxin enzyme immunoassay (EIA) and toxigenic culture (TC).

The investigators found that nine of 111 patients had positive C difficile testing by TC, and four were positive by EIA.

Most patients had a low pretest probability (65%), although 31% had medium and 5% had high pretest probability. Of note, none of the patients with a low pretest probability had a positive EIA, although four were TC positive. Furthermore, none of the seven patients with a positive TC test but negative index EIA developed CDI within 30 days or died within 90 days after the index EIA test.

These findings emphasize the importance of appropriately selecting patients for C difficile testing, including clinical evaluation for signs and symptoms consistent with CDI, as well as alternative causes of diarrhea. A major strength of this study was that the assignment of pretest probability was based on prospective evaluation by a study physician (with interviews and physical examinations), rather than on retrospective medical record review. Given the implications for hospital surveillance, as well as potential inappropriate treatment in asymptomatically colonized patients, consideration of the pretest probability of CDI for patients in the decision to perform C difficile testing is critical.

Testing Asymptomatically Colonized Patients

Terveer and colleagues[2] evaluated the performance characteristics of C difficile tests in asymptomatically colonized patients.

The investigators compared the performance of a commercially available polymerase chain reaction (PCR) directed to toxin A and B, a commercially available enzyme-linked fluorescent assay (ELFA) to glutamate dehydrogenase (GDH), and an in-house developed PCR vs a gold standard of toxigenic culture.

Testing was performed using 765 stool samples obtained from asymptomatic patients admitted to three hospitals.

Overall, 5.1% of samples were positive for C difficile, and 3.1% contained toxigenic C difficile. The GDH ELFA and both PCR tests demonstrated high negative predictive values (>99%).

However, the positive predictive values were low (34.7% for the GDH ELFA and 31.9% for the commercially available PCR test).

The investigators commented that these performance characteristics suggest that these assays would be useful as a first screening test but that the low positive predictive values would preclude their use as stand-alone tests.


This study contributes to the literature on performance characteristics of C difficile tests in asymptomatically colonized patients, although it should be noted that the prevalence of

C difficile colonization in this cohort was somewhat lower than that reported in other studies.

TechLab C. diff. Quik Chek Complete® Antigen and Toxins A&B On A Single Device

C. difficile diagnostics

Clostridium difficile is the major cause
of nosocomial diarrhea and pseudomembranous colitis

C. difficile infection usually occurs when the normal microflora of the intestinal tract is altered or killed by antibiotics. Once C. difficile growth begins, toxins A and B are produced, causing diarrhea and colitis.

The disease can be treated with metronidazole or vancomycin, but relapses occur in about 20% of patients who develop the infection.

TECHLAB produces a panel of in vitro diagnostics for detecting C. difficile and its toxins in fecal specimens from patients suspected of having the disease.


For more information about TechLab and their products/services

click on the following link:




“The C Diff Foundation’s mission is to educate and advocate for Clostridium difficile infection prevention, treatments, support, and environmental safety worldwide.
The C Diff Foundation’s organization is comprised of 100% volunteering members who are dedicated to our mission and adhere to the Foundation’s Code of Ethics
which prohibits  paid endorsements or paid promotion of products, services, medications, or clinical studies in progress.   All website entries, public presentations, and workshops are to raise C. diff. infection awareness in all areas of the C Diff Foundation’s mission statement, including infection prevention, treatments, environmental safety products, diagnostics, sepsis, healthcare-associated infections, antimicrobial resistance, antibiotic stewardship and provide education on all the above.”


Molecular Assay Diagnostic Test by Quidel Corp. Receives FDA Clearance For the Detection of C. difficile Infections

Quidel Receives FDA Clearance for Its New Solana(R) Molecular Assay for the
Detection of Clostridium difficile (C. difficile) Infections


On May 11, 2017
Quidel Corporation, a provider of rapid diagnostic testing solutions, cellular-based
virology assays and molecular diagnostic systems, announced that it has received 510(k) clearance from the United States Food and Drug Administration (FDA) to market its Solana®
C. difficile Assay for the direct, qualitative detection of the Clostridium difficile DNA in unformed stool specimens of patients suspected of having Clostridium difficile-infection (CDI).

Clostridium difficile is the most frequently identified enteric pathogen in patients with antibiotic-associated diarrhea and colitis. Per the Centers for Disease Control and Prevention (CDC), C. difficile was responsible for approximately half a million infections in the United States in 2011, with 29,000 patient deaths occurring shortly after the initial diagnosis.1Clostridium difficile bacterial infections are life threatening, especially for the elderly, for the immunocompromised, and for patients on a prolonged antibiotic regimen.

