In a perfect world, we would be able to prevent diseases, but reality tells us that’s not always possible. The next best thing is to identify illnesses and begin a course of medical treatment as early as possible.
Ste. Genevieve County Memorial Hospital has introduced molecular testing at its lab, which produces faster lab results, reduces the risk of contamination and enables doctors to make quicker, better informed treatment decisions, according to Kathy Gerardot, director of laboratory services at SGCMH.
“This is the closest we’re going to get to any DNA testing,” said Gerardot. “It’s fascinating.”
This molecular testing is made possible by an advanced processing machine Gerardot called “the wave of the future.” The Cepheid GeneXpert allows laboratory technicians to test for specific genes (viral and bacterial) and have results in about a couple of hours. Currently, the SGCMH GeneXpert tests for Influenza A, B and H1N1, C. difficile and Enterovirus. Other test kits are available for such things as MRSA, TB, Chlamydia, etc.
Gerardot explained that she first started hunting for a better solution to rule in or out Enteroviruses in children.
“Dr. Kanani several years ago started asking me about this, and I just couldn’t find any good solution,” she said. “But I kept surfing the web periodically and came across the Cepheid company that originally developed an anthrax testing method for the U.S. Postal service. They kept the ball rolling and subsequently developed the GeneXpert.”
Gerardot said the traditional immunoassay method of testing, is only about 75% accurate. You may come to the ER because you’re sure it’s the flu; your doctor thinks it’s the flu; but the lab test comes back negative. Traditional methods of testing need to detect a large amount of the virus for a positive result.
(Zorhaida Mudag, SGCMH medical technologist)
The GeneXpert needs only one gene strand to positively identify the virus. This machine, not much bigger than a bread box, can potentially detect if you have the flu virus even before you have that first sniffle.
“Physicians can start the antivirals or antibiotics that are most effective within an hour and a half,” she said. “Before molecular diagnostics, samples were used to grow lab cultures, which could take several days to produce results. That meant doctors might have to begin treatment before knowing exactly what they were trying to fight. It’s kind of revolutionized infectious disease treatment.”
Numerous hospitals across the country that have the GeneXpert now use it to routinely screen for MRSA, a contagious staph bacteria, especially with pre-op patients—eliminating any doubt about whether a patient picked up the bacteria before or during a hospital stay.
How does it work?
The GeneXpert takes a DNA sample (nasal swab or stool sample) and sets off a chain reaction to quickly produce millions of copies of it. Chemical indicators glow brighter as the quantity increases, and the color helps the machine identify the bacteria. What once took three separate rooms in order to guard against DNA contamination is now accomplished in a small cartridge with several compartments. The cartridge reduces the chances of contamination and a ruined test.
Said Gerardot, “It’s a very complicated inner working, but it’s been made very simple for the user. It’s really a pretty amazing process that’s going on inside. With a 99.5% accuracy rate the GeneXpert helps us improve patient care and patient safety, especially when it comes to the highly contagious C. diff. The GeneXpert’s ability to rapidly and accurately identify a wide range of diseases and agents through their genetic fingerprint is giving health care professionals powerful new ways to enhance patient management and care. This is huge.”