Tag 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.

 

Sources:

https://www.sciencedaily.com/terms/white_blood_cell.htm

https://baycare.org/health-library/health-encyclopedia/2015/02/04/06/52/white-blood-cell-stool

C. difficile Laboratory Test Information For Patients and Healthcare Providers

Testing for Clostridium difficile toxin with real-time polymerase chain reaction (PCR) can improve the laboratory diagnoses of C difficile–associated diarrhea, compared with A/B enzyme immunoassay (EIA), according to results from a study presented at a Association for Molecular Pathology meeting.

In fact, real-time PCR demonstrated a sensitivity of 100% and a specificity of 96.9%, whereas the A/B EIA was found to generate both false-positive and false-negative results.

“Although C difficile–associated diarrhea has increased in prevalence and severity, the inaccuracy of conventional C difficile toxin EIA for diagnosis is well documented in the literature,” said lead investigator Cynthia Essmyer, MD, medical pathologist at Saint Luke’s Hospital in Kansas City, Missouri. (1)

The Microbiology Laboratory medical pathologist at a University Hospital located in NC shared the following information to answer one of the many questions:  “Why won’t the lab run a test on hard formed stool?”

The lab will not accept a stool specimen that is hard/formed stool due to the fact that the PCR test is regulated by the testing company and a hard/formed stool can produce a false positive result.  Soft, unformed or watery stools are all accepted for the PCR testing.

  • ACCEPTABLE SPECIMEN: FecesCollect specimen as follows:
    1. Collect feces in a clean, dry container or bedpan not contaminated with urine, residual soap, or disinfectants.
    2. Transfer appropriate volume of feces to a clean dry tightly capped specimen cup.
    3. Submit double-bagged specimen cup immediately to laboratory.
  • NOTES:
    1. Patients should be passing at least 3 unformed or watery stool specimens in a 24-hour period. Most patients have more than 3 episodes of watery unformed stools per day.
    2. Soft specimen is defined as specimen assuming the shape of its container (unformed).
    3. Formed or hard fecal specimens will not be tested.
    4. Repeat testing following a negative test during the same episode of diarrhea is NOT recommended for at least 7-days because of high sensitivity (between 98-99% and with a 99% negative predictive value).

* There may be an alternate send out micro. test for hard formed stool and this information can be obtained at the laboratory being utilized.  Have a healthcare provider contact the lab prior to delivering a specimen to the lab location.

When a PCR result is NEGATIVE: the Wait time between testing is 7 days to retest.

When a PCR result is POSITIVE: the Wait time between testing is 14 days to retest.

Q:  Is there a wait time after completing antibiotic treatment (greater than 14 days since first positive result) to retest?
A:  No, since the PCR is testing micro-organisms the antibiotic will not interfere with testing.

 

Q:  Can a stool specimen be kept in a refrigerator and if so for how long?

Storage
REFRIGERATE IF TRANSPORT IS DELAYED. Specimens can be stored at 2-8 degrees C for 24 hours before significant degredation of the toxin is noted. SUBMIT WITH COLD PACKS OR ON ICE IF TRANSPORT WILL TAKE > 1 HOUR.
Transport
DELIVER IMMEDIATELY TO MICROBIOLOGY IN A TIGHTLY SEALED CONTAINER WITH NO EXTERNAL SPILLAGE.
REFRIGERATE IF TRANSPORT IS DELAYED. SUBMIT WITH COLD PACKS OR ON ICE IF TRANSPORT WILL TAKE >1 HOUR.

A specimen can be rejected by the lab if Specimen is received > 2 hours after collection unless submitted on ice or cold pack or with note that specimen stored in refrigerator prior to transport.

Q:  How long does it take to receive lab results?

A:  Routine turn around time is one day.

 

 

Source: (1) Medscape

other:  University Hospital Microbiology Laboratory in NC

ROCHE cobas® C. diff. Test approved by US Food and Drug Administration (FDA)

US Food and Drug Administration (FDA) has provided 510(k) clearance for the cobas® Cdiff Test to detect Clostridium difficile (C. difficile) in stool specimens.

The cobas® Cdiff Test targets the toxin B gene found in toxigenic C. difficile strains directly in specimens from symptomatic patients. The test provides accurate information which assists clinicians in making timely treatment decisions and aids in the prevention of further infection in healthcare settings.

“Having the ability to provide a result quickly is important when supporting infection control for Clostridium difficile,” said Dr. Steve Young, Professor of Pathology, Department of Pathology UNMHSC and Tricore Reference Lab. “The cobas® 4800 System has the capability to allow for mixed batch testing of the cobas® Cdiff Test alongside testing for Methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, and herpes simplex virus 1 and 2*, all on one platform. We can run these assays together at least once in each shift rather than once a day, which can greatly improve laboratory efficiency, ultimately leading to better infection control and patient care.”

In a clinical trial program conducted at sites throughout the United States, the cobas® Cdiff Test demonstrated excellent performance compared to direct and enrichment toxigenic culture. The test combines high assay sensitivity with rapid turnaround time and a minimum number of pre-analytic steps, to facilitate earlier intervention of patients suffering from

C. difficile-associated disease. Earlier intervention can also lead to more effective implementation of infection control measures, which can prevent further transmission to additional patients.

