Randy White, Adnavance’s chief executive officer, says that in laboratory experiments, the test is 10 times more sensitive than existing tests, and it’s able to detect as few as 12,000 copies of bacterial DNA. He says that the company is now planning to test clinical samples from patients. Adnavance expects to launch the MRSA test in 2011, with an estimated price tag of $60 per test.
“It certainly sounds interesting,” says Carol Chenoweth, an epidemiologist at the University of Michigan Health System, in Ann Arbor. “But its success will depend on how well it functions in comparison to other tests out there, how much it costs, and how much technician time it requires to perform.”
Despite a growing interest in hospital surveillance, it’s not yet clear how effective patient testing is in reducing infection rates. Two conflicting studies were released last year: a large Swiss study found that surveillance had no effect, while a second U.S. study found that it significantly decreased infection rates. “I think the main benefit can be found in settings where there is outbreak occurring, either hospital-wide or in a unit,” says Daniel Diekema, a physician and epidemiologist who’s also at the University of Iowa. “Rapid tests provide an advantage in that setting because they give an answer in two to four hours, rather than 24 to 48 hours, during which time you’d have to decide whether to keep a patient isolated.”
If Adnavance can simplify the screening process even further, it may have a market among physicians’ offices. In addition to hospital-related strains, new strains of MRSA are emerging in community settings, such as gyms and day-care facilities. “The real mounting need is in the community,” says Stuart Levy, director of the Center for Adaptation Genetics and Drug Resistance at Tufts University School of Medicine, in Boston. “What you want is quick diagnostics you can do when you see the patient.”
But not everyone agrees that high-tech solutions are the best approach to controlling MRSA and other dangerous bugs that are springing up across the world. Diekema suggests that other drug-resistant bacteria are spreading more rapidly than MRSA, including strains of gram-negative bacteria, some of which can cause severe pneumonia. He says that simpler preventative measures that can stop the spread of all bacteria, such as increased hand washing, may be more effective.