C. diff. Symptoms:   Typical CDI symptoms include nausea, fever, watery diarrhea and abdominal pain due to inflammation of the colon.Traditional methods for diagnosing CDI, such as glutamate dehydrogenase (GDH) or toxin antigen tests, can lack sensitivity and increase lab costs due to additional confirmation testing. In addition to significant technical expertise, cytotoxicity assays and toxigenic culture require 24 to 48 hours and 3 to 5 days, respectively, before reliable results can be obtained.

The Solana C. difficile assay will now enable laboratories to offer a fast and sensitive result generated by molecular methods, without an upfront nucleic acid extraction step.The Solana C. difficile Assay is an easy-to-use, accurate, molecular diagnostic test that generates an accurate result in about 35 minutes.

The Solana molecular platform leverages the Helicase-Dependent Amplification (HDA) technology that is resident in Quidel’s AmpliVue® molecular product line to generate a fast and accurate test result. Solana can process up to 12 different assays or patient samples in each batched run, and provides time-saving workflow advantages to healthcare professionals in moderately complex settings.

“We are excited to introduce a Solana assay that can make a profound difference in the lives of people that are affected by CDI through a quick and accurate diagnosis. The laboratorian will benefit from the Solana platform’s ability to address the particular workflow needs of the moderately complex laboratory setting in a cost-effective manner by neatly balancing higher volume sample testing at scale with customizable, on-demand assay processing,” said Douglas Bryant, president and chief executive officer of Quidel Corporation.

The Solana® C. difficile Assay is Quidel’s first molecular diagnostic test to receive 510(k) clearance from the FDA in the scalable and versatile Solana format for diagnosis of a Healthcare Associated Infection (HAI).

Other 510(k) cleared Solana molecular diagnostic assays include:With the Solana franchise, Quidel has broadened its molecular strategy to include instrumented systems, and grown the number of its molecular platforms that are both 510(k) cleared and available commercially. Quidel’s other FDA cleared molecular solutions include the AmpliVue® non-instrumented system for lower-volume moderately complex labs, and Lyra® reagents for higher throughput, highly complex laboratories that are compatible with existing PCR infrastructure.

About Quidel Corporation

Quidel Corporation serves to enhance the health and well-being of people around the globe through the development of diagnostic solutions that can lead to improved patient outcomes and provide economic benefits to the healthcare system. Marketed under the Sofia®, QuickVue®, D3® Direct Detection and Thyretain® leading brand names, as well as under the new Solana®, AmpliVue® and Lyra® molecular diagnostic brands, Quidel’s products aid in the detection and diagnosis of many critical diseases and conditions, including, among others, influenza, respiratory syncytial virus, Strep A, herpes, pregnancy, thyroid disease and fecal occult blood. Quidel’s research and development engine is also developing a continuum of diagnostic solutions from advanced lateral-flow and direct fluorescent antibody to molecular diagnostic tests to further improve the quality of healthcare in physicians’ offices and hospital and reference laboratories.

For more information about Quidel visit

Contagion Live Shared Interview With Belinda Ostrowsky, MD, How to Be Smarter About C. difficile Testing

 How to Be Smarter About Testing for C. difficile
APR 03, 2017

Belinda Ostrowsky, MD, MPH, Health Systems Director of Epidemiology, Antimicrobial Stewardship & Infection Prevention, Montefiore Medical Center, and Associate Professor of Clinical Medicine, Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, explains how to be more sensible when it comes to testing for Clostridium difficile.

Roche Launches cobas Liat PCR System With Four Assays — C. diff., Strep A, Influenza A/B and Influenza A/B & RSV

Roche launches cobas Liat PCR System with four assays into CE-markets

  • First 20 minute real-time PCR nucleic acid test to detect Clostridium difficile, which supports time-sensitive diagnoses in hospitals, urgent care settings and physician offices
  • Infections with Clostridium difficile can quickly become life threatening to high-risk patients
  • cobas Liat PCR System also includes tests for strep A, influenza A/B and influenza A/B & RSV

Roche  – April 3, 2017 –  announced the CE-IVD launch of the cobas® Liat® PCR System with four assays including first 20 minute real-time PCR nucleic acid test to detect Clostridium difficile (C. diff). Countries accepting CE mark are the first to receive access to the cobas® Cdiff test, which detects C. diff in stool specimens from symptomatic patients1 and provides rapid and definitive results in under 20 minutes. Timely and accurate diagnosis of this infection is important because it can quickly become life threatening, especially to high-risk patients such as the elderly, immuno-compromised and those undergoing antibiotic treatment.

