

On Thursday, the FDA approved a test that doctors can use to quickly diagnose twelve different types of viral infection – including those which cause the common cold, pneumonia, and several varieties of flu.

With only a cotton swab from their patient's nose or mouth, the new diagnostic panel will allow physicians to make better decisions about which medications will be effective. Some drugs, such as Tamiflu (oseltamivir), only work on certain types of viruses.

"This speeds up the usual process of detecting and identifying respiratory viruses, which can take up to a week," Daniel G. Schultz, director of FDA Center for Devices and Radiological Health. "And, because this multiplex viral panel tests for 12 viruses at once, it uses less of a patient's test specimen."

Based in Texas, Luminex Corporation has a long history of building instruments that can check for almost anything – bacteria, viruses, antibodies, disease genes. The key to their technology: tiny beads.

The biotech company produces color-coded spheres that latch onto telltale biological molecules. Each microscopic orb can only attach to molecules from one particular type of organism. In this case, Luminex scientists made beads that can grab onto amplified genetic material from viruses. A special scanner can read which beads have DNA stuck down to them – and thus identify the virus.

You can see a step-by-step explanation of how the new test works here: Link

From the Luminex Website:

With a non-invasive, painless swab, xTAG RVP tests for: Influenza A, influenza A-H1, influenza A-H3 and influenza B,which cause the majority of flu cases in the U.S.;

Adenovirus, which is responsible for approximately 10 percent of respiratory infections and a subtype of which the Centers for Disease Control (CDC) have recently identified as causing multiple deaths

Respiratory syncytial virus (RSV) A and B, the most common cause of bronchiolitis and pneumonia in infants and children

Metapneumovirus, a recently-discovered virus that causes flu-like symptoms and is thought to be the second leading cause of respiratory infection in children

Parainfluenza 1, 2, and 3, which can cause upper or lower respiratory infections in adults and children and, are thought to be responsible for about half of croup cases and 10-15 percent of bronchiolitis and bronchitis cases; and Rhinovirus, which causes the common cold. ... It is the first multiplexed nucleic acid test for respiratory viruses cleared for in vitro diagnostic use by the FDA. It also is the first test of any kind cleared to detect human metapneumovirus, the first test cleared for influenza A subtyping, and the first molecular test cleared for adenovirus.

When I spoke to Luminex CEO Patrick Balthrop at the American Association for Clinical Chemistry meeting in San Diego this spring, he said that their newest equipment can check for five hundred different chemical signatures at once. At that meeting, and on other occasions, he has also indicated that personalized medicine will be a major thrust for his business.

In my book, the new test is a really big deal. Here's why: Last year, a New England Journal of Medicine study showed that when young children with the flu were brought in for a typical medical examination, their physician got the diagnosis wrong 83 percent of the time.

Although the new diagnostic tool is not a panacea, I see it as a sign of what is to come in medicine: a lot less guesswork.

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