Enterovirus D68

Over the past few weeks, hospitals around the country have seen a sharp uptick in cases of respiratory distress in children. The majority of patients test positive for Enterovirus D68, and most seem to have a history of asthma.

Only select laboratories test for this strain of enterovirus. If a suspected case comes to your facility, contact the CDC or your local health department for information about specimen collection and shipping.

 

 

CDC Update on the Ebola Outbreak

Yesterday Dr. Tom Frieden, Director of the Centers for Disease Control in Atlanta, briefed the media about the current Ebola outbreak in Africa and called for an immediate global response to the outbreak. “There’s nothing mysterious about what we need to do,” says Frieden. “The only real question is whether we’ll do it fast enough.”

Read the full transcript on the CDC website.

Read Maryn McKenna’s astute summary on the Superbug blog.

Laboratory Testing in A High-Containment Facility

The team at Emory that cared for the patients infected with the Ebola Virus have published a paper on Lab Medicine about laboratory testing within a high-containment facility. You can read the entire paper on the Lab Medicine website.

Biobanking and Sample Stability

A common question often asked of laboratory professionals is the length of time an analyte is stable in a sample. This question may arise simply because a sample has been delayed reaching the lab, but can also be asked in the case of adding on a test to an existing sample a day later, or a week later. Most laboratory professionals can tell you the stability of an analyte in a patient sample, at both ambient temperature and refrigerated, because assay manufacturers perform those short term stability studies when they create their tests. And many of them also include the stability of the analyte in a frozen sample. Beyond this information, it’s harder to find stability information for analytes.

Some stability information can be found at large reference labs, as they have often done their own stability studies and may know how stable an analyte is when frozen for a month, or for 6 months. The really difficult information to come by is how stable an analyte is for really long term storage. This is a question that needs to be answered as biobanking becomes increasingly popular.

Biobanking is the use of repositories to store biological samples, usually for use in later research. Biological material can be stored frozen in many forms, including tissue, cell culture, serum and plasma and dried blood spots. Determining how stable an analyte is under long term storage conditions is important in order to be able to use those samples for research in the future. And yet sometimes determining the long term stability is itself difficult. For example, if a person wished to see if albumin was stable frozen at -80 degrees for 25 years, the difficulty would be in having the same assay available 25 years apart to perform both sets of measurements. (Not to mention the personnel). Measurement technologies change over time, some very rapidly, making longitudinal studies difficult.

The design of studies utilizing biobanked samples will be important. Even when not performing longitudinal studies, if a sample has been stored for 10 years frozen in a biorepository and I remove it and measure the calcium, how do I know the calcium present is the amount of calcium that was present when the sample was stored? If I have knowledge of the patient the sample came from, I could use this data to say that in stored samples, patients with X disease have higher calcium than patients without disease, but I could not necessarily make the jump to what is true in vivo, without knowing how stable calcium is upon long term storage.

Often stored samples are used for measuring analytes that weren’t able to be measured when the samples were originally stored. In those cases, you may be able to infer stability if the amount of analyte measured in the stored samples is comparable to the amount measured in fresh samples.

Biobanking is a growing enterprise, and stability studies will need to grow along with it.

 

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-Patti Jones PhD, DABCC, FACB, is the Clinical Director of the Chemistry and Metabolic Disease Laboratories at Children’s Medical Center in Dallas, TX and a Professor of Pathology at University of Texas Southwestern Medical Center in Dallas.

Ebola Information for Laboratory Professionals

While it’s unlikely you will ever encounter a case of Ebola, it’s best to be prepared. The CDC has a health advisory page full of information, including specimen requirements for Ebola testing. The laboratory’s first step is to contact their state health department.

 

 

Test Utilization: A Deeper Look

The test utilization seminar I attended at the AACC annual meeting (I talked about it here) presented fascinating information that I’m going to try and sum up for you.

Test utilization isn’t just about ordering the right test, making sure the order entry system is efficient, or even about the accuracy of the test. Sure, all those factors are important, but patients aren’t treated by laboratory data. They’re treated by doctors, and those doctors are human. Humans are irrational and make mistakes for all sorts of reasons like fear, cognitive limitations, and social complications. Medical decisions are incredibly complex and driven my mounds of data. This complexity contributes to medical errors.

I found this notion counter intuitive—one would think that more data would mean better decisions. However, a study conducted by the CIA on horse race prediction found that when analysts were given more data, the accuracy of their predictions didn’t improve. However, the analysts had more confidence in their predictions. What does this mean? Just because your doctor runs fifty tests doesn’t mean he’ll diagnose you accurately. It probably means, though, the doctor will be confident they are right.

Another tidbit from the seminar: diagnostic error is usually the convergence of several different factors that are organizational, cognitive, and technical in nature. Any laboratory professional who has dealt with major errors has seen this in action—an event investigation will usually reveal that anything that could go wrong did, and that’s why the event occurred. The authors of this particular study did note that technical/equipment problems contributed to only a small fraction of diagnostic errors. This speaks to the integrity, critical thinking, dedication to quality that laboratory professionals possess.

If you want to read more, here are a few of the studies mentioned during the talk:

Diagnostic Error in Internal Medicine http://archinte.jamanetwork.com/article.aspx?articleid=486642

CIA: Do You Really Need More Information? https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/psychology-of-intelligence-analysis/art8.html

 

Swails

Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

CDC Interview About Ebola

Medscape interviewed the CDC about the current Ebola outbreak. In it, the CDC reiterates that healthcare workers are at particular risk for infection. While the interview doesn’t specifically mention laboratory professionals, of course they are included in that risk group. Protect yourself using standard precautions (sometimes called contact or droplet precautions). This includes gloves, gowns, face mask, and eye protection when handling specimens from a potential victim.

You can read the entire interview here.