Faster Flu Test

Infectious Disease Specialists Design New Rapid Flu Test

— New flu tests can diagnose the flu in as little as 30 minutes, to cut down on needless antibiotic use, which can build up resistance and make some infections untreatable by current methods.

Every year, up to one in five Americans will get the flu. It's not always easy to make an accurate diagnosis and as many as 90 percent of patients who really have the flu will be prescribed antibiotics, drugs that will not help flu viruses. New, faster flu tests will help doctors diagnose patients quicker, which can cut down on needless antibiotic use.

When patients take antibiotics that they don't need, it leads to antibiotic resistance. Ann Falsey, M.D., an infectious disease specialist at Rochester General Hospital in Rochester, New York, says, "It's a huge problem. There are some bacteria which have become resistant to all antibiotics."

Now, with a simple swab of the nose, rapid flu tests can diagnose the flu in as little as 30 minutes compared to the usual five days. Dr. Falsey told DBIS, "I think the big advantage would be to cut down on needless antibiotic use."

Dr. Falsey found using rapid flu tests reduced the number of antibiotics prescribed and used. She says, "The doctors less-frequently prescribed antibiotics, and if they had started them on antibiotics, when the test came back, then they stopped the antibiotics."

Most hospitals are using rapid flu tests, but the tests are not common in doctor's offices yet. According to Dr. Falsey, that's where they'll have the most impact. The tests will also confirm the need for anti-viral medications, the only drugs that actually help the flu. Dr. Falsey says not every virus is influenza, so the rapid flu test won't provide all the information a doctor needs. However, researchers are hoping to develop rapid tests like these to identify other viruses, like corona viruses and rhino viruses.

The American Society for Microbiology contributed to the information contained in the TV portion of this report.

BACKGROUND: New tests to rapidly detect the flu are allowing doctors to cut down on the number of hospital patients who receive antibiotics, helping soften the rapidly worsening threat of antibiotic resistance. Doctors are less likely to prescribe antibiotics, which work on bacteria but not viruses, if there is documented evidence that a patient has the flu -- which is caused by a virus -- and not a bacterial infection. The research was done by infection control experts at Rochester General Hospital in New York.

ABOUT THE STUDY: The Rochester scientists analyzed the records of 166 patients who had the flu when they were hospitalized. Eighty-six of the patients tested positive with the rapid test, which gives an answer within minutes, while the other 80 either tested negative or did not have the test done. When they checked the later treatment, they found that 86% of patients whose flu was confirmed early on were treated with antibiotics, compared to 99% of patients whose flu was not identified immediately. The overuse of antibiotics makes patients and the community more vulnerable to microbes resistant to most treatments. Yet doctors often prescribe antibiotics in case patients also have a bacterial infection, such as pneumonia, in addition to the flu.

WHAT IS THE FLU: The flu is caused by the influenza virus, which targets the respiratory tract by binding to the surface of cells. Then the virus releases its genetic information into the cell's nucleus to replicate itself. When the cell dies, those copies are released into the body, infecting other cells. Flu symptoms are unpleasant, but not life-threatening by themselves. However, the flu weakens the immune system, making the body vulnerable to more serious infections, such as pneumonia. Because the flu is caused by a virus -- as opposed to bacteria -- antibiotics are not an effective treatment. Both the flu and the common cold are best treated by bed rest, consuming lots of fluids, and taking over-the-counter medication to ease symptoms until the virus runs its course.

ORIGINAL ANTIGENIC SIN: Original antigenic sin occurs when the antibodies produced by the body's immune system to fight exposure to the flu virus become part of the body's "memory" so that it can fight off future exposure the same flu strain. The problem is that those same antibodies end up suppressing the creation of new antibodies when the body is exposed to a new strain of the flu, making last year's flu vaccine ineffective against the newer strain. The phenomenon has also been observed in dengue fever and HIV, among other viruses.


Originally posted May 20007
Source: Science Daily