“Roche is proud to bring the advantages of real-time PCR testing to point-of-care settings with the cobas® Liat® System,” said Roland Diggelmann, CEO of Roche Diagnostics. “The system now includes Europe’s first real-time PCR test for patients suspected of C. diff infection with results in less than 20 minutes. As one of the major causes of healthcare associated infections (HAI), C. diff not only causes significant financial burden on healthcare systems but can also lead to severe complications for the patient if the disease is not caught in time.”

The cobas® Cdiff assay, an automated, in vitro diagnostic, real time PCR test, offers minimal handling steps, a simplified workflow, and access to urgent results. Traditional diagnostic methods may take several hours for results to be delivered to clinicians. The cobas® Cdiff assay’s speed and simplicity make it ideal for STAT and out-of-hours testing, providing results when and where they are needed most.
The benefits of accurate and timely diagnoses for patient care are not unique to HAIs. The cobas® Liat® System brings real-time answers for patients and their caregivers with the assurances of PCR technology in 20 minutes or less for all assays in the portfolio. The expanded menu of assays for use on the cobas® Liat® System includes the respiratory portfolio of cobas® Strep A, cobas® Influenza A/B, cobas® Influenza A/B & RSV. The latest assay, cobas® Cdiff, is the first in the HAI portfolio and will be joined during the second quarter of 2017 by cobas® MRSA/SA for CE marked countries.


To read the article in its entirety – please click on the following link:

About the cobas Liat System

Utilizing PCR technology, the innovative cobas® Liat® System fully automates the testing process, simplifies workflow and enables healthcare professionals to perform molecular testing in a variety of settings with speed, reliability and minimal training. Definitive results are generated in 20 minutes or less to aid in treatment decisions. The current portfolio of assays include cobas® Cdiff, cobas® Strep A, cobas® Influenza A/B and cobas® Influenza A/B & RSV. Assays for other infectious diseases are in development.

For more information please visit

The cobas® Liat® System is not commercially available in all markets.

About Roche

Roche is a global pioneer in pharmaceuticals and diagnostics focused on advancing science to improve people’s lives. The combined strengths of pharmaceuticals and diagnostics under one roof have made Roche the leader in personalised healthcare – a strategy that aims to fit the right treatment to each patient in the best way possible.

Roche is the world’s largest biotech company, with truly differentiated medicines in oncology, immunology, infectious diseases, ophthalmology and diseases of the central nervous system. Roche is also the world leader in in vitro diagnostics and tissue-based cancer diagnostics, and a frontrunner in diabetes management.
Founded in 1896, Roche continues to search for better ways to prevent, diagnose and treat diseases and make a sustainable contribution to society. The company also aims for improving patient access to medical innovations by working with all relevant stakeholders. Twenty-nine medicines developed by Roche are included in the World Health Organization Model Lists of Essential Medicines, among them life-saving antibiotics, antimalarials and cancer medicines. Roche has been recognized as the Group Leader in sustainability within the Pharmaceuticals, Biotechnology & Life Sciences Industry eight years in a row by the Dow Jones Sustainability Indices (DJSI).

The Roche Group, headquartered in Basel, Switzerland, is active in over 100 countries and in 2016 employed more than 94,000 people worldwide. In 2016, Roche invested CHF 9.9 billion in R&D and posted sales of CHF 50.6 billion. Genentech, in the United States, is a wholly owned member of the Roche Group. Roche is the majority shareholder in Chugai Pharmaceutical, Japan. For more information, please visit


“The C Diff Foundation’s mission is to educate and advocate for Clostridium difficile infection prevention, treatments, support, and environmental safety worldwide.
The C Diff Foundation’s organization is comprised of 100% volunteering members who are dedicated to our mission and adhere to the Foundation’s Code of Ethics
which prohibits the endorsement and promotion of products, services, medications, or clinical studies in progress. 
All website entries, public presentations, and workshops are to raise C. diff. infection awareness in all areas of the C Diff Foundation’s mission statement, including infection prevention, sepsis, healthcare-associated infections, antimicrobial resistance, antibiotic stewardship and provide education on all the above.”