Speedy DNA Test for 12 Viruses Approved by FDA

SoyChemist writes "Last week, the FDA approved a test that can check for twelve viruses at once. The device is made by Luminex which has a long history of building instruments that can check for almost anything — bacteria, viruses, antibodies, disease genes. In this case, doctors can simply swab their patient's nose or throat then send the sample to a lab where the viral genetic material is copied and stuck down to color-coated beads. Each type of bead recognizes a different virus. A scanner reads off which beads have DNA on them — thus identifying the pathogens. The new test can detect several types of influenza, but not H5N1, and is the first system approved to detect human metapneumovirus. It is a good step towards taking the guesswork out of medicine, which is desperately needed since viral infections are extraordinarily hard to diagnose, and antiviral medications like Tamiflu only work on some types of virus."

Comments

Unclear

[Cro Magnon]

Is the DNA test approved, or are they testing for approved viruses?

Re:Unclear

[Anonymous Coward]

Is it really so incredibly difficult to read the first line of the summary, or was that a poor attempt at a +funny?

Re:Unclear

[4D6963]

or was that a poor attempt at a +funny?

I don't know about it, but your comment was surely a good attempt at +flamebait ;)

Re:Unclear

[Osurak]

"Last week, the FDA approved a test that can check for twelve viruses at once"

12 Viruses Approved by the FDA?

[Anonymous Coward]

Hmmm. I'd like to know more about those viruses.

Less useful than it might appear

[Masaq]

As a pediatrician/internal medicine physician, this is interesting, but not necessarily as revolutionary as it might appear. Generally, we would like to have tests that are going to change our management. Though it might make us feel better to specifically know what virus a patient has, if it's not going to change our management, it's more debatable as to what the true value of this would be.

Currently of the viruses mentioned in the article, only influenza has a specific treatments - oseltamivir (tamiflu)/zanamivir, or amantadine/rimantadine (for influenza A only). We already have cheap, reliable, rapid influenza testing.

For any of the other viruses mentioned, standard of care will only be supportive therapy (IV fluids, oxygen, etc), and it won't change depending on the virus.

I'm sure this new test will not be cheap, so that if we start using this test widely, we may end up spending a lot of money without signficant clinical benefit to patients. As everyone knows, healthcare in the US is already horrifically expensive - tests such as these won't help..

Re:Less useful than it might appear

[jdgeorge]

I'm sure this new test will not be cheap, so that if we start using this test widely, we may end up spending a lot of money without signficant clinical benefit to patients. As everyone knows, healthcare in the US is already horrifically expensive - tests such as these won't help..

My understanding is that something that helps identify viral infections quickly (and cheaply) would be beneficial in that it would allow doctors to properly diagnose whether an illness is viral or bacterial. This would help reduce the use of "shotgun antibiotics" which are given frequently when the caregiver is uncertain whether the problem in viral or bacterial.

Reducing the use of unnecessary antibiotics seems like the major benefit, if my understanding is correct, as it would help reduce our production of antibiotic-resistant bacteria (though I expect that much of that problem is due to patients not taking their full course of antibiotics... a separate problem).

Re:Less useful than it might appear

[chrisjbuck]

It may not be as expensive as you think, especially if it uses a bioanalyser useful for other research. This reminds me of some of the new techniques for DNA sequencing http://www.454.com/, but is probably just beads with anywhere from 20 to 100 nucleotide pieces of DNA attached, each bead specific to one virus. If a PCR product http://en.wikipedia.org/wiki/Polymerase_chain_reaction/ attaches to the single stranded DNA on the bead then a stain like ethidium bromide will light up the bead (under UV light in the bioanalyzer). Anyway my point on the expense is that machines with UV lamps and cameras are not that pricey, just marked up that way. :P

I think, since as you point out few viruses are specifically treatable, this might be more useful for use at selected hospitals across a country or the world to track the dispersion and spread of viruses. Especcially since scaling up the kit to include many hundreds of viruses and/or bacteria should be easy, look at how many beads the 454 DNA sequencing chips fit, it's amazing.

IAAB (I am a biochemist), but I don't work on medical diagnostics, cheers!

Re:Less useful than it might appear

[AlexBirch]

You may be correct about our current technology for battling viruses, yet imagine if we start getting RNAi's to target viruses if they improve where they can deliver the siRNAs. Also they could use LNA's to knock out these viruses.

I still posit that some obesity is related to a virus (sure call me a quack) yet if a virus could decrease our metabolism by 10%, it would have a wide ranging implication.

Re:Less useful than it might appear

[Masaq]

This is an interesting point - anything that reduces the overuse of antibiotics is likely to be a good thing.

However, much of the time, especially with less sick patients, it is possible to decide by examining a patient (or with the help of a few basic tests such as a CBC and chest xray) whether an infection is likely to be viral or bacterial. Much of the problem of antibiotic overuse in the US (and around the world) is due to use of antibiotics in cases where it's already clinically unlikely to be a bacterial infection.

With life-threateningly ill patients, it might be less clear. However, often in those cases no physician is going to take the chance of missing a treatable infection and use antibiotics anyway. Even if this test showed the presence of a virus - can one be sure that the patient is not infected with both a common respiratory virus AND and bacterial infection?

There are probably a few cases in which this test might make a real difference in avoiding antibiotics, but I think that, most likely, it will be outweighed by overuse of this test in cases where it will make little difference.

Re:Less useful than it might appear

[bagsc]

Doctors who prescribe antibiotics usually know when it's a virus - they prescribe it so you'll think they're doing something for you while you enjoy the placebo effect. It's more customer service than ignorance.

Re:Less useful than it might appear

[NateTech]

So you're immediately recommending that the machine be made available to pharmacy departments at grocery stores, and for the things it can detect, the prescriptions will no longer need a Doctor's signature, if the patient agrees and their symptoms are standard ones for the known diseases, they can self-medicate using the best drugs available for that particular virus.

Excellent! That and the pay cut you're volunteering for, should lower those "horrifically expensive" costs dramatically -- good on you Doc! Good show!

Oh? You just wanted to keep your salary high and your practice intact, no matter what gains there are in "expensive" technology, even if the patient agrees to use it without a doctor's care? Sorry -- I misunderstood you. My bad.

Re:Less useful than it might appear

[SoyChemist]

The New England Journal of medicine paper that is cited in the article would indicate that even if there are cheap virus tests, doctors are not using them when they should. I agree that this could lead to an overuse of antibiotics. The biggest benefits of this test would seem to be: disease surveillance, choosing the right antiviral, not using antibiotics when the infection is viral.

Re:Less useful than it might appear

[SoyChemist]

I am all for using RNAi to target viruses as well as trypanosomes. What do you think about alcohol consumption increasing obesity? That might slow things down a bit too.

Tag: It's VIRUSES

[Pigeon451]

This story was tagged with VIRII?? WTF. It's viruses people. I can understand people misusing virii in messages, but a tag?? Yikes.

The other way around

[DrYak]

My understanding is that something that helps identify viral infections quickly (and cheaply) would be beneficial in that it would allow doctors to properly diagnose whether an illness is viral or bacterial. This would help reduce the use of "shotgun antibiotics" which are given frequently when the caregiver is uncertain whether the problem in viral or bacterial.

Actually, we use the opposite route :
When someone complains about angina, we take a swab and use some do-it-quickly-for-5-min test kit to check if there's a known bacteria causing the infection.
If the test is positive, we prescribe antibiotics accordingly, if the test is negative, we only prescribe drugs that treat the symptoms and let the body take care of the virus.