Quicker Turnaround for Flu Tests A new test can analyze the genetic makeup of a flu virus in just 12 hours. The development could make it easier for health officials to identify and contain an emerging flu that has the potential to start a pandemic.
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Quicker Turnaround for Flu Tests

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Quicker Turnaround for Flu Tests

Quicker Turnaround for Flu Tests

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MICHELE NORRIS, host:

From NPR News, this is ALL THINGS CONSIDERED. I'm Michele Norris.

MELISSA BLOCK, host:

And I'm Melissa Block.

Around the world, health officials are gearing up to try something that's never been done before: They want to stamp out an emerging flu pandemic before it really gets going. The fear is that a bird flu virus called H5N1 will jump to people then start spreading.

NORRIS: And if they want to have any chance of stopping that spread, scientists will need to know if someone has the new flu as soon as possible. The problem is it can take days to run the tests that can tell an ordinary flu virus from a newer, more dangerous one. Now one group of scientists says it has made a faster flu test. NPR's Nell Boyce reports.

NELL BOYCE reporting:

In South Asia, doctors are on high alert. Every time someone comes in with flu symptoms, they want to know immediately which virus is it. David Chu is a flu expert. He says existing quick tests take just 30 minutes to confirm if a person has the flu, but they can't give doctors detailed information about the virus.

Mr. DAVID CHU (National Institute of Allergy and Infectious Diseases): Right now we can't say that with certainty that it is the bird flu strain or whether it's just a normal case of flu.

BOYCE: Chu works at the National Institute of Allergy and Infectious Diseases in Maryland. He says it currently takes days of testing to reliably identify a new strain of flu. That delay is a problem. It can lead to false alarms and public uncertainty. Also, officials would like to move much more quickly to contain a new flu by distributing vaccines and anti-viral drugs.

To shorten the delay, scientists have to overcome some serious technical challenges. One problem is that at any given moment, many different flu strains are circulating. The differences between them are subtle but important. What's more, the viruses are constantly mutating and changing.

Mr. NIRANJAN BHAT (Centers for Disease Control and Prevention): And so it's kind of a moving target and a little bit harder to design a test to detect that moving target.

BOYCE: That's Niranjan Bhat, who works with on flu with the Centers for Disease Control and Prevention in Atlanta. The agency has been working with scientists to find faster ways to analyze flu genes. One result is a new testing device called the flu chip. Robert Kuchta and Kathy Rowlen developed it at the University of Colorado at Boulder. It's a glass slide coated with snippets of DNA, markers for three important flu genes. A doctor can take a nose swab from a patient and a lab then extracts the genetic material and just applies it to the chip. Kuchta says different strains of flu make the chip light up in unique patterns.

Mr. ROBERT KUCHTA (Scientist): And then we can say, `Oh, you have--this is an influenza A sample and it is, for example, the H3N2 subtype'--that's a common human strain--`or it's H5N1.' That's the avian flu strain that's going around.

BOYCE: The entire test takes just 12 hours, and Kuchta says it seems highly accurate. The Colorado team recently tested the device on many different samples of flu.

Mr. KUCHTA: And it just worked spectacularly well with greater than 90 percent accuracy. So we just glance at the chip and it takes about 10 seconds of looking at it, if that long, and then you have your answer.

BOYCE: The chip can detect both known flu strains and newly emerging strains.

Mr. KUCHTA: It would be virtually impossible for a flu to mutate so that we wouldn't be able to detect it because a new flu strain would give a very different signature on the chip. We could say, `You have a flu and it is new and it is weird.'

BOYCE: If more testing goes well, the flu chip could be ready for wider use in less than a year.

The team is also working to improve the chip. They think they can cut the testing time down from 12 hours to two. They also want to make the chip easier to use in places like small villages, where there's no way to test flu strains even though bird flu is a concern. Similar tests could someday come to your doctor's office, but for now doctors say the existing quick tests do give them enough information to start treating patients even though they can't reveal the exact flu strain. Nell Boyce, NPR News.

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