About the cobas® 4800 System
The cobas® 4800 System offers true walk-away automation of nucleic acid purification, PCR set-up and real-time PCR amplification and detection to help laboratories achieve maximum efficiency. The expanding system menu in the U.S. currently includes the cobas® MRSA/SA Test, cobas® CT/NG Test (Chlamydia trachomatis/Neisseria gonorrhoeae), cobas® HPV Test, cobas® BRAF V600 Mutation Test, cobas® EGFR Mutation Test and cobas® KRAS Mutation Test.

“With the addition of the cobas® Cdiff Test to the cobas® 4800 System menu, Roche is able to expand the tools available to assist clinicians in the management of healthcare associated infections,” said Paul Brown, head of Roche Molecular Diagnostics. “The cobas® Cdiff Test requires less sample handling and provides laboratories with a simplified workflow, when compared to other molecular methods. It also delivers a lower inhibition rate, which means fewer repeat samples and chances for error, enabling better patient care.”

 

To access the news article:

http://finance.yahoo.com/news/roche-receives-fda-clearance-cobas-050000123.html

 

Clostridium difficile (C.diff.) Laboratory Test Collection,Storage,Transport

CLOSTRIDIUM DIFFICILE TOXIN, PCR
Label Name: C DIFF
Lab Discipline: Microbiology
Subdiscipline: Bacteriology
Feces (Stool)
Container & Volume
Age Group Container Volume
0  – 18 Years Sterile Specimen Cup 5  ML
Label Reminders
Must include patient name, MRN, date/time of collection and collector’s initials.

 

 

Collection Notes
All:
  • ACCEPTABLE SPECIMEN: Feces

    Collect specimen as follows:
    1. Collect feces in a clean, dry container or bedpan not contaminated with urine, residual soap, or disinfectants.
    2. Transfer appropriate volume of feces to a clean dry tightly capped specimen cup.
    3. Submit double-bagged specimen cup immediately to laboratory.

  • NOTES:
    1. Patients should be passing at least 3 unformed or watery stool specimens in a 24-hour period. Most patients have more than 3 episodes of watery, foul-smelling stools per day.
    2. Soft specimen is defined as specimen assuming the shape of its container (unformed).
    3. Formed or hard fecal specimens will not be tested.
    4. Repeat testing following a negative test during the same episode of diarrhea is NOT recommended for at least 7-days because of high sensitivity (between 98-99% and with a 99% negative predictive value).
Storage
REFRIGERATE IF TRANSPORT IS DELAYED. Specimens can be stored at 2-8 degrees C for 24 hours before significant degredation of the toxin is noted. SUBMIT WITH COLD PACKS OR ON ICE IF TRANSPORT WILL TAKE > 1 HOUR.
Transport
DELIVER IMMEDIATELY TO MICROBIOLOGY IN A TIGHTLY SEALED CONTAINER WITH NO EXTERNAL SPILLAGE.
REFRIGERATE IF TRANSPORT IS DELAYED. SUBMIT WITH COLD PACKS OR ON ICE IF TRANSPORT WILL TAKE >1 HOUR.
Causes for Rejection
All:
  • 1. Specimen not labeled with patient’s name, MRN #, date/time of collection, collector’s initials.
    2. Container leaking.
    3. Specimen received > 2 hours after collection unless submitted on ice or cold pack or with note that specimen stored in refrigerator prior to transport.
    4. Formed or hard specimen.
    5. Specimen in Cary-Blair transport, Para-Pak (formalin/PVA) or in diaper.
    6. Specimen on swab.
    7. Patient has negative test within last 7 days.
    8. Patient has positive test within last 14 days.
Turn Around Time –  Routine: 1 day

 

Sera Care Life Sciences introduces Accurun 501C. difficile control

* In The News *

SeraCare Life Sciences, a provider of high-quality biological materials that help optimize diagnostic performance, reliability and repeatability across the IVD lifecycle, today announced the launch of its new ACCURUN® 501 C. difficile Control – the company’s first molecular control product targeting hospital acquired infections.

ACCURUN 501 C. difficile Control is formulated for use with in vitro diagnostic tests that detect C. difficile DNA in human stool samples. Manufactured from cultured Clostridium bacteria of four different strains or species delivered in a set of four vials, the bacteria are inactivated and in a human synthetic stool matrix. The control is ready-to-use in assays that detect C. difficile DNA with any transport system.

“Hospital acquired infection assays present unique sample challenges which require dependable, whole cell controls. Our new ACCURUN® 501 product is a full process control that is intended to not only estimate laboratory testing performance but also immediately detect analytical errors and monitor the entire testing process. As a result, our customers have greater confidence in fulfilling their QC requirements,” says Christopher Long, Product Manager at SeraCare.

SeraCare’s new ACCURUN® 501 product is available immediately in the U.S. and internationally. For more information, contact SeraCare Customer Service at 1-800-676-1881 or visit www.seracare.com.

About SeraCare Life Sciences, Inc.
SeraCare works with diagnostics researchers, IVD manufacturers, and clinical laboratories to shape the future of medical diagnostics. Our innovative portfolio includes ACCURUN® quality controls, research panels, KPL antibodies and immunoassay reagents, SeraCon processed plasma, specialty human blood products, and Complete BioCollections materials. SeraCare helps bridge the gap between today’s diagnostic solutions and tomorrow’s emerging technologies for molecular diagnostics, next generation sequencing and companion diagnostics.

Company Contact:

Agency Contact:

Marsha Ann Marsh

Shannon Meirzon

SeraCare Life Sciences, Inc.

Pyxis Communications

508.244.6400 ext. 6106

203.550.5978

mmarsh@seracare.com  

shannon@pyxiscommunications.com  

www.seracare.com

www.pyxiscommunications.com